[Genotyping of Mycobacterium tuberculosis. An overview of the major research techniques (Part I)]

The recent development of molecular biology methods has substantially improved the identification of many bacterial pathogens, both at the species and strain level. Microbial strain genotyping refers to the process of discriminating among individuals within particular species based on the detection of genomic DNA polymorphisms by means of different molecular markers. Genetic variability arises mainly from genetic recombinations and spontaneous mutations. Each genotyping assay yields strain-specific genetic profiles, allowing assessment of inter-strain relationships. The ability to differentiate between strains, the so-called discriminatory power of particular genotyping methods depends heavily on the type and level of polymorphism detected. In the case of tuberculosis, a wide variety of methods have already been implemented to genotype its causative agent Mycobacterium tuberculosis. Most of these methods are based on the polymorphic repetitive DNA sequences in tubercle bacilli genome. This review briefly recapitulates the major research techniques used for genotyping of M. tuberculosis.