Abstract
Free-living amoeba (FLA) are ubiquitous protozoa that have been isolated from a wide range of environments particularly water and soil. Only Acanthamoeba, Naegleria, Balamuthia and Sappinia genera are responsible for opportunistic and non-opportunistic infections in humans and other animals. Also, FLA serve as reservoirs for several bacteria, virus and protozoa. The present study has been conducted to characterize the distribution of both Acanthamoeba and Naegleria species in water sources and swimming pools in Jeddah city, in addition to determination of the potential risk of human health through bacterial acquisition by these amoebae.
A total of 64 water samples; houses (32), mosques (16) and swimming pools (16) were collected. Water samples were prepared and sterile cotton swaps were cultured on plate of non-nutrient agar supplemented with E. coli for up to 14 days, in addition, negative controls were carried out, each inoculated with sterile distilled water. And respectively, the total positive samples were 32.8%; houses were 31.25%, mosques were 31.25% and swimming pool achieved 37.5%. Acanthamoeba accounted for 80.95% from the total positives while Naegleria was 19.05%. On examining some positive samples of FLA with electron microscope there were many specimens which showed intracellular micro-organisms which are needed to be further identified by polymerase chain reaction or through specific probes.