Assessment of Microbial Contamination on Street Foods and Food Preparation Surfaces in Nnewi Metropolis, Anambra State, Nigeria

Street-vended ready-to-eat foods constitute a major source of affordable nutrition and income for urban populations in developing countries, yet they frequently pose significant public health risks due to microbial contamination. This cross-sectional study assessed microbial contamination levels in ready-to-eat street foods and associated preparation surfaces (like knives and serving spoons) in Nnewi metropolis, Anambra State, Nigeria. Twenty vendors were sampled across three high-traffic vending clusters using multi-stage sampling. Food samples (25–50 g) and surface swabs were collected aseptically, following FAO, ISO 18593, and FDA BAM protocols, and analyzed for total viable bacterial count (TBC), total coliforms, fecal coliforms, and predominant pathogens. TBC in foods ranged from 1 × 10⠴ CFU/g (popcorn) to 9.2 × 10⠸ CFU/g (rice & stew), with many samples (e.g., okro soup, plantain, akara, doughnut) exceeding international acceptable limits for cooked ready-to-eat foods (>10⠵ CFU/g). Total coliforms were detected in 8/20 food samples (highest in beans & plantain at 4 × 10⠷ CFU/g), while fecal coliforms occurred in tiger-nut and beans & plantain. On Preparation surfaces, TBC reached up to 8.4 × 10⠸ CFU/g (buns), with coliforms in 10 samples. Predominant isolates included Staphylococcusaureus, Staphylococcus epidermidis, Enterobacter spp., Streptococcus spp., Bacillus spp., Bacilluscereus, Salmonella spp., and Escherichia coli, with frequent overlap between food and surface isolates, particularly for S. aureus. Pearson correlation showed a strong, significant positive relationship for fecal coliforms between foods and preparation surfaces (r = 0.823, p