Achromobacter denitrificans

Achromobacter species are gram-negative, rod-shaped bacteria that inhabit soil and water. They are not normal flora of humans and may cause opportunistic infections in the immunocompromised host.

Achromobacter insolitus

Achromobacter species are gram-negative, rod-shaped bacteria that inhabit soil and water. They are not normal flora of humans and may cause opportunistic infections in the immunocompromised host.

Achromobacter piechaudii/spanius

Achromobacter species are gram-negative, rod-shaped bacteria that inhabit soil and water. They are not normal flora of humans and may cause opportunistic infections in the immunocompromised host.

Achromobacter spp.

Achromobacter species are gram-negative, rod-shaped bacteria that inhabit soil and water. They are not normal flora of humans and may cause opportunistic infections in the immunocompromised host.

Achromobacter xylosoxidans

Achromobacter species are gram-negative, rod-shaped bacteria that inhabit soil and water. They are not normal flora of humans and may cause opportunistic infections in the immunocompromised host.

Acidovorax spp.

Acidovorax species are gram-negative, rod-shaped bacteria that inhabit water and soil worldwide. They can be found on fruits and vegetables and some species are plant pathogens. These organisms infrequently cause human infection.

Acinetobacter baumannii

Acinetobacter species are gram-negative, rod-shaped bacteria which are widely distributed in nature and the hospital environment. They are found in water and soil, on fruits and vegetables, and on the healthy human skin. Acinetobacter is able to survive in both wet and dry environments and has been found in sink traps, on floors, and in air samples. It is often isolated where there is a stagnant water source such as improperly drained drip pans, water fountains, faucets, humidifiers, sink traps. These bacteria are generally nonpathogenic to healthy individuals but may cause infections in debilitated persons. The species most commonly isolated from humans is A. baumannii.

Acinetobacter calcoaceticus

Acinetobacter species are gram-negative, rod-shaped bacteria which are widely distributed in nature and the hospital environment. They are found in water and soil, on fruits and vegetables, and on the healthy human skin. Acinetobacter is able to survive in both wet and dry environments and has been found in sink traps, on floors, and in air samples. It is often isolated where there is a stagnant water source such as improperly drained drip pans, water fountains, faucets, humidifiers, sink traps. These bacteria are generally nonpathogenic to healthy individuals but may cause infections in debilitated persons. The species most commonly isolated from humans is A. baumannii.

Acinetobacter johnsonii

Acinetobacter species are gram-negative, rod-shaped bacteria which are widely distributed in nature and the hospital environment. They are found in water and soil, on fruits and vegetables, and on the healthy human skin. Acinetobacter is able to survive in both wet and dry environments and has been found in sink traps, on floors, and in air samples. It is often isolated where there is a stagnant water source such as improperly drained drip pans, water fountains, faucets, humidifiers, sink traps. These bacteria are generally nonpathogenic to healthy individuals but may cause infections in debilitated persons. The species most commonly isolated from humans is A. baumannii.

Acinetobacter junii

Acinetobacter species are gram-negative, rod-shaped bacteria which are widely distributed in nature and the hospital environment. They are found in water and soil, on fruits and vegetables, and on the healthy human skin. Acinetobacter is able to survive in both wet and dry environments and has been found in sink traps, on floors, and in air samples. It is often isolated where there is a stagnant water source such as improperly drained drip pans, water fountains, faucets, humidifiers, sink traps. These bacteria are generally nonpathogenic to healthy individuals but may cause infections in debilitated persons. The species most commonly isolated from humans is A. baumannii.

Acinetobacter lwoffii

Acinetobacter species are gram-negative, rod-shaped bacteria which are widely distributed in nature and the hospital environment. They are found in water and soil, on fruits and vegetables, and on the healthy human skin. Acinetobacter is able to survive in both wet and dry environments and has been found in sink traps, on floors, and in air samples. It is often isolated where there is a stagnant water source such as improperly drained drip pans, water fountains, faucets, humidifiers, sink traps. These bacteria are generally nonpathogenic to healthy individuals but may cause infections in debilitated persons. The species most commonly isolated from humans is A. baumannii.

Acinetobacter radioresistens

Acinetobacter species are gram-negative, rod-shaped bacteria which are widely distributed in nature and the hospital environment. They are found in water and soil, on fruits and vegetables, and on the healthy human skin. Acinetobacter is able to survive in both wet and dry environments and has been found in sink traps, on floors, and in air samples. It is often isolated where there is a stagnant water source such as improperly drained drip pans, water fountains, faucets, humidifiers, sink traps. These bacteria are generally nonpathogenic to healthy individuals but may cause infections in debilitated persons. The species most commonly isolated from humans is A. baumannii.

Acinetobacter schindleri

Acinetobacter species are gram-negative, rod-shaped bacteria which are widely distributed in nature and the hospital environment. They are found in water and soil, on fruits and vegetables, and on the healthy human skin. Acinetobacter is able to survive in both wet and dry environments and has been found in sink traps, on floors, and in air samples. It is often isolated where there is a stagnant water source such as improperly drained drip pans, water fountains, faucets, humidifiers, sink traps. These bacteria are generally nonpathogenic to healthy individuals but may cause infections in debilitated persons. The species most commonly isolated from humans is A. baumannii.

Acinetobacter spp.

Acinetobacter species are gram-negative, rod-shaped bacteria which are widely distributed in nature and the hospital environment. They are found in water and soil, on fruits and vegetables, and on the healthy human skin. Acinetobacter is able to survive in both wet and dry environments and has been found in sink traps, on floors, and in air samples. It is often isolated where there is a stagnant water source such as improperly drained drip pans, water fountains, faucets, humidifiers, sink traps. These bacteria are generally nonpathogenic to healthy individuals but may cause infections in debilitated persons. The species most commonly isolated from humans is A. baumannii.

Acinetobacter ursingii

Acinetobacter species are gram-negative, rod-shaped bacteria which are widely distributed in nature and the hospital environment. They are found in water and soil, on fruits and vegetables, and on the healthy human skin. Acinetobacter is able to survive in both wet and dry environments and has been found in sink traps, on floors, and in air samples. It is often isolated where there is a stagnant water source such as improperly drained drip pans, water fountains, faucets, humidifiers, sink traps. These bacteria are generally nonpathogenic to healthy individuals but may cause infections in debilitated persons. The species most commonly isolated from humans is A. baumannii.

Actinobacillus equuli

Actinobacillus species are slow-growing, gram-negative, rod shaped bacteria. They are considered normal flora of the human oral cavity and of animals such as cows, sheep, and pigs.

Actinobacillus pleuropneumoniae

Actinobacillus species are slow-growing, gram-negative, rod shaped bacteria. They are considered normal flora of the human oral cavity and of animals such as cows, sheep, and pigs.

Actinobacillus seminis

Actinobacillus species are slow-growing, gram-negative, rod shaped bacteria. They are considered normal flora of the human oral cavity and of animals such as cows, sheep, and pigs.

Actinobacillus spp.

Actinobacillus species are slow-growing, gram-negative, rod shaped bacteria. They are considered normal flora of the human oral cavity and of animals such as cows, sheep, and pigs.

Actinobacillus ureae

Actinobacillus species are slow-growing, gram-negative, rod shaped bacteria. They are considered normal flora of the human oral cavity and of animals such as cows, sheep, and pigs.

Actinobacteria

Actinobacteria are rod-shaped, sometimes branching, gram-positive bacteria that are widely distributed in terrestrial and aquatic habitats. Actinobacteria are common in compost piles and often occur in high concentrations in the air when compost is disturbed. As such they are important as causative agents of occupation-related respiratory allergies, hypersensitivity pneumonitis ("farmers lung"). The frequent presence of actinobacteria can be regarded as a sign of moisture damage in concrete buildings. Actinobacteria include such genera as Nocardia, Rhodococcus, Gordonia, Actinomadura, and Streptomyces.

Actinomyces spp.

Actinomyces species are gram-positive, rod-shaped bacteria that are normal flora of the oral cavity and gastrointestinal and urogenital tracts. They can cause infection when normal mucosal barriers are breached.

