Detection of Legionella in Hospitals Water Systems

Legionella is one of the most important agents of human’s respiratory infection. Legionella infections exclusively occur from environmental resources and through inhalation of contaminated aerosols. Water supplies of large buildings such as hospitals are often contaminated with Legionella and there are potential risks of transmission to admitted patients. The purpose of this study was detection of Legionella contamination of water systems in hospitals. One hundred-forty water samples collected from different locatopn of different hospitals were transferred properly to the microbiology laboratory. Each sample immediately was concentrated by using among the city of Tabriz membrane filtration system. Then، they were cultured according to standard methods in BCYE Agar (Buffered Charcoal Yeast Extract Agar). In this study، Legionella species was isolated from 8 of 140 samples (5/7%) by culture method. The locations that positives samples were belong to includings: kitchen (3 positive samples) bathroom (3 positive samples) heating system (1 positive sample) and main entrance water (1 positive sample). The results of this study revealed that the hospital water system may serve as a reservoir for Legionella. Due to its serious effects، it is important to make efforts to eliminate Legionella in the water supplies of hospitals.