Dong Xuan, Zhao Peng, Chang Shuang, Ju Sidi, Li Yang, Meng Fanfeng, Sun Peng, Cui Zhizhong
a College of Veterinary Medicine , Shandong Agricultural University , Tai'an , China.
Avian Pathol. 2015;44(1):43-9. doi: 10.1080/03079457.2014.993359.
To study interactions between avian leukosis virus subgroup J (ALV-J) and reticuloendotheliosis virus (REV) and the effects of co-infection on pathogenicity of these viruses, 1-day-old broiler chicks were infected with ALV-J, REV or both ALV-J and REV. The results indicated that co-infection of ALV-J and REV induced more growth retardation and higher mortality rate than ALV-J or REV single infection (P < 0.05). Chickens co-infected with ALV-J and REV also showed more severe immunosuppression than those with a single infection. This was manifested by significantly lower bursa of Fabricius and thymus to body weight ratios and lower antibody responses to Newcastle disease virus and H9-avian influenza virus (P < 0.05). Perihepatitis and pericarditis related to severe infection with Escherichia coli were found in many of the dead birds. E. coli was isolated from each case of perihepatitis and pericarditis. The mortality associated with E. coli infection in the co-infection groups was significantly higher than in the other groups (P < 0.05). Among 516 tested E. coli isolates from 58 dead birds, 12 serotypes of the O-antigen were identified in two experiments. Different serotypes of E. coli strains were even isolated from the same organ of the same bird. Diversification of O-serotypes suggested that perihepatitis and pericarditis associated with E. coli infection was the most frequent secondary infection following the immunosuppression induced by ALV-J and REV co-infection. These results suggested that the co-infection of ALV-J and REV caused more serious synergistic pathogenic effects, growth retardation, immunosuppression, and secondary E. coli infection in broiler chickens.
为研究禽白血病病毒J亚群（ALV-J）与网状内皮组织增生症病毒（REV）之间的相互作用以及共感染对这些病毒致病性的影响，将1日龄肉仔鸡分别感染ALV-J、REV或同时感染ALV-J和REV。结果表明，与ALV-J或REV单感染相比，ALV-J和REV共感染导致更严重的生长迟缓以及更高的死亡率（P<0.05）。同时感染ALV-J和REV的鸡也表现出比单感染鸡更严重的免疫抑制。这表现为法氏囊和胸腺与体重的比值显著降低，以及对新城疫病毒和H9禽流感病毒的抗体反应降低（P<0.05）。在许多死亡鸡中发现了与大肠杆菌严重感染相关的肝周炎和心包炎。从每例肝周炎和心包炎病例中均分离出大肠杆菌。共感染组中与大肠杆菌感染相关的死亡率显著高于其他组（P<0.05）。在从58只死亡鸡中检测的516株大肠杆菌分离株中，在两个实验中鉴定出12种O抗原血清型。甚至从同一只鸡的同一器官中分离出不同血清型的大肠杆菌菌株。O血清型的多样化表明，与大肠杆菌感染相关的肝周炎和心包炎是ALV-J和REV共感染诱导的免疫抑制后最常见的继发感染。这些结果表明，ALV-J和REV共感染在肉仔鸡中引起更严重的协同致病作用、生长迟缓、免疫抑制和继发大肠杆菌感染。
