| Popis: |
Cultural isolation, identification and biotype characterization of BVD virus is based on monolayer tissue culture techniques using mainly organs of, e.g., bovine fetuses. These might have experienced a transplacental transmission and are therefore of no use for tissue cultures produced, e.g., from kidneys of such fetuses. In order to rule out BVD virus infections, fetuses must be tested for BVD virus, viral antigen or specific nucleotide sequences. BVD virus and other ruminant pestiviruses have been detected in Turkey by cultural isolation. In bovine fetuses BVD virus has not been demonstrated so far. Cultural isolation was attempted in the present investigation in 50 randomly selected pregnant cows which were brought to an abattoir. Of these cows serum samples were assayed for neutralizing antibodies to BVD virus and 40 (80%) found positive with titresor = 1:40. In contrast fetuses 120 days of ontogenic age and therefore supposedly immunocompetent were derived from seropositive dams (n = 16) but did not show any neutralizing antibodies to BVD virus. Leucocyte fractions of peripheral blood samples of the 50 cows as well as 353 fetal blood and organ samples were inoculated and submitted to three passages in fetal calf kidney cell cultures before testing for BVD viral antigen by immunofluorescence technique. BVD virus was thus detected in the fetus of one seropositive cow and also in the leucocyte fraction of one seronegative dam including organs of her fetus. The number of fetuses found positive for BVD virus amongst fetuses collected in abattoirs corresponds well to figures gained by other investigators outside Turkey.(ABSTRACT TRUNCATED AT 250 WORDS) |
