Cheng Zhimin, Li Mengxuan, Wang Yao, Chai Tongjie, Cai Yumei, Li Ning
College of Animal Science and Technology, Shandong Agricultural University, Taian, China.
Sino-German Cooperative Research Centre for Zoonosis of Animal Origin Shandong Province, College of Animal Science and Technology, Shandong Agricultural University, Taian, China.
Front Vet Sci. 2020 Mar 11;7:143. doi: 10.3389/fvets.2020.00143. eCollection 2020.
is a ubiquitous pathogen in poultry farms, causing aspergillosis in chickens. To study the pathogenicity of , 14-days-old chickens were infected with fungal conidia (2 × 10 CFU/mL) via thoracic intra-air sacs inoculation. The clinical symptoms, gross and histopathological lesions, and fungal load in the lungs were examined. Additionally, the mRNAs of Toll like receptors (TLR) and pro-inflammatory cytokines were evaluated by quantitative PCR to explore the immune responses induced by . The results showed that overt depression, ruffled feathers, and dyspnea were observed in the infected chickens as early as 3 days post infection (dpi). Eleven out of 25 infected chickens died from 5 to 9 dpi, and could also be reisolated from the infected lung. Histopathological examination revealed obvious airsacculitis and pneumonia, characterized by inflammatory cell infiltration (heterophils and macrophages), and granulomatous lesions in the lung. The mRNA expressions of TLR1 and TLR2 were upregulated in the lung and spleen, and most pro-inflammatory cytokines including IL-1β, Cxcl-8, TNF-α, IL-12, and IFN-γ were increased in both the lung and spleen during the tested period, suggesting that the innate immune responses were triggered by infection, and these cytokines participated in the inflammatory responses against . These results indicate that infection by thoracic intra-air sacs inoculation can cause severe respiratory damage in chickens, activate TLR1 and TLR2 mediated immune responses, and elicit large expression of pro-inflammatory cytokines such as IL-1β, Cxcl-8, and IFN-γ. These data will help further understanding of the pathogenesis and immune responses of infection in the chicken.
是家禽养殖场中一种普遍存在的病原体，可导致鸡群患曲霉菌病。为研究其致病性，将14日龄的鸡通过胸腔内气囊接种感染真菌分生孢子（2×10 CFU/mL）。检测了临床症状、大体和组织病理学病变以及肺中的真菌载量。此外，通过定量PCR评估Toll样受体（TLR）和促炎细胞因子的mRNA，以探究其诱导的免疫反应。结果显示，感染鸡最早在感染后3天（dpi）出现明显抑郁、羽毛蓬乱和呼吸困难。25只感染鸡中有11只在5至9 dpi死亡，并且也可从感染的肺中重新分离出。组织病理学检查显示明显的气囊炎和肺炎，其特征为炎症细胞浸润（嗜异性粒细胞和巨噬细胞）以及肺中的肉芽肿病变。肺和脾中TLR1和TLR2的mRNA表达上调，并且在测试期间肺和脾中大多数促炎细胞因子包括IL-1β、Cxcl-8、TNF-α、IL-12和IFN-γ均增加，表明先天免疫反应由感染触发，并且这些细胞因子参与了针对的炎症反应。这些结果表明，通过胸腔内气囊接种感染可导致鸡严重的呼吸道损伤，激活TLR1和TLR2介导的免疫反应，并引发促炎细胞因子如IL-1β、Cxcl-8和IFN-γ的大量表达。这些数据将有助于进一步了解鸡感染的发病机制和免疫反应。
