USE OF PCR TO DETECT CLASSICAL ENTEROTOXINS GENES (ENT) AND TOXIC SHOCK SYNDROME TOXIN-1 GENE (TST) IN STAPHYLOCOCCUS AUREUS ISOLATED FROM CRUDE MILK AND DETERMINATION OF TOXIN PRODUCTIVITIES OF S. AUREUS ISOLATES HARBORING THESE GENES

USO DA REAÇÃO DA POLIMERASE EM CADEIA (PCR) PARA DETECÇÃO DE GENES DE ENTEROTOXINA (ENT) E GENES DA TOXINA DA SÍNDROME DO CHOQUE TÓXICO (TST) EM STAPHYLOCOCCUS AUREUS ISOLADOS DO LEITE CRU E DETERMINAÇÃO DA PRODUÇÃO DE TOXINAS EM ISOLADOS PORTADORES DESTES GENES

ABSTRACT

During a 2-year period (2003-2004), 132 strains of Staphylococcusaureus isolated from crude milk (without thermal treatment) collected in different places in Piracicaba, São Paulo State, Brazil, were investigated for the presence of genes for enterotoxins (ent) and toxic shock syndrome toxin-1 (tst). Polymerase-chain reaction (PCR) was performed by using 6 pairs of relevant oligonucleotide primers. Ninety isolates (68.18%) were positive for (47 strains) or 2 (43 strains) toxin genes. The combination of entA and tst showed the highest prevalence (33 strains).The good correlation between PCR results and toxin protein detection and identification by optimum-sensitivity-plate (OSP) test was observed when 44.45% of strains showed positive for toxin production.

KEY WORDS
Enterotoxin; toxic shock syndrome toxin-1; crude milk; Staphylococcus aureus