FIG 6.
Histological examination of lungs and kidneys from chickens infected with H9N2 virus housing the BJ/94-like or G1-like M gene. Shown are representative H&E (A to D) and immunohistochemical (IHC) (E to H) stainings of lung and kidney sections at 3 dpi. (A and C) rCK1023:M-BJ/94 virus infection causes mild bronchitis and inflammatory changes (A) and no apparent pathological changes in the kidney (C). (B and D) rCK1023:M-G1 virus infection causes severe interstitial pneumonia and bronchopneumonia (B) and hyperemic renal congestion (D). (E and F) There is extensive viral NP distribution in the pulmonary tissues with each virus type. (G and H) However, viral NP is detected in the kidney only during rCK1023:M-G1 virus infection. Magnifications, ×100 (A, B, E, and F), ×200 (C and D), and ×400 (G and H).