Scientists from the Centro Nacional de Biotecnología in Madrid and the Brighton and Sussex Medical School at the University of Sussex in Brighton have discovered a "survival gene" that prevents strains of tuberculosis (TB) from mutating into drug-resistant "superbugs."
In the joint study, published in the journal Nature Communications, scientists screened every gene among, a total of 11,000 genes, in TB-causing mycobacteria for mutations on a specific antibiotic and found a DNA repair enzyme, produced by a "NucS" gene that prevents the mutations.
TB, which is communicable through the air, is one of the top 10 causes of deaths worldwide. Reportedly, 1.8 million people died from the disease last year. Drug-resistant strains of TB have already been identified in 105 countries, and the researchers believe that the identification of the key gene is an important step towards understanding how superbugs develop.
The researchers further discovered that genetic variations in the NucS gene significantly influence the mutation rates in isolated strains of mycobacteria. Although more work needs to be done, the scientists believe that this discovery could play a role in understanding the development of antibiotic-resistance in patients already suffering from the disease.
Professor Aidan Doherty from the University of Sussex said that the rise of antibiotic resistance is a major threat to global health and that we first need to identify the mechanisms that prevent bacteria from mutating in the first place.
Professor Jesus Blázquez, from the Centro Nacional de Biotecnología, said that this study identifies that mutations can be reversed in mycobacteria and reveals that the loss of this DNA repair process can cause a huge increase in the mutation rates, significantly increasing the likelihood of these pathogens acquiring mutations.
Professor Doherty's Laboratory at the University of Sussex has been awarded a huge grant from the Biotechnology and Biological Sciences Research Council to further uncover how NucS prevents potentially lethal mutations from arising in mycobacteria.
This study is entitled "A non-canonical mismatch repair pathway in prokaryotes" and can be found here.