Antimicrobial Susceptibility and Toxin Gene Profiles of Commensal Clostridium perfringens Isolates from Turkeys in Hungarian Poultry Farms (2022–2023)

Background: The global spread of antimicrobial resistance (AMR) remains one of the greatest challenges of our time, necessitating collaboration among professionals in both the animal and public health sectors. One bacterial species that is developing AMR is Clostridium perfringens. It causes serious bacterial infections and continues to cause significant economic losses in the poultry industry. Methods: This study aimed to evaluate the antimicrobial susceptibility profiles of commensal C. perfringens strains isolated from large-scale turkey flocks in Hungary using minimum inhibitory concentration (MIC) determination. We complemented our research with polymerase chain reaction (PCR) analysis to detect the major and minor toxin genes that are characteristic of the species and to explore the potential associations between gene presence and antimicrobial resistance profiles. Results: A total of 146 commensal isolates were examined. Sensitivity to penicillin was reduced, with only 44.5% of isolates remaining susceptible, whereas 87.7% of isolates were sensitive to amoxicillin. The PCR results revealed that all isolates carried the alpha major toxin gene, 23.9% harbored the beta major toxin gene, 15.8% the beta2 minor toxin gene, 3.4% the NetB minor toxin gene, and 2.7% the epsilon major toxin gene. No statistically significant associations were observed between the presence of toxin genes and the antimicrobial susceptibility profiles of the isolates; the MIC values showed no correlation with the presence of toxin-producing genes. Conclusions: Clostridium perfringens isolates retained susceptibility to beta-lactam antibiotics, which remain the primary choice for treatment. Regular monitoring can aid in establishing temporal trends. Future studies should include larger sample sizes and employ next-generation sequencing to further investigate multidrug-resistant strains.