台灣南部地區雞傳染性貧血病毒分子流行病學分析

Molecular Epidemiological Analysis of Chicken Anemia Viruses Isolated in Southern Taiwan

黃恭喜(Kung-Hsi Huang)

指導教授 ： 連一洋

國立屏東科技大學/農學院/獸醫學系所/碩士(2015年)

https://doi.org/10.6346/NPUST.2015.00211

摘要

雞傳染性貧血症是由雞隻傳染性貧血病毒所引起，隸屬環狀病毒科之迴旋病毒屬。CAV病毒於任何雞齡均能感染雞隻，尤其是雛雞時期。雞隻感染後會出現貧血、出血及免疫抑制等臨床現象並引起白肉雞及蛋中雞的高致死率，且造成疫苗效力下降，對家禽產業帶來重大的經濟損失。本研究自2013~2014年在台灣地區養雞場採集病例，以CAV VP1及VP2特異引子對以聚合酵素鏈鎖反應技術鑑定出了14個CAV檢體。根據全段基因的親源樹分析，顯示所有2013-2014年所取得的台灣分離株與國外已發表之序列匯整後共可以區分成六種基因群，此六種基因群的序列相似性介於94%到100%之間，基因群III的CAV病毒為主要分群，且近幾年已在台灣造成疫情爆發。雖然大部分的台灣分離株與大陸、日本與韓國等地區的基因型接近，但仍無法證明台灣分離株是從鄰近國家的品系所演化而來。本研究也發現兩個分離株與P4疫苗株極為相似，此乃於3週齡時雞隻不當施打減毒疫苗所造成。目前市售商業CAV活毒疫苗並不推薦施打低於6週齡的雞隻，應確實遵照疫苗製造廠商之使用建議。

關鍵字

雞傳染性貧血病毒 ； 聚合酵素鏈鎖反應 ； 親緣樹分析

並列摘要

The chicken infectious anemia is the disease caused by chicken infectious anemia virus, one of species the family Circoviridae and genus Gyrovirus. The virus can infect chickens of all ages especially young chicks and may develop clinical signs, such as anemia, hemorrhage and immunosuppression. The economic impact of CIA in chicken industry is mainly due to bad performance and increased mortality in broilers and pullets, presence of multiple infections, and bad vaccine efficacy. In this study, 14 CAV isolates were obtained from various locations in Taiwan during 2013-2014, and were genotypically analyzed by using polymerase chain reaction (PCR) with primers specific to the CAV VP1 gene. Our results showed that all Taiwanese isolates collected during 2013–2014, according to the phylogenetic tree, distribute to 6 genotype groups. The sequence identity rate of them was between 94 and 100％. The Group 3 viruses have become dominant and responsible for the majority of Taiwanese outbreaks during recent years. Although most of Taiwanese isolates are closely to those from China, Japan and Korea, it still cannot be fully postulated that these isolates were evolved from previously reported strains obtained in neighbor countries. Two Taiwanese isolates are found to be highly closed to P4 vaccine strain. This is the result because of an inadequate administration of live attenuated vaccine to 3-week-old chicks. Therefore, the usage of commercial CAV live vaccine must follow the manufacture’s recommendation, which is not given chicken with live vaccine less than the age of 6 weeks.

並列關鍵字

Chicken anemia virus ； PCR ； Phylogenetic analysis

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