Detection of enterotoxigenic Staphylococcus aureus in dried skimmed milk: use of the polymerase chain reaction for amplification and detection of staphylococcal enterotoxin genes entB and entC1 and the thermonuclease gene nuc.

摘要: The polymerase chain reaction was used to amplify the staphylococcal enterotoxin B and C genes (entB entC1) nuclease gene (nuc). Two sets of primers ("nested primers") were found be necessary for detection low copy numbers purified DNA in diluent. These allowed ca. 1 fg target DNA, while 100 pg required before entB, entC1, nuc with single primer pairs possible. With nested primers, enterotoxigenic Staphylococcus aureus cells could detected artificially contaminated dried skimmed milk samples at levels 10(5) CFU ml-1 within 8 h. No cross-reaction observed between highly homologous entB entC1 genes. method showed total specificity when tested against a wide variety other bacteria. Images