Evaluation of resistance Genes to Phenolic Antibiotics in Poultry Salmonella

Background and Objectives: Salmonella infection remains a major public health concern worldwide. It causes significant losses to the poultry industry. The selective pressure imposed by incorrect use related antimicrobials in both human and veterinary medicine promotes the spread antimicrobial resistance. The aim of present study was to identify the plasmid genes floR, cat and cmlA in Salmonella strains, isolated from poultry using PCR method and also determine their phenicol antibiotic resistance profiles.Materials and Methods: In this study, a total of 60 Salmonella isolates from poultry in department of bacteriology, faculty of veterinary medicine were collected. The antimicrobial susceptibility test was done using the disk diffusion agar test on Müller-Hinton agar media, according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Then, the presence of resistance genes (cmlA, cat and floR) were investigated using PCR method. Results: Distribution analysis of resistance for the genes cmlA and cat and also for floR genes showed that the frequencies were 0%, 0% and 10%, respectively. Also, the phenotypical resistance to chloramphenicol and florphenicol, were 6/6% and 5% respectively. Conclusion: An increase in antibiotic resistance may indicate an overdose of unnecessary consumption of antibiotics. Therefore, it is advisable to take more appropriate action than using common therapies.