The aim of the present study was to detect free-living amoeba (FLA) in the water resources of Arak, Iran using molecular tools. A total of 154 samples were collected from different water supplies. Molecular analyses, sequencing, and phylogenetic study were conducted to confirm the species and genotypes of FLA. Fisher exact test was used to determine the significance. Of 154 water samples, 19 (12.3%) samples were tested positive for FLA. Three genotypes of Acanthamoeba including T4, subtype D, and T5 were identified among the isolates. The pathogenicity assay showed that the isolate of Acanthamoeba in drinking water was highly pathogenic. Three species of Naegleria, including N. australiensis, N. pagei, and N. gruberi were found among the samples. Six isolates of Vermamoeba were identified as V. vermiformis. Meanwhile, three other species including Vannella sp., Vahlkampfia avara, and Stenamoeba polymorpha were also recovered from the water samples. Statistical analysis showed a significant difference between the various water resources contaminated with FLA. This is the first study to reveal the presence of S. polymorpha in water sources in Iran. According to the findings of the present study, health officials should be beware of potential public health impacts of FLA in water resources.

本研究的目的是使用分子工具检测伊朗阿拉克水资源中的自由生活变形虫 (FLA)。从不同的供水系统共采集了 154 个样品。进行分子分析、测序和系统发育研究以确认 FLA 的物种和基因型。Fisher精确检验用于确定显着性。在 154 个水样中，有 19 个（12.3%）样品的 FLA 检测呈阳性。在分离株中鉴定出三种棘阿米巴基因型，包括T4、D亚型和T5。致病性测定表明，饮用水中的棘阿米巴分离株具有高致病性。Naegleria的 3 种, 包括N. australiensis , N. pagei , 和在样本中发现了N. gruberi 。六株Vermamoeba被鉴定为V. vermiformis。同时，还从水样中回收了其他三种物种，包括Vannella sp.、Vahlkampfia avara和Stenamoeba polymorpha 。统计分析表明，受FLA污染的各种水资源之间存在显着差异。这是第一项揭示伊朗水源中存在多形链球菌的研究。根据本研究的结果，卫生官员应注意 FLA 对水资源的潜在公共卫生影响。