PCR and ELISA for staphylococcal enterotoxins and detection of some exotoxins from Staphylococcus spp. strains by PCR

Abstract

The aims of this study were to determine the existence of some staphylococcal enterotoxin (SE) (sea, seb, sec, sed, and see) proteins and genes in coagulase-positive staphylococci (CPS) by ELISA and PCR and to assess SE-like toxin (SEI) (seg, seh, sei, sej, sem, sen, and seo), exfoliative toxin (eta and etb), toxic shock syndrome toxin-1 (tst) and 16S rRNA genes in 11 different Staphylococcus strains [90 CPS and 118 coagulase-negative staphylococci (CNS)] isolated from 250 ground meat samples by either monoplex or multiplex PCR. SEs were identified in 36 (40%) out of 90 CPS isolates by both ELISA and PCR, with the following distribution: sea was identified in 7 (7.7%), seb in 5 (5.5%), sec in 3 (3.3%), sed in 4 (4.4%), and see in 17 (18.8%). In addition, a total of 90 CPS and 118 CNS isolates were investigated for the presence of 11 SE, SEI, eta-etb, tst, and 16S rRNA genes. Overall, 145 (69.7%) of the Staphylococcus spp. isolates tested positive for one or more toxin genes. These results indicate that CNS may play an important role in food poisoning and that SEI toxins must be investigated in greater detail in future studies of both CPS and CNS.