MOLECULAR CHARACTERIZATION AND ANTIBIOTIC RESISTANCE PATTERNS OF NON-TYPHOIDAL SALMONELLA FROM FRESH PRODUCE

Abstract

Microbial contamination of fruits and vegetables is a major public health concern with several outbreaks of foodborne diseases linked to its consumption. There has been increasing reports on the occurrence of non-typhoidal Salmonella (NTS) contamination of fresh produce worldwide. A total of 63 fresh produce samples were obtained from road side vendors in Lagos and Ogun State. The samples (n = 12) were positive for Salmonella species on XLD and HEA agar. The 12 isolates of Salmonella species were confirmed with Gram staining, catalase test and oxidase test. Molecular typing of the isolates was performed using Salmonella spp specific PCR. Antimicrobial susceptibility testing using Kirk-Bauer disk diffusion method was carried out. Antimicrobial resistance (AMR) was observed in 100% (12 isolates) of all the isolates with each exhibiting resistance to more than three antimicrobial agents, hence; all were multidrug resistant (MDR). The occurrence of MDR Salmonella spp. in this study indicates fresh produce from roadside vendors poses a high risk to human health. Therefore, proper precautions must be taken to prevent contamination of fresh fruits and vegetables from Farm to Fork. Inappropriate use of antibiotics in farm animals should be regulated and antibiotic stewardship would help greatly in slowing down the spread of resistant NT Salmonella.