Johne’s disease costs the U.S. dairy industry more than $200 million per year
A team of Agricultural Research Service (ARS) and university scientists is investigating a new “ingredient” for use in vaccinating cattle against Johne’s disease, a chronic wasting affliction that costs the U.S. dairy industry more than $200 million per year.
The ingredient in question is a type of protein on the surface of the bacterium Mycobacterium aviumsubspecies paratuberculosis, which causes Johne’s disease.
Vaccinating the animals with dead MAP cells can prevent such fecal shedding; however, this process can also generate misleading results called false-positives when vaccinated cattle are tested for bovine tuberculosis, a disease caused by a close relative of the bacterium.
An alternative approach could come from vaccinating the animals with specific pieces of MAP rather than using the entire bacterium, notes John Bannantine, a microbiologist with the ARS National Animal Disease Center in Ames, Iowa.
Toward that end, he and colleagues from Washington State University and Inje University in Gimhae, South Korea, devised a new laboratory procedure called an ex vivo bacterium viability assay. Using it, they evaluated the peptide’s potential as a vaccine through its ability to mobilize certain immune system cells in blood samples drawn from infected cattle rather than using the animals themselves.
Upcoming studies will focus on ways to formulate and deliver the peptide. Once there is a successful formulation, they will conduct cattle vaccine trials. Ultimately, the research could open the door to a new way of preventing Johne’s disease without interference with bovine tuberculosis tests.
The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.