Penn State and the Pennsylvania Department of Health researchers will continue monitoring household sewage at dozens of municipal plants around the commonwealth for foodborne illness pathogens, with new funding from the U.S. Food and Drug Administration (FDA). The grant, anticipated to amount to more than $500,000 over five years, will support research complementing related work funded by the FDA since 2016.
"Our team is expanding the program to isolate and whole genome sequence foodborne pathogens, especially Salmonella enterica and Listeria monocytogenes, from wastewater treatment facilities across Pennsylvania," said team leader Ed Dudley, professor of food science and director of the E. coli Reference Center in the College of Agricultural Sciences at Penn State. "Our hypothesis is that regular sampling, combined with epidemiologic data from the Pennsylvania Department of Health, will demonstrate that foodborne pathogens can routinely be isolated from community wastewaters during outbreaks."
The findings of the surveillance, Dudley noted, will provide valuable insights for public health agencies, potentially leading to improved surveillance and outbreak-response strategies. Wastewater-based surveillance may also help identify communities where contaminated foods are being distributed, he added.
The first demonstration of wastewater monitoring in public health occurred in 1929, according to Dudley, looking for "B. paratyphosus B" - what is today called Salmonella Paratypi B, and it was first used broadly in the 1940s to monitor for polio. Wastewater surveillance proved such a powerful disease-monitoring tool that the U.S. Centers for Disease Control and Prevention established the National Wastewater Surveillance System (NWSS) to support COVID monitoring in 2020 and continues to monitor for infectious diseases. After that the demonstrated effectiveness of NWSS, working jointly, scientists from Penn State and the Pennsylvania Department of Health showed that domestic sewage monitoring is useful for detecting foodborne pathogens as well.
Dudley and his team will conduct all genetic sequencing of the wastewater samples - used to detect and identify specific pathogens - in his laboratory in the Department of Food Science. The researchers will compare their data with information from GalaxyTrakr and the National Center for Biotechnology Information Pathogen Detection website, which is an open-source, cloud-based bioinformatics platform developed by the FDA to help public health laboratories analyze whole-genome sequencing data, particularly for foodborne pathogens.
Once pathogens are identified, the Penn State researchers work with scientists at the state Department of Health to screen past outbreaks and see if they can make a connection to wastewater isolation and community circulation.
"Wastewater-based surveillance is a method that we, along with others, have demonstrated use to detect outbreaks of Salmonella enterica in communities," he said. "As opposed to point-of-care diagnostics and food sampling, wastewater-based surveillance provides a broader picture of the pathogens circulating within populations living in the catchment areas of wastewater treatment plants."
Other members of the team are Nkuchia M'ikanatha, lead epidemiologist, Pennsylvania Department of Health and an affiliated researcher in Penn State's Department of Food Science; and Jie Feng and Erika Biernbaum, both doctoral candidates in food science.
