Free-living amoebae (FLA) are ubiquitous protozoa commonly found in water and soil environments. FLA belonging to various genera, including Acanthamoeba, Balamuthia, Naegleria, and Vermamoeba, can cause opportunistic and non-opportunistic infections in humans and animals such as keratitis or meningoencephalitis. In addition, some of them serve as hosts for a large number of pathogenic bacteria, yeasts, and viruses. The purpose of the present study was to assess the prevalence and molecular characterization of FLA in well water samples in İstanbul. Ten well water samples were collected from the taps and the presence of FLA was monitored both by the culture and polymerase chain reaction methods. FLA were isolated in 8 out of the 10 samples (80%) included in this study. Morphological analysis and partial sequencing of the 18S rDNA revealed the presence of Acanthamoeba genotypes T3 and T4, and Vermamoeba vermiformis in the investigated well water samples. This study reports for the first time the detection of Acanthamoeba genotype T3 in well water samples in İstanbul. The presence of potentially pathogenic amoebae in habitats related to human activities supports the relevance of FLA as a potential public health concern.

自由生活的变形虫（FLA）是普遍存在于水和土壤环境中的原生动物。FLA属于不同属，包括棘阿米巴，Balamuthia原虫，福氏耐格里和Vermamoeba，可引起人和动物的机会性和非机会性感染，例如角膜炎或脑膜脑炎。另外，它们中的一些充当大量病原性细菌，酵母和病毒的宿主。本研究的目的是评估伊斯坦布尔水井样品中FLA的发生率和分子特征。从水龙头收集十个井水样品，并通过培养和聚合酶链反应方法监测FLA的存在。在这项研究中，从10个样本中的8个（80％）中分离出FLA。形态分析和18S rDNA的部分测序表明，存在棘阿米巴基因型T3和T4，以及Vermamoeba vermiformis在调查的井水样品中。这项研究首次报道了在伊斯坦布尔的井水样品中检出棘阿米巴基因型T3。与人类活动有关的栖息地中存在潜在致病性变形虫，这支持FLA作为潜在的公共卫生问题的相关性。