The detection of enterotoxins and toxic shock syndrome toxin genes in Staphylococcus aureus by polymerase chain reaction

A simple polymerase chain reaction (PCR)-based procedure was developed for the detection of fragments of staphylococcal enterotoxins (SEs) SEA, SEB, S EC, SED, SEE, SEG, SEH, and SEI together with the toxic shock syndrome toxi n (TSST-1) genes of Staphylococcus aureus. One hundred and twenty-nine cult ures of S. aureus were selected, 39 of which were recovered from 38 suspect ed staphylococcal food-poisoning incidents. The method was reproducible, an d 32 different toxin genotypes were recognized. The presence of SE genes wa s associated with S. aureus strains reacting with phages in group III, and the TSST-1 gene with phages in group I. There was a 96% agreement between t he PCR results for detection of SEA-D and TSST-1 as compared with a commerc ial reverse passive latex agglutination assay for the detection of SEs from cultures grown in vitro. Enterotoxin gene fragments were detected in S. au reus cultures recovered from 32 of the 38 suspected staphylococcal food poi soning incidents, and of these, 17 were associated with SEE, SEG, SEH, and SEI in the absence of SEA-D. Simple PCR procedures were also developed for the detection of SE directly in spiked food samples, and this was most succ essfully achieved in mushroom soup and ham. Detection was less successful i n three types of cheese and in cream. SEA or SEB were detected by enzyme-li nked immunosorbent assay in three food samples (two of which were associate d with food poisoning incidents) naturally heavily contaminated with S. aur eus: the appropriate SEA or SEB gene fragments were detected directly in th ese three foods by PCR.