University Of Tasmania

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Molecular epidemiology of multi- and extensively-drug-resistant Mycobacterium tuberculosis in Ireland, 2001-2014

journal contribution
posted on 2023-05-19, 12:47 authored by Roycroft, E, O'Toole, RF, Fitzgibbon, MM, Montogmery, L, O'Meara, M, Downes, P, Jackson, S, O'Donnell, J, Laurenson, IF, McLaughlin, AM, Keane, J, Rogers, TR

Objectives: The primary objective of this work was to examine the acquisition and spread of multi-drug resistant (MDR) tuberculosis (TB) in Ireland.

Methods: All available Mycobacterium tuberculosis complex (MTBC) isolates (n = 42), from MDR-TB cases diagnosed in Ireland between 2001 and 2014, were analysed using phenotypic drug-susceptibility testing, Mycobacterial-Interspersed-Repetitive-Units Variable-Number Tandem-Repeat (MIRU-VNTR) genotyping, and whole-genome sequencing (WGS).

Results: The lineage distribution of the MDR-TB isolates comprised 54.7% Euro-American, 33.3% East Asian, 7.2% East African Indian, and 4.8% Indo-Oceanic. A significant association was identified between the East Asian Beijing sub-lineage and the relative risk of an isolate being MDR. Over 75% of MDR-TB cases were confirmed in non-Irish born individuals and 7 MIRU-VNTR genotypes were identical to clusters in other European countries indicating cross-border spread of MDR-TB to Ireland. WGS data provided the first evidence in Ireland of in vivo microevolution of MTBC isolates from drug-susceptible to MDR, and from MDR to extensively-drug resistant (XDR). In addition, they found that the katG S315T isoniazid and rpoB S450L rifampicin resistance mutations were dominant across the different MTBC lineages.

Conclusions: Our molecular epidemiological analyses identified the spread of MDR-TB to Ireland from other jurisdictions and its potential to evolve to XDR-TB.


Publication title

Journal of Infection








Tasmanian School of Medicine


W B Saunders Co Ltd

Place of publication

United Kingdom

Rights statement

© 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

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Socio-economic Objectives

Clinical health not elsewhere classified

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