WHOLE-GENOME SEQUENCING TO STUDY THE GENOTYPIC CHARACTERISTICS OF MULTIDRUG-RESISTANT TUBERCULOSIS MYCOBACTERIA

Abstract

Tuberculosis (TB) remains one of the world’s major public health problems. Although the use of effective treatment protocols allows the successful treatment of most TB cases, challenges remain in the treatment of multidrug-resistant tuberculosis (MDR-TB). MDR-TB treatment is more complicated, more expensive and less effective than standard TB treatment. In order to effectively combat this threat, a detailed study of the genotypic (arrangement of genes) and phenotypic characteristics of MDR-TB mycobacteria is necessary. Whole-genome sequencing is a powerful tool to analyze the genomes of MDR-TB isolates and identify genetic differences associated with drug resistance. This methodology provides the opportunity not only to identify specific mutations associated with drug resistance but also to reveal a broader spectrum of genotypic features that may be associated with the phenotypic features of MDR-TB. Several studies using this methodology have yielded useful insights into the genotypic diversity of MDR-TB. In addition to known resistance-determining mutations, new, previously undiscovered mutations that may influence the MDR-TB phenotype have been identified. It has also been observed that unique MDR-TB genotype profiles exist in different geographic locations. Such genotypic diversity of TB mycobacteria shows that whole genome sequencing can be useful for better understanding the spread and transmission of MDR-TB in different regions of the world.