Isolation and Genotyping of Acanthamoeba Strains from Corneal Scrap

To determine the prevalence and genotype of Acanthamoeba keratitis in patients referred to Farabi reference eye center In this study, corneal scraping specimens that obtained from keratitis patients examined for Acanthamoeba and its genotype identifications. Direct smears, cultivation in non-nutrient agar followed by PCR were chosen as the basic diagnostic methods. The positive patients checked by confocal microscopy. For genotypic identifications of isolates from keratitis patients, DF3 region of rRNA gene amplified in PCR. Five clinical specimens (5.6%) out of 89 collected samples showed positive by culture and PCR analysis. Then the results compared with confocal microscopy and all five patients confirmed for Acanthamoeba keratitis. The statistical analysis showed significance relation between infection with Acanthamoeba and wearing contact lenses (p=0.001). A logistic regression analysis showed, there is an inverse weak statistical relation between age and infection (p=0.07). Sequence analysis demonstrated that T4 is the predominant genotype in these isolates and the primary genotype in keratitis Acanthamoeba infections. All the patients complain from one eye only, and pain, redness, tearing, and light sensitivity were the common clinical symptoms among them. Genotypic identification of the microorganism helps epidemiologists and parasitologists to study the transmission routs of infection in different areas. The results of this study also showed that non-nutrient agar as diagnostic and economical method could be used in areas with low ophthalmic equipment such as confocal microscopy, but time consuming.