斯文豪氏攀蜥血液寄生蟲：巴氏簇蟲與微血絲蟲在台灣的檢測
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2016
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蜥蜴血液寄生蟲的多樣性是一個尚待探查的領域。過去的研究多僅靠蜥蜴血液抹片呈現的顯微影像鑑定物種，然而血液抹片所能提供的寄生蟲形態特徵相當有限，且僅包含一個生活史階段的特徵，易造成誤判與同物異名（synonyms）的現象。另外，顯微影像技術在低感染強度（intensity）的個體中，較易產生偽陰性（false-negative）結果。近年分子技術的開發，提供了另一種有效檢測血液寄生蟲的方法。本研究發現在台東鯉魚山公園、蘭嶼及綠島等地的斯文豪氏攀木蜥蜴身上，至少存在兩種分屬頂複器門（Apicomplexa）和線蟲門（Nematoda）的血液寄生蟲，由於過去在台灣並沒有相關的研究資料，因此，本研究除了蒐集血液寄生蟲的基礎生態與分子資料外，欲檢測以下問題：（1）所發現的血液寄生蟲其近源類群為何？（2）分子技術與顯微影像技術檢測血液寄生蟲的何者有較高的敏感度？（3）在不同地區所發現的血液寄生蟲是否分屬不同物種？（4）何時是血液寄生蟲盛行率最高的季節？（5）寄生蟲感染與哪些宿主的特徵有關？本研究收蒐集了不同季節6個地點共1,196隻攀蜥，藉由血液抹片、分子鑑定技術與親緣關係重建技術（phylogenetic reconstruction），確認所感染寄生蟲分別為巴氏簇蟲屬（Bartazoon spp.）與盤尾絲蟲科（Onchocercidae spp.）物種。而在形態資料比較上顯示兩種血液寄生
蟲在不同島上皆有顯著差異，然而，仍有待進一步的生活史資料證實，是否分屬為不同物種。巴氏簇蟲（Bartazoon sp.）在春季有最高的盛行率（6%）而微血絲蟲（microfilaria）則在秋季有最高的盛行率（16%）。相對感染風險（Relative Risk）的結果顯示，在蘭嶼的成蜥與幼蜥相比有顯著較高的感染風險（約21倍；95% CI: 7-68）。本研究提供台灣蜥蜴血液寄生蟲首次的發現記載，並成功開發巴氏簇蟲（Bartazoon sp.）的高檢測敏感度（sensitivity）的專一性引子。
Research of saurian blood parasite diversity represents a rather unexplored field. Definition of new species in previous studies based mainly on direct observation on reptile blood smears. However, specimens with low infection intensity could result to false-negative during the evaluation process. In recent years, molecular technique provides novel detection methods with higher precision. In this research, I collected 1,196 lizard specimens from 6 population in different seasons, and recorded at least two different phyla (Apicomplexa and Nematoda) of hemoparasites in Japalura swinhonis from Taitung Liyushan Park, Green Island and Orchid Island. Observation on blood smears, PCR assays and phylogenetic reconstruction indicated that the two blood parasites are close related to Bartazoon spp. and Onchocercidae spp. respectively. Both parasites, Bartazoon spp. and microfilaria, represent genetic similarity but morphological difference between two islands. Bartazoon spp. represent the highest prevalence in Spring (6%), while microfilaria in Autumn (16%). Evaluation on Relative Risk showed that adult lizards had 21 times (95% CI: 7-68) risk of infection by blood parasites compared to juveniles in Orchid Island. This research provides the first records of lizard blood parasites in Taiwan, and successfully improve the detection efficiency of Bartazoon spp. by using molecular techniques.
Research of saurian blood parasite diversity represents a rather unexplored field. Definition of new species in previous studies based mainly on direct observation on reptile blood smears. However, specimens with low infection intensity could result to false-negative during the evaluation process. In recent years, molecular technique provides novel detection methods with higher precision. In this research, I collected 1,196 lizard specimens from 6 population in different seasons, and recorded at least two different phyla (Apicomplexa and Nematoda) of hemoparasites in Japalura swinhonis from Taitung Liyushan Park, Green Island and Orchid Island. Observation on blood smears, PCR assays and phylogenetic reconstruction indicated that the two blood parasites are close related to Bartazoon spp. and Onchocercidae spp. respectively. Both parasites, Bartazoon spp. and microfilaria, represent genetic similarity but morphological difference between two islands. Bartazoon spp. represent the highest prevalence in Spring (6%), while microfilaria in Autumn (16%). Evaluation on Relative Risk showed that adult lizards had 21 times (95% CI: 7-68) risk of infection by blood parasites compared to juveniles in Orchid Island. This research provides the first records of lizard blood parasites in Taiwan, and successfully improve the detection efficiency of Bartazoon spp. by using molecular techniques.
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內寄生蟲, 分子鑑定, 血簇蟲科, 微絲蟲, 舊大陸鬣蜥科, Agamidae, endoparasite, Hemogregarine, Hepatozoon, molecular detection