Occurrence of Salmonella species in local and commercial chickens slaughtered at Samaru and Sabon-gari live bird markets, Kaduna State

Abstract

ABSTRACTSalmonellosis is a bacterial infection caused by members of the genusSalmonella. It is one of the most common and important zoonotic diseases. The route of infection from animals to humans is usually through contaminated food, water and environment. Bacteriological investigation on 303 cloacal swab samples collected from local (139) and commercial (164) chickens slaughtered at Samaru and Sabon-gari live bird markets, Kaduna State was carried out to determine the occurrence ofSalmonellaspecies. Cultural isolation and identification using conventional biochemical tests, microgen test kit™ and Polymerase Chain Reaction (PCR) amplification ofinvA gene of theSalmonellaisolates was carried out. Isolates were subjected to antimicrobial susceptibility tests, phenotypic detection of Extended Spectrum Beta Lactamases (ESBLs) producingSalmonellaisolates using the modified Clinical and Laboratory Standards Institute (CLSI) ESBL confirmatory test. The occurrence ofSalmonellaspecies based on cultural and biochemical tests was found to be 13 (4.29%), microgen kit identified 7 (53.8%) of the 13Salmonellaspecies while PCR based oninvA gene confirmed 9 (69.2%) as the overall occurrence rate ofSalmonellaspecies. Meanwhile, the study also revealed rate of occurrence ofSalmonellaspecies in local chickens 8 (61.5%) which was higher compared to commercial chickens 1 (7.69%) with a statistical significant association (χ2= 8.775, P = 0.003) between the occurrence ofSalmonellaspecies in local and commercial chickens. Antimicrobial susceptibility testing was carried out using panel of 12 antibiotics from 8 different antibiotic classes. Highest rate of sensitivity of the isolates to antibiotics was observed for Ofloxacin with 90%, while all the isolates (100%) were resistant to Nalidixic Acid, Cefazolin, Amoxicillin + Clavulanic Acid, Oxacillin and Penicillin. This study revealed multidrug-resistance (MDR) profile ofSalmonellawith a total of (25%) ofSalmonellaisolates being resistant to 5 antibiotics belonging to 4 different classes of antimicrobials with the highest multiple antibiotic-resistant (MAR) indices ranging from 0.58 to 0.91. All the nine (9) isolates ofSalmonellatested were found to be negative for ESBLs production. Therefore, it is concluded thatSalmonellaspecies are present in local and commercial chickens slaughtered at Samaru and Sabon-gari live bird markets, Kaduna State and could pose serious public health risks to handlers and to consumers of poultry meat and its products.