Agrobacterium tumefaciens

Agrobacterium tumefaciens is a gram-negative, rod-shaped bacterium that inhabits the soil. It is a plant pathogen responsible for crown gall disease. No human infections have been reported.

Agrococcus terreus

Agrococcus species are gram-positive, spherical bacteria that have been isolated from various environments including soil, food, and plants. No known human infections have been reported.

Alcaligenes faecalis

Alcaligenes species are gram-negative, rod-shaped bacteria found in the intestinal tracts of vertebrates, decaying materials, dairy products, water, and soil. They occasionally cause opportunistic infections in humans.

Alcaligenes spp.

Alcaligenes species are gram-negative, rod-shaped bacteria found in the intestinal tracts of vertebrates, decaying materials, dairy products, water, and soil. They occasionally cause opportunistic infections in humans.

Aneurinibacillus aneurinilyticus

Aneurinibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Aneurinibacillus spp.

Aneurinibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Arcanobacterium bernardiae

Arcanobacterium species are non-spore-forming, gram-positive, rod-shaped bacteria. They are normal inhabitants of the human skin and pharynx and infrequently cause infection.

Arcanobacterium haemolyticum

Arcanobacterium species are non-spore-forming, gram-positive, rod-shaped bacteria. They are normal inhabitants of the human skin and pharynx and infrequently cause infection.

Arcanobacterium pyogenes

Arcanobacterium species are non-spore-forming, gram-positive, rod-shaped bacteria. They are normal inhabitants of the human skin and pharynx and infrequently cause infection.

Arcanobacterium spp.

Arcanobacterium species are non-spore-forming, gram-positive, rod-shaped bacteria. They are normal inhabitants of the human skin and pharynx and infrequently cause infection.

Arcticibacter pallidicorallinus

Arcticibacter species are gram-negative, rod-shaped bacteria that are members of the Sphingobacteriaceae family. Arcticibacter species have been isolated from soil. No human infections have been reported.

Arthrobacter cumminsii

Arthrobacter species are gram-positive, rod-shaped bacteria that are the most frequently isolated bacteria from soil samples. Only a few species have been associated with human disease.

Arthrobacter spp.

Arthrobacter species are gram-positive, rod-shaped bacteria that are the most frequently isolated bacteria from soil samples. Only a few species have been associated with human disease.

Aureimonas altamirensis

Aureimonas species are gram-negative, rod-shaped bacteria that have been isolated primarily from environmental sources. A. altamirensis has caused infections in immunocompromised individuals.


Bacillus amyloliquefaciens

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus anthracis

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus atrophaeus

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus beringensis

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus cereus

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus cereus group

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus coagulans

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus firmus

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus licheniformis

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus megaterium

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus mycoides

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus pumilus

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus simplex

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus sporothermodurans

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus spp.

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

For more information, visit our Bacillus Species page.

Bacillus subtilis

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bacillus weihenstephanensis

Bacillus species are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential with the exception of Bacillus cereus group, which can cause opportunistic local and systemic infections.

Bergeyella spp.

Bergeyella species are gram-negative, rod-shaped bacteria that inhabit the oral and nasal cavities of dogs and cats. Rare but severe human wound infections following an animal bite have been caused by B. zoohelcum.

Bhargavaea beijingensis

Bhargavaea species are gram-positive, non-spore forming, rod-shaped bacteria that are members of the family Planococcaceae. Bhargavaea species have been isolated from coastal sands and deep-sea sediments. No human infections have been reported.

Bifidobacterium spp.

Bifidobacterium species are gram-positive, rod-shaped bacteria found in the intestinal tracts of mammals. No known human infections have been reported.

Brachybacterium spp.

Brachybacterium species are gram-positive, rod-shaped bacteria which can found in the environment, foods, and animals. Rare cases of human infection have been described.

Brevibacillus borstelensis

Brevibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Brevibacillus invocatus

Brevibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Brevibacillus spp.

Brevibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Brevibacterium casei

Brevibacterium species are gram-positive, rod-shaped bacteria that are part of normal human flora. They can also be isolated from soil, water, and various foods, particularly dairy products. Human infections occur most often in immunocompromised hosts.

Brevibacterium luteolum

Brevibacterium species are gram-positive, rod-shaped bacteria that are part of normal human flora. They can also be isolated from soil, water, and various foods, particularly dairy products. Human infections occur most often in immunocompromised hosts.

Brevibacterium spp.

Brevibacterium species are gram-positive, rod-shaped bacteria that are part of normal human flora. They can also be isolated from soil, water, and various foods, particularly dairy products. Human infections occur most often in immunocompromised hosts.

Brevundimonas diminuta

Brevundimonas species are gram-negative, rod-shaped bacteria that were formerly classified within the genus Pseudomonas. They inhabit environmental sources such as water, soil, and plant surfaces, including fruits and vegetables. Because of their ability to survive in aqueous environments, these organisms have become particularly opportunistic as a health-care associated pathogens.

Brevundimonas spp.

Brevundimonas species are gram-negative, rod-shaped bacteria that were formerly classified within the genus Pseudomonas. They inhabit environmental sources such as water, soil, and plant surfaces, including fruits and vegetables. Because of their ability to survive in aqueous environments, these organisms have become particularly opportunistic as a health-care associated pathogens.

Brevundimonas vesicularis

Brevundimonas species are gram-negative, rod-shaped bacteria that were formerly classified within the genus Pseudomonas. They inhabit environmental sources such as water, soil, and plant surfaces, including fruits and vegetables. Because of their ability to survive in aqueous environments, these organisms have become particularly opportunistic as a health-care associated pathogens.

Brochothrix spp.

Brochothrix species are gram-positive, rod-shaped shaped bacteria that are associated with meat and meat product spoilage. No known human infections have been reported.

Budvicia aquatica

Budvicia aquatica is a gram-negative, rod-shaped bacterium found in fresh water sources including brooks, rivers, and well water. One case of human infection has been described following exposure to flood water.

Burkholderia ambifaria

Burkholderia species (B. cepacia complex) are gram-negative, rod-shaped bacteria that belong to a complex of 18 distinct species that are difficult to differentiate from one another. They are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia anthina

Burkholderia species (B. cepacia complex) are gram-negative, rod-shaped bacteria that belong to a complex of 18 distinct species that are difficult to differentiate from one another. They are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia cenocepacia

Burkholderia species (B. cepacia complex) are gram-negative, rod-shaped bacteria that belong to a complex of 18 distinct species that are difficult to differentiate from one another. They are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia cepacia

Burkholderia species (B. cepacia complex) are gram-negative, rod-shaped bacteria that belong to a complex of 18 distinct species that are difficult to differentiate from one another. They are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia dolosa

Burkholderia species (B. cepacia complex) are gram-negative, rod-shaped bacteria that belong to a complex of 18 distinct species that are difficult to differentiate from one another. They are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia fungorum

Burkholderia species are gram-negative, rod-shaped bacteria that are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia gladioli

Burkholderia species are gram-negative, rod-shaped bacteria that are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia multivorans

Burkholderia species (B. cepacia complex) are gram-negative, rod-shaped bacteria that belong to a complex of 18 distinct species that are difficult to differentiate from one another. They are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia pyrrocinia

Burkholderia species (B. cepacia complex) are gram-negative, rod-shaped bacteria that belong to a complex of 18 distinct species that are difficult to differentiate from one another. They are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia spp.

Burkholderia species are gram-negative, rod-shaped bacteria that are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia stabilis

Burkholderia species (B. cepacia complex) are gram-negative, rod-shaped bacteria that belong to a complex of 18 distinct species that are difficult to differentiate from one another. They are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.

Burkholderia vietnamiensis

Burkholderia species (B. cepacia complex) are gram-negative, rod-shaped bacteria that belong to a complex of 18 distinct species that are difficult to differentiate from one another. They are found in water, soil, rhizospheres, and in and on plants, including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments and their innate antimicrobial resistance, these organisms have become particularly problematic as opportunistic health-care associated pathogens.


