Enterococcus lactis sp. nov., from Italian raw milk cheeses

Abstract

Ten atypical Enterococcus strains were isolated from Italian raw milk cheeses. The 16S rRNA gene, phenylalanyl-tRNA synthase alpha subunit (pheS), RNA polymerase alpha subunit (rpoA) and the 16S–23S rRNA intergenic transcribed spacer (ITS) sequences, randomly amplified polymorphic DNA (RAPD) PCR and the phenotypic properties revealed that the isolates represent a novel enterococcal species. On the basis of 16S rRNA gene sequence analysis, the isolates were closely related to Enterococcus hirae ATCC 8043T, Enterococcus durans CECT 411T and Enterococcus faecium ATCC 19434T, with 98.8, 98.9 and 99.4 % sequence similarity, respectively. On the basis of sequence analysis of the housekeeping gene pheS, the reference strain, BT159T, occupied a position separate from E. faecium LMG 16198. The group of isolates could be easily differentiated from recognized species of the genus Enterococcus by 16S–23S rRNA ITS analysis, RAPD-PCR and phenotypic characteristics. The name Enterococcus lactis sp. nov. is proposed, with BT159T ( = DSM 23655T = LMG 25958T) as the type strain.