The compound TB47 is highly bactericidal against Mycobacterium ulcerans in a Buruli ulcer mouse model

Nat Commun. 2019 Jan 31;10(1):524. doi: 10.1038/s41467-019-08464-y.

Abstract

Buruli ulcer (BU) is an emerging infectious disease that causes disfiguring skin ulcers. The causative agent, Mycobacterium ulcerans, secretes toxin called mycolactone that triggers inflammation and immunopathology. Existing treatments are lengthy and consist of drugs developed for tuberculosis. Here, we report that a pyrazolo[1,5-a]pyridine-3-carboxamide, TB47, is highly bactericidal against M. ulcerans both in vitro and in vivo. In the validated mouse model of BU, TB47 alone reduces M. ulcerans burden in mouse footpads by more than 2.5 log10 CFU compared to the standard BU treatment regimen recommended by the WHO. We show that mutations of ubiquinol-cytochrome C reductase cytochrome subunit B confer resistance to TB47 and the dissimilarity of CydABs from different mycobacteria may account for their differences in susceptibility to TB47. TB47 is highly potent against M. ulcerans and possesses desirable pharmacological attributes and low toxicity that warrant further assessment of this agent for treatment of BU.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / therapeutic use*
  • Buruli Ulcer / drug therapy*
  • Buruli Ulcer / microbiology*
  • Electron Transport Complex III / genetics
  • Mice
  • Mutation
  • Mycobacterium ulcerans / drug effects*
  • Mycobacterium ulcerans / genetics
  • Mycobacterium ulcerans / pathogenicity*

Substances

  • Anti-Bacterial Agents
  • Electron Transport Complex III