Antibiotic susceptibility of Staphylococcus aureus strains isolated from various clinical specimens in a tertiary hospital

Abstract

Aims: Multi-drug resistance is currently approaching alarming levels in Staphylococcus aureus (S. aureus) strains, which are often identified in community-acquired and hospital-acquired infectious illnesses. This study aimed to examine the antibiotic susceptibility of S. aureus strains isolated from patients treated in a tertiary state hospital for four years. Methods: A retrospective analysis was performed on S. aureus strains (n=584) identified from clinical samples delivered to the Medical Microbiology Laboratory of Niğde Ömer Halisdemir University Training and Research Hospital for bacterial culture between January 2016 and December 2019. The strains were identified using both conventional methods and the VITEK 2 (bioMerieux) automated identification system. Antibiogram results were performed with the same automated system, taking into account EUCAST (the European Committee on Antimicrobial Susceptibility Testing) criteria. Results: Strains were most commonly isolated from wound swabs (n=168, 28.7%) and blood cultures (n=108, 18.4%). Cefoxitin resistance ranged from 27.11% to 22.98% depending on the year. Among isolated S. aureus strains, the most antimicrobial resistance evolved against erythromycin (n=232). Vancomycin and teicoplanin resistance were not observed. Conclusion: Multi-drug resistance and MRSA resistance still exist today. Due to the resistance rates, it was thought that more care should be taken in the use of erythromycin in the treatment. It is encouraging to observe that resistance to vancomycin and teicoplanin is absent in our hospital and also that resistance to trimethoprim-sulfamethoxazole is minimal in comparison to resistance to other antibiotics. This information about the susceptibility of S. aureus may be helpful in determining how to administer antibiotics.