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.
Enterococcus is a large genus of lactic acid bacteria of the phylum Bacillota. Enterococci are gram-positive cocci that often occur in pairs (diplococci) or short chains, and are difficult to distinguish from streptococci on physical characteristics alone. Two species are common commensal organisms in the intestines of humans: E. faecalis (90–95%) and E. faecium (5–10%). Rare clusters of infections occur with other species, including E. casseliflavus, E. gallinarum, and E. raffinosus.
Peptostreptococcus is a genus of anaerobic, Gram-positive, non-spore forming bacteria. The cells are small, spherical, and can occur in short chains, in pairs or individually. They typically move using cilia. Peptostreptococcus are slow-growing bacteria with increasing resistance to antimicrobial drugs. Peptostreptococcus is a normal inhabitant of the healthy lower reproductive tract of women.
Streptococcus bovis is a species of Gram-positive bacteria that in humans is associated with urinary tract infections, endocarditis, sepsis, and colorectal cancer. S. gallolyticus is commonly found in the alimentary tract of cattle, sheep, and other ruminants, and may cause ruminal acidosis or feedlot bloat. It is also associated with spontaneous bacterial peritonitis, a frequent complication occurring in patients affected by cirrhosis. Equivalence with Streptococcus equinus has been contested.
Gemella morbillorum is a species of bacteria within the genus Gemella. It is a facultative anaerobic Gram positive coccus usually preferring capnophilic or microaerophilic environments. From its discovery in 1917 until 1988, it was known as Streptococcus morbillorum. The name change followed closer examination with DNA filter hybridization which found it was very close to the species Gemella haemolysans.
Eikenella corrodens is a Gram-negative facultative anaerobic bacillus that can cause severe invasive disease in humans. It was first identified by M. Eiken in 1958, who called it Bacteroides corrodens. E. corrodens is a rare pericarditis associated pathogen. It is a fastidious, slow growing, human commensal bacillus, capable of acting as an opportunistic pathogen and causing abscesses in several anatomical sites, including the liver, lung, spleen, and submandibular region. E. corrodens could independently cause serious infection in both immunocompetent and immunocompromised hosts.
Staphylococcus is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical (cocci), and form in grape-like clusters. Staphylococcus species are facultative anaerobic organisms.
Clostridium innocuum is an anaerobic, non-motile, gram-positive bacterium that reproduces by sporulation. While there are over 130 species of Clostridium, C. innocuum is the third most commonly isolated. Although it is not normally considered an aggressive human pathogen, it has been isolated in some disease processes. C. innocuum and other Clostridium line the oropharynx and gastrointestinal tract, and are considered normal gut flora.
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.
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.
Peptoniphilus is a genus of bacteria in the phylum Bacillota (Bacteria).
Finegoldia is a genus of Gram-positive bacteria. They are anaerobic cocci of the class Clostridia, with Finegoldia magna being the type species. F. magna was formerly known, along with several other Gram-positive anaerobic cocci (GPACs), as Peptostreptococcus magnus, but was moved into its own genus in 1999. The name is in honor of Sydney M. Finegold, an American microbiologist, while magna is Latin for large. It is an opportunistic human pathogen that normally colonizes skin and mucous membranes. It is often seen in biofilms on chronic ulcers such as in diabetic foot or decubitus ulcers. Most surveys have found it to be susceptible to penicillins, carbapenems and metronidazole, though resistant strains have been identified. Resistance to clindamycin is common and has been seen in over 10% of isolates in the US. One review stated that "the combination of diminished antimicrobial susceptibility, its prevalence, and the described virulence factors gives F. magna a special position among the GPAC."
Anaerococcus is a genus of bacteria. Its type species is Anaerococcus prevotii. These bacteria are Gram-positive and strictly anaerobic. The genus Anaerococcus was proposed in 2001. Its genome was sequenced in August 2009. The genus Anaerococcus is one of six genera classified within the group GPAC. These six genera are found in the human body as part of the commensal human microbiota.
Globicatella sulfidifaciens is a Gram-positive bacteria from the family of Globicatella which has been isolated from the lungs of cattle and lambs in Belgium. It is associated with purulent infections of domestic mammals and urinary tracts of swine. Unlike other Globicatella species and species of related genera, G. sulfidifaciens is PYR negative. Globicatella sulfidifaciens bacteria are resistant against the antibiotics neomycin, erythromycin and clindamycin.
Peptoniphilus duerdenii is a Gram-positive and anaerobic bacterium from the genus of Peptoniphilus which has been isolated from a human wound.
Peptoniphilus gorbachii is a Gram-positive and anaerobic bacterium from the genus of Peptoniphilus which has been isolated from a human abscess from Los Angeles in the United States.
Peptoniphilus lacydonensis is a Gram-positive, anaerobic and microaerophilic bacterium from the genus of Peptoniphilus which has been isolated from a patient with chronic refractory sinusitis.
Peptoniphilus stercorisuis is a Gram-positive and anaerobic bacterium from the genus of Peptoniphilus which has been isolated from a swine manure storage tank from Oklahoma in the United States.
Staphylococcus argenteus are gram-positive cocci from the genus Staphylococcus which have been isolated from blood culture of a 55-year-old Indigenous Australian female in 2006 in Darwin, Northern Territory, Australia. The species is close related to S. aureus and the differentiation is challenging. Staphylococcus argenteus is cytotoxic to human cells due to high expression of alpha-hemolysin.
Christensenella hongkongensis is a species of clinically relevant gram-positive coccobacilli, first isolated from patients in Hong Kong and Canada in 2006. Although the species remains relatively rare, it has a high mortality rate of up to 50%. Christensenella is thought to be broadly distributed globally, as it has been isolated from patient blood cultures around the world including Hong Kong, South Korea, New Zealand, Canada, Sweden, France and Italy. Fewer than 15 cases of C. hongkongensis have been observed worldwide.
