Legionella pneumophila is an important pathogen and is involved in more than 95% of cases of severe atypical pneumonia. The current study focused on the ablution water in the grand mosque in Makkah as well as water tanks in hotels surrounding the holy mosque. A total of 100 water samples were collected from ablution water in the Haram and the hotels in the central area around the grand mosque and sent to the research laboratory of microbiology, faculty of medicine, university of Umm Al Qura. Samples were filtrated and inoculated onto buffer charcoal-yeast extract agar base and incubated at 37ºC in a CO2 incubator. The plates were examined after seven days of incubation. Isolated organisms were confirmed by using the “Microgen Legionella” (latex agglutination test). Out of the 100 water samples tested, 11 samples were positive for L. pneumophila. All positive water samples were from hotels water tanks. This indicates that this type of bacteria existing in the water sources. So requires further research to cover all sources of water to avoid an outbreak of this infection among the pilgrims. To avoid the possibility of this, constant maintenance of hotel water tanks regularly and the use of chlorine in specific proportions according to recommended specifications can help reduce the spread of these microbial infections.
Keywords: Holy Mosque, Legionella pneumophila, water tanks, environmental