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 (Gram-Positive Anaerobic Cocci). These six genera (

Peptostreptococcus ''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- ...

Peptoniphilus ''Peptoniphilus'' is a genus of bacteria in the phylum Bacillota (Bacteria). Etymology The name ''Peptoniphilus'' derives from:Neo-Latin noun ''peptonum'', peptone; Neo-Latin adjective ''philus'' from Greek adjective ''philos (φίλος)'' mean ...

, Parvimonas, Finegoldia, Murdochiella, and Anaerococcus) are found in the human body as part of the commensal human microbiota. It is commonly found in the human

microbiome A microbiome () is the community of microorganisms that can usually be found living together in any given habitat. It was defined more precisely in 1988 by Whipps ''et al.'' as "a characteristic microbial community occupying a reasonably wel ...

and is associated with various infections. Most of the species in this genus can be found among microbes of the skin, human vagina, nasal cavity, oral cavity and feces, often as a pathogen found in ovarian

abscess An abscess is a collection of pus that has built up within the tissue of the body, usually caused by bacterial infection. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pre ...

es,

chronic wound A chronic wound is a wound A wound is any disruption of or damage to living tissue, such as skin, mucous membranes, or organs. Wounds can either be the sudden result of direct trauma (mechanical, thermal, chemical), or can develop slowly over t ...

s and

vaginal discharge Vaginal discharge is a mixture of liquid, cells, and bacteria that lubricate and protect the vagina. This mixture is constantly produced by the cells of the vagina and cervix, and it exits the body through the vaginal opening. The composition, ...

. Moreover, some of the species can be isolated from foot ulcers and

knee arthritis Arthritis of the knee is typically a particularly debilitating form of arthritis. The knee may become affected by almost any form of arthritis. The word ''arthritis'' refers to inflammation of the joints. Types of arthritis include those related ...

. It can be present in

urinary tract infection A urinary tract infection (UTI) is an infection that affects a part of the urinary tract. Lower urinary tract infections may involve the bladder (cystitis) or urethra (urethritis) while upper urinary tract infections affect the kidney (pyel ...

s, chronic ulcers,

pleural empyema Pleural empyema is a collection of pus in the pleural cavity. It is caused by microorganisms, usually bacteria. It often happens in the context of a pneumonia, injury, or chest surgery. It is one of the various kinds of pleural effusion. Pleural ...

blood infection Bloodstream infections (BSIs) are infections of blood caused by blood-borne pathogens. The detection of microbes in the blood (most commonly accomplished by blood cultures) is always abnormal. A bloodstream infection is different from sepsis, w ...

s, and soft tissue

infection An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

s. It is involved in polymicrobial infections. Strains of Anaerococcus were found in the armpit microbiota suggesting some species in this genus could play a role in axillary odor.

Physiology

The genus Anaerococcus are non motile bacteria who can not form spores. Depending on the species the arrangement can be different. The most common arrangements within this genus are pairs, tetrads, short chains and irregular formations. Their cells size can differ from 0.6μm to 0.9μm. However, when they are grown using enrinched blood agar their size can go from 0.5μm to 2μm. In this genus, there are more than one major cellular fatty acids: C18:1, C16:1, C18 and C16. Most species in this genus are indole-negative and coaguase-negative. In general, the species of Anaerococcus presents susceptibility to penicillins but are resistant to

tetracycline Tetracycline, sold under various brand names, is an antibiotic in the tetracyclines family of medications, used to treat a number of infections, including acne, cholera, brucellosis, plague, malaria, and syphilis. It is available in oral an ...

erythromycin Erythromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used ...

and

clindamycin Clindamycin is a lincosamide antibiotic medication used for the treatment of a number of bacterial infections, including osteomyelitis (bone) or joint infections, pelvic inflammatory disease, strep throat, pneumonia, acute otitis media (mi ...

Metabolism

The genus Anaerococcus are classified as saccharolytic bacteria. Its species can be arranged from weakly saccharolytic (ex. ''A. prevotii'', ''A. lactolyticus'') to strongly saccharolytic (ex. ''A. hydrogenalis''). This genus can ferment carbohydrates weakly. The major sources of energy use in the metabolism of Anaerococcus are peptones and aminoacids. The three major sugars fermented within this genus are glucose, mannose, fructose and sucrose. After fermenting the sugars, Anaerococcus produce weak acids as their metabolic end product. Within these metabolic end products, this genus ca produce butyric acid, lactic acid, and some propionic and succinic acid. Nonetheless, the major metabolite produced by Anaerococcus is butyrate.

Phylogeny

The currently accepted taxonomy is based on the

List of Prokaryotic names with Standing in Nomenclature List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the naming and taxonomy of prokaryotes, following the taxonomy requirements and rulings of the International Code of Nomenclatu ...

(LPSN) and

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is lo ...

(NCBI) Incertae sedis: * "''A. faecalis''" Yu et al. 2021 * "''Ca.'' A. massiliensis" Fenollar et al. 2006 * "''Ca.'' A. phoceensis" Fenollar et al. 2006 * "''Ca.'' A. timonensis" Fenollar et al. 2006

Species

Until recently, the genus Anaerococcus have 14 known species. Six of the species were initially classified in the genus Peptostreptococcus but then based on their characteristics were re-classified in the new genus Anaerococcus: ''A. hydrogenalis'', ''A. lactolyticus'', ''A. octavius'', ''A. prevotii'', ''A. tetradius'', and ''A. vaginalis.'' Throughout the years, the specie who has been more commonly found on the body within this genus is ''A. prevotii.''

