Determination of antimicrobial susceptibility and virulence-related genes of Trueperella pyogenes strains isolated from various clinical specimens in animals

Abstract

In this study, a total of 32 Trueperella pyogenes strains isolated from different disease specimens in cattle, sheep and goats were examined. Antimicrobial susceptibility of the isolates to 10 antimicrobials were determined using the E-test method and MIC values of the antimicrobials were investigated. The genes that play a role in the antimicrobial resistance or virulence of T. pyogenes were determined by PCR using gene specific primers. In the study, all the isolates were susceptible to penicillin and cephalosporin. The highest resistance rate in the isolates was determined against streptomycin (56.25%) and tetracycline (53.12%) and MIC90 values for these antimicrobials were found to be >256 μg/ml and 12 μg/ml, respectively. The ermX gene was found to be positive in 8 (80%) of 10 isolates that were resistant to macrolide group antimicrobials. Among 20 aminoglycoside resistant isolates, aadA1, aadA9, strA-strB, and aac(6’)-aph(2’’) genes were determined in 5 (25%), 14 (70%), 7 (35%) and 1 (5%) of the isolates, respectively. When the presence of virulence-related genes in the isolates was examined, nanP (93.75%), fimA (93.75%) and plo (90.62%) genes were detected in the majority of the isolates. While the cbpA gene was negative in all isolates, the fimG gene was found in a limited number of the isolates (15.62%). It was concluded that streptomycin and tetracycline resistance should be considered in T. pyogenes isolates. Also, nanP, fimA and plo genes may have an important role in the pathogenesis of the infections.