Salmonella Serovars and Antimicrobial Resistance Profiles in Commercial Layer Flocks

Abstract

Salmonellosis is a worldwide problem for both poultry and human health. Uninformed, common usage of antibiotics in commercial layer flocks and circulation of antibiotic resistance patterns from flock to flock is an obstacle to combat Salmonellosis. Transmission of resistant paratyphoid Salmonellae to people by consumption of chicken meat, egg and chicken by-products which are prepared under inappropriate conditions or undercooked, induces a transfer of antibiotic resistance patterns. The purpose of the study was to determine the Salmonella prevalence, distribution of Salmonella serovars in different ages of laying hens, and also antibiotic resistance profiles of the serovars from birds which appear healthy in the Bandirma Region of Turkey, where commercial laying hen breeding was intensively performed. Isolation was performed according to ISO 6579:2002/Amd 1:2007 (Annex D) and isolated Salmonella strains were serotyped according to Kauffmann-White scheme. Of the examined randomly collected 362 fecal samples, 45 (12.4%) were found to be Salmonella positive. S. Infantis, S. Kentucky, S. Enteritidis, S. Mbandaka were found to be common serovars. A total 45 Salmonella isolates was tested for susceptibility to 10 antibiotics by Kirby Bauer Disk Diffusion Method. Approximately fifty-three percent (24/45 of Salmonella isolates) were found to be resistant to one or more of the antibiotics. Of the tested antibiotics, none of the isolates exhibited resistance to ciprofloxacin and gentamycin while the highest resistance was found in tetracycline, the lowest resistance was determined in ciprofloxacin. All S. Mbandaka isolates were determined to be resistant solely to kanamycin. The other serovars were determined to be multi-drug resistanct (MDR). In summary, when the results of the study were evaluated it was judged that there was a need for effective vaccination programs, precautions of biosecurity planned for each flock and also application of concious antibiotic usage inorder to protect both poultry and human health.