Cellulomonas spp.

Cellulomonas species are gram-positive, rod-shaped bacteria that inhabit soil and sludge. Rare cases of human infection have been reported.

Cellulomonas uda

Cellulomonas species are gram-positive, rod-shaped bacteria that inhabit soil and sludge. Rare cases of human infection have been reported.

Chromobacterium violaceum

Chromobacterium violaceum is a gram-negative, rod-shaped bacterium that is a common inhabitant of soil and water in tropical and subtropical areas. It is an occasional opportunistic pathogen in humans, causing severe wound and systemic infections.

Citrobacter amalonaticus

Citrobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed on plants and in soil, water, and the intestines of humans and animals. Members of this genus are recognized human pathogens.

Citrobacter amalonaticus/farmeri

Citrobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed on plants and in soil, water, and the intestines of humans and animals. Members of this genus are recognized human pathogens.

Citrobacter braakii

Citrobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed on plants and in soil, water, and the intestines of humans and animals. Members of this genus are recognized human pathogens.

Citrobacter farmeri

Citrobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed on plants and in soil, water, and the intestines of humans and animals. Members of this genus are recognized human pathogens.

Citrobacter freundii

Citrobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed on plants and in soil, water, and the intestines of humans and animals. Members of this genus are recognized human pathogens.

Citrobacter koseri

Citrobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed on plants and in soil, water, and the intestines of humans and animals. Members of this genus are recognized human pathogens.

Citrobacter spp.

Citrobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed on plants and in soil, water, and the intestines of humans and animals. Members of this genus are recognized human pathogens.

Coagulase-negative Staphylococcus spp.

Coagulase-negative staphylococci (CoNS) are gram-positive, spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Coagulase-positive Staphylococcus spp.

Coagulase-positive staphylococci (CPS) are gram-positive, spherical bacteria which are considered action organisms under USP 797 guidelines. S. aureus is the most common CPS; additional species include S. lugdunensis and S. schleiferi. All CPS are known human pathogens.

Comamonas aquatica

Comamonas species are gram-negative, rod-shaped bacteria. They are ubiquitous in the environment and have been isolated from soil, water, sludge, and hospital settings. They are infrequent human pathogens.

Comamonas spp.

Comamonas species are gram-negative, rod-shaped bacteria. They are ubiquitous in the environment and have been isolated from soil, water, sludge, and hospital settings. They are infrequent human pathogens.

Comamonas testosteroni

Comamonas species are gram-negative, rod-shaped bacteria. They are ubiquitous in the environment and have been isolated from soil, water, sludge, and hospital settings. They are infrequent human pathogens.

Corynebacterium accolens

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium afermentans

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium amycolatum

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium aurimucosum

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium glucuronolyticum

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium jeikeium

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium kutscheri

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium macginleyi

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium propinquum

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium pseudodiphtheriticum

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium renale

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium spp.

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

For more information, visit our Coryneform Bacilli page.

Corynebacterium striatum

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium tuberculostearicum

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium ulcerans

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Corynebacterium urealyticum

Corynebacterium species are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Coryneform bacillus

Coryneform bacilli are gram-positive, irregular, rod-shaped bacteria. Many species are part of the normal flora of the skin and mucous membranes in human and mammals. Other coryneform bacilli have been found in the inanimate environment, e.g. dairy products, plants, soil, and activated sludge. Coryneforms are a large group and include genera such as Corynebacterium, Dermabacter, Brevibacterium, Microbacterium, and Cellulomonas. Some species are opportunistic human pathogens.

Cupriavidus pauculus

Cupriavidus species are gram-negative, rod-shaped bacteria found in water, soil, the rhizosphere, and in and on plants including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments, these organisms have become particularly problematic as opportunistic pathogens in hospitals and health care settings.

Curtobacterium spp.

Curtobacterium species are gram-positive, rod-shaped bacteria which are widely distributed plant pathogens found in the soil. Infrequent infections have been reported in humans.


Deinococcus spp.

Deinococcus species are large, gram-positive, spherical bacteria that are highly resistant to radiation and heat. No known human infections have been reported.

Delftia acidovorans

Delftia acidovorans is a gram-negative, rod-shaped bacterium with a world-wide distribution. It can be found in water, soil, the rhizosphere, and in and on plants including fruits and vegetables. It is an infrequent cause of human infection.

Delftia spp.

Delftia species are gram-negative, rod-shaped bacteria with a world-wide distribution. They can be found in water, soil, the rhizosphere, and in and on plants including fruits and vegetables. They are infrequent causes of human infection.

Dermabacter hominis

Dermabacter hominis is a gram-positive, spherical to rod-shaped bacterium that is a part of the normal flora of the skin and mucous membranes of humans and mammals. It is an infrequent agent of human infection.

Dermacoccus nishinomiyaensis

Dermacoccus species are gram-positive, spherical bacteria which are commonly found, along with coagulase-negative Staphylococcus spp., on the skin of humans and mammals. They are infrequent agents of human infection.

Dermacoccus spp.

Dermacoccus species are gram-positive, spherical bacteria which are commonly found, along with coagulase-negative Staphylococcus spp., on the skin of humans and mammals. They are infrequent agents of human infection.

Dietzia spp.

Dietzia species are gram-positive, rod-shaped bacteria that are members of a group of bacteria known as actinomycetes. These bacteria are widely distributed in the environment and are associated with the decomposition of plant material. Dietzia is an infrequent cause of human infection.

Domibacillus indicus

Domibacillus species are gram-positive, spore-forming, rod-shaped bacteria that have been found in marine sediments. They are related to Bacillus species. No known human infections have been reported.


Edwardsiella spp.

Edwardsiella species are gram-negative, rod-shaped bacteria that are primarily fish pathogens. Edwardsiella tarda has a broad host range and can cause opportunistic infections in humans.

Elizabethkingia meningoseptica

Elizabethkingia meningoseptica (formerly Chryseobacterium meningoseptica) is gram-negative, rod-shaped bacterium that can be isolated from soil, plants, foodstuffs, and water sources, including those in hospitals. E. meningoseptica is the species most often associated with significant disease in humans, causing neonatal meningitis and healthcare associated outbreaks.

Empedobacter brevis

Empedobacter brevis is a gram-negative, rod-shaped bacterium found in soil, plants, foodstuffs, and water sources, including those in hospitals. These bacteria are rarely cause disease in humans.

Enterobacter aerogenes

Enterobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Some species of Enterobacter are frequent human pathogens.

Enterobacter asburiae

Enterobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Some species of Enterobacter are frequent human pathogens.

Enterobacter cancerogenus

Enterobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Some species of Enterobacter are frequent human pathogens.

Enterobacter cloacae

Enterobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Some species of Enterobacter are frequent human pathogens.

Enterobacter cowanii

Enterobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Some species of Enterobacter are frequent human pathogens.

Enterobacter gergoviae

Enterobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Some species of Enterobacter are frequent human pathogens.

Enterobacter hormaechei

Enterobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Some species of Enterobacter are frequent human pathogens.

Enterobacter pulveris

Enterobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Some species of Enterobacter are frequent human pathogens.

Enterobacter spp.

Enterobacter species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Some species of Enterobacter are frequent human pathogens.

Enterococcus avium

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus casseliflavus

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus cecorum

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus columbae

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus durans

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus faecalis

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus faecium

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus gallinarum

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus hirae

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus raffinosus

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus saccharolyticus

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Enterococcus spp.

Enterococcus species are gram-positive, spherical bacteria which are found in soil, food, water, and as normal flora of the gastro- and genitourinary tracts of animals, birds, and humans. These organisms are frequent causes of human infection.

Erwinia rhapontici

Erwinia species are gram-negative, rod-shaped bacteria that are part of the Enterobacteriaceae family. It is usually pathogenic to plants, but may cause infrequent human infections.

Escherichia coli

Escherichia coli is a gram-negative, rod-shaped bacterium belonging to the Enterobacteriaceae family. It is considered a normal inhabitant of the gastrointestinal tracts of humans and animals. It is a frequent human pathogen causing urinary tract infections, bacteremia, meningitis, and diarrheal disease.

