The Prevalence of antimicrobial resistance in Staphylococcus aureus and coagulase-negative Staphylococci strains isolated from inpatients

Objectives: Globally nosocomial infection is a significant problem. Methicillin resistant Staphylococcus aureus (MRSA) and Methicillin resistant coagulase negative staphylococci (MRCoNS) are major causes of nosocomial infections. Aim of this study was to determine the prevalence and antimicrobial susceptibility of MRSA and MRCoNS in the southwest of Iran. This cross-sectional study was conducted on 221 non-duplicated staphylococci isolates collected from teaching hospital in Shiraz. The prevalence of MRSA and MRCoNS in clinical samples was identified with conventional microbiological tests. After identification, all of the isolates were subjected to antimicrobial susceptibility test and PCR to identify the presence of femA , mecA and pvl genes. Results: : 70 (41.7 %) MRSA among 168 S. aureus , and 26 (15.48%) MRCoNS among 53 CoNS were examined. All of the isolates were susceptible to Trimethoprim/Sulfamethoxazole (100%). Chloramphenicol (65%) and Gentamicin (23%) were the other most active antibacterial agents against MRSA and MRCoNS. The frequency of pvl gene among S. aureus strains was 3.57%. There is need for developing the antibiotic policy and limiting the use of powerful antibiotics.