Staphylococcus aureus is the major pathogen that causes clinical infection as well as food poisoning. Enterotoxin produced by
Staphylococcus aureus strains are, among others, staphylococcal enterotoxin (SE) A, SEB, SEC, SED, SEE, SEG, SEH, SEI, SEJ, SEK,
SEL and SEM. For SEC, there are three major antigentically distinct SEC subtypes, i.e. SEC1, SEC2 and SEC3, in addition to other
molecular variants. The nucleotide sequence homology between SEC1, SEC2, and SEC3 genes is higher than 97%; however, we were
able to develop a second set of PCR primers that allowed us to differentiate the three SECs, i.e., SEC1, SEC2 and SEC3, S. aureus
strains. These PCR primers and their combinations were C12F/C1BR, C12F/C23R and C3BF/C23R, for specific detection of the
SEC1, SEC2 and SEC3 genes of S. aureus strains, respectively. Using these primers, we examined 39 SEC S. aureus isolates, which
were obtained from foods that were likely the source of food-borne outbreaks between 1995 and 1997 in central Taiwan, and from the
patients of the outbreaks. The results were consistent with those obtained from the first set of primers reported earlier, indicating that
the present primers could be used for specific detection of these three toxin types.