Isolation of Legionella pneumophila from hospital cooling towers

Water from twenty cooling towers from three major hospitals (A, B, C) were screened for the presence of Legionella pneumophila. Three of the water specimens were found to be positive for the organism. Serogroup 1 was isolated from the two cooling towers in Hospital A, while serogroup 4 was isolated from one of the cooling towers in Hospital B, this being the first time L. pneumophila has been isolated in Singapore.