High-quality draft genome sequences of five anaerobic oral bacteria and description of Peptoanaerobacter stomatis gen. nov., sp. nov., a new member of the family Peptostreptococcaceae

Abstract

Here we report a summary classification and the features of five anaerobic oral bacteria from the family Peptostreptococcaceae. Bacterial strains were isolated from human subgingival plaque. Strains ACC19a, CM2, CM5, and OBRC8 represent the first known cultivable members of "yet uncultured" human oral taxon 081; strain AS15 belongs to "cultivable" human oral taxon 377. Based on 16S rRNA gene sequence comparisons, strains ACC19a, CM2, CM5, and OBRC8 are distantly related to Eubacterium yurii subs. yurii and Filifactor alocis, with 93.2 - 94.4 % and 85.5 % of sequence identity, respectively. The genomes of strains ACC19a, CM2, CM5, OBRC8 and AS15 are 2,541,543; 2,312,592; 2,594,242; 2,553,276; and 2,654,638 bp long. The genomes are comprised of 2277, 1973, 2325, 2277, and 2308 protein-coding genes and 54, 57, 54, 36, and 28 RNA genes, respectively. Based on the distinct characteristics presented here, we suggest that strains ACC19a, CM2, CM5, and OBRC8 represent a novel genus and species within the family Peptostreptococcaceae, for which we propose the name Peptoanaerobacter stomatis gen. nov., sp. nov. The type strain is strain ACC19a(T) (=HM-483(T); =DSM 28705(T); =ATCC BAA-2665(T)).

Keywords: Anaerobic oral bacteria; Human oral taxa; Peptoanaerobacter stomatis; Peptostreptococcaceae; Uncultivable bacteria.

Fig. 1

Maximum-Likelihood phylogenetic tree based on 16S rRNA gene sequence comparisons of strains ACC19a, CM2, CM5, OBRC8, and AS15 (shown in bold) together with other representatives of the Peptostreptococcaceae family and other related human bacteria. The tree was derived based on Tamura-Nei model using MEGA 5 [39]. Bootstrap values > 50 % calculated for 1000 subsets are shown at branch-points. Bar 0.02 substitutions per position. Strains whose genomes have been sequenced are marked with an asterisk

Fig. 2

Transmission and scanning electron micrographs of anaerobic oral bacteria from the family Peptostreptococcaceae. General morphology and Gram-positive cell wall structure of strains CM5 (a) and ACC19a (b), peritrichous flagella of strain CM2 (c), rosettes or brush-like structures formed by strain AS15 (d). Bars, 500 nm (a, b), 1 μm (c) and 5 μm (d)