The Prevalence, Isolation and Morphotyping of Potentially Pathogenic Free-Living Amoebae from Tap Water and Environmental Water Sources in Sivas

Abstract

To our knowledge, there is no study dealing with the prevalence of free-living amoebas (FLA) in water sources in Turkey, previous studies were mostly case presentations. The aim of the present study was to investigate the prevalence of FLA from tap water and natural water sources in different parts of the city. In the study, 250 samples were collected from the city centre, districts and villages. Two litres of water was collected from each source and filtered through a vacuum filtration system. The filter papers were washed in "Page's Amoeba Saline (PAS)" solution and incubated overnight. Filter papers were removed from the tubes and centrifuged; the final pellet was inoculated on non-nutrient agar (NNA) plates. The growth rate of FLA was checked after three days of inoculation and the flagellation test was performed to determine the presence of Naegleria spp. Heat tolerance of isolated strains was checked at 37, 42 and 52°C for the presence of pathogenic Acanthamoeba species. The cyst and trophozoite morphology of amoebas were examined under a light microscope and the genera was identified according to morphotyping keys. FLA were found in 75 (30.0%) of examined water samples. Eleven (4.4%) were identified as Acanthamoeba spp., 25 (10.0%) as Naegleria spp. and 39 (15.6%) as Hartmannella spp. after microscopic examination. Our study revealed that FLA are common inhabitants of household water as they are in the environment, so their own potential risks as well as transferring bacteria as other pathogens is important for human health.