Anaerobic cocci of clinical importance

The current knowledge is reviewed concerning the anaerobic cocci, in particular those of clinical relevance. The anaerobic cocci are defined and their current taxonomic positions discussed. It is clear that new genera and species await to be characterised fully. The overwhelming majority found in clinical material belong to the genus Peptostreptococcus, with the remainder belonging to the veillonellae and, possibly, ruminococci. Human infections with other anaerobic cocci are extremely rare. Their morphology, metabolism and culture, and role in clinical infections are assessed. The methods for isolation and identification, which for some species are difficult, are presented, together with brief summaries of the clinically important species. The review concludes with the current status of antibiotic susceptibilities and the methods used to test susceptibility in vitro. There is no current consensus as to which susceptibility test method is the method of choice.