Molecular Characterization and Antibiotic Susceptibility Profile of Salmonella Species Isolated from Municipal Wastewater in Jos, Plateau State

Abstract

Aim: This study is aimed at characterizing antibiotic-resistant Salmonella species from Municipal wastewater in Jos, Plateau State. Study Design: A descriptive cross-sectional study was used in this research. Place and Duration of Study: One hundred and fifty (150) wastewater samples were collected from ten (10) sample sites (Gada Juth, Bingham, Tudun Wada, Village Hostel, Vom, Abbatoir, Jenta, Farin-Gada, K-Vom, and Angwan-Rukuba) of Plateau State from October to November 2023. Methods: Conventional (culture-based techniques and confirmation with biochemical tests) and molecular laboratory (PCR) methods were employed to isolate Salmonella species and detect their resistant genes. A disc diffusion assay by Kirby-Bauer was performed to determine the sensitivity of antibiotics against Salmonella isolates. Results: There was a 2.7% overall prevalence of Salmonella spp in wastewater, with higher rates found in wastewater collected from Jenta (2%) and a lower prevalence rate of 0.67% from wastewater collected from Angwan Rukuba. High susceptibility was recorded for Streptomycin, high resistance was recorded for Gentamicin (75%), Azithromycin (75%) and Ciprofloxacin (50%). All isolates showed 100% resistance to Pefloxacin, Cefotaxime, Ceftazidime, and Ceftriaxone and 100% sensitivity towards Imipenem. Furthermore, all isolates were multi-drug resistant, with the most common multidrug resistance patterns being PEF, CH, CN, CRO, CAZ, CTX, and AZM (50%). All isolates reported multiple antibiotic resistance (MAR) index > 0.2 in the study, indicating high levels of resistance. None of the resistant genes (mph (A) and blaCTX-M) tested were detected among the isolates. Conclusion: There was a low occurrence of Salmonella and none of the tested genes associated with antibiotic resistance were detected, interestingly, most of the isolates were multidrug resistant, thereby constituting a menace to food safety and general health in the study area.