Histopathology and immunohistochemistry of renal lesions due to infectious bronchitis virus in chicks

Abstract

SUMMARYTwo-day-old specific-pathogen-free chicks were inoculated intranasally with the MA-87 strain of infectious bronchitis virus, and trachea and kidney lesions studied histologically and immunohistochemically. Lesions and viral antigen were first detected in the trachea; severe damage was then observed in the kidney. Viral antigen appeared prior to the development of renal lesions and was detected in the cytoplasm of epithelial cells by 4 days post-inoculation (p.i.). The epithelial cells of the collecting ducts, collecting tubules and distal convoluted tubules were first affected, followed by involvement of Henle's loops, whereas the proximal convoluted tubules were only minimally affected. Antigen-positive cells of ducts and tubules were degenerated and desquamated. The severe epithelial cell damage resulted in infiltration of heterophils and macrophages in the interstitium, ducts and tubules. The detection of viral antigen was consistent with the distribution of histological lesions at 6 to 8 days p.i. At a later stage, antigen-positive cells disappeared and repair of epithelial cells was seen, accompanied by interstitial lymphoplasmacytic infiltration and lymphoid nodular formation.

Comparison of the pathogenicity of QX-like, M41 and 793/B infectious bronchitis strains from different pathological conditions

“…However, unlike previous studies where either severe kidney damage (Butcher et al, 1990;Chen et al, 1996) or alterations to the reproductive tract (Crinion & Hofstad, 1971) was reported following M41 infection, in our study no remarkable lesions or presence of viral RNA was detected in the other organs. This discrepancy might be caused by different passage levels, experimental conditions and design, breed or age of the birds, or by the use of different strains of M41.…”

Detection of infectious bronchitis virus

“…The performance of the IPA in detecting IBV antigen after inoculation of SPF chickens compares very favourably with IFA (Nakamura et al, 1991;Owen et al, 1991;Janse et al, 1994;Chen et al, 1996). Naqi (1990) showed that IBV could be detected by IPA in the CAM of inoculated eggs within 15 h p.i., with a detection limit of 10 6.2 EID 50 .…”

Natural case of salpingitis apparently caused byMycoplasma gallisepticumin chickens

“…Briefly, the rehydrated sections were placed in plastic containers filled with 0.01 M phosphate buffer (PB), pH 6.0 and autoclaved at 121°C 3 under 2 atm for 15 min. After autoclaving, the containers were allowed to cool prior to incubation overnight at 4°C with the primary antibody, either rabbit anti-S6 strain of MG serum (1:10,000, hyperimmune serum prepared in our laboratory), rabbit anti-chicken IgA serum (1:1,000, affinity purified, Bethyl Lab Inc., Montgomery), mouse monoclonal antibody recognizing the nucleoprotein of IBV (Chen et al, 1996), chicken IgG or IgM (1:10,000, prepared by Hoshi). They were then reacted with either peroxidaselabeled goat anti-rabbit IgG, peroxidase-labeled rabbit anti-mouse IgG (Sigma Chemical Co., St Louis), a Histofine SAB-PO kit for rabbit primary antibody or mouse primary antibody (Nichirei Inc., Japan), visualized with 3-amino-9-ethylcarbazole (Sigma Chemical Co., St Louis) -hydrogen peroxide staining solution, and counterstained lightly with Mayer's haematoxylin (McManus & Mowry, 1964).…”