Abdel-Moneim Ahmed S, Zlotowski Priscila, Veits Jutta, Keil Günther M, Teifke Jens P
Virology Department, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt.
Virol J. 2009 Feb 5;6:15. doi: 10.1186/1743-422X-6-15.
Infectious bronchitis virus primarily induces a disease of the respiratory system, different IBV strains may show variable tissue tropisms and also affect the oviduct and the kidneys. Proventriculitis was also associated with some new IBV strains. Aim of this study was to investigate by immunohistochemistry (IHC) the tissue tropism of avian infectious bronchitis virus (IBV) strain M41 in experimentally infected chicken embryos.
To this end chicken embryos were inoculated in the allantoic sac with 10(3) EID(50) of IBV M41 at 10 days of age. At 48, 72, and 120 h postinoculation (PI), embryos and chorioallantoic membranes (CAM) were sampled, fixed, and paraffin-wax embedded. Allantoic fluid was also collected and titrated in chicken embryo kidney cells (CEK). The sensitivity of IHC in detecting IBV antigens in the CAM of inoculated eggs matched the virus reisolation and detection in CEK. Using IHC, antigens of IBV were detected in nasal epithelium, trachea, lung, spleen, myocardial vasculature, liver, gastrointestinal tract, kidney, skin, sclera of the eye, spinal cord, as well as in brain neurons of the inoculated embryos. These results were consistent with virus isolation and denote the wide tissue tropism of IBV M41 in the chicken embryo. Most importantly, we found infection of vasculature and smooth muscle of the proventriculus which has not seen before with IBV strain M41.
IHC can be an additional useful tool for diagnosis of IBV infection in chickens and allows further studies to foster a deeper understanding of the pathogenesis of infections with IBV strains of different virulence. Moreover, these results underline that embryonic tissues in addition to CAM could be also used as possible source to generate IBV antigens for diagnostic purposes.
传染性支气管炎病毒主要引发呼吸系统疾病，不同的传染性支气管炎病毒毒株可能表现出不同的组织嗜性，还会影响输卵管和肾脏。腺胃炎也与一些新型传染性支气管炎病毒毒株有关。本研究的目的是通过免疫组织化学（IHC）研究禽传染性支气管炎病毒（IBV）M41株在实验感染鸡胚中的组织嗜性。
为此，在10日龄鸡胚的尿囊腔接种10³ EID₅₀的IBV M41。在接种后（PI）48、72和120小时，采集胚胎和绒毛尿囊膜（CAM）样本，固定并石蜡包埋。还收集尿囊液并在鸡胚肾细胞（CEK）中进行滴定。免疫组织化学检测接种蛋的绒毛尿囊膜中IBV抗原的敏感性与在鸡胚肾细胞中的病毒分离和检测结果相符。使用免疫组织化学方法，在接种胚胎的鼻上皮、气管、肺、脾、心肌血管、肝、胃肠道、肾、皮肤、眼巩膜、脊髓以及脑神经元中检测到了IBV抗原。这些结果与病毒分离结果一致，表明IBV M41在鸡胚中具有广泛的组织嗜性。最重要的是，我们发现腺胃的血管和平滑肌受到感染, 这在之前的IBV M41毒株中未曾见过。
免疫组织化学可作为诊断鸡传染性支气管炎病毒感染的一种额外有用工具，并有助于进一步研究，以更深入地了解不同毒力的传染性支气管炎病毒毒株感染的发病机制。此外，这些结果强调，除绒毛尿囊膜外，胚胎组织也可作为生成用于诊断目的的传染性支气管炎病毒抗原的可能来源。
