Biologie moléculaire : accès libre

Drug Resistance Mechanisms and Molecular Diagnosis Methods for Tuberculosis

Abstract

Tekeba Sisay, Nega Berhane and Deepak Verma

Mycobacterium tuberculosis is the main cause of death worldwide. It has been thought that one third of the world population has been infected with Mycobacterium tuberculosis (MTB). To assure effective treatment, TB is treated with a combination of anti-TB drugs in the strategy called directly observed treatment short-course (DOTS), which is a treatment regimen that may, lasts from six to eight months. Even though DOTS strategy and effective chemotherapy are used in the past decades, drug-resistant TB is the worldwide problem since the introduction of chemotherapy. Especially, drug resistance is recognized as a worldwide problem after the dramatic outbreaks of Multidrug-resistant Mycobacterium tuberculosis (MDR-TB) strains. MDR-TB is a type of drug resistant TB which is developed when MTB strains can withstand at least two potential anti-TB antibiotics, isoniazid and rifampin. Antibiotic resistance can be developed either by natural or acquired mechanisms. Bacterium like Mycobacterium tuberculosis can acquire drug resistance by changing their genetic materials which can be targeted for drug resistance diagnosis for early and rapid diagnosis of drug resistant tuberculosis. Since early disease diagnosis can minimize the risk of transmission and improve the patients’ survival rate, now a day’s molecular techniques have madesignificant progress in the identification of genetic mutations that are related with antibiotic resistance development to offer a rapidly screening of antibiotic resistant M. tuberculosis. Such mutation screening methods include DNA sequencing, hybridization, single strand conformation polymorphism and heteroduplex analysis. The diagnosis of drug resistance with molecular techniques help to avoid unnecessary treatments and reduce health complications.