Produce related outbreaks have been traced back to the preharvest environment. A longitudinal study was conducted on five farms in New York State to characterize prevalence, persistence, and diversity of foodborne pathogens in fresh produce fields and to determine landscape and meteorological factors that predict their presence. Produce fields were sampled four times per year for two years. A total of 588 samples were analyzed for L. monocytogenes, Salmonella and Shiga toxin-producing E. coli (STEC). The prevalence measures of L. monocytogenes, Salmonella and STEC were 15.0, 4.6, and 2.7%, respectively. L. monocytogenes and Salmonella were detected more frequently in water samples, while STEC was detected with equal frequency across all sample types (soil, water, feces and drag swabs). L. monocytogenes sigB gene allelic types 57, 58 and 61, and Salmonella Cerro, were repeatedly isolated from water samples. Soil available water storage (AWS), temperature, and proximity to three land cover classes: water, roads and urban development, and pasture/hay grass, influenced the likelihood of detecting L. monocytogenes. Drainage class, AWS, and precipitation were identified as important factors in Salmonella detection. This information was used in a geographic information systems framework to hypothesize locations of environmental reservoirs where the prevalence of foodborne pathogens may be elevated. The map indicated that not all croplands are equally likely to contain environmental reservoirs of L. monocytogenes. These findings advance recommendations to minimize the risk of preharvest contamination by enhancing models of the environmental constraints on the survival and persistence of foodborne pathogens in fields.
KSWFoodWorld
FoodWorld 