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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Environmentally Integrated Dairy Management Research » Research » Publications at this Location » Publication #415567

Research Project: Managing Nutrients and Assessing Pathogen Emission Risks for Sustainable Dairy Production Systems

Location: Environmentally Integrated Dairy Management Research

Title: Laboratory assessment of porcine circovirus 2 and porcine reproductive and respiratory syndrome virus recovery using 2 commercial hollow-fiber ultrafilters

Author
item FIRNSTAHL, AARON - Us Geological Survey (USGS)
item DOUGHAN, GABI - Iowa State University
item Opelt, Sarah
item Cook, Rachel
item Heffron, Joseph
item KRUEGER, KAREN - Iowa State University
item Borchardt, Mark
item KARRIKER, LOCKE - Iowa State University
item STOKDYK, JOEL - Us Geological Survey (USGS)
item Burch, Tucker

Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Porcine reproductive and respiratory syndrome virus (PRRSV) causes expensive disease for the U.S. swine herd, costing an estimated $664 million per year. Given the strict biosecurity practices on U.S. swine farms, it is difficult to understand how the virus gains entry to many farms. Groundwater is one possible route that has not yet been investigated, but available methods for sampling groundwater have not been validated for their ability to recover PRRSV. ARS researchers in Marshfield, Wisconsin worked with collaborators from Iowa State University and the U.S. Geological Survey to check whether hemodialysis ultrafilters could be used to recover PRRSV from water samples spiked with PRRSV in the laboratory. They tested two types of ultrafilters and also investigated recovery of other waterborne microorganisms for comparison. PRRSV could be recovered in amounts comparable to other waterborne microorganisms, and recovery did not vary between ultrafilter types. These results can be used to design and interpret field studies searching for PRRSV in groundwater near swine farms.

Technical Abstract: Groundwater near swine farms is an uninvestigated reservoir for porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circoviruses (PCV). Enteric microorganisms are often collected from groundwater via dead-end ultrafiltration, but recovery of PRRSV and PCV with this method has not been assessed. We recovered PRRSV2 and PCV2 by dead-end ultrafiltration followed by polyethylene glycol (PEG) precipitation, nucleic acid extraction, and reverse-transcription quantitative real-time PCR. We also compared 2 commercial hemodialysis ultrafilters (Asahi Kasei Rexeed-25A , Nipro Elisio-25H) and compared PRRSV2 recovery in these filters to other waterborne microorganisms. On average, 8 ± 1% of PRRSV2 was recovered by dead-end ultrafiltration and PEG precipitation, compared to 25 ± 6% for adenovirus 41. Full-process recovery of bacteria in the same filters was 5–15%; Cryptosporidium parvum recovery was 42 ± 12%. PCV2 was detected in 4 of 12 replicate filters, but low stock concentrations precluded quantitative recovery estimates. Elisio-25H ultrafilters performed similarly to Rexeed-25As for all organisms tested. Thus, the Elisio-25H is an effective replacement for the Rexeed-25A, which is no longer available in the United States. Our recovery of PRRSV2 and PCV2 by dead-end ultrafiltration in the laboratory suggests PRRSV2 detection limits as low as 3-50 genomic copies/L in sample volumes of 100-1,500 L. Based on quantitative microbial risk assessment, these concentrations are relevant to PRRSV2 infection rates in the U.S. swine herd.