In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall.
Campylobacterota are a phylum of bacteria. All species of this phylum are Gram-negative.
Alteromonas is a genus of Pseudomonadota found in sea water, either in the open ocean or in the coast. It is Gram-negative. Its cells are curved rods with a single polar flagellum.
Prevotella melaninogenica is a species of bacterium in the normal microbiota of the upper respiratory tract. It is an important human pathogen in various anaerobic infections, often mixed with other aerobic and anaerobic bacteria. P. melaninogenica is an anaerobic, Gram-negative rod, named for its black colonies, and black pigment.
Porphyromonas is a Gram-negative, non-spore-forming, obligately anaerobic and non-motile genus from the family Porphyromonadaceae. There were 16 different Porphyromonas species documented as of 2015, which reside in both animal and human reservoirs. It was discovered more recently that Porphyromonas also exist in the environment, albeit to a lesser extent. This genus is notably implicated in the modulation of oral cavity, respiratory tract, and gastrointestinal tract disease states. It is suggested that Porphyromonas either operate as benign bacteria pertinent to host immunity or are potential pathobionts that opportunistically provoke diseased states when homeostasis is disrupted. Despite its characterization not being fully elucidated due to sparse research, various studies report the prevalence of this genus at 58.7% in healthy states compared with 41.3% in diseased states.
Tannerella forsythia is an anaerobic, Gram-negative bacterial species of the Bacteroidota phylum. It has been implicated in periodontal diseases and is a member of the red complex of periodontal pathogens. T. forsythia was previously named Bacteroides forsythus and Tannerella forsythensis.
Arcobacter is a genus of Gram-negative, spiral-shaped bacteria in the phylum Campylobacterota. It shows an unusually wide range of habitats, and some species can be human and animal pathogens. Species of the genus Arcobacter are found in both animal and environmental sources, making it unique among the Campylobacterota. This genus currently consists of five species: A. butzleri, A. cryaerophilus, A. skirrowii, A. nitrofigilis, and A. sulfidicus, although several other potential novel species have recently been described from varying environments. Three of these five known species are pathogenic. Members of this genus were first isolated in 1977 from aborted bovine fetuses. They are aerotolerant, Campylobacter-like organisms, previously classified as Campylobacter. The genus Arcobacter, in fact, was created as recently as 1992. Although they are similar to this other genus, Arcobacter species can grow at lower temperatures than Campylobacter, as well as in the air, which Campylobacter cannot.
Campylobacter concisus is a Gram-negative, highly fastidious, mesophilic bacterium that grows under both anaerobic and microaerobic conditions with the presence of hydrogen significantly aiding growth. Motile, with either unipolar or bipolar flagella, the organisms have a characteristic spiral/corkscrew appearance and are oxidase-positive. Although the human oral cavity is the natural colonization site of the bacterium, C. concisus may also colonize the intestinal tract of some individuals. In particular, several studies have reported higher intestinal prevalence of C. concisus in patients with IBD compared to healthy controls, which has led to current speculation of the bacterium's implication in the induction of Crohn's disease.
Lautropia mirabilis is a Gram-negative, facultatively anaerobic, oxidase- and catalase-positive, motile bacterium of the genus Lautropia and family Burkholderiaceae, isolated from the mouth of children who were infected with human immunodeficiency virus.
Campylobacter lanienae is a species of Campylobacter found in humans and other animals. Like other Campylobacter species, it is rod-shaped, non-glucose-fermenting, oxidase- and catalase-positive, Gram-negative and motile.
Helicobacter muridarum is a bacterium in the Helicobacteraceae family, Campylobacterales order. It is microaerophilic and helical and was first isolated from the intestinal mucosa of rodents, hence its name. It is characterised by the presence of 9 to 11 periplasmic fibers which appear as concentric helical ridges on the surface of each cell. The cells are motile and have bipolar tufts of 10 to 14 sheathed flagella. These bacteria are nutritionally fastidious and physiologically similar to other Helicobacter species and Wolinella succinogenes, but can be differentiated from these organisms by their unique cellular ultrastructure. ST1T is its type strain.
Actinobacillus succinogenes is a bacterium. It is a succinic acid-producing strain first isolated from the bovine rumen. It is a facultatively anaerobic, pleomorphic, Gram-negative rod. Its type strain is ATCC 55618T.
Leptospira alexanderi is a species of Leptospira. Its type strain is strain L 60T.
Dialister pneumosintes is a nonfermentative, anaerobic, gram-negative rod that grows with small, circular, transparent, shiny, smooth colonies on blood agar. D. pneumosintes has been recovered from deep periodontal pockets, but little is known about the relationship between the organism and destructive periodontal disease.
Actinotignum schaalii is a bacterium first isolated from human blood cultures. Its type strain is CCUG 27420. It is a Gram-positive, facultative anaerobic coccoid rod, considered a human pathogen.
Campylobacter showae is a species of Campylobacter found in humans. It is gram-negative, straight rod-shaped, motile by means of multiple unipolar flagella. It is asaccharolytic and prefers an anaerobic atmosphere. SU A4 is its type strain. Its genome has been sequenced.
Treponema lecithinolyticum is a species of Treponema. It is implicated as a pathogen in chronic periodontitis which can induce bone loss. This motile bacillus is a gram negative, facultative anaerobe and a spirochaete.
Arhodomonas aquaeolei is a species of the bacterial genus Arhodomonas noted for its ability to grow in an environment of high salinity. It is an aerobic, oval rod-shaped, gram-negative bacterium. It is motile by means a single polar flagellum.
Peptoniphilus is a genus of bacteria in the phylum Bacillota (Bacteria).
Runella is a Gram-negative, aerobic and non-motile bacterial genus from the family Spirosomaceae.
