NADC Examines TB In Cattle...( Food Safety Consortium researchers ha...)

Food Safety Consortium researchers have made some advances in researching tuberculosis in cattle and swine. Tests in two aspects of the problem are being conducted by Consortium affiliated personnel at the National Animal Disease Center in Ames, Iowa.

Carole Bolin, an NADC research leader and a Consortium principal investigator, conducted tests for diagnosis of bovine tuberculosis with NADC researchers Diana Whipple and Belinda Goff. They sought to determine if tuberculin skin tests used in the U.S., Canada and Mexico are compatible with each other, an important issue with the passage of the North American Free Trade Agreement.

The tuberculins used for skin testing in the three countries are prepared by different methods and from different strains of the bacterium Mycobacterium bovis. The researchers compared tuberculins from each country to determine if there is a need to standardize the tuberculins used in North America.

Cattle from a herd with bovine tuberculosis reacted similarly to all three tuberculins with small variation among the responses. Cattle tested positively for M. bovis most often when the Mexican tuberculin was used. But the research team concluded that there was no need to standardize the tuberculins.

Plans are being made to use swine in studies by the NADC team to research the risk of M. bovis infection caused by the consumption of meat contaminated by the organism. The project began with studies determine if swine could be used as an animal model of human tuberculosis. The researchers found through their experiments that swine are susceptible to infection with M. bovis when inoculated. Lesions characteristic of tuberculosis were visible as early as two weeks following high doses of the inoculations and in 30 days following low dosages.