en انگل شناسی Parasitology پژوهشي Research <div style="text-align: justify;"><strong>Background and Aims:</strong> Amoebae of the genus <em>Acanthamoeba</em> are unicellular amphizoic opportunistic pathogens that may cause fatal granulomatous encephalitis, eye keratitis, amebic pneumonitis and skin nodules as well as abscesses in humans and animals. <em>Acanthamoeba</em> <em>keratitis</em> is caused by trauma to the eye, contaminated cleaning solutions and the use of contact lenses. The aim of the present study was to identify the genotypes of <em>Acanthamoeba</em> in all patients with a clinical diagnosis of <em>Acanthamoeba</em> <em>keratitis</em> referring to eye clinic in Tehran using polymerase chain reaction (PCR).<br> <strong>Materials and Methods:</strong> In this study, samples were collected from 35 patients who had referred to the eye clinic and were cultured on 1.5% non-nutrient agar. DNA was extracted, and then PCR amplification was performed using genus specific primers. Sequencing analysis and basic local alignment search tool search were conducted to determine the genotypes. Phylogenetic tree was generated using maximum likely algorithm in phylogenetic program MEGA version 6.<br> <strong>Results:</strong> Eight cases were positive for <em>Acanthamoeba</em> using genus specific primer pairs. All specimens were reported as genotype T4.<br> <strong>Conclusions:</strong> Determination of genotypes showed all isolates belonging to genotype T4; this abundance may be due to its higher prevalence in the environment or its greater virulence<span dir="RTL">.</span> However, further analysis of clinical and environmental samples is necessary to clarify this property.</div> Acanthamoeba, Genotyping, Keratitis, PCR 259 265 http://ijml.ssu.ac.ir/browse.php?a_code=A-10-305-2&slc_lang=en&sid=1 Tooran Nayeri Chegeni توران نیری چگنی tooran.nayeri@ modares.ac.ir 0000-0001-5766-0120 No Department of Parasitology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. دانشگاه تربیت مدرس Fatemeh Ghaffarifar فاطمه غفاری فر ghafarif@modares.ac.ir 0000-0003-0891-8214 Yes Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran. دانشگاه تربیت مدرس Majid Pirestani مجید پیرستانی pirestani@modares.ac.ir 0000-0003-0046-4772 No Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran. دانشگاه تربیت مدرس Fariba khoshzaban فریبا خوش زبان fkhosh_99@yahoo.com 0000-0003-2738-0552 No Department of Parasitology, Shahed University of Medical Sciences, Tehran, Iran. دانشگاه علوم پزشکی شاهد Abdolhossein Dalimi Asl عبدالحسین دلیمی اصل dalimi_a@modares.ac.ir 0000-0001-5591-5513 No Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran. دانشگاه تربیت مدرس Nahid Maspi ناهید ماسپی mmaspi82@gmail.com 0000-0002-3607-6598 No Department of Parasitology, Faculty of Paramedicine, Ilam University of Medical Sciences, Ilam, Iran. ایلام