Varibaculum anthropi sp. nov. represented by three genetically different genomovars isolated from clinical material and emended description of the genus Varibaculum.

During the years 1994-2011 five strictly anaerobic, Gram-stain-positive, diphtheroid bacteria (strains CCUG 31793(T), CCUG 44221, CCUG 61255, CCUG 45114, and CCUG 44993) were isolated from different clinical samples in Sweden and the United Kingdom. Comparative analysis of 16S rRNA gene sequences showed that the five strains shared 99-100% 16S rRNA gene sequence similarity among each other and 98.3-98.6% sequence similarity to Varibaculum cambriense DSM 15806(T). Genomic fingerprint patterns generated with ERIC-, BOX-, and RAPD-PCR, and whole genome sequence (WGS) based comparison by in silico DNA-DNA hybridization (isDDH), average nucleotide identity (ANI) analysis and six housekeeping gene (atpA, rpoB, pgi, metG, gltA and gyrA) based multilocus sequence analysis (MLSA) showed that the strains could be differentiated from V. cambriense DSM 15806(T) and formed three genomic groups, which could only be differentiated at the species border level. Based on physiological characterizations the five strains could not be clearly distinguished among each other. Based on those data a new Varibaculum species, Varibaculum anthropi (type strain CCUG 31793(T)=JCM 19104(T)) is proposed including three genetically distinct genomovars (gv 1: CCUG 31793(T), CCUG 44221, CCUG 61255; gv 2: CCUG 45114, and gv 3: CCUG 44993).