Exiguobacterium indicum

Exiguobacterium species are gram-positive, rod-shaped bacteria. These organisms have been isolated from extreme environments, such as glacial ice and hot springs, and from other diverse sources such as food processing plants and soil. No known human infections have been reported.

Exiguobacterium spp.

Exiguobacterium species are gram-positive, rod-shaped bacteria. These organisms have been isolated from extreme environments, such as glacial ice and hot springs, and from other diverse sources such as food processing plants and soil. No known human infections have been reported.


Fictibacillus spp.

Fictibacillus spp. – Fictibacillus species are gram-positive, ospore forming, rod-shaped bacteria that are related to Bacillus. No known human infections have been reported.

Flavobacterium spp.

Flavobacterium species are gram-negative, rod-shaped bacteria that are found in soil and water. They are primarily pathogens of fish.


Geobacillus thermodenitrificans

Geobacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Geobacillus thermoglucosidasius

Geobacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Gordonia spp.

Gordonia species are gram-positive, rod-shaped bacteria typically found in soil and aquatic habitats, but a growing number of Gordonia species are becoming associated with human and animal diseases. In all known cases of infection by Gordonia species, patients were immunosuppressed and infection occurred subsequent to illness.


Hafnia alvei

Hafnia alvei is a gram-negative, rod-shaped bacterium belonging to the Enterobacteriaceae family. It inhabits the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. It is an infrequent human pathogen in immunocompromised patients.

Herbaspirillum huttiense

Herbaspirillum species are gram-negative, rod-shaped bacteria that inhabit the soil around plant roots. They are also found in water, including ground and well water. Human infections have been reported in immunocompromised patients.


Janibacter spp.

Janibacter species are gram-positive, non-spore-forming bacteria isolated from the environment. Infrequent infections have been reported in humans.


Kineococcus spp.

Kineococcus species are gram-positive, spherical bacteria isolated from soil. No human infections have been reported.

Klebsiella oxytoca

Klebsiella species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed in the environment and are part of the normal flora of the intestinal tracts of humans and animals. These organisms cause a variety of human infections with K. pneumoniae being the most common implicated species.

Klebsiella pneumoniae

Klebsiella species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed in the environment and are part of the normal flora of the intestinal tracts of humans and animals. These organisms cause a variety of human infections with K. pneumoniae being the most common implicated species.

Klebsiella spp.

Klebsiella species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. They are widely distributed in the environment and are part of the normal flora of the intestinal tracts of humans and animals. These organisms cause a variety of human infections with K. pneumoniae being the most common implicated species.

Kluyvera ascorbata

Kluyvera species are gram-negative, rod-shaped bacteria that have been recovered from a variety of foods, water, and animals (snails and slugs). These organisms can cause opportunistic infections in humans.

Kluyvera cryocrescens

Kluyvera species are gram-negative, rod-shaped bacteria that have been recovered from a variety of foods, water, and animals (snails and slugs). These organisms can cause opportunistic infections in humans.

Kluyvera intermedia

Kluyvera species are gram-negative, rod-shaped bacteria that have been recovered from a variety of foods, water, and animals (snails and slugs). These organisms can cause opportunistic infections in humans.

Kluyvera spp.

Kluyvera species are gram-negative, rod-shaped bacteria that have been recovered from a variety of foods, water, and animals (snails and slugs). These organisms can cause opportunistic infections in humans.

Kocuria kristinae

Kocuria species (formerly Micrococcus) are gram-positive spherical bacteria. They are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. These organisms rarely cause disease in humans.

Kocuria palustris

Kocuria species (formerly Micrococcus) are gram-positive spherical bacteria. They are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. These organisms rarely cause disease in humans.

Kocuria rhizophila

Kocuria species (formerly Micrococcus) are gram-positive spherical bacteria. They are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. These organisms rarely cause disease in humans.

Kocuria rosea

Kocuria species (formerly Micrococcus) are gram-positive spherical bacteria. They are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. These organisms rarely cause disease in humans.

Kocuria spp.

Kocuria species (formerly Micrococcus) are gram-positive spherical bacteria. They are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. These organisms rarely cause disease in humans.

Kocuria varians

Kocuria species (formerly Micrococcus) are gram-positive spherical bacteria. They are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. These organisms rarely cause disease in humans.

Kytococcus sedentarius

Kytococcus species (formerly Micrococcus) are gram-positive spherical bacteria. They are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. These organisms rarely cause disease in humans.


Lactobacillus acidophilus

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus brevis

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus buchneri

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus crispatus

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus curvatus

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus delbrueckii

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus fermentum

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus helveticus

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus iners

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus ingluviei

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus jensenii

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus johnsonii

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus paracasei

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus pentosus

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus rhamnosus

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus sakei

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactobacillus spp.

Lactobacillus species are gram-positive, rod-shaped bacteria that are common flora of the skin and digestive tracts of humans and animals. These organisms infrequently cause disease in immunosuppressed individuals.

Lactococcus garvieae

Lactococcus species are gram-positive, spherical bacteria that do not normally colonize humans. They are used extensively in the dairy industry to generate fermented products such as yogurt, cheese, and sour cream. These species are considered nonpathogenic, although rare cases of human infection have been reported.

Lactococcus lactis

Lactococcus species are gram-positive, spherical bacteria that do not normally colonize humans. They are used extensively in the dairy industry to generate fermented products such as yogurt, cheese, and sour cream. These species are considered nonpathogenic, although rare cases of human infection have been reported.

Lactococcus raffinolactis

Lactococcus species are gram-positive, spherical bacteria that do not normally colonize humans. They are used extensively in the dairy industry to generate fermented products such as yogurt, cheese, and sour cream. These species are considered nonpathogenic, although rare cases of human infection have been reported.

Leclercia adecarboxylata

Leclercia adecarboxylata is a gram-negative, rod-shaped bacterium that has been recovered from a variety of foods, water, and animals (snails and slugs). It is a rare cause of human infection.

Leifsonia aquatica

Leifsonia aquatica is a gram-positive, rod-shaped bacterium that can be recovered from fresh water. L. aquatica is a rare cause of human infection.

Leifsonia spp.

– Leifsonia species are gram-positive, rod-shaped bacteria related to coryneform bacillus. L. aquatica has caused rare infections in immunocompromised individuals.

Lelliottia amnigena

Lelliottia amnigena is a gram-negative, rod-shaped bacteria that was previously a member of the genus, Enterobacter. Enterobacter species inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. L. amnigena is a rare cause of human infection.

Lysinibacillus fusiformis

Lysinibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.


Massilia timonae

Massilia species are gram-negative, rod-shaped bacteria that colonize the roots of many types of plants. M. timonae has caused infections in immunocompromised humans.

Methylobacterium mesophilicum

Methylobacterium species are gram-negative, rod-shaped bacteria that occur mostly on vegetation but may also be found in the hospital environment. Methylobacterium species have been reported to cause infections, especially in immunocompromised patients. Tap water has been implicated as a possible agent of transmission in hospital environments.

Methylobacterium radiotolerans

Methylobacterium species are gram-negative, rod-shaped bacteria that occur mostly on vegetation but may also be found in the hospital environment. Methylobacterium species have been reported to cause infections, especially in immunocompromised patients. Tap water has been implicated as a possible agent of transmission in hospital environments.

Methylobacterium spp.

Methylobacterium species are gram-negative, rod-shaped bacteria that occur mostly on vegetation but may also be found in the hospital environment. Methylobacterium species have been reported to cause infections, especially in immunocompromised patients. Tap water has been implicated as a possible agent of transmission in hospital environments.

Microbacterium liquefaciens

Microbacterium species are gram-positive, rod-shaped bacteria that are found in the environment, e.g. soil, sludge, and hospitals. They are rare agents of human disease.

Microbacterium paraoxydans

Microbacterium species are gram-positive, rod-shaped bacteria that are found in the environment, e.g. soil, sludge, and hospitals. They are rare agents of human disease.

Microbacterium spp.