''Anaerococcus octavius''

Contrary to most of the species in the genus, '' Anaerococcus octavius'' was not related to human infections. Nevertheless, recently a new case revealed ''A. octavius'' can cause

bacteremia Bloodstream infections (BSIs) are infections of blood caused by blood-borne pathogens. The detection of microbes in the blood (most commonly accomplished by blood cultures) is always abnormal. A bloodstream infection is different from sepsis, wh ...

. Even though it is uncommon, ''Anaerococcus octavius'' can be the cause for human infections. Other studies have found ''A. octavius'' as part of the nasal, skin and vaginal normal flora. This bacteria can ferment ribose, glucose, and mannose.

''Anaerococcus prevotii''

'' A. prevotii'' is normally found in vaginal discharge, human plasma and some types of abscesses - such as ovarian, peritoneal sacral and/or lung abscesses. ''Anaerococcus prevotii'' is part of the normal flora in the skin, oral cavity and the gut. Studies has shown ''Anaerococcus prevotii'' presents resistance to

Ceftazidime Ceftazidime, sold under the brand name Fortaz among others, is a third-generation cephalosporin antibiotic useful for the treatment of a number of bacterial infections. Specifically it is used for joint infections, meningitis, pneumonia, sepsi ...

Clindamycin Clindamycin is a lincosamide antibiotic medication used for the treatment of a number of bacterial infections, including osteomyelitis (bone) or joint infections, pelvic inflammatory disease, strep throat, pneumonia, acute otitis media (mi ...

Levofloxacin Levofloxacin, sold under the brand name Levaquin among others, is a broad-spectrum antibiotic of the fluoroquinolone drug class. It is the left-handed isomer of the medication ofloxacin. It is used to treat a number of bacterial infections ...

. Unlike the other species, ''A. prevotii'' can not ferment glucose.

''Anaerococcus vaginalis''

'' A. vaginalis'' was first recovered from vaginal discharges and ovarian abscesses although this bacteria can also be found in pressure ulcers and diabetic foot. Some strains from this species can be indole-positive.

''Anaerococcus provencensis''

'' A. provencensis'' was isolated from a cervical abscess. This species can ferment lactose, unlike ''A. tetradius, A. prevotii,'' and ''A. octavius''. The first analysis made on ''Anaerococcus provencensis'' showed it is susceptible to

penicillin G Benzylpenicillin, also known as penicillin G (PenG) or BENPEN, is an antibiotic used to treat a number of bacterial infections. This includes pneumonia, strep throat, syphilis, necrotizing enterocolitis, diphtheria, gas gangrene, leptospiros ...

imipenem Imipenem (trade name Primaxin among others) is a synthetic beta-lactam, β-lactam antibiotic belonging to the carbapenems chemical class. developed by Merck scientists Burton Christensen, William Leanza, and Kenneth Wildonger in the mid-1970s. Car ...

, amoxillin,

metronidazole Metronidazole, sold under the brand name Flagyl and Metrogyl among others, is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vagino ...

cefotetan Cefotetan is an injectable antibiotic of the cephamycin type for prophylaxis and treatment of bacterial infections. It is often grouped together with second-generation cephalosporins and has a similar antibacterial spectrum, but with additional a ...

and

vancomycin Vancomycin is a glycopeptide antibiotic medication used to treat certain bacterial infections. It is administered intravenously ( injection into a vein) to treat complicated skin infections, bloodstream infections, endocarditis, bone an ...

''Anaerococcus senegalensis''

'' A. senegalensis'' is one of the few species in the genus whose genome has been sequenced. The genome has a size of 1,790,835 bp. Analysis did not show presence of a plasmid. Initially, ''Anaerococcus senegalensis'' was found in the fecal flora of a healthy person.

''Anaerococcus rubiinfantis''

''A.'' ''rubiinfantis'' was discovered from a stool sample taken from an infant with severe acute malnutrition in Senegal. Based on a genomic analysis, ''Anaerococcus rubiinfantis'' has high antibiotic susceptibility. For that reason this bacteria can be treated with common oral antibiotics. ''A.'' ''rubiinfantis'' have catalase activity, which is not common from an anaerobic bacteria.

''Anaerococcus marasmi''

'' A. marasmi'' was first found in 2016 from a stool sample on a child with

marasmus Marasmus is a form of severe malnutrition characterized by energy deficiency. It can occur in anyone with severe malnutrition but usually occurs in children. Body weight is reduced to less than 62% of the normal (expected) body weight for the ...

. Just like ''A. rubiinfantis, Anaerococcus marasmi'' is catalase positive. ''A. marasmi'' can grow in a range of pH between 6.5 and 8. Moreover, ''A. marasmi'' has a high 16S rRNA sequence similarity (97.6%) with ''A. prevotii''

''Anaerococcus urinomassiliensis''

A. urinomassiliensis'' was isolated from a urine sample of a male adolescent with membranoproliferative glomerulonephritis and

autoimmune hepatitis Autoimmune hepatitis, formerly known as lupoid hepatitis, plasma cell hepatitis, or autoimmune chronic active hepatitis, is a chronic, autoimmune disease of the liver that occurs when the body's immune system attacks liver cells, causing the liv ...

. It took 10 days of anaerobic incubation to observe growth from this bacteria. Anaerococcus urinomassiliensis does not have either oxidase or catalase activity.''

References

{{Taxonbar, from=Q3614900 Bacterial vaginosis Peptoniphilaceae Pathogenic bacteria Microbiomes Bacteria genera