Genomic analysis of globally diverse Mycobacterium tuberculosis strains provides insights into the emergence and spread of multidrug resistance

Nat Genet. 2017 Mar;49(3):395-402. doi: 10.1038/ng.3767. Epub 2017 Jan 16.

Abstract

Multidrug-resistant tuberculosis (MDR-TB), caused by drug-resistant strains of Mycobacterium tuberculosis, is an increasingly serious problem worldwide. Here we examined a data set of whole-genome sequences from 5,310 M. tuberculosis isolates from five continents. Despite the great diversity of these isolates with respect to geographical point of isolation, genetic background and drug resistance, the patterns for the emergence of drug resistance were conserved globally. We have identified harbinger mutations that often precede multidrug resistance. In particular, the katG mutation encoding p.Ser315Thr, which confers resistance to isoniazid, overwhelmingly arose before mutations that conferred rifampicin resistance across all of the lineages, geographical regions and time periods. Therefore, molecular diagnostics that include markers for rifampicin resistance alone will be insufficient to identify pre-MDR strains. Incorporating knowledge of polymorphisms that occur before the emergence of multidrug resistance, particularly katG p.Ser315Thr, into molecular diagnostics should enable targeted treatment of patients with pre-MDR-TB to prevent further development of MDR-TB.

MeSH terms

  • Antitubercular Agents / therapeutic use
  • Bacterial Proteins / genetics
  • Catalase / genetics
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Genomics / methods
  • Humans
  • Isoniazid / therapeutic use
  • Mutation / genetics
  • Mycobacterium tuberculosis / drug effects
  • Mycobacterium tuberculosis / genetics*
  • Polymorphism, Genetic / genetics
  • Rifampin / therapeutic use
  • Tuberculosis, Multidrug-Resistant / drug therapy
  • Tuberculosis, Multidrug-Resistant / genetics*

Substances

  • Antitubercular Agents
  • Bacterial Proteins
  • Catalase
  • katG protein, Mycobacterium tuberculosis
  • Isoniazid
  • Rifampin