OBJECTIVETo investigate the detection limit of multicolor combinational probe coding real-time PCR (MCPC-PCR) in detection of Salmonella and Staphylococcus aureus suspended in the food samples, and to apply MCPC-PCR to detect the samples of food poisoning.

METHODSSeries concentration of bacterium suspension (10(1) - 10(9) CFU/ml) was prepared by using 22 simulated samples including fresh meat and cakes and then MCPC-PCR was applied to detect Salmonella and Staphylococcus aureus in 22 samples. Enrichment broth of 101 frozen samples and 5 early patients' anal swabs in food poisoning cases were detected after the DNA samples were extracted.

RESULTSThe limits of MCPC-PCR assay in detecting Salmonella and Staphylococcus aureus were about 10(2) copies/test; 101 frozen enrichment broth of samples in food poisoning cases were detected by MCPC-PCR assay, of 23 positive samples, 18 were confirmed by bacteriology techniques; 96 samples detected by MCPC-PCR and bacteriology techniques had the same results, and the coincidence rate was 95.05%. Anal swabs, collected from 5 of early patients in a food poisoning case gave a clue to be Vibrio parahaemolyticus by MCPC-PCR assay and then were perfectly consistent with bacteriology assay.

CONCLUSIONAs a method of high sensitivity and good specificity, MCPC-PCR assay can quickly and conveniently detect multiple pathogens existing in food samples, therefore we recommend it to be used in rapidly screening or simultaneous detection of food-borne diseases.