Padua Mark F F E, Masangkay Frederick Ramirez, Alejandro Grecebio Jonathan D, Milanez Giovanni De Jesus
The Graduate School, University of Santo Tomas, Manila 1015, Philippines; Department of Medical Technology, Far Eastern University, Manila 1008, Philippines.
Department of Medical Technology, Faculty of Pharmacy, University of Santo Tomas, Manila 1015, Philippines E-mail:
J Water Health. 2023 Jan;21(1):138-146. doi: 10.2166/wh.2023.258.
Research on free-living amoebae (FLA) and its public health implication as an etiologic agent of parasitic infection in humans has recently gained traction in the Philippines. This study aimed to identify potential FLAs in collected groundwater samples from Masinloc, Zambales, Philippines. Fifty-four (54) water samples were collected in 250-mL sterile polyethylene containers by purposive sampling from selected groundwater sources in six (6) barangays of Masinloc. The samples were vacuum filtered through a 1.2-μm pore glass microfiber filter, cultured onto non-nutrient agar (NNA) lawned with Escherichia coli, and observed microscopically for amoebic growth for 14 days using light microscopy. Amoebic growth was observed in 11.1% (6/54) of water samples. DNAs from positive samples were extracted and were made to react with polymerase chain reaction using Acanthamoeba-specific JDP1 (5'-GGCCCAGATCGTTTACCGTGAA-3') and JDP2 (5'-TCTCACAAGCTGCTAGGGAGTCA-3') primers, and universal primer Euk A (5'-AACCTGGTTGATCCTGCCAGT-3') and Euk B (5'-TGATCCTTCTGCAGGTTCACCTAC-3'). The presence of Acanthamoeba genotypes T4, T7, and T11 was confirmed using molecular and phylogenetic analysis. Our results confirmed that groundwater sources from two of six sampling sites (33.3%) in Masinloc, Zambales, were contaminated with potentially pathogenic FLAs. Proper identification of risk factors that may cause contamination consequently leads to the implementation of programs that will prevent future infections.
对自由生活阿米巴（FLA）及其作为人类寄生虫感染病原体的公共卫生影响的研究最近在菲律宾受到关注。本研究旨在确定从菲律宾三描礼士省马辛洛克采集的地下水样本中的潜在FLA。通过有目的抽样，从马辛洛克6个 barangays 的选定地下水源采集了54个250毫升无菌聚乙烯容器中的水样。样本通过1.2微米孔径的玻璃微纤维过滤器进行真空过滤，接种在接种有大肠杆菌的非营养琼脂（NNA）上，并使用光学显微镜在14天内进行显微镜观察以检测阿米巴生长。在11.1%（6/54）的水样中观察到阿米巴生长。从阳性样本中提取DNA，并使用棘阿米巴特异性引物JDP1（5'-GGCCCAGATCGTTTACCGTGAA-3'）和JDP2（5'-TCTCACAAGCTGCTAGGGAGTCA-3'）以及通用引物Euk A（5'-AACCTGGTTGATCCTGCCAGT-3'）和Euk B（5'-TGATCCTTCTGCAGGTTCACCTAC-3'）进行聚合酶链反应。通过分子和系统发育分析确认了棘阿米巴基因型T4、T7和T11的存在。我们的结果证实，三描礼士省马辛洛克六个采样点中的两个（33.3%）的地下水源被潜在致病性FLA污染。正确识别可能导致污染的风险因素，进而导致实施预防未来感染的计划。
