Rapid method for detection of Staphylococcus aureus enterotoxins in food
2012
Abd El-Salam, W. E. E.
In the present study a total of 250 food samples (50 milk samples, 50 soft white cheese samples, 50 yoghurt samples, 50 meat products and 50 chicken products samples) were investigated bacteriologically to detect the occurrence of enterotoxigenic S. aureus among the examined food samples. out of 250 examined food samples, 127 isolates were identified as Staphylococcus species (50.8 %), The highest rate of isolation of Staphylococcus species was observed in milk samples (58%) followed by yoghurt samples, cheese samples, meat products samples (50%) each and chicken products samples (46%). 32 S. aureus isolates were identified from the examined samples with an incidence of (12.8%). The highest isolation rate was observed in milk samples (30%) followed by yoghurt samples (22%), chicken products samples (6%), soft white cheese samples (4%) and meat products samples (2%). Using PCR, out of 32 S. aureus isolated from the examined food samples 10 could produce enterotoxins. Enterotoxin was extracted from 8 enterotoxigenic S. aureus strains (raw milk, yoghurt and chicken sausage) and analyzed by sodium dodecyl sulphate poly acrylamide gel electrophoresis (SDS-PAGE) analysis. It is clear that all enterotoxigenic isolates had one or two bands at 26-29 kDa. Direct detection of S. aureus enterotoxins were investigated among 6 samples )3 raw milk samples, 2 yoghurt samples, one chicken sausage sample( and the results were both entA and entC could be detected from yoghurt and milk samples, both entB and entD could be detected from chicken sausage and raw milk samples and entE could be detected from yoghurt and raw milk samples.
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