Identification of drug resistant tuberculosis

Aims and objectives: Multidrug resistant TB (MDR-TB) and extensively drug resistant (XDR) are responsible for significant obstruction to global control of tuberculosis (TB). Drug resistance in Mycobacterium tuberculosis mainly occurs through chromosomal mutations in genes encoding for drug target or drug activating enzymes. However, alternative mechanisms, such as efflux pumps may also be responsible for drug resistance. Methods: Insight into the mechanisms of drug resistance would help in limiting the disease through the use and development of better diagnostic and therapeutic tools. The importance of rapid and effective methods of identification of drug resistance in M. tuberculosis cannot be over emphasized. Traditional laboratory techniques are time consuming and cumbersome and not sufficiently sensitive or specific to fight this menace. Results: Though rapid molecular methods such as GeneXpert and line probe assays are vital tools in the fight against drug resistant TB, major advances in next generation sequencing (NGS) technology are allowing increasingly rapid and accurate sequencing of entire bacterial genomes, providing unprecedented depth of information. Conclusion: NGS has the ability to cause a revolutionary paradigm shift in the diagnosis of drug resistant tuberculosis and in understanding the evolution of drug resistance. However, certain challenges need to be overcome to enable the use of this promising technology in routine diagnosis and research, especially in resource limited regions of the world.