中国兽医科学

为查明禽白血病病毒J亚群(ALV-J)和网状内皮组织增殖病病毒(REV)共感染临床鸡群的原因,对河北省某鸡场患病的产蛋种鸡进行组织病理学检查、病毒分离和可疑病原的间接免疫荧光检测、PCR和ELISA检测,同时对该鸡群所用疫苗中可疑病毒进行病原分离和PCR鉴定。结果,组织病理学检查发现,发病鸡的肝脏、腺胃、肾脏均出现灶状淋巴细胞增殖;用发病鸡肝脏浸液接种DF1细胞后,分别用特异性单抗进行间接免疫荧光检测发现培养物中ALV-J抗原和REV抗原均呈阳性。用ALV-J特异性引物对病鸡肝组织样品进行PCR检测时部分结果呈阳性,产物大小为924 bp;用REV特异性引物对病鸡肝组织样品进行PCR检测时部分结果也呈阳性,产物大小为438 bp。经PCR检测的17份活毒疫苗DNA中,2份为REV核酸阳性,5份为ALV-J核酸阳性,其中有1份疫苗样品呈双阳性,并且PCR阳性产物的序列分别与从蛋鸡体内分离的病毒毒株相一致。系统进化分析表明,分离的疑似REV毒株与中国其他地方分离的REV毒株的同源性高于与REV HA株的同源性,而本研究中分离的ALV-J毒株与ALV-J原型株HPRS-103的亲缘关系最近。以上结果表明,疫苗污染ALV-J和REV与田间ALV-J与REV的高感染率存在着因果关系。

To find out the causes of co-infection of avian leukosis virus subgroup J(ALV-J) and reticuloendotheliosis virus(REV) in clinical chicken flocks,layer hens from Hebei Province were detected by histopathological examination,virus isolation,and indirect immunofluorescence detection of suspected pathogen,PCR,and ELISA.At the same time,the vaccines inoculated in this flock were used to isolate the suspected virus and identified by PCR.Histopathology study revealed that focal lymphocyte proliferations were existed in liver,glandular stomach,and kidney of the diseased chickens.After the liver extracts from sick chickens were inoculated on the DF1 cells,the antigen of ALV-J and the antigens of REV were positive in the cultures by indirect immunofluorescence with specific monoclonal antibodies.PCR results revealed that ALV-J nucleic acids were positive in the chicken liver and the amplification product sizes were 924 bp,and REV nucleic acids were also positive and amplification product sizes were438 bp.PCR results indicated that,two samples of 17 live vaccines were positive for REV nucleic acids,five samples were positive for ALV-J nucleic acid,and one of the vaccine samples was double positive.The sequences of PCR positive products were consistent with that from the layer chickens,respectively.Phylogenetic relationship analysis showed that REV isolated from this study had higher homology with REV strain isolated in other parts of China than that with the REV HA strain.However,the ALV-J strain isolated in this study was closely related to the ALV-J prototype strain HPRS-103.In conclusion,there were a causal relationship between vaccine contamination and the high infection rates of ALV-J and REV in the field.