Abstract
Some properties of infectious bronchitis virus (IBV) passed through 50nm mesh filter were compared with IBV nonpassed through the filter and were tried to purify a small size IBV isolated from nephritic infectious bronchitis of chicken.
There were markedly difference in size of the virus passed through 50nm mesh filter by electron microscopic observation. However, no differences were observed in other properties such as typical structure, resistance to treatments with pH3.0 and heating, trypsin, ether and chloroform between large and small size virus groups. Pathogenicity to chickens of the two virus groups was also the same. Moreover, the small size of IBV could not purified, even if the virus was passaged in chicken embryo. In addition, population of small size IBV was not increased in the progeny virus after passage.
