Characterization and Phylodiversity of Implicated Enteric Bacteria Strains in Retailed Tomato (Lycopersicon esculentum Mill.) Fruits in Southwest Nigeria

BACKGROUND: Tomatoes (Lycopersicon esculentum Mill.) have very huge health-promoting benefits due to high nutritional composition; however, these fruits are potential reservoir of enteric food-borne pathogens causing major public health concerns. AIM: Characterization and phylo-analysis of implicated enteric bacteria strains in retailed Tomato fruits in southwest Nigeria were studied. METHODS: Ready to be retailed fresh tomato fruits were purchased from common food markets in southwest, Nigeria, which lies between latitudes 6° 21′ to 8° 30′ N and longitudes 2° 30′ to 5° 30′ E. Observation of sample storage potentials at different conditions and bio-typing of associated bacterial strains were carried out for consecutive 14 days. Enteric bacteria strains were genotyped with 16S rRNA assay and further profiled for antibiotic susceptibility to common antibiotics. High population rate frequently consume tomatoes. RESULTS: Early spoilage characterized with yellow fluid, fungal growth and visible lesions were observed at 25°C storage compare to few patches of lesion at 4°C after 14 days. Higher bacterial count of 4.0–7.18 Log CFU/g was recorded at ambient storage compare to refrigerated samples with more than 10% occurrence rate of Citrobacter spp., Klebsiella spp. and Enterobacter spp. Identified Citrobacter spp. and Klebsiella spp. showed 100% resistant to beta-lactam antibiotics (ceftazidime, cefuroxime, cefixime, ciprofloxacin, and amoxicillin-clavulanic acid). Two-resistant enteric bacteria strains, Klebsiella aerogenes B18 and Citrobacter freundii B27 obtained from Nigerian tomato clustered with Citrobacter strains in food (China), water strains (India, Poland, Malaysia), milk (Germany), and human fecal (China). CONCLUSION: Implicated multidrug-resistant enteric bacilli in retailed tomatoes can cause severe food-borne diseases which public oriented awareness, strategic farm to market surveillance are needed to be intensified.