The immunohistochemistry study of lesions due to avian infectious bronchitis (Serotype 4/91) on different tissues in specific pathogen free chicks

Thirty specific pathogen free (SPF) 20-day-old chicks were inoculated by the intratracheal(n=15) or oral (n=15) routes with serotype 793/B of IBV, isolated of Iran. Two groupsof 15 SPF chicks which as controls received PBS, either by the intra-tracheal or oral route. Allthe chicks were observed and examined daily for clinical signs. Each day for 5 days three chicksfrom each infected and control group were post-mortemed and examined pathological changesin the trachea, lungs, kidneys and intestines. Sections of these tissues were prepared, stained andexamined microscopically for histopathological and immunohistochemical changes. Grossly, asmall amount of clear mucus and slight congestion were found only in the lumen of the tracheaand the lungs of the group chicks which were infected with IBV. The kidneys were pale andslightly enlarge. Immunohistochemical examination revealed similar changes in the kidneys ofboth groups of chicks infected by the intra-tracheal and oral routes. Viral antigens were detectedin the infected cells. The viral antigens were apparent prior to the development of lesions andwere detected in the cytoplasm of epithelial cells by 3 days post infection with IBV. The resultsof this study clearly indicate that IBV (serotype 793/B), isolated in Iran by Momayes et al. (2001),is capable of causing lesions in different tissues most severely in the kidneys of experimentallyinfected chicks. On the other hand, the serotype has a greater affinity and positive tropism forthe kidney than to other tissues.

کلیدواژه ها:

infectious bronchitis ، serotype 793/B ، immunohistochemistry ، avian diseases