Comparative nephropathogenicity of different strains of infectious bronchitis virus in chickens.

Two-week-old White Leghorn chickens were injected intravenously with Australian T, Holte, Gray, and M 41 strains of infectious bronchitis virus. A total of 100, 90, 85, and 20% of the chickens infected with Australian T, Holte, Gray, and M 41, respectively, had variable degrees of nephritis. The Australian T strain induced the most rapid and the most severe kidney lesions followed by Holte, Gray, and M 41 in descending order.