Isolation of Escherichia coli in foods

This study was carried out to assess contamination of foods and drinks with Escherichia coli as well as to detect pathogenic strains of the organism associated with diarrhoea in a rural community. Cooked or prepared food and drink samples were collected from homes of families with children less than five years old. The samples were cultured for E. coli and the E. coli isolates were tested for enteropathogenic, enterotoxigenic and enterohaemorrhagic E. coli. The commonest cooked or prepared foods and drinks found in the homes were sadza (thick maize meal porridge), vegetables, mahewu (a non-alcoholic fermented cereal gruel), tea and home baked bread. Thirty seven pc of all the foods and drinks examined had E. coli, indicating faecal contamination. The foods with high percentages of faecal contamination were sadza (48 pc), mahewu (39 pc), home baked bread (27 pc) and vegetables (26 pc). Pathogenic strains of E. coli were rarely isolated despite the high isolation rate of E. coli in the foods and drinks. Sadza had the highest isolation rate of enterotoxigenic E. coli (7 pc). The community studied need to be educated on thorough reheating of stored food before it is consumed in order to reduce the transmission of bacterial enteric pathogens through contaminated food.