Laguna de Bay or Laguna Lake is one of the six major lakes in the Philippines to be in close contact with population activities due to the expansion of urban settlements in the immediate cities surrounding the lake, thus pushing the population to settle upon its shores. To date, there are no data showing the biodiversity of free-living amoebae (FLA) present in this lake. The present study aims to isolate and identify the FLA present in Laguna de Bay, Philippines. Thirty subsurface water samples were taken from Laguna De Bay using random purposive sampling in May 2018 and were examined for amoebic growth under light microscopy (LM). Results show that 8 out of 30 (26.6%) water samples were positive for amoebic growth and were further tested for more advanced data and genetic variation of the species. Initial molecular analysis using polymerase chain reaction (PCR) and sequencing showed the presence of potentially pathogenic FLA Naegleria australiensis (MK418954). The detection of potential pathogenic FLA in lakes and dams may prove useful in preventing and controlling possible human infections in the country. More data from this study will aid in public awareness and establishing safety guidelines and control programs.

中文翻译：

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菲律宾的一个主要湖泊中奈斯菌的发生和首次报道。

拉古纳德湾（Laguna de Bay）或拉古纳湖（Laguna Lake）是菲律宾六大与人口活动紧密联系的主要湖泊之一，原因是该湖附近各城市的城市定居点不断扩大，从而迫使人们定居在其海岸上。迄今为止，尚无数据显示该湖中存在的自由活动变形虫（FLA）的生物多样性。本研究旨在分离和鉴定菲律宾拉古纳德湾的FLA。2018年5月，从拉古纳·德湾（Laguna De Bay）随机抽取了30个地下水样，并在光学显微镜（LM）下检查了厌氧菌的生长。结果表明，在30个样本中，有8个（26.6％）的水样生长呈阳性，并进一步测试了该物种的更高级数据和遗传变异。使用聚合酶链反应（PCR）和测序的初步分子分析显示，存在潜在致病性FLA澳洲产Naegleria australiensis（MK418954）。在湖泊和水坝中发现潜在的致病性FLA可能被证明有助于预防和控制该国可能的人类感染。这项研究的更多数据将有助于提高公众意识，并建立安全准则和控制程序。