|Scientists: CWD binds to particles in the soil|
Date Posted: 01-01-2010
MADISON (AP) – UW-Madison researchers say they have found that the infectious nature of abnormal proteins that cause chronic wasting disease in deer dramatically increase when bound to certain soil particles.
The scientists, led by animal health and biomedical science professor Judd Aiken, published a study July 6 in the journal Public Library of Science Pathogens saying that proteins known as prions, which cause CWD and other brain-wasting diseases, bind tightly to a common soil mineral.
They studied how prions interact with the mineral mont-morillonite, which generally is found in clay soils.
Mr. Aiken said he and Joel Pedersen, a soil science professor, were shocked at how tightly the prions bound to the mineral and found they had to boil the soil in detergent to remove them.
The scientists said that, when they fed the prion-mineral mix to hamsters, they expected to see a lower rate of
infection than in animals fed just the infectious protein without the mineral.
But Mr. Aiken said the prion-mineral mix was nearly 700 times more infectious.
He and Mr. Pedersen speculated that the soil particles may protect the prions from breaking down in the digestive tract.
Other possibilities are that the clay-bound prions are more easily taken up into a deer’s digestive system or that the mineral causes more clumping of prions into aggregates, which are more infectious than single prions, the
The fatal brain disease was discovered in Wisconsin deer more than five years ago, and 856 of 129,539 deer
tested have been found to have the disease.
Alan Crossley, who oversees the Wisconsin Department of Natural Resources’ battle against CWD, said the
finding will be important as the agency begins working with hunters and others to evaluate the effectiveness of the agency’s control efforts.