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Antibacterial factors in cows’ milk and colostrum : immunoglobulins and lactoferrin Facon, Michel Jean
Abstract
The objectives of this study were: 1) to test the antibacterial activity of a pepsin digest of bovine lactoferrin, containing the peptide lactoferricin, in complex media; 2) to detect specific antibodies to human enterotoxigenic Escherichia colt in bovine milk or colostrum; and 3) to investigate the potential of a cell culture system to study and estimate the biological activity of milk immunoglobulins. The pepsin digest of lactoferrin was bactericidal against Salmonella enteritidis in 1% peptone, but no substantial antibacterial activity could be demonstrated in trypticase soy broth or in some selected foods. Calcium at a concentration of 5 m?s’I was sufficient to inhibit the antibacterial activity of the digest. Addition of lysozyme or EDTA enhanced the antibacterial activity of the digest, but not sufficiently to overcome the effect of inhibitors in the foods of interest. The activity of the digest was also inhibited by bile salts. These findings raise doubts about the potential for addition of lactoferricin to foods. Antibodies to the colonization factor antigen CFA 1 of enterotoxigenic E. colt were detected in bovine colostrum by hemagglutination inhibition. Concentrations of antibodies to CFA 1, estimated by ELISA, ranged from 0.55 to 5.2 .tg/ml in colostrum samples of nonvaccinated cows. Samples of milk immune concentrates from vaccinated and non-vaccinated cows were also tested. Vaccination increased the concentration of specific antibodies relative to the total IgG content of the samples tested. Invasion of HeLa cells by Salmonella enteritidis, S. typhimurium and enteropathogenic E. coli was inhibited by addition of bovine colostrum to cell culture medium. Inhibition levels ranged from 73% to over 99%. The immunoglobulin-containing fraction, isolated from colostrum by affinity chromatography on a protein G-agarose column, inhibited invasion by S. typhimurium. An unidentified high molecular weight factor in the non-immunoglobulin fraction also inhibited invasion of HeLa cells. No inhibitory activity was found in low molecular weight fractions. The results suggest that bovine colostrum contains both immunoglobulin and non-immunoglobulin inbibitors of invasion of HeLa cells by the bacteria tested. HeLa cell cultures have the potential to be a convenient method for the study and evaluation of antibacterial properties of bovine milk.
Item Metadata
Title |
Antibacterial factors in cows’ milk and colostrum : immunoglobulins and lactoferrin
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1995
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Description |
The objectives of this study were: 1) to test the antibacterial activity of a pepsin
digest of bovine lactoferrin, containing the peptide lactoferricin, in complex media; 2) to
detect specific antibodies to human enterotoxigenic Escherichia colt in bovine milk or
colostrum; and 3) to investigate the potential of a cell culture system to study and estimate
the biological activity of milk immunoglobulins.
The pepsin digest of lactoferrin was bactericidal against Salmonella enteritidis in 1%
peptone, but no substantial antibacterial activity could be demonstrated in trypticase soy
broth or in some selected foods. Calcium at a concentration of 5 m?s’I was sufficient to inhibit
the antibacterial activity of the digest. Addition of lysozyme or EDTA enhanced the
antibacterial activity of the digest, but not sufficiently to overcome the effect of inhibitors in
the foods of interest. The activity of the digest was also inhibited by bile salts. These
findings raise doubts about the potential for addition of lactoferricin to foods.
Antibodies to the colonization factor antigen CFA 1 of enterotoxigenic E. colt were
detected in bovine colostrum by hemagglutination inhibition. Concentrations of antibodies to
CFA 1, estimated by ELISA, ranged from 0.55 to 5.2 .tg/ml in colostrum samples of nonvaccinated
cows. Samples of milk immune concentrates from vaccinated and non-vaccinated
cows were also tested. Vaccination increased the concentration of specific antibodies relative
to the total IgG content of the samples tested.
Invasion of HeLa cells by Salmonella enteritidis, S. typhimurium and
enteropathogenic E. coli was inhibited by addition of bovine colostrum to cell culture
medium. Inhibition levels ranged from 73% to over 99%. The immunoglobulin-containing
fraction, isolated from colostrum by affinity chromatography on a protein G-agarose column,
inhibited invasion by S. typhimurium. An unidentified high molecular weight factor in the
non-immunoglobulin fraction also inhibited invasion of HeLa cells. No inhibitory activity was found in low molecular weight fractions. The results suggest that bovine colostrum
contains both immunoglobulin and non-immunoglobulin inbibitors of invasion of HeLa cells
by the bacteria tested.
HeLa cell cultures have the potential to be a convenient method for the study and
evaluation of antibacterial properties of bovine milk.
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Extent |
3668794 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-06-04
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0088841
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1995-05
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.