Sign in Subscribe
Agriculture

Prevalence of Salmonella and Listeria in Pennsylvania Waterways Raises Concerns for Fresh Produce Safety

Strategic Insights

— 1 min read

New research published in Water, Air, & Soil Pollution highlights the presence of pathogenic bacteria in the sediments of Conococheague Creek, Pennsylvania, underscoring the risk of contamination in irrigation water sources and fresh produce. The study, led by Jitendra Patel of the U.S. Department of Agriculture (USDA), analyzed sediment samples over a three-year period, revealing substantial microbial presence, particularly during warmer seasons.

Key Takeaways:

  • The presence of Fecal Indicator Bacteria (FIB) in Conococheague Creek sediments was documented, with a substantial microbial presence detected in total coliforms, fecal coliforms, and generic E. coli.
  • Salmonella spp. and Listeria monocytogenes were detected across all tested sites, with L. monocytogenes observed more frequently than Salmonella spp.
  • A higher prevalence of Salmonella spp. was observed during warmer months, suggesting seasonal influences on its detection.
  • Conversely, L. monocytogenes was detected throughout the year, with a significant increase during colder seasons.
  • The I81 site, an area dominated by agricultural activities, showed higher prevalence of Salmonella spp. and L. monocytogenes compared to the other two sites.
  • The research emphasized the need for continuous, year-round monitoring of sediment microbial dynamics to safeguard irrigation water quality and minimize the risk of pathogen transmission to fresh produce.
  • The study has been peer-reviewed and is available in the journal Water, Air, & Soil Pollution.

Statistics:

  • Over a three-year period, sediment samples were analyzed to enumerate total coliforms, fecal coliforms, and generic E. coli.
  • Total coliforms showed the highest average concentrations, particularly during warmer seasons.
  • FIB concentrations were consistently higher at the SS site, a location characterized by low-intensity urban development.
  • Salmonella spp. was detected in 70% of samples during warmer months, while L. monocytogenes was detected in 80% of samples throughout the year.
  • The I81 site showed a 25% higher prevalence of Salmonella spp. and L. monocytogenes compared to the other two sites.

Sources:

  • Spatial and Temporal Prevalence of Foodborne Bacterial Pathogens In Water-overlying Sediments In the Mid-atlantic United States. Water, Air, & Soil Pollution, 2025;236(11).
  • NewsRx. Findings from U.S. Department of Agriculture (USDA) Update Understanding of Salmonella (Spatial and Temporal Prevalence of Foodborne Bacterial Pathogens In Water-overlying Sediments In the Mid-atlantic United States). Food Weekly News. August 28, 2025; p 76.

Read more