Phenotypic and genetic diversity of enterococci isolated from Italian cheeses

In the present study 124 enterococcal strains. isolated from traditional It alian cow. goat and buffalo cheeses. were characterized using phenotypic fe atures and randomly amplified polymorphic DNA polymerase chain reaction (RA PD PCR), The RAPD-PCR profiles obtained with four primers and five differen t amplification condition, were compared by numerical analysis and allowed an inter- and intraspecific differentiation of the isolates. Whole-cell pro tein analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used as a reference method for species identification. The s trains were identified as Enterococcus faecalis (82 strains). E. faecium, ( 27 strains). E. durans (nine strains), E. gallinarum (four strains) and E. hirae (two strains). Species recognition by means of RAPD PCR, was in agree ment with the SDS-PAGE results except for eight strains of E. faecium that clustered in separated groups. On the other hand. phenotypic identification based on carbohydrate fermentation profiles, using the rapid ID 32 STREP g alleries, gave different results from SDS PAGE in 12.1% of the cases. The m ajority of the strains had weak acidifying and proteolytic activities in mi lk. One E. faecium strain showed canA (vancomycin resistance) genotype whil e four strains showed a beta -haemolytic reaction on human blood. Several s trains showed antagonistic activity towards indicator strains of Listeria i nnocua. Clostridium tyrobutyricum and Propionibacterium freudenreichii subs p. shermanii.