Identification and ribotyping of Staphylococcus xylosus and Staphylococcus equorum strains isolated from goat milk and cheese.

Twenty-five strains of staphylococci isolated from goat milk and cheese were identified as belonging to the Staphylococcus xylosus/equorum group using the ID 32 Staph system (bioMérieux, Marcy-L'Etoile, France). This system, however, was not able to discriminate between these two species for 19 of the strains tested. Ribotyping was performed on these 25 strains, as well as on three reference strains of each of these two species. Hybridization membranes were scanned and analyzed using the Taxotron software package (Taxolab, Institut Pasteur, Paris, France). A dendrogram representation showed that ribotypes were distributed in two clear-cut clusters corresponding to S. equorum (21 strains) and S. xylosus (four strains).