- 學位論文
花蓮伴侶動物外寄生蜱蟲、野生小型哺乳動物及其外 寄生蜱蟲之嗜吞噬球無形體分子檢測
Molecular detection of Anaplasma phagocytophilum in companion animals’ ticks, free ranging small mammals and their ectoparasitic ticks in Hualien
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摘要
蜱蟲為動物的主要體外寄生蟲，也是多種病原體的傳播媒介，包括無形體(Anaplasma spp.) 、艾利希氏體 (Ehrlichia spp.) 和立克次體 (Rickettsia spp.)等，對人類健康造成危害。近年來，隨著飼養伴侶動物的人數上升，新興蟲媒傳染病在全球公共衛生的重要性日漸增加。動物提供蜱蟲血液來源，使其成為病原體的宿主，從而影響人類的健康。人類無形體症 (Anaplasmosis) 是一種新興的人畜共通傳染病，其病原體為嗜吞噬球無形體 (Anaplasma phagocytophilum)，由蜱蟲傳播，可感染人類、牛、犬、貓及囓齒類等動物。 本研究目的為透過分子技術檢測花蓮伴侶動物外寄生蜱蟲、野生小型哺乳動物脾臟及其外寄生蜱蟲之嗜吞噬球無形體。於2021年和2023年，分別自伴侶動物和小型哺乳動物採集共115隻和23隻蜱蟲樣本，蜱蟲種類包含板齒鼠血蜱 (Haemaphysalis bandicota)、豪豬血蜱 (Haemaphysalis hystricis)、粒型硬蜱 (Ixodes granulatus)、鐮型扇頭蜱 (Rhipicephalus haemaphysaloides) 和血紅扇頭蜱 (Rhipicephalus sanguineus)。此外，所採集之41隻野生小型哺乳動物中，包括8隻赤背條鼠 (Apodemus agrarius)、11隻小黃腹鼠 (Rattus losea)、6隻溝鼠 (Rattus norvegicus) 和16隻臭鼩 (Suncus murinus)。伴侶動物收集之115隻蜱蟲中，無形體科 (Anaplasmataceae) 和立克次體的盛行率分別為84.3% (97/115) 和2.6% (3/115)。基因序列比對顯示，在1隻血紅扇頭蜱和2隻豪豬血蜱中檢測到艾利希氏體；此外，於豪豬血蜱中檢測到片狀邊蟲 (Anaplasma platys)與嗜吞噬球無形體，且於3隻豪豬血蜱中檢測到立克次體陽性，經由gltA、ompA、ompB和sca4基因分析，發現一立克次體物種Rickettsia sp. HH-1。同時，2023年所採集的41隻野生小型哺乳動物脾臟和23隻蜱蟲中，無形體科於蜱蟲與野生小型哺乳動物脾臟之盛行率為0% (0/23) 和19.5% (8/41)。嗜吞噬球無形體於3隻赤背條鼠和2隻小黃腹鼠檢出，並於2隻小黃腹鼠和1隻臭鼩檢測出Neoehrlichia mikurensis，依據16S rDNA 基因擴增片段顯示小型哺乳動物中之嗜吞噬球無形體和N. mikurensis與臺灣小黃腹鼠脾臟中之嗜吞噬球無形體 (Accession no.: MK394178) 以及中國小黃腹鼠脾臟之N. mikurensis (Accession no.: MH722225) 之序列具有100% 相似度。以上結果顯示，嗜吞噬球無形體、立克次體和艾利希氏體存在於花蓮地區之蜱蟲和野外小型哺乳動物。在健康一體 (One Health) 的概念下，高盛行率之無形體科和多種病原體表明，飼主應更加重視動物身上之蜱蟲和蜱媒傳疾病。
並列摘要
Ticks are the primary ectoparasites of animals and serve as vectors for multiple pathogens, including Anaplasma, Ehrlichia, and Rickettsia spp., making threats to human health and animal health. Emerging vector-borne zoonoses have increased public health importance worldwide, as the number of people raising companion animals has risen in recent years. Animals provide blood sources for ticks, hence becoming a reservoir for pathogens and may damage either human or animal health. The aim of the study was to identify Anaplasma phagocytophilum via molecular diagnostic techniques in companion animals’ ticks, free ranging small mammals and their ectoparasitic ticks in Hualien, eastern Taiwan by PCR. In 2021 and 2023, a total number of 115 and 23 ticks were collected as samples from companion animals and small mammals, respectively. Tick species included Haemaphysalis bandicota, Haemaphysalis hystricis, Ixodes granulatus, Rhipicephalus haemaphysaloides and Rhipicephalus sanguineus.A total of 41 free ranging small mammals were observed, including 8 Apodemus agrarius, 11 Rattus losea, 6 Rattus norvegicus, and 16 Suncus murinus. Of the 115 ticks sourced from companion animals in 2021, the prevalence rate of Anaplasmataceae and Rickettsia were 84.3% (97/115) and 2.6% (3/115), respectively. Gene pairwise comparison showed Ehrlichia spp. was found in 1 R. sanguineus and 2 H. hystricis. On the other hands, Anaplasma platy and A. phagocytophilum were found in H. hystricis. Meanwhile, the results of pairwise comparison in gltA, ompA, ompB and sca4 gene suggested a novel Rickettsia species, Rickettsia sp. HH-1, in H. hystricis. Of the 41 small mammals’ spleens and 23 ticks collected in 2023, 0% (0/23) of ticks and 19.5% (8/41) of small mammals were infected with Anaplasmataceae. As a result, A. phagocytophilum were detected in 3 A. agrarius and 2 R. losea. Besides, Neoehrlichia mikurensis were detected in 2 R. losea and 1 S. murinus. The 16S rDNA amplicons showed 100% identical to A. phagocytophilum clone 10699S (Accession no.: MK394178.1) isolate from spleen in R.losea in Taiwan and 100% identical to N. mikurensis strain JXRLSY-59 (Accession no.: MH722225) isolate from spleen in R. losea in China. These results demonstrate the presence of ticks and small mammals infected with A. phagocytophilum, Ehrlichia spp. and Rickettsia spp. in Hualien. Under the One Health concept, the high prevalence of Anaplasmataceae and various species of other pathogens indicates that pet owners should pay more attention to ticks on animals and tick-borne diseases.
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