Abstract
Background Non-tuberculous mycobacteria are environmental microorganisms and opportunistic pathogens in individuals with pre-existing lung conditions such as cystic fibrosis (CF) and non-CF bronchiectasis (BX). Whilst recent studies of Mycobacterium abscessus have identified transmission within single CF centres as well as nationally and globally, transmission of other NTM species is less well studied.
Methods To investigate the potential for transmission of the Mycobacterium avium complex (MAC) we sequenced 996 isolates from 354 CF and non-CF patients at the Royal Brompton Hospital (RBH), London (collected 2013-2016), and analysed them in a global context. Epidemiological links were identified from patient records. Previously published genomes were used to characterise global population structures.
Results We identified putative transmission clusters in three MAC species, although few epidemiological links could be identified. For M. avium, lineages were largely limited to single countries, whilst for M. chimaera, global transmission clusters previously associated with heater cooler units (HCUs) were found. However, the immediate ancestor of the lineage causing the major HCU-associated outbreak was a lineage already circulating in patients.
Conclusions CF and non-CF patients shared transmission chains, although the lack of epidemiological links suggested that most transmission is indirect and may involve environmental intermediates or asymptomatic carriage in the wider population.
Footnotes
This manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.
Conflicts of interest: Julian Parkhill received consulting fees from and holds stock in Next Gen Diagnostics Llc.
Conflicts of interest: Michael Loebinger received consulting fees from Savara, Astra Zeneca, Insmed, Grifols, Zambon, Armarta and 30T. Additionally, he received honoraria from Insmed and Grifols.
Conflicts of interest: No other authors have potential competing interests.
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- Received June 22, 2022.
- Accepted October 22, 2022.
- Copyright ©The authors 2022.
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