隱形眼鏡配戴者其盥洗台及清潔保養液之棘阿米巴分離及基因分型

Abstract

棘阿米巴 ( Acanthamoeba spp. ) 為營自由生活之阿米巴原蟲，分布的環境範圍極廣。水、土壤和空氣都可以發現他們的蹤跡。具有致病性之棘阿米巴蟲株會造成極嚴重的棘阿米巴角膜炎、肉芽腫性阿米巴腦炎及其他器官感染。本實驗收集了197組隱形眼鏡配戴者盥洗台及清潔保養液之檢體作棘阿米巴之培養。此外，也收集了台大醫院自2006年9月~2008年6月，從患者角膜刮取物所分離出來之棘阿米巴原蟲。所得蟲株並進行18S rRNA基因序列分析以確定其基因型。我們從盥洗台分離出17株棘阿米巴，從病人角膜刮取物分離出7株棘阿米巴；隱形眼鏡盒、生理食鹽水、隱形眼鏡清潔保養液及拋棄式隱形眼鏡則皆未培養出棘阿米巴原蟲。 18S rRNA 基因分型之結果顯示：19株屬T4型，3株為T3型，而2株為T6型。我們所分離出來之棘阿米巴大多屬於T4型，此點與國外研究之結果一致的。

Acanthamoeba is a free-living protozoan genus found in a wide variety of natural habitats, including water, soil, and air. Pathogenic isolates of Acanthamoeba are medically relevant as the causative agent of sight-threatening Acanthamoeba keratitis (AK), serious infections of other organs, and fatal granulomatous amebic encephalitis. A total of 197 sets of contact lens care system and bathroom basin samples from contact lense users were cultured for the isolation of Acanthamoeba. In addition, Acanthamoeba isolates obtained, between September 2006 till June 2008, from cornea scraping of patients suspected of amebic kerattitis were also included in this study. Genotype of the isolates were identified by 18S rRNA gene sequence analysis. We obtained 17 Acanthamoeba isolates from bathroom basin of contact lens users and 7 isolates from patients with keratitis in National Taiwan University Hospital. Acanthamoeba was not detected in contact lens box, normal saline, contact lens care fluid and disposable contact lenses. Among the 24 isolates, 19 were identified as Rns genotype T4 , 3 were Rns genotype T3 and 2 Rns genotype T6. Thus most Acanthamoeba strain isolated from home water supplies of contact lens users and patients with keratitis in National Taiwan University Hospital belong to Rns genotype T4, which agree with findings of similar studies abroad.