Journal of Applied & Environmental Microbiology
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Journal of Applied & Environmental Microbiology. 2020, 8(2), 46-52
DOI: 10.12691/jaem-8-2-2
Open AccessArticle

Pine Species Provide a Niche for Legionella Longbeachae

Stephen T. Chambers1, , Sandy Slow1, Alice Withers1, Michael Chim1, Krista Dawson1, John Clemens2, Trevor Anderson3, Jonathan Williman4, David Murdoch1 and 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

Pub. Date: November 02, 2020

Cite this paper:
Stephen T. Chambers, Sandy Slow, Alice Withers, Michael Chim, Krista Dawson, John Clemens, Trevor Anderson, Jonathan Williman, David Murdoch and 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


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.

legionella longbeachae pine trees season reservoir

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[1]  McKinney, R. M., Porschen, R. K., Edelstein, P. H., Bissett, M. L., Harris, P. P., Bondell, S. P., Steigerwalt, A. G., Weaver, R. E., Ein, M. E., Lindquist, D. S., Kops, R. S., and Brenner, D. J, “Legionella longbeachae species nova, another etiologic agent of human pneumonia”, Annals of internal medicine 94(6). 739-43. June 1981.
[2]  Cameron, S., Roder, D., Walker, C., and Feldheim, J, “Epidemiological characteristics of Legionella infection in South Australia: implications for disease control”, Australian and New Zealand journal of medicine, 21(1). 65-70. February 1991.
[3]  Anon, Centers for Disease Control and Prevention (CDC). “Legionnaires' Disease associated with potting soil--California, Oregon, and Washington”, MMWR Morb Mortal Wkly Rep.1; 49(34). 777-8. May-June 2000.
[4]  Phares, C. R., Wangroongsarb, P., Chantra, S., Paveenkitiporn, W., Tondella, M. L., Benson, R. F., Thacker, W. L., Fields, B. S., Moore, M. R., Fischer, J., Dowell, S. F., and Olsen, S. J, “Epidemiology of severe pneumonia caused by Legionella longbeachae, Mycoplasma pneumoniae, and Chlamydia pneumoniae: 1-year, population-based surveillance for severe pneumonia in Thailand”, Clinical infectious diseases 45(12). e147-55. December 2007.
[5]  Cameron, R. L., Pollock, K., Lindsay, D., and Anderson, E, “Comparison of Legionella longbeachae and Legionella pneumophila cases in Scotland; implications for diagnosis, treatment and public health response”, Journal of medical microbiology, 65 (2). 142-146. February 2016.
[6]  Isenman, H. L., Chambers, S. T., Pithie, A. D., MacDonald, S. L., Hegarty, J. M., Fenwick, J. L., Maze, M. J., Metcalf, S. C., and Murdoch, D. R, “Legionnaires' disease caused by Legionella longbeachae: Clinical features and outcomes of 107 cases from an endemic area”, Respirology (Carlton, Vic.) 21(7). 1292-1299. October 2016.
[7]  Beauté, , and The European Legionnaires' Disease Surveillance Network, “Legionnaires' disease in Europe, 2011 to 2015”, Euro surveillance 22(27). 30566. July 2017.
[8]  Amemura-Maekawa, J., Kura, F., Chida, K., Ohya, H., Kanatani, J. I., Isobe, J., Tanaka, S., Nakajima, H., Hiratsuka, T., Yoshino, S., Sakata, M., Murai, M., Ohnishi, M., and Working Group for Legionella in Japan, “Legionella pneumophila and Other Legionella Species Isolated from Legionellosis Patients in Japan between 2008 and 2016”, Applied and environmental microbiology, 84(18). e00721-18. August 2018.
