Diversity and evolution of Mycobacterium tuberculosis: Moving to whole-genome- based approaches

Abstract

Genotyping of clinical Mycobacterium tuberculosis complex (MTBC) strains has become a standard tool for epidemiological tracing and for the investigation of the local and global strain population structure. Of special importance is the analysis of the expansion of multi- drug (MDR) and extensively drug-resistant (XDR) strains. Classical genotyping and, more recently, whole-genome sequencing have revealed that the strains of the MTBC are more diverse than previously anticipated. Globally, several phylogenetic lineages can be distin- guished whose geographical distribution is markedly variable. Strains of particular (sub)- lineages, such as Beijing, seem to be more virulent and associated with enhanced resistance levels and fitness, likely fueling their spread in certain world regions. The upcoming gener- alization of whole-genome sequencing approaches will expectedly provide more compre- hensive insights into the molecular and epidemiological mechanisms involved and lead to better diagnostic and therapeutic tools.