Extended Spectrum Beta-Lactamase (ESBL) Resistant genes in Salmonella species Isolated from Ready-to-eat Foods and Food Handlers in Port Harcourt Metropolis, Nigeria

Aim: To assess the Extended Spectrum Beta-Lactamase (ESBL) resistant genes in Salmonella spp isolated from ready-to-eat foods and food handlers in Port Harcourt Metropolis, Nigeria.

Study Design: A cross-sectional study.

Place and Duration of Study: This study was conducted in selected places in Port Harcourt, between November 2019 and June 2021.

Methodology: A total of 350 food specimens and 230 food handlers were collected and the social demographic information were collected using a questionnaire survey. The samples were analysed for contamination with Salmonella species using conventional and molecular methods. Salmonella species were isolated from samples using Salmonella-Shigella agar (SSA), Xylose-lysine desoxycholate agar (XLD), MacConkey agar (MA), Blood agar (BA) after pre-enrichment and enrichment method has been done using peptone water broth and Selenite F. Salmonella Chromogenic medium (SCM) was also used to confirm the isolate. Antibiotic susceptibility patterns of the Salmonella isolates were determined using Kirby Bauer disk diffusion method. The presence of Extended Spectrum Beta Lactamase genes (CTX-M, SHV, and TEM) in the Salmonella isolates were screened using double disc synergy method and also investigated using Polymerase chain reaction (PCR) technique.

Results: Results showed that of the 11 Salmonella species isolated from the food handlers, 7(63.6%) harboured extended spectrum beta-lactamase (ESBL) genes while 18 (64.3%) out of 28 Salmonella isolated from street vended food sample were positive for ESBL genes. However, there was no significant difference in the proportion of ESBL producers observed in the street vended food and those in food handlers’ sample (P= 0.964) PCR result revealed the presence of genes encoding for TEM, SHV and CTX-M.

Conclusion: Street vended foods such as white rice/stew, jollof rice, rice/beans stew, porridge beans, beans/stew, moi moi, abacha, and roasted plantain in Port Harcourt harbour Salmonella species that possess the following Extended Spectrum Beta Lactamase (ESBL) genes as CTX-M, SHV and TEM. This should receive particular attention, as the presence of extended spectrum beta-lactamase genes isolated, indicate public health hazard and gives a warning signal for the possible occurrence of food borne diseases and multi-drug resistance.