广东省规模化种鸡场禽白血病流行病学调查

Epidemiological Investigation of Avian Leukosis in Large-scale Breeder Chicken Farms in Guangdong Province

为了解广东省规模化种鸡场中禽白血病(Avian leukosis,AL)的流行情况,2020年5月—2021年1月,从广东省7个规模化种鸡场(A~G)的祖代和父母代鸡群(25周龄以上)随机采集血清样本780份、新鲜死淘鸡的组织样本(肝脏和脾脏)134份,抗凝血样本840份,利用ALV-J抗体ELISA试剂盒检测血清样本,采用SYBR GreenⅠ荧光定量PCR检测组织样本中的ALV-J,通过DF-1细胞分离抗凝血样本中的外源性ALV。结果显示:血清样本中ALV-J抗体的个体总阳性率为11.4%(89/780),组织样本中ALV-J核酸个体总阳性率为14.2%(19/134),抗凝血样本中外源性ALV的个体总阳性率为5.1%(43/840)。结果表明,广东省种鸡场的ALV净化呈现出多层分化的特点,部分种鸡场存在ALV-J和ALV-K混合感染的现象,并且部分种鸡场存在着多重遗传背景的ALV-J和ALV-K毒株的流行。

In order to understand the epidemic situation of avian leukosis(AL)in large-scale breeder chicken farms in Guangdong,780 serum samples,134 tissue samples(liver and spleen)and 840 plasma samples were collected from the grandparent and parental flocks(over 25 weeks of age)of seven large-scale breeding chicken farms(A to G)in Guangdong during the period of May 2020 to January 2021.Serum samples were detected using ALV-J antibody ELISA kits.ALV-J in tissue samples based on SYBR GreenⅠfluorescence quantitative PCR.Exogenous ALV in plasma was isolated by DF-1 cells.The results showed that positive rate of ALV-J antibody in serum samples was 11.4%(89/780).The positive rate of ALV-J in tissue samples was 14.2%(19/134).The positive rate of exogenous ALV was 5.1%(43/840).It′s suggested that ALV purification of chicken farms in Guangdong exhibited a multi-layered differentiation,and some chicken farms had a phenomenon of ALV-J and ALV-K mixed infections,and the prevalence of ALV-J and ALV-K strains with multiple genetic backgrounds were in various chicken farms.