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, Peptoniphilus, 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 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 abscesses, chronic wounds and vaginal discharge. Moreover, some of the species can be isolated from foot ulcers and knee arthritis. It can be present in urinary tract infections, chronic ulcers, pleural empyema, blood infections, and soft tissue infections. 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.