Akademik Veri Yönetim Sistemi
FLORA INFEKSIYON HASTALIKLARI VE KLINIK MIKROBIYOLOJI DERGISI, cilt.31, sa.1, ss.1-11, 2026 (ESCI, TRDizin)
Introduction: Serratia marcescens is a gram-negative bacterium that causes severe infections and contributes to increased morbidity and mortality due to rising antimicrobial resistance. This study evaluated the prevalence of extended-spectrum beta-lactamase (ESBL) and plasmid-mediated quinolone resistance (PMQR) genes.
Materials and Methods: A total of 640 S. marcescens strains isolated from various clinical samples over five years were included in this study. The strains were identified by mass spectrometry, and their antimicrobial susceptibility was determined using an automated system (Becton, Dickinson and Company, Franklin Lake, USA) and the Kirby-Bauer disk diffusion method, with evaluation based on The European Committee on Antimicrobial Susceptibility Testing 2022 criteria. Seventy strains that exhibited intermediate (I) or resistant (R) profiles to third-generation cephalosporins or quinolones were further screened by in-house polymerase chain reaction for beta-lactamase genes (blaTEM, blaSHV, blaCTX-M, blaOXA), and PMQR genes (qnrA, qnrB, qnrS, aac(6’)-Ib-cr, and qepA), as well as for integron content. The blaCTX-M gene and the variable region of class 1 integrons were analyzed by Sanger sequencing.
Results: The detected resistance genes included 5.7% (n= 4) blaTEM, 2.9% (n= 2) blaSHV, 1.4% (n= 1) blaCTX-M-15, 4.3% (n= 3) qnrS, 2.9% (n= 2) aac(6’)-Ib-cr, and 4.3% (n= 3) intI1. The blaOXA, qnrA, qnrB, qepA, and intI2 genes were not detected. Two strains harboring class 1 integrons contained gene cassettes including aadA2, dfrA12, and ANT(2”)-Ia.
Conclusion: This study provides valuable epidemiological data on ESBL production and quinolone resistance genes among S. marcescens strains in our region, indicating an overall low level of resistance to carbapenems and aminoglycosides, but a noticeable increase in resistance to third-generation cephalosporins and quinolones over the years. Further studies and surveillance are needed to better guide the use of antibiotics in S. marcescens infections.