Stephen T. Chambers1,
,
Sandy Slow1,
Alice Withers1,
Michael Chim1,
Krista Dawson1,
John Clemens2,
Trevor Anderson3,
Jonathan Williman4,
David Murdoch1,
Amy Scott-Thomas1 1Department of Pathology and Biomedical Science, University of Otago, Christchurch, Christchurch New Zealand
2School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
3Canterbury Health Laboratories, Christchurch, New Zealand
4Population Health, University of Otago, Christchurch, Christchurch New Zealand
Journal of Applied & Environmental Microbiology.
2020,
Vol. 8 No. 2, 46-52
DOI: 10.12691/jaem-8-2-2
Copyright © 2020 Science and Education PublishingCite this paper: Stephen T. Chambers, Sandy Slow, Alice Withers, Michael Chim, Krista Dawson, John Clemens, Trevor Anderson, Jonathan Williman, David Murdoch, Amy Scott-Thomas. Pine Species Provide a Niche for
Legionella Longbeachae.
Journal of Applied & Environmental Microbiology. 2020; 8(2):46-52. doi: 10.12691/jaem-8-2-2.
Correspondence to: Stephen T. Chambers, Department of Pathology and Biomedical Science, University of Otago, Christchurch, Christchurch New Zealand. Email:
Steve.chambers@otago.ac.nzAbstract
Legionella longbeachae is the commonest cause of Legionnaires’ disease (LD) nationwide in New Zealand (NZ). Most cases occur in spring and summer (October - January) and are associated with the use of commercial potting mix, which usually contains pine bark. L. longbeachae is an environmental organism but its niche has not yet been defined. Bark samples were taken at chest height from trees in three stands of Pinus radiata (Monterey pine) located in the central South Island of NZ. L. longbeachae DNA was detected by qPCR in 28/400 (7%) samples and from 22/50 (44%) different trees. There was a significant difference in the proportion of positive tests by season: summer 0/50 (0%); autumn 0/50 (0%); winter1/50 (2%); spring 22/50 (44%); (p<0.001). Bark samples from non-P. radiata pine species and adjacent mixed species were then tested. More samples from pine species 22/28 (79%) than non-pine species 6/37 (16%) tested positive for L. longbeachae (p<0.001). Pine species appear to be an important ecological niche for L. longbeachae. To our knowledge this is the second human pathogen to have an arboreal niche. The use of bark from P. radiata in commercial potting mix may contribute to the incidence of LD in New Zealand.
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