37-2 |
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H.-P. M. BLASCHEK, Dept. of Food Science & Human Nutrition, Univ. of Illinois, Urbana-Champaign, 1207 W. Gregory Dr., 488 ASL, MC-630, Urbana, IL 61801 Recent trends in produce-related outbreaks with a focus on sources of contamination and the ecology of microbes on plant surfaces will be discussed . Recent status of post-harvest approaches for cleaning and sanitizing produce will be examined. A case study focused on a 1998 foodborne outbreak in the Chicago area involving bean salad and Shigella boydii 18 will serve as the basis for experimental investigation. The experimental plan involved the characterization of Shigella boydii with respect to its ability to grow and/or survive in bean salad at different storage temperatures. The next step involved examining the removal of Shigella from parsley and cilantro, ingredients which are present in the bean salad and which have been implicated in a number of multi-state outbreaks as likely vehicles for transmission of Shigella. Electron microscopy (SEM and ESEM) was used to examine biofilm production on produce. ESEM offers the advantage of not having to fix the sample using traditional techniques which may produce artifacts. ESEM uses water as the imaging gas and allows for observation of the plant/microbial interaction in an essentially unaltered state. Finally, we will examine the genetic basis for biofilm formation in Shigella using approaches which have been developed for Escherichia coli.
Session 37, Biofilms in the food industry: Problems and solutions
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