Molecular Identification and Genotyping of Acanthamoeba Isolated from Environmental Sources in Kashan, Central Iran

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.
The aim of the present study was to identify Acanthamoeba genotypes in soil, hospital dust, and stagnant water samples from Kashan, Central Iran.
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.
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.
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.