Investigation into the genetic polymorphism of the SLC11A1 gene and its influence on the resistance and susceptibility to bovine tuberculosis in Tunisia

Bovine tuberculosis (bTB), caused by Mycobacterium bovis (M. bovis), is a contagious infectious disease with considerable economic impact on dairy and meat farms worldwide. Host genetics could potentially affect susceptibility or resistance to this disease. The aim of this study was to discover the association between tuberculosis and the polymorphism of a gene playing an important role in resistance/susceptibility to this disease. Blood samples were taken from 200 Holstein cows, including 50 cows classified as cases, tested positive for tuberculosis, and 150 cows as controls, tested negative for tuberculosis. To study polymorphism of the gene coding for SLC11A1, genomic DNA was extracted using the salt method and the analytik jena kit (n=200). DNA was amplified using specific primers. PCR produced 374 pb amplifiates, which were then digested by PCR-RFLP with the PstI restriction enzyme. Two genotypes, CC and CG, with allele frequencies of 0.85 and 0.15 for the C and G alleles respectively, were revealed. Homozygous GG individuals show resistance to the disease, and the observed C> G mutation may play a role in controlling the individual's resistance to the tuberculin reaction, but the results obtained are insufficient to confirm the association between the polymorphisms and susceptibility to tuberculosis. This is the first work to indicate that rs109453173 C>G polymorphisms may contribute to SLC11A1 mediated bTB susceptibility. SLC11A1 may be a useful candidate gene linked to bTB in Holstein cows.