Phenotypically profiling a Mycobacterium bovis mutant library, through a chemical-genetic screening

Mycobacterium tuberculosis and M. bovis BCG can adapt to various chemical and environmental stresses and thereby evade therapeutic treatment. The genetic basis for this response remains mysterious, as up to 40% of the genome is unannotated and functional classification of many important genes remains elusive. High-throughput reverse chemical genetics have proven immensely powerful in dissecting and annotating the gene-network of complex cellular processes. I will use this technology to gain a detailed, genome-wide stress-response map of the tuberculosis vaccine strain BCG. I will subject a transposon derived, single gene deletion library (~10,000 mutants) to ~300 mycobacterial drugs and environmental perturbations to mimic the harsh environments M. tuberculosis and BCG can encounter. This will generate a comprehensive fitness signature for each mutant and perturbation tested, allowing me to: (i) discover functions for orphan genes, (ii) identify pathways and/or processes involved in antimicrobial resistance and (iii) record drug and mutant responses to identify primary and secondary targets. We envision that those insights may improve antimicrobial therapies for humans and livestock.