Genotyping of Acanthamoeba Isolated from Soil in Varamin City, Iran

The soil is one of the important sources of Acanthamoeba human infection. Regarding the increasing number of Acanthamoeba keratitis cases in recent years in Iran, more attention to investigating this amoeba now is made. The present study aimed to identify the genotypes of Acanthamoeba in Varamin City using polymerase chain reaction (PCR) technique.

Totally, 18 samples of soil were collected from 12 parks in Varamin City. The samples were filtered using 0.45µm nitrocellulose membrane filters. Then, they were cultured in non-nutrient agar medium 1.5% enriched with killed cultured bacteria Escherchia coli. Genomic DNA was extracted by DNG-plusTM solution and PCR amplification was performed using specific primers to amplify a 500bp 18S rRNA. Sequencing analysis and BLAST search were done for genotype identification of positive samples.

Out of 18 soil samples, 6 isolates (33.3%) were found to be positive for Acanthamoeba in medium by microscopic observation meanwhile 4 isolates (22.2%) were confirmed by Acanthamoeba genus-specific primers. Genotype identification was revealed that all samples belonged to T4 type.

Considering this result, the soil of parks is possible be a risk factor for people, particularly children in this area. Therefore, more attention of public health authorities is recommended.