Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
Vet Res. 2021 Apr 29;52(1):61. doi: 10.1186/s13567-021-00932-y.
Infectious bursal disease virus (IBDV) and fowl adenovirus serotype 4 (FAdV-4) cause infectious bursal disease (IBD) and hydropericardium-hepatitis syndrome, respectively. Recently, studies have reported co-infections of poultry with IBDV and FAdV-4, which is an important problem in the poultry industry. Here, the variant IBDV strain ZD-2018-1 and FAdV-4 isolate HB1501 were used to assess the pathogenicity of co-infection in 1-day-old specific pathogen-free (SPF) chickens. Compared with chickens infected with only FAdV-4, those coinfected with IBDV and FAdV-4 showed enhanced clinical symptoms, higher mortality, more severe tissue lesions, and higher biochemical index levels. Furthermore, the expression of interleukin (IL)-6, IL-1β, and interferon-γ mRNAs in the IBDV-FAdV-4 coinfected chickens was delayed, and the antibody response levels were significantly lower in those birds compared with the FAdV-4-infected chickens. These results indicate that co-infection with variant IBDV ZD-2018-1 and FAdV-4 HB1501 could significantly promote the pathogenicity of FAdV-4 and reduce the immune response in chickens. This study provides the foundation for further investigation of the interaction mechanism in IBDV and FAdV-4 co-infection.
传染性腔上囊炎病毒（IBDV）和禽腺病毒血清型 4（FAdV-4）分别引起传染性腔上囊炎（IBD）和包涵体肝炎-心包炎综合征。最近的研究报告称，家禽同时感染 IBDV 和 FAdV-4 的情况较为常见，这是家禽业的一个重要问题。本研究中，使用变异的 IBDV 株 ZD-2018-1 和 FAdV-4 分离株 HB1501 来评估 1 日龄无特定病原体（SPF）鸡中这两种病毒的共感染致病性。与仅感染 FAdV-4 的鸡相比，同时感染 IBDV 和 FAdV-4 的鸡表现出更严重的临床症状、更高的死亡率、更严重的组织病变和更高的生化指标水平。此外，IBDV-FAdV-4 共感染鸡中白细胞介素（IL）-6、IL-1β 和干扰素-γ mRNA 的表达延迟，与感染 FAdV-4 的鸡相比，这些鸡的抗体反应水平显著降低。这些结果表明，变异的 IBDV ZD-2018-1 和 FAdV-4 HB1501 的共感染可显著促进 FAdV-4 的致病性，并降低鸡的免疫反应。本研究为进一步研究 IBDV 和 FAdV-4 共感染的相互作用机制提供了基础。
