An-Najah Staff

The taxonomic relatedness between the species Enterococcus casseliflavus and Enterococcus flavescens and between Enterococcus italicus and Enterococcus saccharominimus was investigated. Literature data had already indicated the synonymy between E. casseliflavus and E. flavescens, but this observation had not been formally published. Additional evidence that the two taxa represent a single species was provided by comparison of the partial sequences for three housekeeping genes, phenylalanyl-tRNA synthase alpha subunit (pheS), RNA polymerase alpha subunit (rpoA) and the alpha subunit of ATP synthase (atpA). Additional genomic data derived from DNA-DNA hybridization demonstrated that the two species are synonymous. For E. italicus and E. saccharominimus, two recently described taxa, a high 16S rRNA gene sequence similarity of >99% and analogous phenotypic features indicated a close taxonomic relatedness. The same multilocus sequence analysis scheme for the three housekeeping genes was also applied for E. italicus and E. saccharominimus and indicated possible conspecificity, an observation that was also confirmed by a high DNA-DNA hybridization value  >or=78% . Data from the present study led to the proposal that E. flavescens should be reclassified as a later synonym of E. casseliflavus and that E. saccharominimus should be reclassified as a later synonym of E. italicus.