Related Experiment Videos
Isolation of Legionella pneumophila from water systems: methods and preliminary results
Abstract:
A preliminary survey of water systems in hospitals and hotels showed that Legionella pneumophila may be found in water storage and distribution systems as well as in the recirculating cooling water of air-conditioning plants. Altogether 42 isolates of L pneumophila were made from 31 establishments, six of which were associated with cases of legionnaires' disease but in 25 of which there was no known association with disease. In the six establishments implicated epidemiologically as the source of legionnaires' disease, these organisms were found in each of their water-distribution systems and also in the cooling water from each of the three with cooling towers. In establishments not associated with cases, water from three out of nine cooling towers, four out of 24 taps or showers, and one out of 15 storage tanks was found to contain legionellae. The organisms were isolated by guinea-pig inoculation and subsequent culture of their peritoneal fluid, liver, and spleen. Finding L pneumophila in water systems in the absence of cases of legionnaires' disease should not at present be an indication for attempts at eradication.
Insights
Legionella pneumophila, a cause of legionnaires' disease, was found in hospital and hotel water systems. Its presence in water does not always indicate an active disease outbreak.
Area of Science:
- Environmental Microbiology
- Public Health Microbiology
Background:
- Legionella pneumophila is a bacterium known to cause legionnaires' disease.
- Water systems in buildings can serve as reservoirs for L. pneumophila.
Purpose of the Study:
- To investigate the prevalence of L. pneumophila in water systems of hospitals and hotels.
- To determine the association between L. pneumophila presence and legionnaires' disease cases.
Main Methods:
- Survey of water systems in 31 hospitals and hotels.
- Isolation of L. pneumophila using guinea-pig inoculation and culture.
- Epidemiological investigation of legionnaires' disease cases.
Main Results:
- 42 L. pneumophila isolates were recovered from 31 establishments.
- L. pneumophila was detected in water systems of 6 establishments linked to disease cases.
- The bacterium was also found in 25 establishments without known disease associations.
Conclusions:
- L. pneumophila is present in diverse building water systems, including cooling towers, taps, showers, and storage tanks.
- Detection of L. pneumophila in water systems without associated disease cases should not prompt immediate eradication efforts.