Distribution of antibiotic resistance and virulence genes in Trueperella pyogenes isolated from Korean native cattle.

Trueperella pyogenes is a commensal and opportunistic pathogen found on the skin and mucous membranes of livestock and wildlife. Although the clinical significance of T. pyogenes in livestock is well recognized, information about this pathogen is scarce in the Republic of Korea (ROK). This study aimed to investigate the distribution of virulence and antibiotic resistance genes in T. pyogenes isolates from clinical infections. A total of 52 T. pyogenes isolates were obtained from cattle with respiratory distress or suppurative infections across five different farms in the ROK. PCR assays were used to detect virulence and antibiotic resistance genes, and antimicrobial susceptibility testing was performed using the disk diffusion method. Among the virulence genes, plo was detected in all isolates (100 %), followed by cbpA (65.4 %), fimG (51.9 %), and fimC (42.3 %). The most common genotype was plo/fimG/cbpA (17.3 %). Resistance to penicillin, erythromycin, and oxytetracycline was widespread, whereas all isolates remained susceptible to fluoroquinolones. Among antibiotic resistance genes, ermB (84.6 %) was the most prevalent, followed by tetM (57.7 %), dfrG (48.1 %), and blaZ (46.2 %). Eight isolates (15.4 %) exhibited multidrug resistance to five antibiotics. Notably, significant associations were observed between antibiotic resistance and virulence factor genes: cbpA with blaZ; fimG and cbpA with dfrG; fimG with tetM; and fimC with aph3-IIIa. These results suggest that this interaction may contribute to the pathogenicity of T. pyogenes. Our findings will provide valuable insights for the development of targeted strategies to control T. pyogenes infections.