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Poster: Epidemiology: Risk Assessment


Evaluation of the microbial quality of cantaloupe fruit produced on raised or flat beds following a flooding event
I. KIKWAY (1), M. Lewis Ivey (1), I. Kikway (1) (1) Louisiana State University, U.S.A.

Floodwaters can harbor human and plant pathogens and present a major risk of contamination to fresh fruit and vegetable production in Louisiana. This study evaluated the effect of flooding on the microbial quality and safety of cantaloupe in an agricultural setting. Fields (raised or flat bed) containing mature cantaloupe fruit were flooded with surface water spiked with generic Escherichia coli ATCC strains 23716, 25922, and 11775. Generic E. coli levels on the surface of cantaloupe were enumerated at 24, 48 and 72 hr after flooding. Incidence of Sclerotium rolfsii and Phytophthora capsici was measured weekly beginning 7 days prior to flooding. A significant reduction of generic E. coli was observed on the surface of cantaloupe 24, 48 and 72 hr post flooding on fruit harvested from flat beds but only after 72 hr on the fruit from raised beds. Coliform levels remained the same over the 72 hr on fruit from both bed types. After 72 hr E. coli populations were reduced by an average of 1.8 and 2.5log MPN on fruit harvested from raised beds and flat beds respectively. No differences in S. rolfsii or P. capsci incidence on fruit from flat compared to raise beds were observed. However, disease incidence was significantly higher in flooded plots compared to non-flooded plots. These results provide science-based data that can be used to develop good agricultural practices programs to minimize food safety and plant disease hazards in flood stricken production regions.