Microbacterium species are gram-positive, rod-shaped bacteria that are found in the environment, e.g. soil, sludge, and hospitals. They are rare agents of human disease.

Micrococcus luteus

Micrococcus species are gram-positive, spherical bacteria which are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. They are carried on the skin of most (~96%) people, with M. luteus being the predominant species. Animal and dairy products are considered secondary sources. While micrococci are generally non-pathogenic, they may act as opportunistic pathogens.

Micrococcus lylae

Micrococcus species are gram-positive, spherical bacteria which are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. They are carried on the skin of most (~96%) people, with M. luteus being the predominant species. Animal and dairy products are considered secondary sources. While micrococci are generally non-pathogenic, they may act as opportunistic pathogens.

Micrococcus spp.

Micrococcus species are gram-positive, spherical bacteria which are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. They are carried on the skin of most (~96%) people, with M. luteus being the predominant species. Animal and dairy products are considered secondary sources. While micrococci are generally non-pathogenic, they may act as opportunistic pathogens.

Micrococcus/Kocuria spp.

Micrococcus and Kocuria species are gram-positive, spherical bacteria which are widespread in nature and commonly found, along with coagulase-negative Staphylococcus spp., as normal flora on the skin of humans and mammals. They are carried on the skin of most (~96%) people, with M. luteus being the predominant species. Animal and dairy products are considered secondary sources. While these organisms are generally non-pathogenic, they may act as opportunistic pathogens.

For more information, visit our Micrococcus & Kocuria Species page.

Moraxella atlantae

Moraxella species are gram-negative, rod-shaped bacteria that are normal flora of the mucous membranes covering the nose, throat, and respiratory tract of humans. They may also colonize the skin. M. catarrhalis is the most commonly isolated species from human infection, typically involving the respiratory tract.

Moraxella bovis

Moraxella species are gram-negative, rod-shaped bacteria that are normal flora of the mucous membranes covering the nose, throat, and respiratory tract of humans. They may also colonize the skin. M. catarrhalis is the most commonly isolated species from human infection, typically involving the respiratory tract.

Moraxella catarrhalis

Moraxella species are gram-negative, rod-shaped bacteria that are normal flora of the mucous membranes covering the nose, throat, and respiratory tract of humans. They may also colonize the skin. M. catarrhalis is the most commonly isolated species from human infection, typically involving the respiratory tract.

Moraxella caviae

Moraxella species are gram-negative, rod-shaped bacteria that are normal flora of the mucous membranes covering the nose, throat, and respiratory tract of humans. They may also colonize the skin. M. catarrhalis is the most commonly isolated species from human infection, typically involving the respiratory tract.

Moraxella lacunata

Moraxella species are gram-negative, rod-shaped bacteria that are normal flora of the mucous membranes covering the nose, throat, and respiratory tract of humans. They may also colonize the skin. M. catarrhalis is the most commonly isolated species from human infection, typically involving the respiratory tract.

Moraxella nonliquefaciens

Moraxella species are gram-negative, rod-shaped bacteria that are normal flora of the mucous membranes covering the nose, throat, and respiratory tract of humans. They may also colonize the skin. M. catarrhalis is the most commonly isolated species from human infection, typically involving the respiratory tract.

Moraxella osloensis

Moraxella species are gram-negative, rod-shaped bacteria that are normal flora of the mucous membranes covering the nose, throat, and respiratory tract of humans. They may also colonize the skin. M. catarrhalis is the most commonly isolated species from human infection, typically involving the respiratory tract.

Moraxella spp.

Moraxella species are gram-negative, rod-shaped bacteria that are normal flora of the mucous membranes covering the nose, throat, and respiratory tract of humans. They may also colonize the skin. M. catarrhalis is the most commonly isolated species from human infection, typically involving the respiratory tract.

Morganella morganii

Morganella morganii is a gram-negative, rod-shaped bacterium belonging to the Enterobacteriaceae family. This organism inhabits the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. M. morgannii is a known human pathogen.

Myroides odoratimimus

Myroides species are gram-negative, rod-shaped bacteria that inhabit soil and water. They are rare causes of human infection in in immunocompromised patients.

Myroides spp.

Myroides species are gram-negative, rod-shaped bacteria that inhabit soil and water. They are rare causes of human infection in in immunocompromised patients.


Neisseria weaveri

Neisseria weaveri is a gram-negative, rod-shaped bacterium that is part of the oral flora of dogs. Human infections are typically associated with dog bite wounds.

Nocardia spp.

Nocardia species are gram-positive, branching, rod-shaped bacteria. They are found worldwide in soil that is rich in organic matter. The majority of human infections stem from environmental sources as a result of trauma or inhalation.


Oceanobacillus caeni

Oceanobacillus species are gram-positive, rod-shaped, spore-forming bacteria that are related to Bacillus species. They have been found on the skin of rainbow trout and on oceanic sediment. No known human infections have been reported.

Ochrobactrum anthropi

Ochrobactrum anthropi is a gram-negative, rod-shaped bacterium. It has been isolated from various environmental sources such as polluted soil, water, plants, nematodes, insects, animals, and humans. It is recognized as an opportunistic pathogen in patients with indwelling medical devices.

Oerskovia turbata

Oerskovia turbata is a gram-positive, rod-shaped bacteria found in the soil. It is a rare cause of human infection.

Oligella spp.

Oligella species are gram-negative, rod-shaped bacteria that inhabit the human urinary tract. They are infrequent causes of infection.

Oligella ureolytica

Oligella species are gram-negative, rod-shaped bacteria that inhabit the human urinary tract. They are infrequent causes of infection.

Oligella urethralis

Oligella species are gram-negative, rod-shaped bacteria that inhabit the human urinary tract. They are infrequent causes of infection.

Ornithinibacillus contaminans

Ornithinibacillus species are gram-positive, spore-forming, rod-shaped bacteria that are members of the family Bacillaceae, which includes Bacillus species. They are widely distributed in the environment. Most species are not associated with human infections with the exception of O. contaminans, which has been isolated from a human blood sample.


Paenibacillus durus

Paenibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Paenibacillus macerans

Paenibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Paenibacillus provencensis

Paenibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Paenibacillus spp.

Paenibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Paenibacillus validus

Paenibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Pandoraea spp.

Pandoraea species are gram-negative, rod-shaped bacteria that inhabit soil, fresh and salt water. These species primarily cause respiratory infection in cystic fibrosis patients.

Pantoea agglomerans

Pantoea species (formerly Enterobacter) are gram-negative rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Pantoea species are frequent human pathogens, with P. agglomerans being the most common species.

Pantoea dispersa

Pantoea species (formerly Enterobacter) are gram-negative rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Pantoea species are frequent human pathogens, with P. agglomerans being the most common species.

Pantoea spp.

Pantoea species (formerly Enterobacter) are gram-negative rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Pantoea species are frequent human pathogens, with P. agglomerans being the most common species.

Paracoccus yeei

Paracoccus yeei is a gram-negative, spherical to rod-shaped bacterium found naturally in soil and brines. It is a rare opportunistic pathogen in humans.

Pasteurella aerogenes

Pasturella species are gram-negative, rod-shaped bacteria that colonize the nasal and oral cavities of animals and humans. These species can cause wound and soft tissue infections following an animal bite.

Pasteurella canis

Pasturella species are gram-negative, rod-shaped bacteria that colonize the nasal and oral cavities of animals and humans. These species can cause wound and soft tissue infections following an animal bite.

Pasteurella multocida

Pasturella species are gram-negative, rod-shaped bacteria that colonize the nasal and oral cavities of animals and humans. These species can cause wound and soft tissue infections following an animal bite.

Pasteurella pneumotropica

Pasturella species are gram-negative, rod-shaped bacteria that colonize the nasal and oral cavities of animals and humans. These species can cause wound and soft tissue infections following an animal bite.

Pasteurella spp.

Pasturella species are gram-negative, rod-shaped bacteria that colonize the nasal and oral cavities of animals and humans. These species can cause wound and soft tissue infections following an animal bite.

Pedobacter spp.

