First isolation of Legionella pneumophila in Sri Lanka.

To determine the presence of legionellae and species composition of the genus Legionella in Sri Lankan hotel cooling towers, and to determine the previous exposure of hotel workers to Legionella pneumophila.Collection of water samples from 16 cooling towers of air conditioning plants from 7 representative hotels, and blood samples from hotel workers.Department of Bacteriology, Medical Research Institute, Colombo 8.Water samples from 4 (57.4%) hotels selected were positive for legionellae. Five (38.4%) selected cooling towers yielded legionellae with viable counts ranging from 1 to 5 colony forming units (CFU)/ml. 93.7% of the isolates were Legionella pneumophila. Only one hotel worker had significant antibody levels denoting past infection to Legionella pneumophila.Legionella does occur in the Sri Lankan hotel environment and Legionella pneumophila appears to be the most common species.