傳染性支氣管炎病毒序列分析及血清學檢測

Abstract

家禽傳染性支氣管炎是一種高度傳染性的病毒性疾病，主要在雞造成感染。由於此病毒很容易因自發性突變及基因重組而改變，因此世界上有許多不同的毒株。本研究為探討最近傳染性支氣管炎在台灣雞場的盛行率及的基因型。白肉雞樣本為屠宰場採樣之檢體，每場隨機取樣20隻肉雞之氣管進行調查；土雞場樣本為現場疑似病例之檢體，採集疑似發病土雞之氣管進行調查。以反轉錄聚合酶鏈鎖反應檢測是否有病毒感染，再以針對傳染性支氣管炎S1基因上N端HVR1的引子進行反轉錄聚合酶鏈鎖反應，並進行核酸定序及序列分析。結果在台灣2012年11月至2014年1月間之屠宰場隨機採樣場陽性率為39.4%（26/66），且以台灣二型為主要流行之毒株。序列分析後可發現除了台灣毒株及疫苗毒株外，也檢測到之前未在台灣檢測到之類日本毒株，然而此類日本毒株之N基因卻與台灣型毒株較相近。以100-191隻血清進行測試，並以HI test作為標準，評估商品化ELISA套組之可信度。以3263/04之HI test為標準，商品化ELISA之敏感度為43.6%，特異度為92.1%；而以H120之HI test為標準，商品化ELISA之敏感度則為33.8%，特異度為90.6%。本研究結果顯示，台灣IBV毒株基因變異有趨向多樣化的現象。

Avian infectious bronchitis (IB) is a highly contagious viral disease of the chicken. Because IBV can change its genome by spontaneous mutation and genetic recombination easily, many strains emerge all over the world. This study investigated the prevalence and genotypes of IBVs in Taiwan recently. The samples of broilers were collected from poultry slaughter houses and the Taiwan Country chickens from IBV suspected case in the fields. IBV in samples were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and grouped based on HVR1 in S1 sequence analysis. The result showed that the prevalence in poultry slaughter houses in Taiwan from November 2012 to January 2014 was 39.4% (26/66) with TW-II predominantly. The phylogenetic tree analysis showed that some Japan-like strains were detected besides Taiwan strains and vaccine strains. However, the N genes of those Japan-like strains were grouped into Taiwan strains. The 100-191 serum samples from fields were used to evaluate the relationship between HI test and a commercial ELISA kit. Base on HI result using 3263/04 as an antigen, the sensitivity and specificity of the commercial ELISA kit were 43.6% and 92.1%, respectively and 33.8% and 90.6%, respectively base on HI result using H120 as an antigen. The result of this study showed that the genetic variants of IBV have appeared in Taiwan.