Prevalence and antibiotic resistant salmonella in retail broiler chickens in Ibadan, Oyo State, Nigeria

Poultry meat has been identified as one of the principal food-borne sources of salmonella. In this study, the prevalence of contamination with Salmonella spp. of broiler carcasses sold for human consumption at retail markets in Ibadan metropolis were identified and confirmed by cultural and molecular methods, susceptibility of the isolates to commonly used antibiotics was also determined. Two hundred samples were randomly collected from broiler carcasses from selected retail markets in Ibadan metropolis. The presence of salmonella spp. in the samples was determined after pre-enrichment, enrichment and culture on selective agar. Biochemical tests and molecular identification were further carried out to confirm the isolates. Polymerase Chain Reaction (PCR) assays were carried out using the invA specific primers for the detection of Salmonella spp. The confirmed isolates were then subjected to antibiotic sensitivity test using the disc diffusion method. Cultural isolation and biochemical characterization of retail broiler carcasses yielded 25.5% prevalence while molecular identification (PCR) yielded 4% prevalence. Antibiotic sensitivity test showed 100% resistance to Cefixime, Celflozidime and Oxytetracycline. Also, a high percentage resistance of Gentamicin (87.5%) and Cefuroxime (75%) to the isolated Salmonella spp. was observed. The prevalence of salmonella spp. from broiler chickens sold for consumption in the selected retail markets in Ibadan metropolis obtained using the molecular identification (PCR) method- 4% should be considered the true picture of the prevalence. Therefore, in order to provide a more accurate profile of the prevalence of Salmonella spp. in broiler carcasses, it is pertinent to use invA gene specific PCR method that could be considered as an appropriate alternative (Standard) to conventional culture method. The high percentage of resistance to the commonly used antibiotics obtained in this study could also be attributed to the irrational, persistent, unrestricted and uncontrolled use of these antibiotics in poultry production as curative; prophylactic or growth promoter in the study area. This study established the need to improve on hygiene at the point of slaughtering and dressing of broiler chickens so as to eradicate Salmonella spp. from poultry markets. Also, the need for proper use of antibiotics to increase bacteria sensitivity to antibiotic for better results when needed was emphasized.