A major compound in soil organic matter degrades chronic wasting disease prions and decreases infectivity in mice, according to a study published November 29 in the open-access journal PLOS Pathogens by Judd Aiken of the University of Alberta, and colleagues.
Chronic wasting disease is an environmentally transmissible, fatal prion disease affecting free-ranging deer, moose, elk and reindeer. It is endemic in North America, present in South Korea and has recently been confirmed in northern Europe. Environmental prion contamination plays a major role in the increasing incidence of chronic wasting disease, with infectivity being released into the environment by decaying carcasses, or through shedding of biological fluids including urine, feces, and saliva. The transmission of chronic wasting disease involves soils as an environmental reservoir of infectivity. Different soil compounds can differentially bind prions and change their infective properties.
Aiken and colleagues tested the role of a major soil organic matter compound, humic acid, for its ability to bind chronic wasting disease prions and impact infectivity. The researchers examined a wide range of humic acid concentrations, representing the extensive spectrum of humic acid levels present in native soils. The findings suggest that soil organic material degrades chronic wasting disease prions. Incubation of chronic wasting disease prions with high concentrations of humic acids decreased both the chronic wasting disease prion signal and infectivity in mice, whereas lower levels of humic acids did not significantly impact protein stability or infectivity. According to the authors, the study provides new insights into soil-prion interactions, the persistence of prions in soil, and their bioavailability to grazing animals.
Aiken adds, "CWD is a significant emerging and fatal disease of deer, elk and moose. Given it is shed from infected animals into the environment where it can serve as a source of infection, it is essential that we understand the impact of soil and soil components on this unusual infectious agent."
Peer-reviewed; Experimental study; Cells
Funding: This work was supported by Alberta Innovates BioSolutions through the Alberta Prion Research Institute grants 201300025 and PAA13007. Also this research was funded from Genome Canada, the Alberta Prion Research Institute and Alberta Agriculture and Forestry, through Genome Alberta in support of the Systems Biology and Molecular Ecology of Chronic Wasting Disease project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Citation: Kuznetsova A, Cullingham C, McKenzie D, Aiken JM (2018) Soil humic acids degrade CWD prions and reduce infectivity. PLoS Pathog 14(11): e1007414. https://doi.org/10.1371/journal.ppat.1007414
Agricultural, Life and Environmental Sciences Faculty, University of Alberta, Edmonton, AB, Canada
Faculty of Science, University of Alberta, Edmonton, AB, Canada
In your coverage please use this URL to provide access to the freely available paper: http://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat. 1007414