Published: 16 Dec 2020 | Last Updated: 16 Dec 2020 09:00:35

Scientists from the Universidad Nacional Autónoma de México (Facultad de Medicina Veterinaria y Zootecnia,), the Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco (Guadalajara Jalisco, México), Public Health England (Porton Down, Salisbury), the Department of Bacteriology (APHA Weybridge, UK), IBERS, Aberystwyth University (Aberystwyth, UK), and The Department of Pathobiology and Population Sciences, Royal Veterinary College collaborated on a British Council funded Institutional Link Newton grant to assess the impact of an infection with Mycobacterium bovis on different cow breeds.

Mycobacterium bovis is the main causative agent of bovine tuberculosis (BTB) in cattle and it is also responsible for a proportion of human TB cases. The annual cost of BTB worldwide is estimated at US$3 billion. Zebu cattle are considered to be more resistant to some infectious diseases than Holstein-Friesian (HF) cattle, including BTB. However, epidemiological studies do not necessarily take into account usage differences of the two types of cattle breeds, being either dairy or beef. In their work, the researchers used a recently developed vaccination-and-BCG challenge model to compare the ability of naïve and vaccinated Zebu and HF cattle, housed in the same accommodation in Mexico, to control/kill mycobacteria. Whereas fewer bacteria were recovered from vaccinated HF cattle, no such trend was observed in Zebu cattle. In contrast, evaluation of antigen-specific IFNγ secretion indicated that Zebu and HF cattle differed in their response to mycobacteria. However, it became also apparent that animals of both breeds, all sourced in Mexico, were infected with environmental Mycobacteria, which impacted on the trial and showed that current European test systems may be not transferred directly to other environmental conditions.  

Alcaraz‐López, O A and Flores‐Villalva, S and Cortéz‐Hernández, O and Vigueras‐Meneses, G and Carrisoza‐Urbina, J and Benítez‐Guzmán, A and Esquivel‐Solís, H and Werling, D and Salguero Bodes, F J and Vordemeier, M and Villarreal‐Ramos, B and Gutiérrez‐Pabello, J A (2020) 
Association of immune responses of Zebu and Holstein‐Friesian cattle and resistance to mycobacteria in a BCG challenge model. 
Transboundary and Emerging Diseases. ISSN 1865-1674