Synthetic enterotoxin B DNA probes for detection of enterotoxigenic Staphylococcus aureus strains.

DNA-DNA colony hybridization experiments with three different synthetic probes were carried out with 210 strains of Staphylococcus aureus. The synthetic probes encoded the amino acids 15 to 29 (probe 1), 179 to 192 (probe 2), and 207 to 219 (probe 3) of staphylococcal enterotoxin B (SEB). The amino acid sequences of these parts of SEB are identical to those of SEC1. All 21 SEB-producing strains tested reacted with each of the three probes. Of the 69 SEC-producing strains, 21 reacted with probe 1, none reacted with probe 2, and all 69 reacted with probe 3. With other strains no hybridization signals were obtained. The results presented here show that with a single synthetic DNA probe (probe 3) both SEB- and SEC-producing strains are detectable.