VIRAL NEPHRITIS INDUCED BY AN ISOLANT RELATED TO INFECTIOUS BRONCHITIS VIRUS. I:ISOLATION AND IDENTIFICATION OF THE ISOLANT

Several outbreaks of nephritis were noticed in laying flocks in Egypt. The disease reported in a flock aging 70 days old suffering from severe emaciation, profuse whitich diarrhoea, paresis and high mortality. The predominant gross lesions in the most examined cases were severe nephritis, dilitation of ureters and atrophy of the kidneys, some cases showed catarrhal trachitis. The causal agent was isolated, produced curling, dwarfing and deaths of infected chicken embryos after several passages.
The physico-chemical proparaties of the isolant revealed that the isolant viral agent sensitive to chloroform (25%) and sensi tive to 56°C for one hour. The isolant failed to agglutinate chicken, horse, sheep and rat erythrocytes. Serological studies by agar gel presipitation test revealed its relationship to infect ious bronchitis virus, by cross neutralization test revealed its variation than infectious bronchitis virus. Intraoperitanial infection of one day, 30 days and 60 days old chicks with the isolant gave the typical symptoms, lesions and also the reisolation of the isolant from the affected kidneys. From the above properaties of the isolant suggested its tentative grouping as infectious bronchitis (variant strain of renal tropism).