Legionella longbeachae explained

Legionella longbeachae is one species of the family Legionellaceae. It was first isolated from a patient in Long Beach, California. It is found predominantly in potting soil and compost. Human infection from L. longbeachae is particularly common in Australia,^{[1] [2] [3]} but cases have been documented in other countries including the United States,^[4] Japan,^[5] Greece^[6] and the UK.^[7]

Like other Legionella species, person-to-person transmission has not been documented, but unlike other species, the primary transmission mode has not been proven, but likely is inhalation or aspiration of dust from contaminated compost or soil that contains the organism causing legionellosis.^[8]

Modes of transmission include poor hand-washing practices after gardening, long-term smoking, and being near dripping, hanging flower pots.^[9] Awareness of a possible health risk with potting mix protected against illness.^[9] Inhalation and ingestion are possible modes of transmission.^[9] Exposure to aerosolized organisms and poor gardening hygiene may be important predisposing factors to L. longbeachae infection.^[9]

Compost and potting mix warning labels

Taxid:	1393
Ploidy:	haploid
Chromosomes:	1
Size:	4.14 Mb
Year:	2009

Compost must be handled with care, damped down with water to reduce dust before handling, and use of a face mask covering the nose and mouth to reduce the risk of inhaling the dust is needed, especially for those at high risk from infection.

Studies advocate the introduction of an industry standard that ensures the use of face masks when handling potting mix and attaching masks and warning labels to potting mix bags sold to the public.^[10]

Compost packaging in Australia has an L. longbeachae warning label. The New South Wales state government recommends that people reduce exposure to potting mix dust by following the manufacturers' warning present on potting mix labels, including:

• Wetting down the potting mix to reduce the dust
• Wearing gloves and a P2 mask when using potting mix
• Washing hands after handling potting mix or soil, and before eating, drinking or smoking^[11]

Symptoms

Early symptoms include fever, chills, headache, shortness of breath, sometimes dry cough, and muscle aches and pain.^[12]

Most people who breathe in the bacteria do not become ill. The risk of disease is increased with increased age and smoking, and in people with weakened immune systems.^[12]

External links

• Tasmanian Health and Human Services Legionella page
• Type strain of Legionella longbeachae at BacDive - the Bacterial Diversity Metadatabase

Notes and References

1. Alli OA, Zink S, von Lackum NK, Abu-Kwaik Y . Comparative assessment of virulence traits in Legionella spp . Microbiology . 2003 . 631–41 . 149 . Pt 3 . 12634332 . 10.1099/mic.0.25980-0 . free .
2. Grove DI, Lawson PJ, Burgess JS, Moran JL, O'Fathartaigh MS, Winslow WE . An outbreak of Legionella longbeachae infection in an intensive care unit? . J Hosp Infect . 2002 . 250–8 . 52 . 4 . 12473468 . 10.1053/jhin.2002.1322 .
3. Korman . TM. . Fuller . A. . Ibrahim . J. . Kaye . D. . Bergin . P. . Fatal Legionella longbeachae infection following heart transplantation. . Eur J Clin Microbiol Infect Dis . 17 . 1 . 53–5 . Jan 1998 . 10.1007/BF01584366. 9512185 .
4. Legionnaires' disease associated with potting soil--California, Oregon, and Washington, May-June 2000. . MMWR Morb Mortal Wkly Rep . 49 . 34 . 777–8 . Sep 2000 . 10987244 . Centers for Disease Control and Prevention (CDC) .
5. Kubota . M. . Tomii . K. . Tachikawa . R. . Harada . Y. . Seo . R. . Kaji . R. . Takeshima . Y. . Hayashi . M. . Nishimura . T. . [Legionella longbeachae pneumonia infection from home garden soil] . Nihon Kokyuki Gakkai Zasshi . 45 . 9 . 698–703 . Sep 2007 . 17929472 .
6. Velonakis . EN. . Kiousi . IM. . Koutis . C. . Papadogiannakis . E. . Babatsikou . F. . Vatopoulos . A. . First isolation of Legionella species, including L. pneumophila serogroup 1, in Greek potting soils: possible importance for public health. . Clin Microbiol Infect . 16. 6. 763–6. Sep 2009 . 10.1111/j.1469-0691.2009.02957.x . 19747214 . free .
7. News: Gardeners warned about Legionnaire's risk . BBC News . 2010-09-02.
8. Steele TW, Lanser J, Sangster N . Isolation of Legionella longbeachae serogroup 1 from potting mixes . Appl Environ Microbiol . 1990 . 49–53 . 56 . 1 . 1968736 . 183249 .
9. O'Connor . BA. . Carman . J. . Eckert . K. . Tucker . G. . Givney . R. . Cameron . S. . Does using potting mix make you sick? Results from a Legionella longbeachae case-control study in South Australia . Epidemiol Infect . 135 . 1 . 34–9 . Jan 2007 . 10.1017/S095026880600656X . 16780608 . 2870547 .
10. Cramp . GJ. . Harte . D. . Douglas . NM. . Graham . F. . Schousboe . M. . Sykes . K. . An outbreak of Pontiac fever due to Legionella longbeachae serogroup 2 found in potting mix in a horticultural nursery in New Zealand . Epidemiol Infect . 138. 1. 15 . Sep 2009 . 10.1017/S0950268809990835 . 19781115 . free .
11. Web site: Legionnaires disease Factsheet - NSW Department of Health . www.health.nsw.gov.au . 2009-10-28 .
12. Web site: Media Release: GARDEN ALERT: WARNING TO HANDLE POTTING MIX SAFELY . www.legislation.vic.gov.au . 2009-10-28 .