This work aims to be studying the genetic characteristics of Staphylococcus aureus strains isolated from 200 samples collected from humans (mouth, pharynx and hand) and different sources as poultry, milk and human food. With a focusing on their genetic characteristics interesting to their resistance genes against to some antibiotics that well be used for treatment of infected cases with these isolated S.aureus strains. A total of 23 isolates of S. aureus were identified from the collected 200 samples in an incidence rate of (11.5%). additionally, the strains were screened for resistance against to 11 different antimicrobial agents. The strains showed a high level of resistance about (85-90%) to methicillin, penicillin, tobramycin, trimethoprim, sulfamethoxazone-trimethoprim and ciprofloxacin. furthermore, moderate resistance to gentamycin, levofloxacin and lomfloxacin about (40-60%). While the clindamycin and tetracycline antimicrobial agents were had a very low resistance, reaching (5-10%).
The isolated S.aureus strains were monitored for the most important resistant genes including mecA, blaZ and tetK were recorded in an incidence rate of (100%), while the resistant genes aac(6')aph(2") and norA were (45.5%) and (90.9%) respectively.This work revealed that about 70% of the isolated S.aureus strains were resistant to most of applied antibiotic drugs, .i.e. there is a high level of drug resistant S. aureus strains. Therefore, the miss, hub-hazzarad and uncontrolled use of antibiotics in veterinary medicine must be prevented.