Scientists at The University of Nottingham are studying whether harmful bacteria found in cattle could be harnessed to protect livestock from the devastating disease bovine tuberculosis (TB).
The research, being led by Paul Barrow in the university's School of Veterinary Medicine & Science, could offer an important step towards developing a vaccine against bovine TB, which affects tens of thousands of cattle every year.
The study will investigate the disease in cattle in the U.K. and China in collaboration with Xiangmei Zhou at Beijing's China Agricultural University. The two-year project has been funded with a £200,000 grant from the Research Councils UK (RCUK) and Chinese Ministry of Science & Technology (MoST) China-UK Cooperation Program in Global Priorities.
Barrow said, “We have discovered very interesting and novel interactions between different bacterial types during mixed infections. One bacterial type can stimulate short-term immunity against unrelated bacteria providing a degree of protection. We want to look to see if a similar relationship occurs between the bovine tubercle bascillus and other bacteria which are present in the tissues at the same time.”
Bovine TB is a bacterial disease that in 2011 resulted in the slaughter of approximately 25,000 cattle in England at a cost of more than £90 million. Recent figures released by DEFRA show that the slaughter of cows increased by 10% in 2012, with more than 38,000 animals being destroyed. In an effort to control the disease, the government has introduced the bovine TB eradication program including the proposed cull of badgers, which have been found to be carriers of the disease (The badger cull is a very controversial part of the program).
In China, bovine TB is now a major economic problem, causing hardship for farmers and their families living in rural communities. In any one herd, up to 70% of cattle can be affected.
Bovine TB is also a zoonosis — an infectious disease that can cross the species barrier to spread from animal to human. In the U.K., early detection means the disease is never allowed to reach the point where it can threaten human health. However, in China some spread of the bacterium that causes the disease, Mycobacterium bovis, does result in some human tuberculosis. TB is a chronic disease that eats away at the lungs over a long period of time, eventually leading to breathing difficulties.
The Nottingham scientists will be investigating whether being infected by other related bacteria could offer a protective effect against bovine TB. In particular, they are looking at another common cattle bacterium called Mycobacterium paratuberculosis, which causes the gut wasting condition Johne's disease and has been tentatively linked with Crohn's disease in humans.
The researchers will be using advanced microarray technology to test samples from cattle from both the U.K. and China to detect the mixture of bacteria that may be present in a single animal. Colleagues in China will be conducting in vitro assays in cell culture to study whether the presence of one bacterium may affect the immune system in response to another.
The research could potentially lead to the development of an emergency vaccine that could be used to stimulate rapid resistance to bovine TB in the event that infection is found within a herd. Similarly, the application could also apply to people, with family members being vaccinated quickly after the diagnosis of TB in a close relative.