Abstract

Microbial contamination of wheat flour can result in food borne illness and disease outbreak from consumption of contaminated wheat flour and its derivative products. Hence this study is aimed to investigate the prevalence of microorganisms in different stages in the production of wheat flour in a Port Harcourt Flour Mill. Two sets of samples were obtained from three different stages of wheat flour production lines namely; UTF, production, and bagging on two different sampling periods. The samples were collected using sterile containers properly labeled according to standard microbiological procedures and then transported to the Laboratory for analyses using standard microbiological techniques. Antibiotic sensitivity profile of the isolated bacteria was carried out according to methods recommended by Clinical Laboratory Standard Institute. Results showed that mean total heterotrophic bacterial counts ranged from 6.3×10⁵ to 2.25×10⁶CFU/g; Total fungi counts ranged from 5.0×10³ to 2.2×10⁴CFU/g, Salmonella/Shigella counts ranged from 1×10² to 5.0×10²CFU/g, and Total coliforms 0.0CFU/g. Three Gram positive bacteria belonging to the genera: Bacillus, Clostridium, and Staphylococcus, and three Gram negative bacterial species which includes Escherichia coli, Serratia, and Salmonella species were isolated and identified from samples of the three different stages in the production of wheat flour. The Most Probable Number results showed presence of coliform bacteria and was identified as Escherichia coli and Serratia spp. Results of Antibiotic sensitivity revealed that all the Gram positive isolates were susceptible to Gentamycin while all the gram negative bacterial isolates were susceptible to Ciproflox, Nalidixic Acid and Septrin. Findings of the study revealed the presence of potential pathogens in the flour samples investigated. Therefore, it is recommended that microbial test should be carried out on wheat grains and decontaminated before flour production, proper handling of wheat before and during production and addition of antimicrobial agent during tempering.