血清4型禽腺病毒的分离鉴定及致病性分析

Isolation,identification and pathogenicity analysis of fowl adenovirus serotype 4

旨在从送检的病鸡中分离鉴定出禽腺病毒(fowl adenovirus,FAdV),为临床诊断和疫病防控提供参考依据。本研究将阳性样品接种SPF鸡胚并传代,利用PCR检测、基因序列分析、动物回归试验等方法鉴定病毒。结果:经过鸡胚传代及病毒特异性检测获得了纯净的FAdV,命名为HB2306;分析Hexon基因序列可知,HB2306株属于血清4型分支,与国内外分离的FAdV-4毒株核苷酸序列同源性为98.2%~99.9%,HB2306株与国内外的4型高致病性毒株氨基酸序列相似性在97.9%~99.8%;受试动物临床病理变化显示,HB2306株以104.5EID50/只的剂量经胸部肌肉注射后,引起宿主心包积液,肝脏变黄肿胀、淤血出血,肾出血、肿胀等典型的病理变化,与流行的高致病性毒株所致临床症状相似,且死亡率为100%。综上,本研究成功分离并鉴定出一株FAdV-4高致病力毒株,丰富了毒种库,为该病毒感染的流行情况调查和综合防控奠定了基础。

Fowl adenovirus(FAdV)was isolated and identified from the infected chickens,in order to provide reference for clinical diagnosis and disease control.The positive samples were inoculated with SPF chicken embryos and passed down to the next generation.The virus was identified as avian serum type 4 adenovirus by PCR detection,gene sequence analysis and animal regression test.The results showed that pure FAdV was obtained by chicken embryo passage and virus specific detection,and was named HB2306.The Hexon gene sequence analysis showed that the HB2306 strain belonged to the serum type 4 branch,and its nucleotide sequence homology with FAdV-4 isolates from both domestic and international sources was 98.2%-99.9%.The amino acid sequence similarity between HB2306 and other highly pathogenic type 4 was 97.9%-99.8%.The clinical pathological changes of the tested animals showed that HB2306 strain caused typical pathological changes,such as pericardial effusion,yellow swelling of liver,congestion and hemorrhage,kidney hemorrhage and swelling after injection into the chest muscle at the dose of 104.5 EID50/strain.The clinical symptoms were similar to those of other popular highly pathogenic strains,and the mortality rate was 100%.In conclusion,in this study,a highly virulent strain was successfully isolated and identified,which enriched the virus reservoir and provided data for the prevalence and for the comprehensive prevention and control of FAdV.