Detection of Extended Spectrum Beta-Lactamase Genes in Vibrio Strains Associated with Selected Local Vegetables Sold in Public Markets in Ondo City, Nigeria

Abstract

Extended spectrum beta-lactamses (ESBLs) are bacterial enzymes that hydrolyse extended-spectrum cephalosporins, primarily in Gram-negative bacteria. Mutated from TEM-1, TEM-2, or SHV-1 genes, they break down multiple beta-lactam antibiotics through plasmid-encoded mechanisms. This study investigated the prevalence of ESBL genes in Vibrio strains isolated from purposively selected pumpkin, water leaf, and amaranth green vegetables sold in Ondo City, Nigeria, to investigate ESBL genes in Vibrio strains. One hundred vegetable samples were collected and analysed via microbiological and polymerase chain reaction (PCR) to detect specific ESBL genes. The antibiotic sensitivity profile was estimated via disc diffusion following the Clinical Laboratory Standard Institute guidelines. Vibrio cholerae exhibited intermediate resistance to gentamycin (15.17 ± 0.44 mm) and erythromycin (17.00 ± 0.57 mm) but complete resistance to ciprofloxacin (0.00 ± 0.00 mm). V. parahaemolyticus was susceptible to pefloxacin (21.17 ± 0.44 mm) but resistant to ceftriaxone. The TEM and SHV genes were detected in V. cholerae and V. alginolyticus, with band sizes of approximately 258 bp and 318 bp, respectively. However, V. parahaemolyticus did not harbour any detectable ESBL genes. Vibrio species exhibited complex antibiotic resistance profiles, requiring precise antimicrobial selection based on strain-specific susceptibility patterns, which calls for improved food safety measures in urban markets to mitigate the risk of antibiotic-resistant infections transmitted through contaminated vegetables. This study contributes valuable insights into the clinical implications of antibiotic resistance in foodborne pathogens. It highlights the importance of monitoring agricultural practices that may facilitate the spread of beta-lactamase resistance genes.