Biological control of pathogen infestation in pre and postharvest strawberry crops

Strawberry is a significantly consumed fruit in Australia, mostly without being subjected to disinfection processes, and its surface may harbor pathogens due to the nature of the fruit. During the first milestone of the project we examined the diversity of bacteria belonging to the family Enterobacteriaceae to determine presence of human pathogenic species on strawberry fruit available for public consumption. Different brands of strawberry were obtained directly from farms (at harvest time sales) or purchased from markets (post-harvest). Bacterial isolates found on post-harvest strawberries belonged to the genera Escherichia, Raoultella, Klebsiella, Pantoea, Citrobacter and were shown to colonize CaCo-2 cell line which represents the human gut epithelial cells. Samples from organic farms contained more enteric bacteria compared to the ones obtained from markets suggesting that organic amendments might encourage pathogenic bacterial contamination.