Legionella

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Related to legionellae: Legionella pneumonia

Legionella

 [le″jun-el´ah]
a genus of gram-negative, aerobic rod-shaped bacteria, the cause of legionellosis. Species include L. micda´dei, the etiologic agent of Pittsburgh pneumonia, and L. pneumo´phila, the etiologic agent of legionnaires' disease and pontiac fever.

Legionella

(lē'jŭn-el'lă),
A genus of aerobic, motile, nonacid-fast, nonencapsulated, gram-negative bacilli (family Legionellaceae) that have a nonfermentative metabolism and require l-cysteine HCl and iron salts for growth; they dwell in water, spread in air, and are pathogenic for humans. Over 40 species have been identified; the type species is Legionella pneumophila.

Legionella

/Le·gion·el·la/ (le″jah-nel´ah) a genus of gram-negative, aerobic, rod-shaped bacteria (family Legionellaceae), normal inhabitants of lakes, streams, and moist soil; they have often been isolated from cooling-tower water, evaporative condensers, tap water, shower heads, and treated sewage. L. micda´dei is the causative agent of Pittsburgh pneumonia. L. pneumo´phila is the causative agent of legionnaires' disease.

Le·gion·el·la

(lējŏ-nelă)
A genus of aerobic, motile, non-acid-fast, nonencapsulated, gram-negative bacilli; they dwell in water and are borne by air; pathogenic for humans. The type species is L. pneumophila.

Le·gion·el·la

(lējŏ-nelă)
A genus of aerobic, motile, non-acid-fast, nonencapsulated, gram-negative bacilli; they dwell in water and are borne by air; pathogenic for humans. The type species is L. pneumophila.

Legionella

(lē´jənel´ə),
n a genus of areobic, motile, non acid-fast, nonencapsulated, gram-negative bacilli that have a nonfermentative metabolism. They are water dwelling, airborne spread, and pathogenic for man.
L. pneumophila,
n the causative agent of Legionnaires' disease.
References in periodicals archive ?
6% of domestic hot water samples, with a mean number of legionellae in positive samples of 1.
Recent studies, however, found that contamination was consistent throughout the year, both in terms of the species of legionellae isolated and in the concentration of organisms (18), suggesting that the occurrence of Legionnaires' disease most frequently in the summer is not necessarily linked to a higher water contamination.
Furthermore, compared with the other legionellae, serogroup 1 was found in water with a lower temperature, less Pseudomonas contamination, and a relatively higher residual chlorine concentration.
Amoebae, the natural hosts of legionellae, have not been controlled successfully in vitro by adding metal (42), suggesting that legionellae survive inside protozoa and are destroyed by metal ions when released into free water.
Legionellae concentrations of 3-7,000 CFU/L could be sufficient to produce one case per year in a susceptible population (43), and these contamination levels correspond to those found in our study at the domestic level.
Birtles RJ, Rowbotham TJ, Raoult D, Harrison TG; Phylogenetic diversity of intra-amoebal legionellae as revealed by 16S rRNA gene sequence comparison.
Current views on the relationships between amoebae, legionellae and man.
Clinical cases have also occurred because of the inhalation of water droplets containing the blue-white fluorescent group of legionellae, e.
However, if the appropriate detection systems are in place to culture and detect nonculturable organisms, it is likely that legionellae will be found in distribution systems (12).
If storing water at 60 [degrees] C is not practical or acceptable or the calorifier is not in use for 1 week or more, raising the temperature of the calorifier water to 70 [degrees] C to 75 [degrees] C for 1 hour will kill legionellae.
Some biocides are effective against legionellae if used in sufficient concentrations for a sufficient time.
Copper-silver ionization can be used to control legionellae in hospital hot-water recirculating systems (16).