The possibility that parasitic liver fluke may affect the accuracy of bovine tuberculosis (bTB) testing in cattle is being investigated by Nottingham Trent University.
BTB, caused by the bacterium Mycobacterium bovis, is one of the biggest challenges facing the cattle farming industry, while the flatworm liver fluke Fasciola hepatica is becoming more prevalent due to the warmer, wetter climate.
The primary screening test for bTB in UK cattle is a tuberculin skin test, whereby animals exposed to, or infected with, bTB should show a significant swelling in the skin following intradermal injection with Mycobacterium proteins.
However, according to researchers, the immune response to bTB may be reduced if the animal is primed to defend itself against a completely different type of threat, such as that posed by liver fluke.
The study at the university will investigate how immune cells react when stimulated with proteins derived from M bovis alone or M bovis and liver fluke, determining the effect by measuring the levels of proteins known to be important in immune responses.
As well as increasing understanding of bovine immunity during co-infection, the researchers also hope to be able to predict how pre-existing fluke infestation may affect TB disease progression.
Heather Imrie, a researcher in Nottingham Trent University’s School of Animal, Rural and Environmental Sciences, is working on the project with scientists from the University of Nottingham and University of Liverpool.
She said: “BTB and biliary fibrosis caused by liver fluke pose substantial welfare and economic burdens on the UK cattle industries. One of the primary problems relating to bTB is the tuberculin skin test, which can be unreliable as it is dependent on the animal mounting an immune response to tuberculin.
“The presence of liver fluke is increasing and cases of bTB remain high, so it is likely that co-infections will become more common. It is therefore important to understand exactly what is happening in the bovine immune system, and how immune cells are responding, so steps may be taken in future to address the problem.”
Dr Imrie is a Daphne Jackson Fellow, sponsored by the Biotechnology and Biological Sciences Research Council. Daphne Jackson Fellowships are designed to return scientists, technologists, engineers and mathematicians to their careers after a break.