Exploring the association between polymorphisms at 3'UTR SLC11A1 gene microsatellites and resistance to tuberculosis: A case-control study in Bos taurus dairy cattle

Bovine tuberculosis is a contagious infectious disease that causes significant economic impact in dairy and meat farms throughout the world. Multiple factors, including host genome, determine the outcome of the infection. Several studies have associated polymorphisms at the two microsatellites (Ms) -Ms1 and Ms2- at the 3´unstranslated (UTR) region of the SLC11A1 bovine gene with innate resistance or susceptibility to some facultative intracellular bacterial infections, such as Brucella abortus and Mycobacterium avium subsp. paratuberculosis. Today, the few studies that investigated the association of those polymorphisms with innate resistance or susceptibility to tuberculosis in cattle, have shown opposite results. The aim of this study was to evaluate the role, if any, of the Ms1 and/or Ms2 polymorphisms at the 3´UTR of the SLC11A1 gene in Mycobacterium bovis infection phenotypes in Bos taurus dairy cattle. Jersey (n = 149) and Holstein (n = 427) cattle under risk of natural M. bovis infection were classified like controls (n = 326) and cases (n = 250) based on the response to caudal fold tuberculin skin test. Cattle population was genotyped by capillary electrophoresis based on polymorphisms in Ms1 and Ms2 at the 3´UTR SLC11A1 gene. The results presented here showed a lack of association (p > .05) between polymorphisms at the 3´UTR SLC11A1 gene and the response to tuberculin skin test in dairy Bos taurus cattle. Further studies are necessary to establish robustly genes or genome regions determining the innate R/S phenotype to Mycobacterium bovis.