中文摘要：

禽波氏菌可引起禽类的高度接触性上呼吸道疾病，且经常与免疫抑制性病毒发生共感染。为研究免疫抑制状态下禽波氏菌致病性的变化，试验中以网状内皮组织增殖病病毒（REV）感染鸡胚构建雏鸡的免疫抑制状态，雏鸡孵出后再经呼吸道感染禽波氏菌，模拟临床二者的混合感染。分别监测混合感染与单纯感染条件下雏鸡的生长状况、免疫器官指数、NDV灭活苗免疫抗体水平、禽波氏菌抗体水平、禽波氏菌入侵组织时间、组织病理学变化以及其他细菌的继发感染状况等。结果发现REV感染可导致雏鸡严重的生长抑制和免疫抑制作用，感染禽波氏菌后使抑制作用加重，且干扰了针对禽波氏菌的抗体的产生。禽波氏菌在REV免疫抑制状态雏鸡肝、心和肾中的检出时间比单纯感染组提前了1 d。混合感染组雏鸡气管黏膜完全脱落，肝、心等组织内细胞广泛性坏死，细菌继发感染病例数增多。REV免疫抑制状态下，机体防御体系被破坏，对禽波氏菌的免疫应答降低，为禽波氏菌在组织中的侵袭扩散提供了便利，使禽波氏菌对雏鸡的致病性增强。

英文摘要：

Bordetella avium （B. avium） can cause a highly contagious disease of upper respiratory tract of poultry and often co-infect with immunosuppressive viruses. In order to study the effect of immunosuppressive state on pathogenicity of B. avium, chick embryos were inoculated with reticuloendotheliosis virus （REV） and infected with B. avium after they were hatched. The body weight, immune organ index, NDV antibody level, B. avium antibody level, the invasion time point of B. avium in different tissues, histopathological changes, and secondary infections of other bacteria were observed respectively under co-infection and simple infection. The results showed that REV caused severe growth inhibition and immunosuppression in chicks which were aggravated by B. avium infection. At the same time, the antibody level of B. avium was interfered. The detection time of B. avium in the liver, heart and kidney of chicks in the immunosuppressive state was 1 d earlier than that in B. avium simple infection group. Chick tracheal mucosa completely fell down and extensive necrosis appeared in liver, heart and other tissues in co-infection group. And the number of secondary infection cases was significantly increased. In conclusion, in the REV immunosuppressive state, the body defense system of chick is destroyed, and the immune response to B. avium decreased. At the same time it provides convenient for the invasion and spread of B. avium in tissues, so the pathogenicity of Bordetella avium increased in the immunosuppressive state induced by REV.