Taxonomy--General comments and update on taxonomy of Clostridia and Anaerobic cocci.

Since such things as sites of normal carriage, type and severity of infections produced, and antimicrobial susceptibility patterns may vary according to the particular species involved, accurate taxonomy for differentiation of species is important. For example, reclassification of the 'Bacteroides gracilis group' revealed that Sutterella wadsworthensis is actually responsible for the antimicrobial resistance seen in that group. With clostridia and anaerobic cocci, as with other taxa, there have been a number of recent changes in classification of existing taxa as well as description of novel taxa. It is important that both clinicians and microbiologists adapt quickly to new classification schemes and new taxa as soon as they are validated. For example, Peptostreptococcus is now restricted to the species P. anaerobius and five new genera have been created. There has also been significant reclassification of clostridia and new species of clostridia have also been described.