[9]  Priest, P. C., Slow, S., Chambers, S. T., Cameron, C. M., Balm, M. N., Beale, M. W., Blackmore, T. K., Burns, A. D., Drinković, D., Elvy, J. A., Everts, R. J., Hammer, D. A., Huggan, P. J., Mansell, C. J., Raeder, V. M., Roberts, S. A., Robinson, M. C., Sathyendran, V., Taylor, S. L., Thompson, A. W., Ussher J.E., van der Linden A.J., Williams M.J., Podmore R.G., Anderson T.P., Barratt K., Mitchell J.L., Harte D.J., Hope V.T., and Murdoch D.R, “The burden of Legionnaires' disease in New Zealand (LegiNZ): a national surveillance study”, The Lancet. Infectious diseases 19(7). 770-777. July 2019.
[10]  Murdoch, D. R., Podmore, R. G., Anderson, T. P., Barratt, K., Maze, M. J., French, K. E., Young, S. A., Chambers, S. T., and Werno, A. M, “Impact of routine systematic polymerase chain reaction testing on case finding for Legionnaires' disease: a pre-post comparison study”, Clinical infectious diseases 57(9). 1275-81. November 2013.
[11]  Kenagy, E., Priest, P. C., Cameron, C. M., Smith, D., Scott, P., Cho, V., Mitchell, P., & Murdoch, D. R “Risk Factors for Legionella longbeachae Legionnaires' Disease, New Zealand.” Emerging infectious diseases. 23(7): 1148-1154. July 2017.
[12]  O'Connor, B. A., Carman, J., Eckert, K., Tucker, G., Givney, R., and Cameron, S, “Does using potting mix make you sick? Results from a Legionella longbeachae case-control study in South Australia”, Epidemiology and infection 35(1). 34-9. June 2007.
[13]  Cramp, G. J., Harte, D., Douglas, N. M., Graham, F., Schousboe, M., and Sykes, K, “An outbreak of Pontiac fever due to Legionella longbeachae serogroup 2 found in potting mix in a horticultural nursery in New Zealand”, Epidemiology and infection 138(1). 15-20. January 2010.
[14]  den Boer, J. W., Yzerman, E. P., Jansen, R., Bruin, J. P., Verhoef, L. P., Neve, G., and van der Zwaluw, K, “Legionnaires' disease and gardening”, Clinical microbiology and infection 3(1). 88-91. January 2007.
[15]  Kubota, M., Tomii, K., Tachikawa, R., Harada, Y., Seo, R., Kaji, R., Takeshima, Y., Hayashi, M., Nishimura, T., and Ishihara, K. Nihon Kokyuki Gakkai zasshi “Legionella longbeachae pneumonia infection from home garden soil”, 45(9). 698-703. September 2007.
[16]  Lindsay, D., Brown, A. W., Brown, D. J., Pravinkumar, S. J., Anderson, E., and Edwards, G, “Legionella longbeachae serogroup 1 infections linked to potting compost”, Journal of medical microbiology 61(Pt 2). 218-222. February 2012.
[17]  Picard-Masson, M., Lajoie, É., Lord, J., Lalancette, C., Marchand, G., Levac, É., Lemieux, M. A., Hudson, P., and Lajoie, L, “Two Related Occupational Cases of Legionella longbeachae Infection, Quebec, Canada”, Emerging infectious diseases 22(7). 1289-91. July 2016.
[18]  Steele, T. W., Lanser, J., and Sangster, N, “Isolation of Legionella longbeachae serogroup 1 from potting mixes”, Applied and environmental microbiology 56(1). 49-53. January 1990.
[19]  Steele, T. W., Moore, C. V., and Sangster, N, “Distribution of Legionella longbeachae serogroup 1 and other legionellae in potting soils in Australia”, Applied and environmental microbiology 56(10). 2984-8. October 1990.
[20]  Koide, M., Arakaki, N., and Saito, A, “Distribution of Legionella longbeachae and other legionellae in Japanese potting soils”, Journal of infection and chemotherapy 7(4). 224-7. December 2001.
