Bison's Big Defense: Battling Tuberculosis

These are not good times for the wild bison of Wood Buffalo National Park in northern Canada. Since the 1920s, when infected bison were introduced, these animals have been grappling with a serious health issue: bovine tuberculosis (BTB). This disease, brought on by a certain bacteria called Mycobacterium bovis, poses a significant threat to both the bison and the wider ecosystem. The path of this disease can have consequences. For one, it endangers the bison population. Secondly, there is a risk that the disease may spread to other animals and even to humans. In a nutshell, the well-being of bison and the safety of the environment at large rely on successfully managing BTB. Researchers faced a challenge: to determine effective protective measures for young bison. They exposed a group of these animals to varying amounts of the harmful bacteria to simulate the disease's spread. This tough process involved closely monitoring the bison for signs of illness, including reactions to tuberculin (a substance used to detect TB) and examining the impact on their organs. The study involved two different approaches to combat the disease: using live BCG (Bacillus Calmette-Guerin) and heat-inactivated Mycobacterium bovis (HIMB). The goal was to see which method offered better protection against BTB. Both methods were administered orally, mimicking a natural route of exposure. While both BCG and HIMB provided some level of protection, BCG seemed to be the winner. Bison treated with BCG showed fewer lung issues and had less of the harmful bacteria in their systems. The most amazing result was that the oral HIMB vaccine nearly eliminated the bison's reaction to tuberculin, while the BCG vaccine generated a minimal response. This is crucial because it means that these vaccines could be used to tell apart infected animals from those that have been vaccinated, a tool known as a DIVA vaccine. Delving into the details, this work has opened up promising avenues for protecting this crucial wildlife species. The findings present valuable insights into the potential for oral vaccines to safeguard bison against bovine tuberculosis. These results also offer a new tool to vaccine producers to better control bovine tuberculosis. The hope of course is to mitigate the impact this disease has on the ecosystem. The research has brought us a step closer to achieving it. It's clear we need to work hard to protect our wildlife.