Enterococcus ureasiticus sp. nov. and Enterococcus quebecensis sp. nov., isolated from water

Abstract

Three enterococcal isolates, CCRI-16620, CCRI-16986T and CCRI-16985T, originating from water were characterized using morphological, biochemical and molecular taxonomic methods. 16S rRNA gene sequence analysis classified all three strains in the Enterococcus faecalis species group. The phylogenetic tree of 16S rRNA gene sequences showed that the three isolates form two separate branches. The first branch is represented by strains CCRI-16620 and CCRI-16986T and the second branch by strain CCRI-16985T. Further sequence analysis of the housekeeping genes rpoA (encoding RNA polymerase α subunit), pheS (phenylalanyl-tRNA synthase), tufA (elongation factor Tu) and atpD (ATP synthase β-subunit) as well as the results of amplified fragment length polymorphism (AFLP) DNA fingerprinting and DNA–DNA hybridization experiments confirmed the distinct status of these strains. Moreover, biochemical tests allowed phenotypic differentiation of the strains from the other species of the E. faecalis species group. On the basis of the results obtained, the names Enterococcus ureasiticus sp. nov. (type strain CCRI-16986T = CCUG 59304T = DSM 23328T = LMG 26304T) and Enterococcus quebecensis sp. nov. (type strain CCRI-16985T = CCUG 59306T = DSM 23327T = LMG 26306T) are proposed for the two hitherto undescribed species.