Sep. 1, 2010 - Aug. 31, 2013Award Number
Elsa Murano, Ph.D.
Texas A&M University
Cisneros, L., Castillo, A., Taylor, M., Snciso, J., and Fonseca, J.Summary
In the past several years, there has been a significant increase in both the number and magnitude of disease outbreaks attributed to consumption of contaminated fruits and vegetables. The largest outbreak in U.S. history occurred in early 2008 from consumption of contaminated peppers grown in Mexico, which were then transported and sold in the U.S. through Border States such as Texas and Arizona. In spite of much research over the last decade, questions as to the factors that affect the persistence of harmful bacteria on the surface of certain fruits and vegetables remain unanswered. For example, how do the chemical and physical properties of the surface of produce, as well as the presence of nutrients, affect the ability of pathogens to invade and colonize it Do the types of non-harmful bacteria comprising the microbial community of fruits and vegetables affect the ability of pathogenic ones to thrive in these environments This project seeks to answer these and other questions by determining whether the persistence of Escherichia coli O157:H7 and Salmonella on the surface of produce and their ability to resist removal with antimicrobial treatments is affected by the surface properties of the product, the availability of nutrients, and by the presence of specific harmless bacteria on the product. Further, we will investigate whether these three factors are affected by seasonal changes and differences in irrigation methods used in growing fruits and vegetables in Texas vs. Mexico through parallel field studies in these locations during the Spring and Fall using spinach lettuce, leafy greens, peppers, tomatoes and cantaloupe. Knowledge gained from these studies will be used to develop education and training materials for industry and inspectors, delivering them as workshops and distance-education modules in Texas, Arizona, and Mexico.