血清4型禽腺病毒强毒株GY株的分离鉴定和致病性研究

从山东某疑似感染禽腺病毒的发病鸡群中采集病料并分离到一株禽腺病毒,克隆纯化后进行PCR检测和序列分析,鉴定该毒株为血清4型禽腺病毒,命名为GY株。用LMH细胞繁殖的GY株病毒滴度可以达到107.5 TCID₅₀/0.1mL,并建立了纯净稳定的种子批。动物致病性试验结果显示,攻毒鸡只8/10死亡,剖检均出现心包积液,肝脏肿大、出血或坏死,表明该毒株为强毒株。就攻毒途径、攻毒剂量等方面研究发现,GY株经胸部肌肉注射后发病率和发病时间相对颈部皮下注射途径更有优势,确定攻毒途径为肌肉注射;通过比较不同剂量(5×10^3.0~5×10^6.0 TCID50)GY株病毒攻击SPF鸡的致病性,将攻毒剂量定为5×10^5.0 TCID₅₀。研究表明,GY株可作为禽腺病毒4型攻毒用强毒株。

Isolation, Identification and Pathogenicity Study of GY strain of Serotype 4 Fowl Adenovirus

Fowl Adenoviruses (FAdV) are one of the most prevalent vertically transmitted viruses diseases caused by these viruses. It is important to the identify high virulent stains of these viruses in order to develop effective vaccines. In this study, strain GY of serotype 4 fowl adenovirus was isolated from a diseased chicken flock in Shandong. Virulent test on purified clone of GY strain, propagated on LMH cells, showed high virus titer, reaching 107.5TCID50/0.1ml. Tests on SPF chickens showed high pathogenicity, mortality reaching 80%, pathological dissection result showed pericardial effusion, liver enlargement, bleeding and necrosis. Different dosages and routes of infections were tested , showing chest intramuscular injection to be the most effective route of infection, and 5×105.0 TCID50 to be the optimum dosage of infection. This study demonstrates that the GY strain is high virulent and is promising to be adopted as reference strain for inspection of serotype 4 fowl adenovirus, and provides evidence-based guidance for future applications.