Although the presence of free-living amoebae (FLAs) in various water sources has been reported, few studies have been surveyed on their abundance in medical-unit and dental-unit water samples. The current study aimed to identify morphological and molecular characteristics of FLA isolates in the water samples of the dental unit in Iran. A total of 232 water samples were collected from 17 dental units. Then, filtration and cultivation were conducted on a non-nutrient agar (NNA) medium. Also, polymerase chain reaction (PCR) assay and sequencing were performed by using the genus/species-specific primers plus a common primer set on positive samples. One hundred and sixty-six samples were positive for FLA by the microscopic method, whereas 114 samples were positive by the molecular method with a common primer set. Considering the PCR assay with genus/species-specific primers, 23.27% (54/232) samples were identified as Acanthamoeba spp. (belonging to T4 genotype), 36.63% (85/232) as Vermamoeba vermiformis, and 1.72% (4/232) as Vahlkampfiidae family (Naegleria lovaniensis). These results highlight a need to improve filtration systems in dental units and periodic screenings for FLA in dental-unit water.

尽管已经报道了在各种水源中存在自由生活阿米巴 (FLA)，但很少有研究调查它们在医疗单位和牙科单位水样中的丰度。目前的研究旨在确定伊朗牙科单位水样中 FLA 分离株的形态和分子特征。从 17 个牙科单位共采集了 232 个水样。然后，在非营养琼脂（NNA）培养基上进行过滤和培养。此外，聚合酶链式反应 (PCR) 测定和测序是通过使用属/种特异性引物加上对阳性样品的通用引物组进行的。166 份样品通过显微镜法检测为 FLA 阳性，而 114 份样品通过使用普通引物组的分子法检测为阳性。棘阿米巴属 （属于T4基因型），36.63%（85/232）为Vermamoeba vermiformis，1.72%（4/232）为Vahlkampfiidae科（Naegleria lovaniensis）。这些结果强调了改进牙科病房过滤系统和定期筛查牙科病房水中 FLA 的必要性。