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Antimicrobial resistance, Enterococcus faecalis, Enterococcus faecium, sheep mastitis, virulence genes


This study aimed to investigate the formation of antimicrobial resistance genes associated with vancomycin and gentamicin, as well as the capacity to develop biofilms, in Enterococcus sp. strains isolated from subclinical mastitis in sheep. In total, Enterococcus faecalis (22/26, 84.62%) was found to be the most prevalent species among the samples of mastitic milk collected from sheep. In general, E. faecalis strains exhibited higher resistance compared to Enterococcus faecium. After isolation and identification using polymerase chain reaction, a total of twenty-six enterococci (22 E. faecalis, 4 E. faecium) were submitted to susceptibility tests against eight antimicrobial agents. The isolates indicated multidrug resistance to amoxicillin-clavulanic acid (100%), kanamycin (100%), and trimethoprim-sulfamethoxazole (100%). All isolates were susceptible to ampicillin (100%), and florfenicol (100%) and vancomycin susceptibility was observed in 53.85% of the isolates. The dominant antimicrobial resistance genes detected in our isolates were vanB (19.23%), aph(2”)-Ia1 (61.54%), aph(2”)-Id1 (26.92%), and esp (65.38%) as the most common virulence gene. This research indicated a significant occurrence of antimicrobial resistance in E. faecalis and E. faecium strains obtained from subclinical sheep mastitis. The increasing resistance of enterococci to antibiotics poses a growing challenge to both human well-being and the environment.


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How to Cite

Özavci, V., Yüksel Dolgun, H. T., Seferoğlu, Y. ., & Kırkan, Şükrü. (2023). EVALUATION OF VIRULENCE AND ANTIMICROBIAL RESISTANCE GENES OF ENTEROCOCCUS SPECIES ISOLATED FROM SHEEP MILK WITH SUBCLINICAL MASTITIS. Journal of Applied Biological Sciences, 17(3), 467–479. Retrieved from https://jabsonline.org/index.php/jabs/article/view/1253