Background: Acanthamoeba is one of the most common opportunistic free-living amoebae, with ubiquitous presence in various environmental sources. Pathogenic strains of Acanthamoeba are the causative agents of amoebic keratitis and granulomatous amoebic encephalitis. Objectives: The aim of the present study was to identify Acanthamoeba genotypes in soil, hospital dust, and stagnant water samples from Kashan, Central Iran. Methods: In this cross sectional study, a total of 122 samples from soil (n, 32), hospital dust (n, 40), and stagnant water (n, 50) were collected and examined for the presence of free-living amoebae and Acanthamoeba species. All the samples were cultured onto non-nutrient agar plates for detection of free-living amoebae. Acanthamoeba species was identified by polymerase chain reaction (PCR) assay, using specific primers. A total of 29 Acanthamoeba isolates were sequenced, and different genotypes were detected via sequence analysis. Results:The results showed that 82.8% (101/122) of samples were positive for free-living amoebae. The PCR assay revealed that 62.5%, 52.5%, and 50% of soil, hospital dust, and stagnant water samples were positive for Acanthamoeba species, respectively. Moreover, T4, T5, T2, T7, and T11 genotypes were identified. The most common genotype was T4 (76%), isolated from stagnant water. Conclusions: Acanthamoeba is a prevalent species in the soil, hospital dust, and stagnant water of Kashan. As this protozoon can cause severe infections, health education and improvement of sanitation services are recommended for prevention of infection.

Background and Aims: Acanthamoeba, the causative agent of granulomatous amebic encephalitis)GAE), is among the most prevalent free-living amoebas (FLA) existing in water, soil and dust. This study was conducted to determine FLA and identify Acanthamoeba genotypes isolated from stagnant water in Kashan, Iran. Materials and Methods: In this descriptive study, 138 stagnant water samples were collected from Kashan mosques and public parks. The samples were filtered (0.45µm) and cultured onto non-nutrient agar for the presence of FLA. Acanthamoeba spp. was identified by polymerase chain reaction (PCR) using specific primers, which amplified a 490 bp fragment. Among ten sequenced isolates of Acanthamoeba, different genotypes were determined by sequence analysis. The parameters such as pH, temperature, sampling season and related results were recorded and analyzed using SPSS16. Results: The rate of FLA was 88.4 %, 59.4% of which were confirmed as Acanthamoeba spp. using PCR method. The rate of Acanthamoeba T4 and T2 genotypes were 80% and 20%, respectively. There was a significant relation between FLA rate and sampling season (P= 0.01). The highest rate of FLA and Acanthamoeba was observed at pH 7. There was no significant relationship between FLA and Acanthamoeba spp. with pH and temperature. Conclusions: The rate of FLA and Acanthamoeba in stagnant water were high in Kashan. The dominant Acanthamoeba genotype (T4) is pathogen. Due to serious amoeba-induced complications, hygienic education is recommended to increase the public awareness on transmission and health/preventive measurements.