Origin and Dynamics of Mycobacterium tuberculosis Subpopulations That Predictably Generate Drug Tolerance and Resistance

• DOI: 10.1128/mbio.02795-22
• Publication Date: 2022-11-08T14:00:45Z
• Authors: Jees Sebastian; Anooja Thomas; Carly Levine; Riju Shrestha; Shawn Levy; Hassan Safi; Sri Ram Pentakota; Pradeep Kumar; David Alland
• Keywords: Drug tolerance; Multidrug tolerance

Initial responses to tuberculosis treatment are poor predictors of final therapeutic outcomes in drug-susceptible disease, suggesting that success depends on features hidden within a small minority the overall infecting Mycobacterium population. We developed multitranswell robotic system perform numerous parallel cultures genetically barcoded M. exposed steady-state concentrations rifampicin uncover these difficult-to-eliminate populations. found tolerance emerged repeatedly from at least two subpopulations cells, namely, one could not grow solid agar media and second form colonies, but whose kill curves diverged general bacterial population 4 16 days drug exposure, respectively. These tolerant reproducibly passed through phase characterized by multiple unfixed resistance mutations followed emergent some cultures. Barcodes associated with identified an especially privileged subpopulation was rarely eliminated despite 20 even did contain any drug-resistant mutants. The association this evolutionary scenario defined subset barcodes across independent suggested transiently heritable phenotype, indeed, glpK variation mutants were up 16% resistant Drug ΔruvA mutant, consistent importance stress responses. This work provides window into origin dynamics drug-tolerant elimination may be critical for developing rapid resistance-free cures. IMPORTANCE Tuberculosis is unusual among diseases treatments which can rapidly resolve symptoms do predictably lead durable cure unless continued months after all clinical microbiological signs disease have been eradicated. Using novel antibiotic exposure combined chromosomal barcoding, we enter state predisposition develop fixed first cloud mutations. existence difficult-to-eradicate explain need extended regimen tuberculosis. Their identification opportunities test genetic approaches result shorter more effective TB treatments.