In order to recognize the prevalence and variation status of Group I fowl adenovirus and to provide basis for adjusting comprehensive prevention and treatment measures for the future,samples including duck embryos, ducklings and breeding ducks were regularly collected from some large-scale duck farms in Shandong Province, and virus isolation and PCR assay were carried out. The results showed that a total of 461 embryos were collected, 137 embryos were detected positive,the positive rate was 37.5%. The earliest detection of Fowl adenovirus occurred in the 8-day-old duck embryos. A total of 120 1-day-old duckling samples were collected,41 samples were detected positive,the positive rate was 34.2%. A total of 120 cloacal swab samples of healthy ducks were collected from a breeding duck farm in Dezhou City,34 positive samples were detected,the positive rate was 28.3%. Sequence analysis was conducted towards the isolated 4 strains of Group I fowl adenovirus,and results revealed that 1 strain belonged to serotype 1,the other 3 strains belonged to serotype 4. There were extremely high homology between the isolated strains in this study and other isolates from mainland China in recent years,but mutations were found in 19 nucleotide sites in Hexon gene region. The detection results showed that there was a high prevalence rate of Group I avian adenovirus among ducks in some areas of Shandong Province,and the epidemic strains mainly belonged to serotype 4. Although the homology between the isolates and other strains was high,the risk of variation still existed. Besides,there was inapparent infection of Group I fowl adenovirus in China's breeding duck farms,and the risk of vertical transmission existed,which indicated more attention should be paid to.%为了解Ⅰ群禽腺病毒在山东省种鸭场中的流行及变异情况,从而为今后调整综合防治措施提供依据,对定期从山东省部分大型种鸭场采集的鸭胚、雏鸭及种鸭样品,进行病毒分离和PCR鉴定.本研究共采集鸭胚461枚,检出阳性137枚,阳性率为37.5%,最早可从8日龄鸭胚中检测到阳性;采集1日龄雏鸭样品120份,检出阳性41份,阳性率为34.2%;从德州市某种鸭场采集120份健康鸭泄殖腔棉拭子,检出阳性34份,阳性率为28.3%.对分离到的4株Ⅰ群禽腺病毒进行基因序列分析发现:1株为血清1型,3株为血清4型;分离株与近年来我国大陆地区的其他分离株具有极高的同源性,但在Hexon基因区域有19个核苷酸位点出现突变.检测结果表明:Ⅰ群禽腺病毒在山东省部分地区鸭群中有较高的流行率,其中以血清4型为主;虽然分离株与其他毒株同源性较高,但存在变异风险;我国种鸭场存在Ⅰ群禽腺病毒隐形感染情况,有垂直传播风险,应引起高度重视.
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