Identification of Staphylococcus aureus and Escherichia coli isolated from Egyptian food by conventional and molecular methods

Staphylococcus aureus and Escherichia coli were enumerated and isolated from ready-to-eat vegetables salad and meat luncheon on their selective media (Baird-parker and Macconkey agar, respectively). Twenty suspicious colonies of each (10 from each product) were randomly chosen and identified using conventional based on morphological and physiological characteristics. S. aureus and E. coli isolates which gave the highest pathogenicity were chosen for identification and confirmation with molecular method based on 16S rRNA gene. The PCR amplification method of 16S rRNA gave the same identification results as conventional method, but it was sensitive and fast. This molecular method takes about 48 h in comparison with 6 days for conventional method. The 16S rRNA of S. aureus and E. coli were deposited in the Genebank database under accessions (AB599719.1 and AB599716.1, respectively).