INTRODUCTION: Packaged and unpackaged cereals are most commonly consumed food products, and their microbiological quality is important for consumer health. This study examined the isolation and identification of bacterial and fungal pathogens in packaged and unpackaged cereal samples.
METHODS: Fresh packaged and unpackaged cereal products were collected from different local markets in Anambra state, Nigeria. A total of 100 samples were analyzed. Each sample (10.0 g) was homogenized with 90.0 mL of sterile normal saline to prepare stock solution. Then, 0.1 mL of the diluted samples was inoculated on Nutrient Agar (NA), Mannitol Salt Agar (MSA), MacConkey Agar, Salmonella Shigella Agar, Eosine Methylene Blue Agar, Thiocitrate Bile Salt Sucrose Agar, and Potato Dextrose Agar (PDA) (chloramphenicol (40 mg/L) media and incubated at 37 °C for 18 - 24 hr except for PDA which was incubated at 25 °C for 48 - 72 hr. The suspected typical colonies of the bacteria and fungi CFU/g of each sample were counted and further identified after various biochemical tests. RESULTS: All the samples were contaminated with different bacteria and fungus spp. The highest bacterial count was (4.30) logCFU/gm and there was no heterotrophic bacterial count in some samples. The percentage of contamination of the samples is as follows: Total Heterotrophic Bacteria (50%), Total Coliforms (50%), Staphylococcus spp. (70%), Vibrio spp. (60%), Salmonella/Shigella spp. (60%), Fungi (packaged samples) 80%, and Fungi (unpackaged samples) 100%. Fungal pathogens were isolated from all unpackaged cereal samples. The highest fungal (Aspergillus genus) count (4.30 logCFU/g) was found in sample D. The amount of yeast and mold (1.0 × 106 CFU/g) in unpacked flour sample from local market was higher than the recommended limit (105 CFU/g). Therefore, stringent regulatory actions on the microbiological quality control on packaged and unpackaged cereal products together with the training of salespeople on food spoilage are necessary for the better management of public health in Nigeria.