Molecular epidemiology of multi- and extensively-drug-resistant Mycobacterium tuberculosis in Ireland, 2001–2014 - 20/12/17
Highlights |
• | Prevalence of MDR/XDR-TB in Ireland, while low, still poses a threat to Public Health. |
• | High lineage diversity was found among MDR/XDR-TB strains. |
• | “Cross-border” European Union strains have been found in Ireland. |
• | Evidence of in vivo micro-evolution of strains was found during the study. |
• | Putative transmission between an Irish-born patient and a non-Irish born patient was discovered. |
Summary |
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.
Le texte complet de cet article est disponible en PDF.Keywords : Tuberculosis, Molecular epidemiology, Drug resistance
Plan
Vol 76 - N° 1
P. 55-67 - janvier 2018 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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