西南部分地区Ⅰ群禽腺病毒的分子流行病学调查及致病性研究

摘要

2015—2016年,西南地区多个养鸡场发生疑似禽腺病毒感染病例.实验从发病鸡场采集肝组织,利用鸡胚肾细胞(CEK)进行病毒分离,共分离出16株Ⅰ群禽腺病毒(FAdV).通过对hexon基因L1环临近的保守序列进行PCR扩增和序列测定,发现16株FAdV分属4个血清型,其中13株为FAdV-4型,FAdV-8a,FAdV-8b和FAdV-2型各占1株.选取不同血清型的4个代表毒株CH/SCDY/1604(FAdV-4)、CH/GZXF/1512(FAdV-2)、CH/CQBS/1504(FAdV-8a)、CH/CQBS/1512(FAdV-8b)进行鸡的致病性实验,结果显示,感染CH/SCDY/1604(FAdV-4)的死亡率达80%,CH/CQBS/1504(FAdV-8a)感染组死亡率为20%,而CH/GZXF/1512(FAdV-2)和CH/CQBS/1512(FAdV-8b)组的鸡只有发病没有死亡.FAdV-4是西南地区流行的主要血清型且其致病性极高,其致病性主要表现为心包积液综合征(HPS).试验结果可为西南地区Ⅰ群禽腺病毒感染的防治提供参考.%In 2015-2016, suspected fowl adenoviruses infections were observed in many chicken farms in south-western China. The liver samples were collected from diseased chickens and inoculated into chicken embryo kidney cells ( CEK) cultures for virus isolation, and 16 fowl adenoviruses ( FAdV) strains were isolated. After PCR amplifi-cating, sequencing and comparing the conserved sequences located in the pedestal regions adjacent to the L1 loop of the hexon genes of FAdV, all of the 16 stains could be grouped into four serotypes including FAdV-4 ( 13/16 ) , FAdV-8a (1/16), FAdV-8 (1/16) and FAdV-2 (1/16). Then, the delegate strains from those four different sero-types were selected to infect chickens to observe its pathogenicity to chickens, the results showed that the mortality of chickens infected with CH/SCDY/1604(FAdV-4) and CH/CQBS/1504 (FAdV-8a) was 80% and 20%, respec-tively, while no death of chicken was observed in chickens infected by CH/GZXF/1512(FAdV-2)and CH/CQBS/1512(FAdV-8b). It was concluded that the FAdV-4 was the predominant serotype and was highly pathogenic tochickens, and hydropericardium syndrome ( HPS) was the main clinical manifestation. This results could provide reference for the epidemiological investigation and prevention of FAdVⅠinfection in southwestern China.