Abstract：
Chickens infected with FAdV-4 and FAdV-8b both exhibit hepatic lesions characterized by hemorrhagic necrosis and intranuclear inclusion body formation. However, only FAdV-4 induces pericardial effusion and acute mortality in chickens. To investigate the similarities and differences in the pathogenicity of HPS and IBH, this study intends to compare the infectivity and pathogenicity of FAdV-4 and FAdV-8b, 2 serotypes of fowl adenovirus isolated in our laboratory. The 2 viruses were respectively inoculated subcutaneously into SPF chicks at the neck. The clinical manifestations and pathological changes in these infected groups of chickens differed to some extent. Chickens infected with FAdV-4 exhibit evident depression and acute mortality, with a mortality rate of 60%; while those infected with FAdV-8b only display mild depression. Postmortem examination reveals serosanguinous effusion in the pericardial sac, spot-like hemorrhage, and focal necrosis in the liver of chickens infected with FAdV-4. Additionally, various degrees of edema are observed in organs such as the lungs, spleen, kidneys, and pancreas. In contrast, chickens infected with FAdV-8b exhibit spot-like hemorrhage and focal necrosis in the liver but do not display pericardial effusion or widespread organ edema. Histopathological examination demonstrates that both FAdV-4 and FAdV-8b can induce inflammatory reactions of varying degrees in the kidneys, pancreas, and duodenum of chickens, while reducing the necrosis of bursa of Fabricius, thymus, and spleen lymphocytes. Our data preliminarily reveal that both FAdV-4 and FAdV-8b can induce strong pathogenicity in chickens.
摘要：
感染FAdV-4和FAdV-8b的鸡都表现出以出血性坏死和核内包涵体形成为特征的肝脏病变。然而,只有FAdV-4诱导鸡的心包积液和急性死亡。探讨HPS与IBH致病性的异同,本研究旨在比较FAdV-4和FAdV-8b的感染性和致病性,我们实验室分离出2种血清型家禽腺病毒。将2种病毒分别皮下接种到SPF雏鸡的颈部。这些感染组鸡的临床表现和病理变化在一定程度上有所不同。感染FAdV-4的鸡表现出明显的抑郁和急性死亡率，死亡率为60％；而感染FAdV-8b的患者仅表现出轻度抑郁。尸检显示心包囊内有血膜血积液，斑点样出血,和感染FAdV-4的鸡肝脏局灶性坏死。此外,在肺等器官中观察到不同程度的水肿，脾,脾肾脏，和胰腺。相比之下,感染FAdV-8b的鸡在肝脏中表现出斑点样出血和局灶性坏死，但不显示心包积液或广泛的器官水肿。组织病理学检查表明，FAdV-4和FAdV-8b均可诱导肾脏不同程度的炎症反应，胰腺,和鸡的十二指肠，同时减少法布里修斯法氏囊的坏死,胸腺,和脾淋巴细胞。我们的数据初步表明，FAdV-4和FAdV-8b都可以在鸡中诱导强致病性。
