台灣豬生殖和呼吸道綜合症病毒基因變異之研究

Genetic Variation of Porcine Reproductive and Respiratory Syndrome Viruses in Taiwan

沈姝瑜(Shu-Yu Shen) ； 馬尉真(Wei-Jhen Ma) ； 余章游(Chang-You Yu) ； 張志成(Chih-Cheng Chang)

《臺灣獸醫學雜誌》 36卷4期 (2010/12) Pp. 305-314

https://doi.org/10.7009/TVJ.201012.0305

摘要

豬生殖和呼吸道綜合症病毒(porcine reproductive and respiratory syndrome virus; PRRSV)目前主要分為北美及歐洲兩型，依開放讀碼區(open reading frame; ORF)的不同，兩者基因之相似度約在50%-80%間。本研究於2005年7至9月間對台灣北、中、南地區田間共21家豬場，分別各採6週齡豬隻10頭共210個血清樣本，經病毒分離後以間接螢光抗體檢測初步確認病毒分離株，再將所得之分離株利用RT-PCR對PRRSV ORF1b、5、7這3段基因進行增幅、定序，並以DNASTAR軟體比對各分離株之序列差異度。結果得到共42株分離株，將所有分離株和北美標準株VR2332相比對，ORF1b、5和7核苷酸（胺基酸）之差異度分別為0.7% (0%)-8% (11.4%)、11.6% (12.4%)-14.8% (17.4%)和5.4% (4.8%)-9.1% (7.3%)。而和台灣標準株MD001 (accession no. AF035409)相比對，ORF5核苷酸（胺基酸）差異度範圍1.8% (1.5%)-11.9% (11.9%)，ORF7差異度0.3% (0.8%)-8.9% (7.3%)。基因親緣分析結果發現，目前所分離到的台灣PRRSV分離株皆屬於北美型，另外由ORF5基因親緣樹分析顯示，台灣PRRSV可大致區分為5個族群，並有依地理位置分群的現象。本研究結果顯示PRRSV廣泛存在台灣豬場，且病毒株之間具有明顯基因變異性。

關鍵字

豬生殖和呼吸道綜合症 ； 開放讀碼區 ； 基因變異

並列摘要

To investigate the genetic variation of porcine reproductive and respiratory syndrome virus (PRRSV) in Taiwan, 210 blood samples were collected from 21 pig farms from July to November in 2005. PRRSVs were isolated by cell culture and confirmed by indirect immunofluorescent antibody test using SDOW17 monoclonal antibody. Positive samples were performed by RT-PCR and sequencing for PRRSV ORF1 b, 5, and 7. Then, genetic variation was analyzed by DNASTAR software. Totally, forty-two viruses were isolated. Compared with VR2332, divergence of ORF1b, 5 and 7 were ranged from 0.7% (0%)-8% (11.4%), 11.6% (12.4%)-14.8% (17.4%), and 5.4% (4.8%)-9.1% (7.3%) at nucleotide (amino acid) level, respectively. When compared with MD-001, the divergence of ORF5 and 7 were ranged from 1.8% (1.5%)-11.9% (11.9%) and 0.3% (0.8%)-8.9% (7.3%) at nucleotide (amino acid) level respectively. Phylogenetic analyses of these 42 ORF5 fragments indicated that Taiwan PRRSVs belonged to the North American-type and formed at least 5 major genetic clusters distinctively distributed in Taiwan pig farms. We conclude that PRRSVs were widely prevailed in Taiwan pig farms in 2005 and distinctly genetic variation were revealed among these isolates.

並列關鍵字

generic variations ； open reading frame ； PARSV