[21]  Casati, S., Gioria-Martinoni, A., and Gaia, V, “Commercial potting soils as an alternative infection source of Legionella pneumophila and other Legionella species in Switzerland”, Clinical microbiology and infection 15(6). 571-5. June 2009.
[22]  Pravinkumar SJ, Edwards G, Lindsay D, Redmond S, Stirling J, House R, Kerr J, Anderson E, Breen D, Blatchford O, McDonald E, Brown A, “A cluster of Legionnaires' disease caused by Legionella longbeachae linked to potting compost in Scotland, 2008-2009\”, Euro surveillance. 15:19496. February 2010.
[23]  Velonakis, E. N., Kiousi, I. M., Koutis, C., Papadogiannakis, E., Babatsikou, F., and Vatopoulos, A, “First isolation of Legionella species, including L. pneumophila serogroup 1, in Greek potting soils: possible importance for public health”, Clinical microbiology and infection 16(6). 763-6. June 2010.
[24]  Currie, S. L., Beattie, T. K., Knapp, C. W., and Lindsay, D. S, “Legionella spp. in UK composts--a potential public health issue?, Clinical microbiology and infection 20(4). O224-9. April 2014.
[25]  Ellis, D. H., and Pfeiffer, T. J, “Ecology, life cycle, and infectious propagule of Cryptococcus neoformans” Lancet 13. 336(8720). 923-5. October 1990.
[26]  Potočnjak, M., MagdaleniĆ, Z., Dijan, M., RebiĆ, D., & Gobin, I, “Environmental factors affecting the survival of soil dwelling Legionella longbeachae in water”, Annals of agricultural and environmental medicine. 23(3). 452-455. September 2016.
[27]  Halsby, K. D., Joseph, C. A., Lee, J. V., & Wilkinson, P, “The relationship between meteorological variables and sporadic cases of Legionnaires' disease in residents of England and Wales”, Epidemiology and infection.142(11). 2352-9. November 2014.
[28]  Cassell, K., Gacek, P., Warren, J. L., Raymond, P. A., Cartter, M., & Weinberger, D. M, “Association Between Sporadic Legionellosis and River Systems in Connecticut”, The Journal of infectious diseases 217(2): 179-187. January 2018.
[29]  Potočnjak, M., MagdaleniĆ, Z., Dijan, M., RebiĆ, D., & Gobin, I. “Environmental factors affecting the survival of soil dwelling Legionella longbeachae in water.” Annals of agricultural and environmental medicine: AAEM. 23(3). 452-455. September 2016.
[30]  Spencer, S., and Benson, D. M, “Pine bark, hardwood bark compost, and peat amendment effects on development of Phytophthora spp. and lupine root rot”, Phytopathology 72(3). 346-351. July 1982.
[31]  Wright, A. N., Neimiera, A. X., Harris, J. R., Wright, R. D.. “Micronutrient fertilization of woody seedlings essential regardless of pine bark pH.” Journal of Environmental Horticulture. 17(2): 69-72. March 1999)
[32]  Wadowsky, R. M., Wolford, R., McNamara, A. M., & Yee, R. B, “Infection of Tetrahymena pyriformis by Legionella longbeachae and other Legionella species found in potting mixes”, Applied and environmental microbiology 49(5). 1197-205 March 1985.
[33]  Cazalet, C., Gomez-Valero, L., Rusniok, C., Lomma, M., Dervins-Ravault, D., Newton, H. J., Sansom, F. M., Jarraud, S., Zidane, N., Ma, L., Bouchier, C., Etienne, J., Hartland, E. L., and Buchrieser, C, “Analysis of the Legionella longbeachae genome and transcriptome uncovers unique strategies to cause Legionnaires' disease”, PLoS genetics 6(2). e1000851. February 2010.
[34]  Mead, D.J, “Sustainable management of Pinus radiata plantations”, FAO paper 170
[35]  Meerow A.W, “Growth of two subtropical ornamentals using coir (coconut mesocarp pith) as a peat substitute,” HortScience 29(12). 1484-1486. December 1994.