Molecular analysis of artisanal Italian cheeses reveals Enterococcus italicus sp. nov.

The taxonomic positions of seven atypical Enterococcus strains, isolated from artisanal Italian cheeses, were investigated in a polyphasic study. By using 16S rRNA gene sequencing, DNA-DNA hybridization and intergenic transcribed spacer analysis, as well as by examining the phenotypic properties, the novel isolates were shown to constitute a novel enterococcal species. Their closest relatives are Enterococcus sulfureus and Enterococcus saccharolyticus, having a 16S rRNA gene sequence similarity of 96.7 %. This group of strains can be easily differentiated from the other Enterococcus species by DNA-DNA hybridization and by their phenotypic characteristics: the strains do not grow in 6.5 % NaCl, and they do not produce acid from L-arabinose, melezitose, melibiose, raffinose or ribose. The name Enterococcus italicus sp. nov. is proposed for this species, with strain DSM 15952T (= LMG 22039T) as the type strain.