<http://purl.org/dc/terms/description>
"The objectives of this study were: 1) to test the antibacterial activity of a pepsin\r\ndigest of bovine lactoferrin, containing the peptide lactoferricin, in complex media; 2) to\r\ndetect specific antibodies to human enterotoxigenic Escherichia colt in bovine milk or\r\ncolostrum; and 3) to investigate the potential of a cell culture system to study and estimate\r\nthe biological activity of milk immunoglobulins.\r\nThe pepsin digest of lactoferrin was bactericidal against Salmonella enteritidis in 1%\r\npeptone, but no substantial antibacterial activity could be demonstrated in trypticase soy\r\nbroth or in some selected foods. Calcium at a concentration of 5 m?s\u2019I was sufficient to inhibit\r\nthe antibacterial activity of the digest. Addition of lysozyme or EDTA enhanced the\r\nantibacterial activity of the digest, but not sufficiently to overcome the effect of inhibitors in\r\nthe foods of interest. The activity of the digest was also inhibited by bile salts. These\r\nfindings raise doubts about the potential for addition of lactoferricin to foods.\r\nAntibodies to the colonization factor antigen CFA 1 of enterotoxigenic E. colt were\r\ndetected in bovine colostrum by hemagglutination inhibition. Concentrations of antibodies to\r\nCFA 1, estimated by ELISA, ranged from 0.55 to 5.2 .tg/ml in colostrum samples of nonvaccinated\r\ncows. Samples of milk immune concentrates from vaccinated and non-vaccinated\r\ncows were also tested. Vaccination increased the concentration of specific antibodies relative\r\nto the total IgG content of the samples tested.\r\nInvasion of HeLa cells by Salmonella enteritidis, S. typhimurium and\r\nenteropathogenic E. coli was inhibited by addition of bovine colostrum to cell culture\r\nmedium. Inhibition levels ranged from 73% to over 99%. The immunoglobulin-containing\r\nfraction, isolated from colostrum by affinity chromatography on a protein G-agarose column,\r\ninhibited invasion by S. typhimurium. An unidentified high molecular weight factor in the\r\nnon-immunoglobulin fraction also inhibited invasion of HeLa cells. No inhibitory activity was found in low molecular weight fractions. The results suggest that bovine colostrum\r\ncontains both immunoglobulin and non-immunoglobulin inbibitors of invasion of HeLa cells\r\nby the bacteria tested.\r\nHeLa cell cultures have the potential to be a convenient method for the study and\r\nevaluation of antibacterial properties of bovine milk."@en
<https://open.library.ubc.ca/cIRcle/collections/ubctheses/831/items/1.0088841>