Departamento de Biología Funcional-Microbiología, Universidad de Oviedo, Oviedo,1 Laboratorio Interprofesional Lechero y Agroalimentario de Asturias (LILA), Llanera,2 Instituto de Productos Lácteos de Asturias (CSIC), Villaviciosa, Asturias, Spain3
Received 21 July 2004/ Returned for modification 5 September 2004/ Accepted 17 October 2004
A set of 84 Staphylococcus aureus isolates collected from the milk of cows with subclinical mastitis in Asturias (a cattle region of Spain) and six control strains were tested for sequences of genes encoding hemolysins (hla, hlb, hld, hlg, and hlg-2), leukotoxins (lukPV, lukM, and lukED), toxic shock syndrome toxin (tst), and enterotoxins (sea to see, seg to ser, and seu) by conventional and multiplex PCR. It was found that 84, 83, 11, and 39 isolates carried some type of hl, luk, tst, or se gene, respectively, which were arranged in 14 exotoxin genotypes. All of the isolates were negative for lukPV, hlg, sea, sed, see, sej, sek, sep, seq, and ser. Two gene groupings could be related with pathogenicity islands[lukED, seg, sei, sem, sen, seo ± seu] with Saß-1 and [tst, sec, sel] with SaPIbov, present in 45 and 13.1% of the isolates, respectivelywhile 11.9% of them carried both islands. Only one contained seb (together with
Saß-1), and another contained seh (together with lukED). The isolates were also analyzed by pulsed-field gel electrophoresis performed with SmaI. Thirty-nine SmaI profiles (similarity coefficient [S] = 0.94 to 0.21) were differentiated; 12, 1, and 10 of these, respectively, were generated by isolates presumptively carrying Saß-1, SaPIbov, or both. Five SmaI profiles (S
0.8) formed a cluster, which contained 20 and 10 isolates carrying one (
Saß-1) or both islands. These data show the high frequency of genes encoding cytotoxins and pyrogenic toxin superantigens, their relationship with pathogenicity islands, and their distribution among a diversity of genetic types of S. aureus related to subclinical mastitis.
This article has been cited by other articles:
| Antimicrob. Agents Chemother. | Clin. Microbiol. Rev. |
|---|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|