A study of the microbial contamination in imported and domestic fresh produce at retail level in Ontario

Globalization has enabled the year-round availability of imported fresh produce in Toronto, supplementing the variety of locally grown produce in Ontario. Increased consumption of produce has led to more foodborne outbreaks, with E. coli O157:H7 as the second most frequent cause of illnesses. In this study, the levels of heterotrophic bacteria, coliforms, and generic E. coli were compared between three types of imported and local produce. Significantly higher levels (p<0.04) of heterotrophic bacteria were found in imported basil. Local romaine (p<0.01) and local spinach (p<0.001) contained significantly higher levels of coliforms. Local spinach also had a significantly higher (p<0.005) number of samples with coliform levels above 100 CFU/g. Although no statistical significance was found between the presence of E. coli and origin of produce, the five imported samples positive for E. coli compared to zero local samples supports the hypothesis that imported produce is more susceptible to microbial contamination.