台灣山羊關節腦炎血清學檢測與在初代培養山羊乳汁體細胞中探討抗反轉錄病毒藥物對抗山羊關節腦炎病毒增殖之效力

Abstract

山羊關節腦炎 (Caprine arthritis encephalitis) 是由一種屬於慢病毒屬 (Lentivirinae genus)，反轉錄病毒科 (Retroviridae family) 的RNA病毒所引起。此疾病在臨床上所造成的病理變化有非化膿性免疫媒介性的關節炎、白質腦炎、間質性肺炎以及乳房炎。為了評估目前此疾病在台灣的感染情況，我們使用商業化的ELISA套組檢測來自羊場的樣本。另外，為了評估抗反轉錄病毒藥物使用於山羊關節腦炎病毒感染控制計畫中的可能性，我們建立了一個可讓病毒存活的細胞外模式，此模式採用血清學陽性羊隻羊乳的體細胞所做的初代培養，另外配合使用可增幅山羊關節腦炎病毒env provirus片段的引子對和探針所建立的可定量即時聚合酶鏈鎖反應以監控病毒量。在2332個山羊血清及乳汁當中，血清學陽性比率為67.30%，其中所有被檢測羊場都是陽性場。乳羊場的血清學陽性比率比肉羊場來的高，而母羊的血清學陽性比率比公羊高，於2007年以後出生的羊隻血清學陽性比率明顯較之前的來的低。來自不同羊隻的山羊乳汁體細胞初代培養，其內的病毒變化曲線之型態不盡相同，所以使用不同來源乳汁體細胞初代培養時實驗內必須加入相同來源的控制組。三株投與stavidine的初代培養中有兩株與未投藥組有顯著差異，而三株投與zidovudine的初代培養中有一組與未投藥組有顯著差異。

Caprine arthritis-encephalitis (CAE) is caused by a RNA virus of Lentivirinae genus, Retroviridae family. The disease is clinically and pathologically manifested by nonsuppurative immune-mediated arthritis, leukoencephalitis, interstitial pneumonia and mastitis. To evaluate CAE infection status in Taiwan, a commercialized ELISA kit was selected to exam goat serum and milk as well as tank milk samples from several selected and voluntary goat herds. In addition, an in vitro model of CAEV propagation was established to investigate the efficacy of anti-retroviral agents, zidovudine and stavudine, on CAE virus propagation in caprine milk primary somatic cell culture. Data indicated that among 2332 serum and milk samples, 67% were serologically positive. 129 tank milk samples were all seropositive, in other words, none of the goat herds were serologically negative. The positive rates were higher for dairy goats, female goats, and goats born after 2008 than others. Additionally, real-time PCR for CAE provirus env gene was able to detect at 101 copy number of the target gene. Both zidovudine and stavudine had no significant cytotoxicity between 1mM to 0.1 μM. Among 3 batches of caprine milk primary somatic cell culture, stavudine treatment significantly suppressed CAE virus propagation in 2 of the batches, and zidovudine suppressed 1 batch. Therefore, anti-retroviral agents might be effective on suppressing CAE virus propagation.