EN
The present study was carried out to determine the presence of virulent factors in C. jejuni isolated from the alimentary tracts and livers of layer and broiler chickens. A tissue culture assay in vivo and invasivenes test in vitro on chicken embryos to detect the presence of the virulent factors mentioned above. It was found that the polymixyn extract of C. jejuni exhibited cytotoxic effects which were most clear in chicken kidney cells (94% of C. jejuni: the titer ranged from 4 log 2 to 12 log 2). Chicken embryo fibroblasts were less sensitive to Campylobacter filtrates (84% of C. jejuni: the titer ranged from 1 log 2 to 9 log 2). The lowest sensitivity was found in Vero cells. The invasive factor was determined in C. jejuni after the inoculation of 11-day-old chicken embryos onto the chorioallantoic membrane and into the allantoic cavity. There was a correlation between mortality of embryos and reisolation C. jejuni from their livers. However, this relationship was not observed after the inoculation of the embryos into the allantoic cavity.