Spatial and temporal prevalence of foodborne bacterial pathogens in water-overlying sediments in the Mid-Atlantic United States

Authors: Patel, Jitendra; Oh, Sookyung; YIN, HSIN-BAI - Us Food & Drug Administration (FDA); HARRIGER, DANA - Harrisburg University

Submitted to: Water, Air, and Soil Pollution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2025
Publication Date: 7/24/2025
Citation: Patel, J.R., Oh, S., Yin, H., Harriger, D. 2025. Spatial and temporal prevalence of foodborne bacterial pathogens in water-overlying sediments in the Mid-Atlantic United States. Water, Air, and Soil Pollution. 236:725. https://doi.org/10.1007/s11270-025-08305-3.
DOI: https://doi.org/10.1007/s11270-025-08305-3

Interpretive Summary: The presence of indicator bacteria such as total and fecal coliforms and generic Escherichia coli in irrigation waters and sediments of water bodies have been evaluated. However, the prevalence of foodborne bacterial pathogens in sediments require investigation. Pathogens surviving in sediment of water bodies can contaminate irrigation water and subsequently transfer pathogens to fresh produce during irrigation. We monitored prevalence of fecal indicator bacteria and bacterial pathogens in sediments of Conococheague Creek in Pennsylvania at three locations for three years. Results indicated substantial presence of indicator bacteria, with total coliforms showing the highest average populations. Both Salmonella spp. and Listeria monocytogenes were detected across all three sites. Higher prevalence of Salmonella was observed during the warmer months whereas L. monocytogenes was detected throughout the year, with a significant increase during the colder season. Further, pathogen prevalence varied with site location. Fresh produce growers and stakeholders can use the results to minimize the risk of pathogen transfer to fresh produce via irrigation water.

Technical Abstract: The presence of Fecal Indicator Bacteria (FIB) in the sediments of Conococheague Creek, PA, has been documented. However, the prevalence of pathogenic bacteria in these sediments and seasonal influence on pathogens, as well as relationship with presence of pathogens and FIB remain largely unexplored. This study aimed to fill this gap by investigating the presence and temporal distribution of foodborne pathogens, including Salmonella spp. and Listeria monocytogenes, in water-overlying sediments at selected locations in Conococheague Creek. Over a three-year period, sediment samples were analyzed to enumerate FIB, including total coliforms, fecal coliforms, and generic Escherichia coli. Results indicated a substantial microbial presence, with total coliforms showing the highest average concentrations, particularly during the warmer seasons. Compared to other sampling sites, FIB concentrations were consistently higher at the SS site, a location characterized by low-intensity urban development. Both Salmonella spp. and Listeria monocytogenes were detected across all tested sites, with Listeria monocytogenes observed more frequently than Salmonella spp. Additionally, a higher prevalence of Salmonella spp. was observed during the warmer months, suggesting seasonal influences on its detection. Conversely, Listeria monocytogenes was detected throughout the year, with a significant increase in during the colder seasons, indicating a seasonal variation in pathogen prevalence. The I81 site, an area dominated by agricultural activities like crops and pasture production, showed higher prevalence of Salmonella spp. and Listeria monocytogenes compared to the other two sites, suggesting a greater contamination risk in irrigation water sources. These findings emphasize the need for continuous, year-round monitoring of sediment microbial dynamics across the watershed to safeguard irrigation water quality and minimize the risk of pathogen transmission to fresh produce.