Lab Test For Prions May Yield Diagnostic
Tool For TSE Diseases
October 21, 1999
WASHINGTON, Oct. 21--An
Agricultural Research Service scientist
in Ames, Iowa, has developed a laboratory assay that might lead to the
development of a diagnostic test for transmissible spongiform encephalopathies
The laboratory assay, developed by ARS chemist Mary Jo Schmerr, detects the
presence of abnormal proteins called prions in the blood of animals and humans.
Prions cause a group of TSE diseases.
The most well-known example of these diseases is
encephalopathy or mad cow disease, which occurred in Great
Britain in 1986. There are no documented cases of BSE in the United States. But
all sheep are susceptible to another type of TSE known as scrapie. Elk and mule
deer get chronic wasting disease, and mink are susceptible to yet another form
of transmissible encephalopathy. Human forms of TSE that affect the brain
include Creutzfeldt-Jakob disease and kuru. Creutzfeldt-Jakob disease is rare
in the United States, and kuru has never been seen outside New Guinea.
Further development of this assay may lead to a diagnostic test for
this fatal disease agent in animals and humans. Such a diagnostic test would be
an important tool for the control of these diseases, said ARS
administrator Floyd Horn.
The presence of BSE in cows has already dealt a severe economic blow to the
British beef industry and would have a devastating impact on American
agriculture if a case of BSE were identified in the United States.
"Schmerrs accomplishment is an excellent example of how long-term
investment in research can benefit American agriculture," Horn said.
Schmerr, who works at ARS National Animal Disease Center in
Ames, and Andrew Alpert of PolyLC, Inc. in Columbia, Md., are co-inventors of
ARS and Fort Dodge
Animal Health of Fort Dodge, Iowa, have signed a Cooperative Research and
Development Agreement (CRADA) to develop a test kit for use in diagnosing TSEs
in animals. ARS--the USDAs chief
scientific agency--is in the process of applying for a patent.
Scientific contact: Mary Jo Schmerr, ARS National Animal Disease
Center, P.O. Box 70, Ames, Iowa 50010, phone (515) 663-7287,