Source:Michael Fielding, MEATINGPLACE, 9/16/13


USDA scientists at the Agricultural Research Service National Animal Disease Center in Ames, Iowa, are developing new methods to prevent and control bovine tuberculosis (TB).

Although the tuberculin cattle skin test has helped eradication efforts, one of its drawbacks is a 72-hour waiting period for results, Ray Waters, a USDA veterinary medical officer said in a news release. Interferon-gamma release tests require live white blood cells that must be processed quickly. Traditional serum tests would be more convenient and less expensive.

Scientists demonstrated that improved antigens—substances that cause the immune system to produce antibodies against foreign bacteria—are crucial in developing effective serum tests.

Another type of test, based on polymerase chain reaction (PCR) analysis of DNA, has been developed by microbiologist Tyler Thacker. The new PCR test detects Mycobacterium bovis, which causes bovine TB, in fresh tissues. It is quicker, accurate and helps distinguish between M. bovis and environmental mycobacteria, which can cause false-positive results.

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Click here to read more in the September 2013 issue of Agricultural Research magazine.