Dr. Anil Ojha[14]
My lab investigates the molecular basis of persistence of one of the deadliest bacterial pathogens, Mycobacterium tuberculosis (Mtb), which kills over a million people every year. Mtb is the causative agent of human tuberculosis (TB), which has inflicted mankind since the prehistoric era. But even in the age of modern medicine, the only possible treatment of TB is a 6-9 month regimen of three specialized anti-TB antibiotics. This lengthy and complicated treatment is in sharp contrast to a week-long mono-drug treatment for most other bacterial infections.
We are focused on addressing unmet challenges in TB control. Our investigations are addressing questions like: a) what makes Mtb the toughest of all bacterial species, with an ability to tolerate virtually all kinds of stress, and b) how we can shorten the TB treatment?
We are testing a hypothesis that the extraordinary persistence of Mtb against antibiotics is facilitated by the pathogen’s ability to grow in organized multicellular structures, called biofilms. We have developed various molecular tools to visualize the location of drug tolerant persisters inside the biofilms. Using these tools, we are asking how localization and frequency of these persisters are perturbed in vitro and in animal models in genetically defined mutants of biofilms. Using a high-throughput analysis of transposon-insertion mutants, we have performed genome-wide mapping of loci required for either development of biofilm architecture or physiological adaption to the microenvironment within. In one of the potential projects, a student joining my laboratory will investigate in detail one of the loci to identify whether it is required for development of biofilms, or for adaption within biofilms. The techniques in addressing these questions would involve making isogenic deletions in a Mtb strain, tagging the strain with a fluorescent reporter, and analyzing biofilm growth of the deletion mutant by confocal laser scanning microscopy.
In another project, we are investigating the molecular principles of drug resistance in zinc-starved Mtb caused by ribosome hibernation. The REU student joining my lab will also have opportunity to identify new factors involved in the regulation of ribosome hibernation. The potential project will involve ribosome purification and analysis, in vitro translation, genome-wide analysis of transcriptomic responses to ribosome hibernation by RNAseq analysis.