Waterborne Viruses and F-Specific Coliphages in Mixed-Use Watersheds: Microbial Associations, Host Specificities, and Affinities with Environmental/Land Use Factors.
From the years 2008 to 2014, a total of 1,155 water samples were collected (spring to fall) from 24 surface water sampling sites located in a mixed-used but predominantly agricultural (i.e., dairy livestock production) river basin in eastern Ontario, Canada. Water was analyzed for viable F-specific DNA (F-DNA) and F-specific RNA (F-RNA) (genogroup I [GI] to GIV) coliphage and a suite of molecularly detected viruses (norovirus [GI to GIV], torque teno virus [TTV], rotavirus, kobuvirus, adenovirus, astrovirus, hepatitis A, and hepatitis E). F-DNA and F-RNA coliphage were detected in 33 and 28% of the samples at maximum concentrations of 2,000 and 16,300 PFU · 100 ml-1, respectively. Animal TTV, human TTV, kobuvirus, astrovirus, and norovirus GIII were the most prevalent viruses, found in 23, 20, 13, 12, and 11% of samples, respectively. Viable F-DNA coliphage was found to be a modest positive indicator of molecularly detected TTV. F-RNA coliphage, unlike F-DNA coliphage, was a modest positive predictor of norovirus and rotavirus. There were, however, a number of significant negative associations among F-specific coliphage and viruses. F-DNA coliphage densities of >142 PFU · 100 ml-1delineated conditions when ∼95% of water samples contained some type of virus. Kobuvirus was the virus most strongly related to detection of any other virus. Land use had some associations with virus/F-specific coliphage detection, but season and surface water flow were the variables that were most important for broadly delineating detection. Higher relative levels of detection of human viruses and human F-RNA coliphage were associated with higher relative degrees of upstream human land development in a catchment.



This study is one of the first, to our knowledge, to evaluate relationships among F-specific coliphages and a large suite of enteric viruses in mixed-use but agriculturally dominated surface waters in Canada. This study suggested that relationships between viable F-specific coliphages and molecularly detected viruses do exist, but they are not always positive. Caution should be employed if viable F-specific coliphages are to be used as indicators of virus presence in surface waters. This study elucidates relative effects of agriculture, wildlife, and human activity on virus and F-specific coliphage detection. Seasonal and meteorological attributes play a strong role in the detection of most virus and F-specific coliphage targets.
Lacombe Research and Development Centre, Agriculture and Agri-Food Canada, Lacombe, Alberta, Canada.
Tineke H
TH
Jones
Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, Saint-Hyacinthe, Québec, Canada.
Julie
J
Brassard
London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada.
Edward
E
Topp
Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada.
Graham
G
Wilkes
Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada David.Lapen@agr.gc.ca.
David R
DR
Lapen
D003090:Coliphages / Q000302:isolation & purification; D004777:Environment; D004784:Environmental Monitoring; D005618:Fresh Water / Q000821:virology*; D058507:Host Specificity; D009864:Ontario; D012621:Seasons; D014777:Virus Diseases; D018406:Virus Physiological Phenomena; D014780:Viruses / Q000302:isolation & purification*
F-specific coliphages; indicators; microbial source tracking; pollution; surface water; viruses