Development of drug resistant mycobacterium tuberculosisstrains

Background and Aim : It is estimated that ۷۵ million people will die from drug-resistanttuberculosis in the next ۳۵ years. Resistance to drugs used in the treatment of tuberculosis is adanger to the strategies that are deployed to control and eliminate multidrug-resistant tuberculosis(MDR-TB) and extensively drug-resistant tuberculosis(XDR-TB). Drug-resistant Mycobacteriumtuberculosis strains have emerged as a threat to public health, highlighting the need to develop newtuberculosis prevention and treatment strategies. There is a critical need to understand themechanisms of resistance development and access to the genetic diversity of Drug-resistantMycobacterium tuberculosis.Methods : An organized review was completed on original research extracted from PubMed,Elsevier, and Google scholar. The search term ''Tuberculosis AND drug resistance ANDinfectiousness AND reproductive fitness'' were used to identify relevant articles reporting theevolution of drug-resistant tuberculosis.Results : Drug-resistant strains often suffer an initial reduction in fitness, they continue to growby acquiring one or more secondary-site mutations that can improve or even restore the f fitnessof these strains over time; this process is known as compensatory evolution. Importantly, thisprocess happens even in the absence of drug pressure. Strain diversity can influence the outcomeof infection and disease in humans. Extensively drug-resistant tuberculosis has the lowesttreatment success rate among other forms of tuberculosis.Conclusion : The evolution of drug-resistant Mycobacterium tuberculosis depends on factors,such as bacterial fitness, the strain’s genetic background, and its capacity to adapt to thesurrounding environment, and host-specific and environmental factors.