Bacteriological and molecular studies of Staphylococcus. aureus isolated from foods and human contact

Document Type : Original Article


1 Bacteriology, Immunology and Mycology Department, Faculty of Veterinary Medicine, Benha University

2 Reference Laboratory for Veterinary Quality Control on Poultry Production- AHRI – Dokki – Giza

3 Faculty of veterinary medicine, Bagdad University. Iraq


A total of 50 samples were collected from different food (meat product, chicken, sandwiches, pasta, Broth, fish,
Appetizer) and human contact (hand). Samples were examined microbiologically for the presence of Staphylococcus
aureus was isolated from the samples in a ratio present (8) and identified by biochemical identification. Staph. aureus
strains were tested for antimicrobial sensitivity and all strains showed a 100% resistant to ampicillin. The resistance to
oxacillin, amoxicillin, trimethoprim, gentamicin and tetracycline was in a different ratio. However, All the strains were
sensitive to levofloxacin and ciprofloxacin. Using PCR technique, amplification of some virulence gene as (tst,icaD, sea)
and antibiotic resistance genes (mecA , blaZ , vanA) was performed from the extracted DNA of Staph. aureus strains
.All extracted DNA samples of Staph. aureus showed a positive results for mecA ,tst , blaZ, icaD and sea genes .
However, all the samples did not give any PCR product on agrasoe gel. Using sequencing technique gene in two positive
strains, the Phylogenetic analysis of mecA gene of these isolates were clustered together and little away from other
published isolates of MRSA, Amino acid identities were 99% which had accession number MF774211 corresponding
GenBank sequence.