Bactericidal activity of bovine fetal serum against smooth and rough strains of Escherichia coli
Barta, O.; Barta, V.; Ingram, D.G.; Hubbert, W.T.
American Journal of Veterinary Research 33(4): 731-740
1972
ISSN/ISBN: 0002-9645 PMID: 4552948 Document Number: 48730
Serum from 73 bovine foetuses ranging in age from 70 days to full term and serum from three newborn calves before they had received colostrum were titrated for complement activity, bactericidal activity (BCA) and antibody against two rough (R) strains and one smooth (S) strain of Eschericha coli. Potent BCA against the R strain 'Lilly' was found in the serum of all the foetuses and newborn calves. The BCA against the R strain 'S16' was not demonstrable in some serum samples from foetuses less than 230 days of age. The level of BCA against both R strains gradually increased with increasing age of the foetuses. This increase varied with E.coli strains and did not correspond to the changes in complement activity against sensitized sheep erythrocytes. Immunoelectrophoresis in agar gel did not detect gamma globulin in the foetal serum tested. Antibody against the bacteria tested was not detectable by agglutination or passive haemagglutination techniques. BCA against the S strain was not demonstrable in foetal serum. Classical specific antibody was apparently not required for killing E.coli R strains but it was essential for killing the S strain.