Staphylococci isolated from abscesses in slaughtered animals: characterization and epidemiological studies.

A total of 71 strains of Gram positive, catalase positive cocci were isolated from 112 abscesses observed during inspection of slaughtered animals (sheep, cattle, pigs and goats). On the basis of lysostaphin sensitivity, all strains were identified as staphylococci. However, 4 of them did not ferment glucose anaerobically. Classification at the species level was accomplished by complete characterization of the strains. Amongst the 35 coagulase positive isolates, 30 were classified as S. aureus, 2 as S. intermedius and 3 could not be classified. Of the 36 coagulase negative cultures, 1 was classed as S. hyicus subsp. hyicus, 3 as S. simulans, 2 as S. haemolyticus, 5 as S. hominis, 3 as S. epidermidis, 2 as S. capitis, 3 as S. warneri, 4 as S. xylosus, 1 as S. cohnii and 1 as S. saprophyticus. The remaining 11 strains could not be classified. Seventeen of the 30 S. aureus strains belonged to biotype C, 7 were classified as intermediate (shared properties of biotypes A and C), 3 as similar to bitype C, 1 as similar to biotype A and 2 could not be biotyped. Twelve of the 16 biotype C strains showed characteristic properties of ovine S. aureus. The number of strains lysed by phages of human and bovine origin was 11 and 18, respectively. As many as 25 strains (23 S. aureus and 2 coagulase positive, unclassified cultures) produced enterotoxins. The enterotoxins produced were: C (14 strains), D (2 strains), A (1 strain), E (1 strain), A + C (1 strain) and A + D (6 strains). A good correlation between the type of enterotoxin produced, biotype and phage type was observed.