Survival and Growth of Salmonella and Shigella on Sliced Fresh Fruit

The ability of five strains of enteropathogenic bacteria ( Shigella sonnei , S. flexneri , S. dysenteriae , Salmonella derby , and S. typhi ) to survive and grow on sliced jicama, papaya, and watermelon was investigated. Fruit portions were obtained aseptically and inoculated on the surface with washed suspensions of each microorganism. The test organisms survived, and in most cases increased in numbers when inoculated fruits were stored at room temperature (25-27°C) for up to 6 h. Suspensions of papaya and watermelon in sterile distilled water supported growth of S. sonnei and S. typhi , respectively. Application of lemon juice to the surface of jicama and papaya reduced the count of S. typhi somewhat, but growth resumed after several hours. Practical recommendations are presented to control risks of contamination and subsequent growth of enteric pathogens on fruits and fruit salads during preparation and sale.