Abstract of research

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

Ashraf A. Abd El- Tawab 1, Wafaa. M . Hassan2 , Suhair .SH.M.AL-Siraj3

Abstract

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.