Investigation of Legionella pneumophila and free living amoebas in the domestic hot water systems in İstanbul

Legionella pneumophila (L. pneumophila), known to cause legionnaires’ disease, has been found in various aquatic environments and man-made water systems. Free living amoebas (FLAs) live in the same environments and can cause infections such as encephalitis, keratitis. Moreover, FLAs play a major role in L. pneumophila transmission. In the present study, the presence of L. pneumophila and FLAs was examined in water and swab samples obtained from shower heads (hot water) in 61 houses in İstanbul. Nonnutrient agar (NNA) was used for isolation of FLAs in all samples and buffered charcoal yeast extract (BCYE) agar with addition of glycine, vancomycine, polymixin, and natamycin (GVPN) was used for isolation of L. pneumophila. These bacteria have been isolated from 21.3% of the houses examined and FLAs from 31%. Of the isolated L. pneumophila, 87.5% were named as L. pneumophila serogroup 2-14 and 12.5% as L. pneumophila serogroup 1. No significant correlation was found between the presence of L. pneumophila and FLAs. A significant correlation was found between the presence of L. pneumophila and the presence of a central heating system.