Med. Weter. 81
full text
| ELÇİN GÜNAYDIN, PINAR MURSALOĞLU KAYNAR, GÜLŞEN GONCAGÜL, MURAT KARAHAN, İNCİ UYSAL, BÜŞRA GÜLAY CELİL ÖZASLAN |
| TEMPORAL RISE IN BETA-LACTAM AND COLISTIN RESISTANCE IN EQUINE REPRODUCTIVE ESCHERICHIA COLI |
| Antimicrobial resistance in equine-associated bacteria is an increasing concern within the One Health framework, particularly because horses may serve as reservoirs of resistant Gram-negative organisms with potential public health relevance. This study aimed to characterize β-lactam and colistin resistance patterns in Escherichia coli isolates recovered from vaginal swabs collected from mares with pneumovagina. A total of 187 vaginal swab specimens were examined by conventional bacteriological methods, and the antimicrobial susceptibility of the E. coli isolates recovered was evaluated by the Kirby-Bauer disk diffusion method. A total of 101 E. coli isolates were identified, including 83 non-haemolytic and 18 haemolytic isolates. Resistance was observed across multiple antimicrobial classes, and 97 isolates were resistant to between two and twelve antibiotics, whereas only four isolates showed resistance solely to penicillin. Over the study period, resistance to several β-lactams and colistin increased, with statistically supported temporal trends for cefquinome, ceftiofur, amoxicillin, and colistin after false discovery rate correction. Although amoxicillin/clavulanic acid resistance varied significantly across years, its increasing trend did not remain significant after correction. Notably, resistance patterns combining β-lactams and colistin became more frequent in the later years of the study. Taken together, these findings identify the reproductive tract of mares with pneumovagina as an emerging reservoir of multidrug-resistant E. coli and support the need for continued surveillance of clinically important β-lactam and colistin resistance in equine reproductive isolates.. |
| Keywords: Antimicrobial resistance, β-lactam resistance, colistin resistance, equine reproductive tract, Escherichia coli, One Health |