Comparative ribotyping of Staphylococcus intermedius from dogs, pigeons, horses and mink

Strains of Staphylococcus intermedius from dogs, pigeons, horses and mink were typed by comparison of rRNA gene restriction fragment length polymorphisms (ribotyping) and the resulting ribotypes examined by cluster analysis. Digestion of whole-cell DNA with HindIII resulted in 9 ribotypes with 3-4 bands. Separation of isolates from different host animal species was not possible. EcoRI yielded 11 different hybridization patterns with 4 to 9 fragments. The EcoRI-ribotypes of all canine strains grouped in one cluster encompassing four closely related ribotypes. Isolates were indistinguishable with respect to their origin from cases of canine pyoderma or from healthy carriers. In contrast, pigeon and equine strains expressed a greater variety of ribotypes including some strains with patterns similar to canine isolates. However, for canine versus pigeon and equine strains the difference in distribution among ribotypes was significant (P< 0.001). The data might suggest that pigeons and horses carry S. intermedius transiently and might be able to spread these bacteria to other animal species.