EVALUATION OF ARBITRARILY PRIMED PCR ANALYSIS AND PULSED-FIELD GEL-ELECTROPHORESIS OF LARGE GENOMIC DNA FRAGMENTS FOR IDENTIFICATION OF ENTEROCOCCI IMPORTANT IN HUMAN MEDICINE

The increasing problems encountered with enterococcal nosocomial infec tions and the intrinsic and acquired resistance of the enterococci to different antimicrobial compounds highlight the need for a rapid ident ification technique. Enterococcus faecalis is readily identified by bi ochemical tests, but species differentiation within the Enterococcus f aecium and Enterococcus gallinarum species groups is less well establi shed. In the present study, 66 strains representing the most prevalent human enterococci were used to develop a PCR-based species-specific i dentification protocol. Whole-cell protein analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used as a reference met hod for species identification, In addition, the genomic SmaI macro-re striction fragment distribution of all of the strains was examined by pulsed-field gel electrophoresis (PFGE), Oligonucleotide D11344-primed PCR was as discriminative as whole-cell protein analysis and resulted in more easily interpreted band patterns, This PCR-based technique al lowed identification of clinical isolates by visual examination of the DNA profiles obtained, The inability of both methods to discriminate between Enterococcus casseliflavus and Enterococcus flavescens brought into question the species status of E. flavescens. PFGE did not resul t in species-discriminative DNA bands or band patterns, but proved to be superior for interpretation of interstrain relationships.