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Identification and Control of Microbiological Hazards in Fruits and Vegetables: A Field Epidemiological and Intervention Study in Mexico


Our overall goal is to identify, quantify and prevent fecally-associated pathogen contamination in produce and, in so doing, to engage the U.S. and Mexican agricultural community.<P> Our three specific aims are through: 1. Research, identify routes and quantify the types and likelihood of contamination with fecal matter and bacterial and viral pathogens during the production of produce, including microbiological analysis of produce, water, soil, and hand hygiene. 2. Through extension, implement and evaluate an intervention aimed at multiple routes of contamination and quantify the change in fecal contamination and pathogen load. 3. Through extension and education, engage the research community and produce associations in Mexico, Texas, North Carolina, and Georgia with our findings and develop an eXtension Internet-based training module.

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Non-Technical Summary: Our goal is to understand how fruits and vegetables become contaminated on farms. We plan to study crops that are at high risk of contamination like jalapeno peppers, cantaloupes, and tomatoes. We will test these fruits and vegetables for bacteria and viruses that cause disease. We will also use new laboratory methods to find where these fruits and vegetables became contaminated (e.g. water, hands, soil). Our study area is the U.S. Mexico border states of Nuevo Leon, Coahuila, and Tamaulipas. Our subgoals are to: 1) study these questions on 15 farms; 2) test a prevention strategy to reduce contamination on fruits and vegetables; 3) develop internet-based education modules and work with produce associations in Georgia, Texas, and North Carolina to share this information. This study and information will help to better fruit and vegetable practices and therefore reduce the number of outbreaks due to fruits and vegetables. <P> Approach: We propose to study at-risk crops (jalapeno peppers, cantaloupes, tomatoes), key bacterial and viral pathogens (E. coli O157, Salmonella, Shigella, norovirus), and bacterial and viral indicators (generic E. coli, Enterococcus, coliphages) on farms. To better understand potential sources of human or animal fecal contamination, we also propose the application of innovative molecular epidemiology and microbial source tracking methods including 1) amplification and discrimination of Bacteroidales 16S rRNA genes; and 2) generic E. coli and F-specific bacteriophage strain typing. Our chosen study area comprises the U.S. Mexico border states of Nuevo Leon, Coahuila, and Tamaulipas.

Leon, Juan
Emory University
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