ProMed has carried a report that could be rather ominous. If the prion that can give deer Chronic Wasting Disease (CWD) can be transmitted by something as common as alfalfa, what does that suggest about pathways to other animals such as cows, humans, or even fish fed on animal protein? In Shakespeare's Hamlet, the prince muses, "A man may fish with the worm that hath eat of a king, and eat of the fish that hath fed of that worm."
Date: Fri 27 Sep 2013
Source: OASIS (Online Abstract Submission and
Invitation System), The Wildlife Society Annual Conference, Milwaukee,
Uptake of prions into plants
Session title: Current science of chronic wasting disease: what have we learned in the last 5 years?
Author: Christopher Johnson, US Geological Survey, Madison, WI
wasting disease (CWD) and scrapie-infected animals shed infectious
prions during both the preclinical and clinical phases of disease.
Contamination of environments with prions released from animals or from
infected carcasses appears to contribute to the transmission of these
Previous work has suggested that soil may serve as an
environmental disease reservoir. Vegetation is ubiquitous in
CWD-contaminated environments and plants are known to absorb a variety
of substances from soil, ranging from nutrients to contaminants.
uptake of proteins from soil into plants has been documented for many
years and we have been investigating the uptake of prions into plants in
vitro. Using laser scanning confocal microscopy, we observed root
uptake of fluorescently-tagged, abnormal prion protein in the model
plant thale cress or mouse-eared cress (_Arabidopsis thaliana_), as well
as the crop plants alfalfa (_Medicago sativa_), barley (_Hordeum
vulgare_), and tomato _(Solanum lycopersicum_). Using serial protein
misfolding cyclic amplification, a sensitive biochemical prion detection
method, we have found evidence of prions in aerial tissues from these
species, as well as maize (_Zea mays_). Both stems and leaves of _A.
thaliana_ grown in culture media containing prions are infectious when
injected into mice and oral bioassays are underway for _A. thaliana_ and
other plants. Our results suggest that prions are taken up by plants
and that contaminated plants may represent a previously unrecognized
risk of human, domestic species, and wildlife exposure to CWD and
Terry S Singeltary Sr