Application of whole genome sequencing technology in the epidemiology of tuberculosis

Objective To delineate the application of whole genome sequencing technology in the epidemiology of tuberculosis. Methods From 2009 to 2012, nine Mycobacterium tuberculosis that sharing identical variable number of tandem repeats genotype (VNTR) patterns were reported from two TB cases designated hospitals. Both whole-genome sequencing analysis (WGS) and epidemiologic investigations were performed to describe the transmission patterns of these Mycobacterium tuberculosis. Results By WGS analysis, two genomic clusters including 7 and 2 Mycobacterium tuberculosis were noticed, respectively. The cluster of 2 cases possessed more than 15 single nucleotide polymorphisms (SNPs) when compared to the cluster of 7 cases and suggesting that the transmission route was independent. The transmission chain based on the SNPs difference showed the process of the propagation direction and the accumulation of drug resistance mutations in each cluster. Conclusion Using a WGS-based genomic epidemiologic approach, we were able to reconstruct the tuberculosis transmission network, tracing the putative source of the transmission and determining the transmission direction or the missing links. Key words: Tuberculosis; Multidrug-resistance; Whole-genome sequencing