Two groups of scientists have each successfully mapped the genetic code for the bacterium that causes Johne’s disease. Researchers at the University of Minnesota and at the National Animal Disease Center in Ames, Iowa, have each sequenced the genome for Mycobacterium paratuberculosis.

This discovery is a major breakthrough in the fight against this chronic and potentially fatal intestinal disorder that inflicts about 8 percent of the beef herds and 22 percent of the dairy herds in the United States.

Having this genetic map could speed the development of new tests that could detect the disease earlier, deliver quicker results as well as ultimately eliminate the disease.

Vivek Kapur, director of the University of Minnesota's Advanced Genetics Analysis Center, said several genes discovered during the sequencing may help differentiate M. paratuberculosis from other closely related bacterial species. "I believe the genomes sequence's availability will provide a much-needed boost to research toward the detection of the disease, the development of vaccines and the ultimate eradication of the disease," he said.

Because of M. paratuberculosis' slow growth, it takes up to six months to identify it in laboratory culture. That time lag impedes diagnosis of infected animals and research on the microbe. "This genome sequence may enable us to not only understand why this pathogen grows so slowly, but to identify it more rapidly," said John Bannantine, microbiologist at the National Animal Disease Center.

USDA Agricultural Research Service