RESISTANCE RATES OF STAPHYLOCOCCUS AUREUS ISOLATES FROM CLINICAL SPECIMENS TO METHICILLIN AND VARIOUS ANTIBIOTICS
Abstract
Objective: Staphylococcus aureus (S. aureus) continues to be a significant health problem due to its widespread methicillin resistance, causing both community- and hospital-acquired infections. The aim of this study was to evaluate the resistance profiles of S. aureus strains isolated from various clinical specimens obtained from our hospital's intensive care units and wards to methicillin and other antibiotics. Methods: The study included S. aureus strains isolated from various clinical samples and studied for methicillin susceptibility at the Medical Microbiology Laboratory of Yalova Training and Research Hospital between January 2019 and December 2023. Bacterial identification was performed using conventional methods and automated systems, and antibiotic susceptibility testing was evaluated according to the current European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines by year. Results: In our study, the rate of methicillin-resistant S. aureus (MRSA) was determined to be 33.3%. When the distribution of MRSA strains was examined, intensive care units (62.9%) were the most commonly isolated units, and the most frequently isolated clinical sample was sputum (58.1%). While no resistance to tigecycline was detected in MRSA and methicillin-susceptible S. aureus (MSSA) strains, the highest resistance rates in MRSA and MSSA strains were found to be against penicillin (100% and 80.0%, respectively). Overall, MRSA isolates showed higher resistance rates to most of the evaluated antibiotics than MSSA isolates. Conclusion: In our study, it was determined that MRSA strains were commonly isolated from intensive care units and sputum samples; MRSA had higher resistance rates to most of the evaluated antibiotics compared to MSSA. Monitoring antibiotic resistance rates, implementing antibiotic stewardship programs, and adhering to infection control measures will contribute to controlling and reducing antibiotic resistance rates.