Infection by Clonally Related <i>Mycobacterium abscessus</i> Isolates: The Role of Drinking Water
Rachel Thomson, Nicole E. Wheeler, Rebecca E. Stockwell, Josephine M. Bryant, Steven Taylor, Lex E.X. Leong, Trieu Le, Geraint B. Rogers, Robyn Carter, Laura J. Sherrard, Harry Powell, Graham Simpson, Kirby Patterson-Fahy, Claire Wainwright, R. Andrés Floto, Julian Parkhill, Scott C. Bell
Abstract
Abstract Rationale Mycobacterium abscessus (MABS) group bacteria cause lethal infections in people with chronic lung diseases. Transmission mechanisms remain poorly understood; the detection of dominant circulating clones (DCCs) has suggested the potential for person-to-person transmission. Objectives This study aimed to determine the role of drinking water in the transmission of MABS. Methods A total of 289 isolates were cultured from respiratory samples (n = 231) and drinking water sources (n = 58) across Queensland, Australia. Results Whole-genome sequences were analyzed to identify DCCs and determine relatedness. Half of the isolates (n = 144; 49.8%) clustered with previously described DCCs, of which 30 formed a clade within DCC5. Pan-genomic analysis of the water-associated DCC5 clade revealed an enrichment of genes associated with copper resistance. Four instances of plausible epidemiological links were identified between genomically related clinical and water isolates. Conclusions We provide evidence that drinking water is a reservoir for MABS and may be a vector in the chain of MABS infection.