Pedobacter species are gram-negative, rod-shaped bacteria that have been primarily isolated from soil. No known human infections have been reported.

Planococcaceae

Planococcaceae is a family of Gram-variable, spore-forming and non-spore-forming, rod-shaped bacteria that are related to Bacillus. Various species have been found in the environment and as normal flora of humans and animals. No known human infections have been reported.

Plantibacter flavus

Plantibacter species are gram-positive, non-spore-forming, rod-shaped bacteria which have been isolated from plants. No known human infections have been reported.

Pontibacter spp.

Pontibacter species are gram-negative, rod-shaped bacteria which occupy a vast array of habitats including soil, marine, and freshwater environments. Infrequent infections have been reported in humans.

Propionibacterium acnes

Propionibacterium species are gram-positive, rod-shaped bacteria that are normal flora of the human skin and gastrointestinal tract. They are usually non-pathogenic but may cause infrequent human infections.

Propionibacterium granulosum

Propionibacterium species are gram-positive, rod-shaped bacteria that are normal flora of the human skin and gastrointestinal tract. They are usually non-pathogenic but may cause infrequent human infections.

Propionibacterium spp.

Propionibacterium species are gram-positive, rod-shaped bacteria that are part of the normal flora of the human skin and gastrointestinal tract. They can also be found in foods such as cheeses and other dairy products. Propionibacterium are usually non-pathogenic but may cause infrequent human infections.

Proteus mirabilis

Proteus species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Proteus species are frequent human pathogens.

Proteus spp.

Proteus species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Proteus species are frequent human pathogens.

Proteus vulgaris

Proteus species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Proteus species are frequent human pathogens.

Providencia alcalifaciens

Providencia species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Providencia species are frequent human pathogens.

Providencia rettgeri

Providencia species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Providencia species are frequent human pathogens.

Providencia rustigianii

Providencia species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Providencia species are frequent human pathogens.

Providencia spp.

Providencia species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Providencia species are frequent human pathogens.

Providencia stuartii

Providencia species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. These organisms inhabit the gastrointestinal tracts of humans and animals, as well as a wide variety of environmental niches, including water, sewage, soil, food, and hospital environments. Providencia species are frequent human pathogens.

Pseudomonas aeruginosa

Pseudomonas aeruginosa is gram-negative rod-shaped bacterium that can be readily isolated from moist environments, such as sink drains, fresh vegetables, river water, and even antiseptic solutions. It survives well in domestic environments (e.g., swimming pools, water slides, hot tubs, whirlpools, contact lens solution, sponges), and hospital environments (e.g., sinks, showers, respiratory equipment). P. aeruginosa can cause superficial infections in normal hosts but more severe infections in immunocompromised individuals.

Pseudomonas alcaligenes

Pseudomonas species are gram-negative, rod-shaped bacteria which are ubiquitous in soil and water. They prefer moist environments but can tolerate a variety of physical conditions. They are able to proliferate at cool temperatures and are responsible for the spoilage of dairy products. Some species are plant pathogens while others, such as P. aeruginosa, are involved in a wide variety of superficial and systemic human infections.

Pseudomonas chlororaphis

Pseudomonas species are gram-negative, rod-shaped bacteria which are ubiquitous in soil and water. They prefer moist environments but can tolerate a variety of physical conditions. They are able to proliferate at cool temperatures and are responsible for the spoilage of dairy products. Some species are plant pathogens while others, such as P. aeruginosa, are involved in a wide variety of superficial and systemic human infections.

Pseudomonas citronellolis

Pseudomonas species are gram-negative, rod-shaped bacteria which are ubiquitous in soil and water. They prefer moist environments but can tolerate a variety of physical conditions. They are able to proliferate at cool temperatures and are responsible for the spoilage of dairy products. Some species are plant pathogens while others, such as P. aeruginosa, are involved in a wide variety of superficial and systemic human infections.

Pseudomonas fluorescens

Pseudomonas species are gram-negative, rod-shaped bacteria which are ubiquitous in soil and water. They prefer moist environments but can tolerate a variety of physical conditions. They are able to proliferate at cool temperatures and are responsible for the spoilage of dairy products. Some species are plant pathogens while others, such as P. aeruginosa, are involved in a wide variety of superficial and systemic human infections.

Pseudomonas luteola

Pseudomonas species are gram-negative, rod-shaped bacteria which are ubiquitous in soil and water. They prefer moist environments but can tolerate a variety of physical conditions. They are able to proliferate at cool temperatures and are responsible for the spoilage of dairy products. Some species are plant pathogens while others, such as P. aeruginosa, are involved in a wide variety of superficial and systemic human infections.

Pseudomonas nitroreducens

Pseudomonas species are gram-negative, rod-shaped bacteria which are ubiquitous in soil and water. They prefer moist environments but can tolerate a variety of physical conditions. They are able to proliferate at cool temperatures and are responsible for the spoilage of dairy products. Some species are plant pathogens while others, such as P. aeruginosa, are involved in a wide variety of superficial and systemic human infections.

Pseudomonas oleovorans

Pseudomonas oleovorans is a gram-negative rod-shaped bacterium found in soil. It has also been isolated from oil-water emulsions used as lubricants and cooling agents in metalworking.

Pseudomonas oryzihabitans

Pseudomonas oryzihabitans is a gram-negative rod-shaped bacterium often recovered in moist hospital environments (e.g., respiratory therapy equipment). It is frequently linked to infections in immunocompromised patients with indwelling medical devices, particularly in association with synthetic bath sponges.

Pseudomonas putida

Pseudomonas species are gram-negative, rod-shaped bacteria which are ubiquitous in soil and water. They prefer moist environments but can tolerate a variety of physical conditions. They are able to proliferate at cool temperatures and are responsible for the spoilage of dairy products. Some species are plant pathogens while others, such as P. aeruginosa, are involved in a wide variety of superficial and systemic human infections.

Pseudomonas spp.

Pseudomonas species are gram-negative, rod-shaped bacteria which are ubiquitous in soil and water. They prefer moist environments but can tolerate a variety of physical conditions. They are able to proliferate at cool temperatures and are responsible for the spoilage of dairy products. Some species are plant pathogens while others, such as P. aeruginosa, are involved in a wide variety of superficial and systemic human infections.

Pseudomonas stutzeri

Pseudomonas species are gram-negative, rod-shaped bacteria which are ubiquitous in soil and water. They prefer moist environments but can tolerate a variety of physical conditions. They are able to proliferate at cool temperatures and are responsible for the spoilage of dairy products. Some species are plant pathogens while others, such as P. aeruginosa, are involved in a wide variety of superficial and systemic human infections.

Psychrobacillus lasiicapitis

Psychrobacillus lasiicapitis is a gram-positive, rod-shaped bacterium related to Bacillus species. It is of environmental origin and can form spores that are resistant to heat, desiccation, radiation, and disinfectants. No known human infections have been reported.

Psychrobacter phenylpyruvicus

Psychrobacter species are gram-negative, rod-shaped bacteria found in saline ecosystems, chilled meat and fish, and the upper respiratory tract of various animals. They are uncommon agents of human infection.

Psychrobacter spp.

Psychrobacter species are gram-negative, rod-shaped bacteria found in saline ecosystems, chilled meat and fish, and the upper respiratory tract of various animals. They are uncommon agents of human infection.

Pueribacillus spp.

Pueribacillus species are gram-positive, spore-forming, rod-shaped bacteria of environmental origin that are related to Bacillus species. No known human infections have been reported.


Rahnella aquatilis

Rahnella species are gram-negative, rod-shaped bacteria which have been found in fresh water, soil, beetles, and snails. They are a rare cause of human infection.

Rahnella spp.

Rahnella species are gram-negative, rod-shaped bacteria which have been found in fresh water, soil, beetles, and snails. They are a rare cause of human infection.

Ralstonia insidiosa

Ralstonia species are gram-negative, rod-shaped bacteria found in water, soil, the rhizosphere, and in and on plants including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments, these organisms have become particularly problematic as opportunistic pathogens in hospitals and health care settings. R. pickettii is the most common species associated with human infection.

