Incidence of multidrug-resistant Salmonella spp. in local food products sold in Ado-Ekiti, South Western Nigeria

Abstract

Background: Contaminated foods of animal origin are the primary reservoirs for human non-typhoidal Salmonellae infections. Transmission of Salmonellae to humans typically occurs by ingesting meat, dairy products, and other foods contaminated by animal faeces from foods contaminated with Salmonellae. Aim: This work aimed at the detection and incidence of viable Salmonella in local food products sold and consumed in Ado – Ekiti. Methods: Typing by pulse-field gel electrophoresis (PFGE), polymerase chain reaction (PCR) detection of antimicrobial drug resistance genes, and antibiotic susceptibility testing were done. Results: Out 105 samples analyzed, Salmonella species was isolated in 77 with highest incidence (100%) observed in kunu, pork meat, egg roll, raw egg and chicken. The antimicrobial drug resistance patterns on the isolates showed that Salmonella species were resistant to cotrimoxazole (100%), chloramphenicol (100%), amoxicillin (100%), ampicillin (86%) and ofloxacin (57%) while decreased susceptibility to ciprofloxacin (100%), streptomycin (100%), gentamycin (86%) and pefloxacin (71%) was found. multidrug resistance was observed in about 77% of the isolates. With PFGE, a total of eighty-three (83) patterns were observed and thirty-six 36(43%) isolates had the 3 most common patterns. All isolates from kunu and pork meat contained qnrB2, 6 (86%) isolates from egg roll contained blaCMY-2’; 9 (75%) isolates from liquid egg and chicken each contained blaCMY-23’. The total isolate of 73% is an indication of high incidence of Salmonella spp. in food products obtained in Ado-Ekiti. Conclusion: This study showed antimicrobial drug resistance in low resource settings and urgent need for surveillance and control of this phenomenon is recommended.