Investigation of antibiotic resistance rates of staphylococcus aureus strains isolated from clinical samples

S. aureus is a Gram-positive bacterium with high morbidity and mortality, which is found in the normal flora, but can cause community and hospital-acquired infections when it is a causative agent. This bacterium continues to be a serious health problem all over the world by rapidly developing resistance to antistaphylococcal drugs. In this study, it was aimed to determine the antibiotic resistance profiles of S. aureus isolates isolated from clinical samples in our hospital and to contribute to the empirical treatment and antibiotic use policies. Conventional methods and VITEK 2 automated system (bioMérieux, France) were used for the bacterial identification of 513 S. aureus isolates isolated from various clinical specimens sent to the Microbiology laboratory from outpatient, clinic and intensive care units between 2018-2021. Antibiotic resistance was assessed according to EUCAST criteria using only the VITEK 2 automated system. In our study, 74.5% of 513 S. aureus isolates were identified as MSSA and 25.5% as MRSA. Of the isolates, 34.1% were isolated from wounds, 29.2% from blood, 15% from sputum and 21.7% from other samples. Of the samples, 39.8% were isolated from outpatient clinics, 36.8% from clinics and 23.4% from intensive care units. No resistance was observed against linezolid, vancomycin, teicoplanin, tigecycline, daptomycin in MSSA and MRSA, additionally gentamicin in MSSAs. Resistance rates to penicillin (79.9%) and erythromycin (13.0%) in MSSAs, and to penicillin (100%), erythromycin (44.4%) and tetracycline (39.2%) in MRSAs detected. In MRSA isolates, resistance to trimethoprim sulfamethoxazole in 2020, 2021 and Levofloxacin resistance in 2021 were found to be decreased. As a result, a decrease in trimethoprim sulfamethoxazole and levofloxacin resistance was detected in MRSAs against S. aureus isolates, and no change was found in antibiotic resistance rates in MSSA and MRSAs in 2018-2021. Knowing the resistance rates when starting empirical antibiotic treatment and performing culture and antibiogram tests before starting the treatment are of great importance both in the treatment and in the prevention of antibiotic resistance. KEYWORDS: S. aureus, Antıbıotıc, Resistance, MSSA, MRSA.