Within the last few years, several changes occurred in the classification of the anaerobic Gram-positive cocci. There are currently five genera of anaerobic Gram-positive cocci which may be isolated from humans (Peptostreptococcus
, Peptoniphilus, Parvimonas
, and Anaerococcus
). Members of the species A. prevotii
are frequently recovered from human clinical specimens such as vaginal discharges and ovarian, peritoneal, sacral or lung abscesses. In particular, A. prevotii
was also described as a common isolate of the normal flora of skin, the oral cavity and the gut [3
]. Historically the Gram-positive anaerobic cocci were identified mainly by using phenotypic traits, but as shown by Song et al.
, this often led to the misidentification of A. vaginalis
strains, which were mistakenly assigned to A. prevotii
or A. tetradius
]. Currently Genbank does not contain any16S rRNA sequences from cultivated strains that can be clearly linked to the species A. prevotii
with over 95% gene sequence similarity. Recently, the temporal diversity of the human skin microbiome was analyzed using 16S rRNA gene phylotyping. It is noteworthy that several clones originated from different skin sites (gluteal crease, occiput, umbilicus, popliteal fossa, volar forearm). These isolates were taken from two patients and showed close relationships to A. prevotii
]. No closely related isolates or uncultivated clones with more than 84% 16S rRNA gene sequence identity are recorded from global ocean screenings and environmental samples (except for human skin).
shows the phylogenetic neighborhood of A. prevotii strain PC1T in a 16S rRNA based tree. The four 16S rRNA gene copies in the genome of strain PC1T differ by up to 15 nucleotides from each other, and by up to 9 nucleotides from the previously published 16S rRNA sequence generated from strain CCUG 41932 (AF542232). The difference between the genome data and the reported 16S rRNA gene sequence is most likely due to sequencing errors in the previously reported sequence data.
Figure 1 Phylogenetic tree highlighting the position of A. prevotii PC1T relative to all type strains of the genus Anaerococcus and the type strains of all other genera within the family ‘Peptostreptococcaceae’ inferred from 1,302 aligned characters (more ...) A. prevotii
cells are Gram-positive and non-motile(). Cells grown in PYG broth are 0.6-0.9 µm in diameter and occur in pairs, tetrads or irregular clumps or short chains (). Colonies range from 0.5 to 2 mm in diameter on Columbia blood agar. Optimum temperature for growth is 37°C. Strain PC1T
metabolizes peptones and amino acids and the major metabolic end product from PYG medium is butyric acid. Most species of the genus Anaerococcus
ferment carbohydrates weakly. A. prevotii
is proteolytic. α-Glucosidase, α –galactosidase, ß-glucuronidase and pyroglutamyl arylamidase activities are detectable [19
]. Production of urease may vary among strains of the species. Most strains produce ammonia from threonine and serine [3
] by deamination of the amino acids to pyruvate. A. prevotii
is resistant to sodium polyanethol sulfonate [21
], but susceptible to the penicillins [19
Table 1 Classification and general features of A. prevotii PC1T in accordance with the MIGS recommendations 
Scanning electron micrograph of A. prevotii PC1T (M. Rohde, HZI Braunschweig)
Cell wall amino acid analysis of strain PC1T
yielded peptidoglycan type A4α′, composed of L-Lys-D-Glu [22
], type A12.2 according to the DSMZ catalogue of strains. Cell wall sugars are glucose, glucosamine and galactose [22
]. Major cellular fatty acid composition of the type strain was analyzed by Lambert and Armfield in 1979 [23
] and by Ezaki et al. in 1983 [3
], but the results of these studies are contradictory. No other chemotaxonomic data are available at present.