Abstract
Vegetables harboring antibiotic-resistant bacteria are a growing concern in food safety. However, data concerning extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase, and carbapenem-resistant Enterobacteriaceae (CRE) in fresh vegetables are still rare. In this study, 50 vegetable samples from six different locations in Iwo, Osun State, Nigeria, were screened for the β-lactamase group. Freshly purchased vegetables: Tomato (Lycopersicon esculentum), Cucumber (Cucumis sativus), Onion (Allium cepa), Garden egg (Solanum melongena), and Carrot (Daucus carota) were aseptically cut into pieces and pre-incubated in Minimum Recovery Diluent (MRD) for 6 h. Afterwards, streaking was done on sterile Eosin Methylene Blue (EMB) agar, and incubated at 37 °C for 24 h. The bacterial isolates obtained were biochemically characterized. The antibiotic susceptibility and beta-lactamase production profile for each isolated strain were determined phenotypically by preparing a 0.5 McFarland bacterial suspension and plating it on Mueller-Hinton agar. Commercially prepared antibiotic discs were used for susceptibility testing, and Mastdisc Combi test kits were used specifically to screen for beta-lactamase production. Forty-six enteric bacterial isolates consisting of Escherichia coli (11%), Klebsiella pneumoniae (52%), K. oxytoca (15%), and Klebsiella aerogenes (22%) were obtained; all were 100% resistant to the beta-lactam antibiotics used, and showed varied phenotypic multi-drug resistant (MDR) and beta-lactamase profiles. The presence of these MDR and beta-lactamase-producing attributes in these organisms may pose potential health risks to consumers of these vegetables.