According to the World Health Organization (WHO), there were 465,000 cases of tuberculosis caused by strains resistant to at least two first-line anti-tuberculosis drugs: rifampicin and isoniazid (MDR-TB). In light of the growing problem of drug resistance in Mycobacterium tuberculosis across laboratories worldwide, the rapid identification of drug-resistant strains of the Mycobacterium tuberculosis complex poses the greatest challenge. Progress in molecular biology and the development of nucleic acid amplification assays have paved the way for improvements to methods for the direct detection of Mycobacterium tuberculosis in specimens from patients. This paper presents two cases that illustrate the implementation of molecular tools in the recognition of drug-resistant tuberculosis.
