Molecular Epidemiology of Tuberculosis

The ability to determine the genotype of Mycobacterium tuberculosis is changing our understanding of the dynamics of tuberculosis transmission. This review summarizes the methods of genotyping and explains how they can assist clinical management. These techniques can be used to evaluate tuberculosis-control programs and provide clues to the pathogenesis of tuberculosis infection. How genotyping can assist in clinical management. The ability to discern the molecular “fingerprint” (genotype) of Mycobacterium tuberculosis isolates has revolutionized our understanding of the transmission of tuberculosis. In this review, we summarize the main methods of determining the genotype and discuss the relevance of genotyping to the control and understanding of the pathogenesis of tuberculosis. Genotyping Methods The standard approach to genotyping M. tuberculosis isolates is restriction-fragment–length polymorphism (RFLP) analysis of the distribution of the insertion sequence IS6110 in different strains, 1 and large data bases of IS6110-based genotypes are available (Figure 1). Isolates from patients infected with epidemiologically unrelated strains of tuberculosis have different RFLP patterns, . . .