Antibiotic-Resistant TB Meets Its Match?

By Anthony Harris

Tuberculosis claims more than one million lives per year, second only to AIDS as the most common death brought on by infectious disease in the world. Research from scientists in the U.S. and India, published in the Journal of Biological Chemistry, has just shown significant progress made in modifying the precursor to one of the main drugs used to treat TB which can exceed antibiotic resistance issues that endanger health all over the map.

In most cases, rifampicin and other related drugs are the best antibiotics used to treat tuberculosis. Two types of TB commonly labeled as extensively drug-resistant (XDR) and multi-drug-resistant (MDR) have developed resistance to rifampicin, making it very difficult to treat. However, these recent discoveries present a new compound called 24-desmethylrifampicin which has a better track record of antibacterial activity than just rifampicin versus the many drug-resistant strains that induce TB. This compound was created by both genetic modification and synthetic drug development, and researchers say it will need more testing before it’s available for human use.

Taifo Mahmud, an OSU professor in the College of Pharmacy and one author of this report, says these results are a vital path towards being able to successfully treat TB, and rifampicin will be needed for a cure. Drug resistance created in rifampicin has occurred when the bacterial RNA polymerase enzymes mutate, he says, which find them unaffected by antibiotics that work by prohibiting RNA synthesis. The new method works to modify the drug so it can bind to the mutated enzyme.

Researchers report the process could help them create a wide variety of analogs that will be tested for their efficiency as new antibiotics to fight the threat of MDR strains of TB.