A Review of Phenotypic and Genotypic Methods for Detection of Drug Resistance in Mycobacterium tuberculosis

Tuberculosis is one of the most dangerous infectious diseases in the world and causes nearly two million deaths each year, especially in developing countries. Meanwhile, multidrug resistance tuberculosis (MDR-TB) is due to the resistance of Mycobacterium tuberculosis (Mtb) strains to two effective first-line drugs, isoniazid and rifampin, which is increasing worldwide. MDR-TB strains are mainly caused by inadequate treatment of TB patients. The emergence and spread of these strains is an obstacle to the control and management of tuberculosis as well as a threat to the World Health Organization's goal of eliminating the disease by 2050. Proper management of MDR-TB relies on early recognition of the disease. Recently, phenotypic and genotypic diagnostic methods have been developed to rapidly identify MDR strains in tuberculosis patients. Some of them are also economically suitable to use in developing countries. Proper treatment of patients with drug-resistant TB requires the rapid detection of resistant strains and appropriate drug administration. Regular monitoring of patients' side effects of medications as well as enhancing the quality of bacterial tests is essential to identify resistant strains. Therefore, in this review, we will describe the available phenotypic and genotypic tests for drug-resistant tuberculosis detection and discuss their advantages and limitations.