Molecular epidemiology of tuberculosis in Tasmania and genomic characterisation of its first known multi-drug resistant case

Abstract or Summary

Background The origin and spread of tuberculosis (TB) in Tasmania and the types of strains of Mycobacterium tuberculosis complex (MTBC) present in the population are largely unknown. Objective The aim of this study was to perform the first genomic analysis of MTBC isolates from Tasmania to better understand the epidemiology of TB in the state. Methods Whole-genome sequencing was performed on cultured isolates of MTBC collected from 2014-2016. Single-locus variant analysis was applied to determine the phylogeny of the isolates and the presence of drug-resistance mutations. The genomic data were then cross-referenced against public health surveillance records on each of the cases. Results We determined that 83.3% of TB cases in Tasmania from 2014±2016 occurred in non-Australian born individuals. Two possible TB clusters were identified based on single locus variant analysis, one from November-December 2014 (n = 2), with the second from May-August 2015 (n = 4). We report here the first known isolate of multi-drug resistant (MDR) M. tuberculosis in Tasmania from 2016 for which we established its drug resistance mutations and potential overseas origin. In addition, we characterised a case of M. bovis TB in a Tasmanian-born person who presented in 2014, approximately 40 years after the last confirmed case in the state's bovids.