牛指狀絲狀蟲診斷性抗原的純化與流行病學調查

外文標題: 
The purification of diagnosis antigen of Setaria digitata and the survey of epidemiology
校院系所: 
國立台灣大學 獸醫學系研究所
指導教授: 
費昌勇
出版年份: 
1994年
主題類別: 
摘要: 

由1992年10月至1994年1月間,來自本省7個縣市34個牛場的牛,於臺灣省 家畜衛生試驗所撲殺時,由腹腔內採集所得之絲狀蟲,經鑑定後發現為 Setaria digitata、Setaria cervi與Setaria marshalli等三種,其中 S. cervi是本省首次在牛體內發現。而在調查的215頭牛有170頭感染指狀 絲狀蟲(S. digitata),感染率達79%;利用雙向免疫擴散法(double immunodiffusion;DID)偵測感染牛血清對蟲體粗抗原(crude somatic antigen)的反應,只有28.5%的檢出率,與剖檢結果相差甚大。取DID陽性 的牛血清純化牛IgG以製備親和層析管柱,再以親和層析管柱抓取蟲體粗 抗原有效的抗原成份;純化的抗原再用DID來比較其與蟲體粗抗原對陽性 牛血清的反應,結果發現兩種抗原屬於部份相同性(partial identity)。 純化抗原的SDS-膠體電泳(SDS-polyacrylamide gel electrophoresis; SDS-PAGE)圖譜較蟲體粗抗原單純,其主要的兩個染色帶出現在24kD與小 於10kD處,而這兩個蛋白質並未出現在蟲體粗抗原的染色帶中。經西方轉 漬(western blot)後,以陽性牛血清做免疫染色,結果僅有43kD的分子同 時存在於蟲體粗抗原與親和層析管柱純化的抗原中,推測此43kD的分子為 蟲體粗抗原中的微量分子,且對酸具抵抗性。另外以抗純化抗原 (anti- purified antigen)的小白鼠抗血清做西方轉漬,結果純化抗原出現許多 於陽性牛血清免疫染色時未出現的呈色帶,未來尚待進一步純化。在蟲體 結節的組織切片免疫染色中,以抗純化抗原的小白鼠抗血清與HRPO染色, 發現純化的抗原主要來自蟲體的表皮組織。

外文摘要: 

During 10/1992 to 1/1994, filariae collected from the abdominal cavity of 215 cattles which came from 34 farms distributing in 7 prefectures sacrificed at Taiwan Provincial Research Institute for Animal Health (TPRIAH) were identified as Setaria digitata, Setaria cervi and Setaria marshalli. This is the first time that S. cervi has been discovered in cattles of Taiwan. Among the cattles surveyed, 79%(n=170) of them contained either free filaria or filarial nodules. A parallel experiment using double immunodiffusion (DID) test against bovine sera from the infected population revealed only 28.5% positive rate, which is much lower than the result of necropsy. To identify the reactive antigen in S. digitata, IgG purified from DID-positive bovine sera was incorporated into affinity column and was used to capture antigen from a crude somatic lysate. The purified antigens and crude somatic antigens were characterized by different methods. DID test showed that both antigens were partially identical when reacted against positive bovine sera. SDS-PAGE of the crude antigens revealed a rather complex pattern; whereas that of the purified antigens revealed two prominent bands, one approximately 24kD and the other smaller than 10kD, which were not detected in SDS-PAGE of the crude antigens. Western blot stained with positive bovine sera revealed a 43kD band shared by both antigens. The 43 kD protein appeared to be acid-resistant, and might exist in low abundance in the worms. Immunohistochemistry of formalin-fixed filarial nodules using mouse sera against purified antigens and peroxidase demonstrated that the purified antigens were located in the cuticle of the worm.