ISOLATION AND IDENTIFICATION OF ESCHERICHIA COLI FROM SPOILT TOMATOES IN GADAU

ABSTRACT Tomato (Solanum lycopersicum) is an important food crop in Nigeria, valued for its nutritional and economic contributions. However, it is highly perishable and susceptible to microbial contamination, which compromises both its shelf life and consumer safety. This study investigated the role of Escherichia coli (E. coli) in the spoilt tomatoes sold in Gadau, Bauchi State. Thirty visibly spoiled tomato samples were randomly collected from different markets in the study area. Standard microbiological techniques were employed, including serial dilution, pour plate counts, culturing on Eosin Methylene Blue (EMB) agar, Gram staining, and biochemical tests such as Catalase, Indole, Citrate utilization, and Coagulase. Data were analyzed descriptively to determine microbial loads and isolate profiles. The results indicated high bacterial counts ranging from 8.1 × 10⁴ cfu/ml to 1.03 × 10⁵ cfu/ml across all samples, exceeding safe limits for fresh produce. E. coli was isolated from all samples (100% occurrence), with isolates consistently exhibiting catalase-positive, indole-positive, citrate-negative, and coagulase-negative characteristics. These findings highlight widespread contamination and underscore significant public health risks, as E. coli is a fecal indicator organism linked to foodborne illnesses. The study concludes that unhygienic handling, unsafe water usage, and poor market sanitation contribute to tomato contamination in Gadau. It recommends improved postharvest handling practices, safe irrigation and washing, enhanced market sanitation, microbial surveillance, and stronger policy enforcement to safeguard food quality and consumer health.