New study reveals bovine TB is evolving differently across Wales

Nation.Cymru Staff

Bovine tuberculosis is evolving in different ways across different regions in Wales, according to the most detailed analysis of the bacterium conducted to date.

The study from Aberystwyth University set out to increase understanding of how the bacterium spreads within and between cattle and wildlife populations, and changes over time, to help develop more effective ways to control the disease.

One of the most significant animal health challenges facing Wales, bovine TB affects cattle health and farm businesses and places considerable emotional, social and financial pressures on farming communities.

The latest research, led by scientists at the university’s Sêr Cymru Centre of Excellence for Bovine Tuberculosis, used whole-genome sequencing to analyse the DNA of the Mycobacterium bovis bacterium.

Published in Nature Scientific Reports, the study examined 379 samples collected from infected animals across Wales in 2021.

Using whole-genome sequencing, a technique that provides greater genetic detail than earlier methods used to characterise the bacterium, the research found that different regions of Wales contain genetically distinct strains of the bacterium.

This suggests that it is evolving differently in different areas in ways that may influence how it survives and interacts with its hosts. The research also identified strains not normally found in Wales, potentially linked to cattle movements from outside the country.

Lead author Dr Amy Healey, Lecturer in Ecology at Aberystwyth University, said: “By analysing the genome sequences of Mycobacterium bovis samples, we were able to build the most detailed picture to date of the bacterium’s genetic diversity in Wales.

“Our findings highlight the importance of understanding disease transmission at a local level and demonstrate how genomics can help us move beyond tracking disease transmission and begin to understand the biology of the pathogen itself.”

Co-author Dr Amanda Gibson, UKRI Future Leaders Fellow and Lecturer in Innate Immunology at Aberystwyth University, added: “As well as identifying distinct genetic clusters and evidence that some strains may have been introduced from outside Wales, we uncovered genetic differences that could influence how the bacterium survives, adapts and interacts with its hosts.

“While further research is needed to understand the significance of these variations, our findings provide the most detailed picture yet of the M. bovis population in Wales.

“This valuable resource will help researchers investigate why bovine TB persists and support the development of more effective disease-control strategies in the future.”