Establishment of PCR-ELISA technology for Staphylococcus aureus in food

The nuc gene was as a target to detect Staphylococcus aureus in food. The PCR products were hybridized with digoxin- labeled probes,and then with streptomycin in microwell plate. PCR- ELISA method had been established by chromogenic reaction with anti- digoxin antibody. This method was applied to detect Staphylococcus aureus in milk artificially contaminated with Staphylococcus aureus,while other bacteria strains,including Escherichia coli,Salmonella,Shigella,Listeria monocytogenes were as negative controls. The results showed that for the pure culture and artificially contaminated milk,Staphylococcus aureus were positive,while negative for negative controls. The sensitivity of detection of Staphylococcus aureus for the pure culture and artificially contaminated milk were 10~1 CFU / m L,a 100- fold higher than that of conventional PCR method( 10~3 CFU / m L). Therefore,PCR- ELISA established in this study for detection of Staphylococcus aureus in milk sample was specifically,sensitively and accurately,which should provide an important technical means for rapid identification,risk assessment and effective monitoring of Staphylococcus aureus in food.