isolation of legionella pneumophila from tehran hospital water samples

over a period of three months (summer), 108 samples of water collected from four hospitals in te-hran. they were taken from numerous potable and non-potable water, including main supply cis-terns, calorifiers, hot and cold tap water, shower, cooling tower and drain of air condition system. culturing of concentrated and non-concentrated water samples on buffered charcoal yeast extract (bcye) agar and selective bcye agar yielded one strain of legionella pneumophila. it was found in cooling tower drain of one hospitals. the strain isolated belonged to sero-group 4 (portland-1 strain). it was also atypical being hippurate negative.