SPECIES DISTRIBUTION OF COAGULASE-POSITIVE STAPHYLOCOCCI IN ANIMALS

Isolates (268) of coagulase-positive staphylococci from a variety of animal species, including dogs, horses, cats, monkeys, goats and cows, were assigned to species on the basis of the API Staph-Ident system. Of 195 isolates from dogs, 179 (91.8%) were Staphylococcus intermedius, as were 9 of 25 (36%) isolates from horses, 7 of 15 (46.6%) from cats and 4 of 6 (66.6%) from goats; 1 of 10 from monkeys and 0 of 7 from cows were S. intermedius. Of the remaining 68 cultures, 63 were identified as S. aureus and 5 as S. hyicus. The latter identifications were rendered doubtful on the basis of conventional tests. Identification appeared to be more certain in the S. aureus sample than in the S. intermedius sample. Distribution of biotypes within the 2 bacterial species as represented by different API profile numbers and reactivity on test substrates showed no significant variations among the host species, except for the S. aureus biotypes in dogs. Both Staphylococcus spp. were represented about equally among samples from different tissues and lesions, apart from skin-related infections in dogs, which were associated exclusively with S. intermedius (P < 0.01). Differences between S. aureus and S. intermedius in antimicrobial susceptibility patterns, prevalence of clumping factor and occurrence of .beta.-toxin were not significant.