Enteric viruses and Pepper Mild Mottle Virus show significant correlation in select Mid-Atlantic agricultural waters

Authors: ANDERSON COUGHLIN, BRIENNA - University Of Delaware; CRAIGHEAD, SHANI - University Of Delaware; KELLY, ALYSSA - University Of Delaware; VANORE, ADAM - University Of Delaware; JOHNSON, GORDON - University Of Delaware; JIANG, CHENSHEN - University Of Maryland; HAYMAKER, JOSEPH - University Of Maryland Eastern Shore (UMES); WHITE, CHANELLE - University Of Maryland Eastern Shore (UMES); FOUST, DEREK - University Of Maryland Eastern Shore (UMES); DUNCAN, RICO - University Of Maryland Eastern Shore (UMES); East, Cheryl - Roberts; HANDY, ERIC - Collaborator; BRADSHAW, RHODEL - Collaborator; MURRAY, RIANNA - University Of Maryland; KULKARNI, PRACHI - University Of Maryland; SOLAIMAN, SULTANA - University Of Maryland; BETANCOURT, WALTER - University Of Arizona; GERBA, CHARLES - University Of Arizona; ALLARD, SARAH - University Of Maryland; PARVEEN, SALINA - University Of Maryland Eastern Shore (UMES); HASHEM, FAWZY - University Of Maryland Eastern Shore (UMES); MICALLEF, SHIRLEY - University Of Maryland; SAPKOTA, AMIR - University Of Maryland; SAPKOTA, AMY - University Of Maryland; Sharma, Manan; KNIEL, KALMIA - University Of Delaware

Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/15/2021
Publication Date: 6/11/2021
Citation: Anderson Coughlin, B., Craighead, S., Kelly, A., Vanore, A., Johnson, G., Jiang, C., Haymaker, J., White, C., Foust, D., Duncan, R., East, C.L., Handy, E., Bradshaw, R., Murray, R., Kulkarni, P., Solaiman, S., Betancourt, W., Gerba, C., Allard, S., Parveen, S., Hashem, F., Micallef, S., Sapkota, A., Sapkota, A., Sharma, M., Kniel, K. 2021. Enteric viruses and Pepper Mild Mottle Virus show significant correlation in select Mid-Atlantic agricultural waters. Applied and Environmental Microbiology. 87:e00211-21. https://doi.org/10.1128/AEM.00211-21.
DOI: https://doi.org/10.1128/AEM.00211-21

Interpretive Summary: Microbiological analysis of agricultural waters is fundamental to ensure microbial food safety. The highly variable nature of nontraditional sources of irrigation water makes them particularly dif'cult to test for the presence of viruses. Multiple characteristics in'uence viral persistence in a water source, as well as affecting the recovery and detection methods that are employed. Testing for a suite of viruses in water samples is often too costly and labor-intensive, making identi'cation of suitable indicators for viral pathogen contamination necessary. The results from this study address two critical data gaps, namely, enteric virus prevalence in surface and reclaimed waters of the Mid-Atlantic region of the United States and subsequent evaluation of physicochemical and atmospheric parameters used to inform the potential for the use of indicators of viral contamination. Results show that a more easily detectable surrogate for enteric viruses, Pepper Mild Mottle Virus (PMMoV), was recovered similarly from surface waters and reclaimed wastewater as enteric viruses. Both PMMoV and enteric viruses were more prevalent in reclaimed waters than surface waters, and the salinity of the affected the recovery of both types of viruses. These results aid farmers by providing irrigation water quality testing strategies and schemes to prevent contamination of fruits and vegetables.

Technical Abstract: Enteric viruses (EVs) are the largest contributors to foodborne illnesses and outbreaks globally. Their ability to persist in the environment, coupled with the challenges experienced in environmental monitoring, creates a critical aperture through which agricultural crops may become contaminated. This study involved a 17-month investigation of select human EVs and viral indicators in nontraditional irrigation water sources (surface and reclaimed waters) in the Mid-Atlantic region of the United States. Real-time quantitative PCR was used for detection of Aichi virus, hepatitis A virus, and norovirus genotypes I and II (GI and GII, respectively). Pepper mild mottle virus (PMMoV), a common viral indicator of human fecal contamination, was also evaluated, along with atmospheric (air and water temperature, cloud cover, and precipitation 24 h, 7 days, and 14 days prior to sample collection) and physicochemical (dissolved oxygen, pH, salinity, and turbidity) data, to determine whether there were any associations between EVs and measured parameters. EVs were detected more frequently in reclaimed waters (32% [n = 22]) than in surface waters (4% [n = 49]), similar to PMMoV detection frequency in sur-face (33% [n = 42]) and reclaimed (67% [n = 21]) waters. Our data show a signi'cant correlation between EV and PMMoV (R2 = 0.628, P , 0.05) detection levels in reclaimed water samples but not in surface water samples (R2 =0.476,P= 0.78). Water salinity signi'cantly affected the detection of both EVs and PMMoV (P=0.05), as demonstrated by logistic regression analyses. These results provide relevant insights into the extent and degree of association between human (pathogenic) EVs and water quality data in Mid-Atlantic sur-face and reclaimed waters, as potential sources for agricultural irrigation.