Differences between Danish bovine and human Staphylococcus aureus isolatesin possession of superantigens

PCR-assays for the detection of staphylococcal enterotoxins A-E, and H, tox ic shock toxin 1, and exfoliative toxins A and B were evaluated against phe notypic methods, and performed well. Four hundred and fourteen isolates of Staphylococcus aureus from Danish cases of bovine mastitis were screened fo r genes encoding these superantigens. One hundred isolates from Danish huma n carriers were also included in the study. In contrast to the frequent pre sence of genes encoding and in vitro expression of superantigens among the human carrier isolates, only one of 414 isolates from bovine mastitis carri ed the genes encoding enterotoxin C and toxic shock toxin-l. These results further support the hypothesis that the bovine and human S. aureus reservoi rs constitute two separate subpopulations of the species S. aureus. The res ults also show that these superantigens are generally not present in Danish S. aureus isolates from bovine mastitis, and thus play no essential role i n the pathogenesis of bovine S. aureus mastitis. (C) 2000 Elsevier Science B.V. All rights reserved.