Mycobacterium tuberculosis must sense and adapt to environmental cues in order to establish and maintain infection in a host. It does this in part via a signal transduction system called PhoPR.
After screening more than 200,000 compounds, US researchers have identified a drug that inhibits the PhoPR regulon, so it could be used to dampen the virulence of M. tuberculosis infection. The drug is ethoxzolamide — a sulfonamide and carbonic anhydrase inhibitor used to treat glaucoma and duodenal ulcers, and a diuretic.
Having identified the compound, the researchers then showed ethoxzolamide reduced M. tuberculosis growth in both macrophages and infected mice. “We propose that ethoxzolamide may be pursued as a new class of antivirulence therapy,” they write in
Antimicrobial Agents and Chemotherapy
 Johnson BK, Colvin CJ, Needle DB et al . The carbonic anhydrase inhibitor ethoxzolamide inhibits the mycobacterium tuberculosis PhoPR regulon and Esx-1 secretion and attenuates virulence. Antimicrob Agents Chemother 2015;59(8):4436–4445. doi: 10.1128/AAC.00719-15.