Ralstonia mannitolilytica

Ralstonia species are gram-negative, rod-shaped bacteria found in water, soil, the rhizosphere, and in and on plants including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments, these organisms have become particularly problematic as opportunistic pathogens in hospitals and health care settings. R. pickettii is the most common species associated with human infection.

Ralstonia pickettii

Ralstonia species are gram-negative, rod-shaped bacteria found in water, soil, the rhizosphere, and in and on plants including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments, these organisms have become particularly problematic as opportunistic pathogens in hospitals and health care settings. R. pickettii is the most common species associated with human infection.

Ralstonia spp.

Ralstonia species are gram-negative, rod-shaped bacteria found in water, soil, the rhizosphere, and in and on plants including fruits and vegetables. They have a worldwide distribution and are widely recognized as phytopathogens. Because of their ability to survive in aqueous environments, these organisms have become particularly problematic as opportunistic pathogens in hospitals and health care settings. R. pickettii is the most common species associated with human infection.

Raoultella ornithinolytica

Raoultella species are gram-negative, rod-shaped bacteria found in aquatic environments. Most species are not associated with human infection with the exception of R. ornithinolytica, which is an emerging hospital-acquired pathogen.

Raoultella spp.

Raoultella species are gram-negative, rod-shaped bacteria found in aquatic environments. Most species are not associated with human infection with the exception of R. ornithinolytica, which is an emerging hospital-acquired pathogen.

Rhizobium radiobacter

Rhizobium radiobacter (formerly Agrobacterium tumefaciens) is a gram-negative, rod-shaped bacterium of leguminous plants. There are several species of Rhizobium and all are plant pathogens occurring worldwide. R. radiobacter has been occasionally associated with disease in humans.

Rhodococcus equi

Rhodococcus species are gram-positive, spherical to rod-shaped bacteria. They can be isolated from soil and farm animals, as well as fresh and salt waters. Most human infections occur in immunocompromised patients and stem from environmental sources, with inhalation being the most probable means of transmission.

Rhodococcus spp.

Rhodococcus species are gram-positive, spherical to rod-shaped bacteria. They can be isolated from soil and farm animals, as well as fresh and salt waters. Most human infections occur in immunocompromised patients and stem from environmental sources, with inhalation being the most probable means of transmission.

Roseomonas mucosa

Roseomonas species are gram-negative, rod-shaped bacteria found in soil and water. R. mucosa can be found as part of the skin microflora of humans and is an opportunistic pathogen.

Rothia dentocariosa

Rothia species are gram-positive, rod-shaped bacteria which inhabit the oral cavity of humans. They are frequently involved in periodontal disease and can cause serious infections in immunocompromised patients.

Rothia mucilaginosa

Rothia species are gram-positive, rod-shaped bacteria which inhabit the oral cavity of humans. They are frequently involved in periodontal disease and can cause serious infections in immunocompromised patients.


Saccharopolyspora

Saccharopolyspora species are gram‐positive, rod-shaped bacteria related to actinomycetes, whose main habitat is soil. No known human infections have been reported.

Salmonella spp.

Salmonella are gram-negative, rod-shaped bacteria that inhabit the gastrointestinal tracts of humans and animals. They can also be found in fecally contaminated food and water, which serve as vehicles for transmission of the organism. In the U.S., intestinal infections are the most common presentation of this pathogen, however, some strains can cause systemic infection.

Shewanella putrefaciens

Shewanella species are gram-negative, rod-shaped bacteria found in fresh and salt water, sewage, and food. They are a normal component of the surface flora of fish and are implicated in fish spoilage. They are infrequent agents of human infection, with S. algae being the most common human isolate.

Shigella spp.

Shigella species are gram-negative, rod-shaped bacteria belonging to the Enterobacteriaceae family. Humans and other large primates are the only natural reservoirs. These organisms have a low infectious dose and are frequent agents of diarrheal disease. Most transmission is by person-to-person spread, but infection can be caused by ingestion of fecally contaminated food and water.

Solibacillus spp.

Solibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Sphingobacterium daejeonense

Sphingobacterium species are gram-negative, rod-shaped bacteria that are found in soil, water and on plants and foodstuffs. These organisms have the ability to survive in moist hospital environments. They are an infrequent cause of human infection.

Sphingobacterium multivorum

Sphingobacterium species are gram-negative, rod-shaped bacteria that are found in soil, water and on plants and foodstuffs. These organisms have the ability to survive in moist hospital environments. They are an infrequent cause of human infection.

Sphingobacterium spiritivorum

Sphingobacterium species are gram-negative, rod-shaped bacteria that are found in soil, water and on plants and foodstuffs. These organisms have the ability to survive in moist hospital environments. They are an infrequent cause of human infection.

Sphingobacterium spp.

Sphingobacterium species are gram-negative, rod-shaped bacteria that are found in soil, water and on plants and foodstuffs. These organisms have the ability to survive in moist hospital environments. They are an infrequent cause of human infection.

Sphingobacterium thalpophilum

Sphingobacterium species are gram-negative, rod-shaped bacteria that are found in soil, water and on plants and foodstuffs. These organisms have the ability to survive in moist hospital environments. They are an infrequent cause of human infection.

Sphingomonas paucimobilis

Sphingomonas species are gram-negative, rod-shaped bacteria that are widely distributed in terrestrial and aquatic habitats as well as plant root systems and aqueous solutions. S. paucimobilis is the most common species encountered in human infections.

Sphingomonas spp.

Sphingomonas species are gram-negative, rod-shaped bacteria that are widely distributed in terrestrial and aquatic habitats as well as plant root systems and aqueous solutions. S. paucimobilis is the most common species encountered in human infections.

Sporosarcina luteola

Sporosarcina luteola is a gram-positive, spore-forming, rod-shaped bacterium that has been isolated from soy sauce production equipment. It is related to members of the Bacillus genus. No human infections have been reported.

Sporosarcina spp.

Sporosarcina species are gram-positive, spore-forming, rod-shaped bacteria that are related to members of the Bacillus genus. They are widely distributed in the soil. No human infections have been reported.

Staphylococcus arlettae

Coagulase-negative staphylococci (CoNS) are gram-positive, spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus aureus

Staphylococcus aureus is a gram-positive, spherical bacterium that can be isolated as normal flora of the human anterior nares and throat. S. aureus is a frequent and important human pathogen, causing a variety of superficial and invasive human infections. It is notable for development of antibiotic resistance, specifically methicillin resistance (MRSA).

Staphylococcus auricularis

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus capitis

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus caprae

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus caprae/capitis

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus carnosus

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus chromogenes

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus cohnii

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus delphini

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus epidermidis

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus equorum

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus gallinarum

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus haemolyticus

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus hominis

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus hyicus

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus intermedius

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus kloosii

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus lentus

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus lugdunensis

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus pasteuri

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus pseudintermedius

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus saccharolyticus

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus saprophyticus

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus schleiferi

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus sciuri

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus simulans

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus spp.

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

For more information, visit our Staphylococcus Species page.

Staphylococcus vitulinus

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus warneri

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Staphylococcus xylosus

Coagulase-negative staphylococci (CoNS) are gram-positive spherical bacteria. The major habitats of CoNS are the skin and mucous membranes of mammals and birds. In humans, S. epidermidis is the most frequently isolated staphylococcal species colonizing the body surface. A few of the CoNS are important human pathogens and include S. epidermidis, S. haemolyticus, S. lugdunensis, and S. saprophyticus. CoNS have been increasingly recognized as health-care associated pathogens, particularly in patients with indwelling medical devices.

Stenotrophomonas maltophilia

Stenotrophomonas maltophilia is a gram-negative, rod-shaped bacterium that is widely distributed in nature, including moist environments, water, and on fruits and vegetables. It can survive in chlorinated water distribution networks. Human infections occur in hospitalized immunocompromised patients, most likely as a result of exposure in the hospital environment.

