RESUMO
Recent insights have been brought to the taxonomy of the genus Enterococcus by studies applying whole-cell protein analysis and DNA-DNA reassociation experiments, in addition to conventional physiological tests. Using these techniques, a group of 10 strains resembling the physiological group III of enterococcal species was characterized. Five strains were recovered from pigs and five from rats with enteric disorders. On the basis of the results of conventional physiological tests, the most likely identity of these strains was Enterococcus durans or Enterococcus hirae. Analysis of the electrophoretic whole-cell protein profiles showed two distinct clusters of virtually indistinguishable profiles: one composed of strains isolated from pigs, and one composed of strains isolated from rats. These protein profiles were not similar to the profiles of any previously described Enterococcus species. The results of DNA-DNA relatedness experiments were consistent with the results of the protein-profile analysis. The high levels of DNA relatedness found for pig isolates demonstrated that they belong to a new enterococcal species, for which the designation Enterococcus porcinus sp. nov. is proposed (type strain =DS 1390-83T =ATCC 700913T =CCUG 43229T =NCIMB 13634T). Strains isolated from rats were found to comprise another new species, for which the designation Enterococcus ratti sp. nov. is proposed (type strain =DS 2705-87T =ATCC 700914T =CCUG 43228T =NCIMB 13635T). This report provides data on the phenotypic and genotypic characterization of these two new enterococcal species, which may represent diarrhoeagenic pathogens for animals.