Streptococcus agalactiae

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus alactolyticus

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus anginosus

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus australis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus bovis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus canis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus constellatus

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus cristatus

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus dysgalactiae

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus equi

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus gallolyticus

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus gordonii

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus hyointestinalis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus hyovaginalis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus infantarius

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus intermedius

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus mitis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus mutans

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus oligofermentans

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus oralis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus ovis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus parasanguinis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus parauberis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus peroris

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus pluranimalium

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus pneumoniae

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus porcinus

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus pyogenes

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus salivarius

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus sanguinis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus sobrinus

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus spp.

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus suis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus thoraltensis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptococcus uberis

Streptococcus species are gram-positive, spherical bacteria that are frequently found as commensals on the mucous membranes of humans, mammals, and fish. They may also be transient colonizers of the human skin. Though most species are considered normal flora, there are some that may be highly virulent, such as S. pyogenes.

Streptomyces spp.

Streptomyces species are gram-positive, filamentous, rod-shaped bacteria that are widely distributed in terrestrial and aquatic habitats. They are most often associated with decomposing plant material. Streptomyces are rare causes of human infection, the most common infection being mycetoma.


Terribacillus spp.

Terribacillus species are gram-positive, spore-forming, rod-shaped bacteria that are related to Bacillus, whose main habitat is soil. No human infections have been reported.


Vibrio alginolyticus

Vibrio species are gram-negative, rod-shaped bacteria that are ubiquitous in aquatic environments, primarily marine waters. Some species can be found in freshwater rivers and lakes. They are commonly isolated from bivalves and crustaceans, their presence peaking during the warmer months. Transmission of the organism to humans is via ingestion or contact with contaminated water, mild to severe intestinal, wound, or systemic infections can result.

Vibrio cholerae

Vibrio species are gram-negative, rod-shaped bacteria that are ubiquitous in aquatic environments, primarily marine waters. Some species can be found in freshwater rivers and lakes. They are commonly isolated from bivalves and crustaceans, their presence peaking during the warmer months. Transmission of the organism to humans is via ingestion or contact with contaminated water, mild to severe intestinal, wound, or systemic infections can result.

Vibrio cholerae/mimicus

Vibrio species are gram-negative, rod-shaped bacteria that are ubiquitous in aquatic environments, primarily marine waters. Some species can be found in freshwater rivers and lakes. They are commonly isolated from bivalves and crustaceans, their presence peaking during the warmer months. Transmission of the organism to humans is via ingestion or contact with contaminated water, mild to severe intestinal, wound, or systemic infections can result.

Vibrio furnissii

Vibrio species are gram-negative, rod-shaped bacteria that are ubiquitous in aquatic environments, primarily marine waters. Some species can be found in freshwater rivers and lakes. They are commonly isolated from bivalves and crustaceans, their presence peaking during the warmer months. Transmission of the organism to humans is via ingestion or contact with contaminated water, mild to severe intestinal, wound, or systemic infections can result.

Vibrio harveyi

Vibrio species are gram-negative, rod-shaped bacteria that are ubiquitous in aquatic environments, primarily marine waters. Some species can be found in freshwater rivers and lakes. They are commonly isolated from bivalves and crustaceans, their presence peaking during the warmer months. Transmission of the organism to humans is via ingestion or contact with contaminated water, mild to severe intestinal, wound, or systemic infections can result.

Vibrio mimicus

Vibrio species are gram-negative, rod-shaped bacteria that are ubiquitous in aquatic environments, primarily marine waters. Some species can be found in freshwater rivers and lakes. They are commonly isolated from bivalves and crustaceans, their presence peaking during the warmer months. Transmission of the organism to humans is via ingestion or contact with contaminated water, mild to severe intestinal, wound, or systemic infections can result.

Vibrio parahaemolyticus

Vibrio species are gram-negative, rod-shaped bacteria that are ubiquitous in aquatic environments, primarily marine waters. Some species can be found in freshwater rivers and lakes. They are commonly isolated from bivalves and crustaceans, their presence peaking during the warmer months. Transmission of the organism to humans is via ingestion or contact with contaminated water, mild to severe intestinal, wound, or systemic infections can result.

Vibrio spp.

Vibrio species are gram-negative, rod-shaped bacteria that are ubiquitous in aquatic environments, primarily marine waters. Some species can be found in freshwater rivers and lakes. They are commonly isolated from bivalves and crustaceans, their presence peaking during the warmer months. Transmission of the organism to humans is via ingestion or contact with contaminated water, mild to severe intestinal, wound, or systemic infections can result.

Vibrio vulnificus

Vibrio species are gram-negative, rod-shaped bacteria that are ubiquitous in aquatic environments, primarily marine waters. Some species can be found in freshwater rivers and lakes. They are commonly isolated from bivalves and crustaceans, their presence peaking during the warmer months. Transmission of the organism to humans is via ingestion or contact with contaminated water, mild to severe intestinal, wound, or systemic infections can result.

Virgibacillus pantothenticus

Virgibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.

Virgibacillus proomii

Virgibacillus species (formerly Bacillus) are gram-positive, rod-shaped bacteria that are ubiquitous in nature. They form spores that are resistant to heat, desiccation, radiation, and disinfectants. Dissemination of spores via aerosols and dust contributes to contamination of indoor environments. Most species have little or no pathogenic potential.


Weeksella virosa

Weeksella virosa is a gram-negative, rod-shaped bacterium that has been found on the mucous membranes of humans and other warm-blooded animals. It is a rare cause of human infection.


Xanthomonas spp.

Xanthomonas species are gram-negative, rod-shaped bacteria that can cause a wide variety of plant diseases, such as leaf spot. No human infections have been reported.


Yersinia aldovae

Yersinia species are gram-negative, rod-shaped bacteria that are found in the gastrointestinal tracts of many animal species and in soil and water. Transmission to humans is most commonly via ingestion of contaminated food and water. Infections typically involve the gastrointestinal tract and can range from mild to severe.

Yersinia enterocolitica

Yersinia species are gram-negative, rod-shaped bacteria that are found in the gastrointestinal tracts of many animal species and in soil and water. Transmission to humans is most commonly via ingestion of contaminated food and water. Infections typically involve the gastrointestinal tract and can range from mild to severe.

Yersinia frederiksenii

Yersinia species are gram-negative, rod-shaped bacteria that are found in the gastrointestinal tracts of many animal species and in soil and water. Transmission to humans is most commonly via ingestion of contaminated food and water. Infections typically involve the gastrointestinal tract and can range from mild to severe.

Yersinia intermedia

Yersinia species are gram-negative, rod-shaped bacteria that are found in the gastrointestinal tracts of many animal species and in soil and water. Transmission to humans is most commonly via ingestion of contaminated food and water. Infections typically involve the gastrointestinal tract and can range from mild to severe.

Yersinia kristensenii

Yersinia species are gram-negative, rod-shaped bacteria that are found in the gastrointestinal tracts of many animal species and in soil and water. Transmission to humans is most commonly via ingestion of contaminated food and water. Infections typically involve the gastrointestinal tract and can range from mild to severe.

Yersinia mollaretii

Yersinia species are gram-negative, rod-shaped bacteria that are found in the gastrointestinal tracts of many animal species and in soil and water. Transmission to humans is most commonly via ingestion of contaminated food and water. Infections typically involve the gastrointestinal tract and can range from mild to severe.

Yersinia pseudotuberculosis

Yersinia species are gram-negative, rod-shaped bacteria that are found in the gastrointestinal tracts of many animal species and in soil and water. Transmission to humans is most commonly via ingestion of contaminated food and water. Infections typically involve the gastrointestinal tract and can range from mild to severe.

Yersinia ruckeri

Yersinia species are gram-negative, rod-shaped bacteria that are found in the gastrointestinal tracts of many animal species and in soil and water. Transmission to humans is most commonly via ingestion of contaminated food and water. Infections typically involve the gastrointestinal tract and can range from mild to severe.

Yersinia spp.

Yersinia species are gram-negative, rod-shaped bacteria that are found in the gastrointestinal tracts of many animal species and in soil and water. Transmission to humans is most commonly via ingestion of contaminated food and water. Infections typically involve the gastrointestinal tract and can range from mild to severe.


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