Inhibition of enteropathogenic escherichia coli (epec) adherence to HEp-2 cells by bovine colostrum and milk
| Autor: | S B Carbonare, Magda Carneiro-Sampaio, Patricia Palmeira, M. L. M. Silva, Luiz Rachid Trabulsi |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Pulmonary and Respiratory Medicine
Immunoblotting Immunology Chemical Fractionation Biology Bacterial Adhesion Cell Line Microbiology fluids and secretions Affinity chromatography Intestinal mucosa Pregnancy Escherichia coli Animals Humans Immunology and Allergy Enteropathogenic Escherichia coli Adhesins Bacterial Escherichia coli Infections Intimin Colostrum Escherichia coli Proteins In vitro toxicology Infant food and beverages General Medicine biochemical phenomena metabolism and nutrition Antibodies Bacterial Molecular Weight Bacterial adhesin Milk Depression Chemical Immunoglobulin G Bacterial Vaccines Diarrhea Infantile biology.protein bacteria Cattle Female Immunization Infant Food Antibody Carrier Proteins |
| Zdroj: | Allergologia et Immunopathologia. 29:229-237 |
| ISSN: | 0301-0546 |
| DOI: | 10.1016/s0301-0546(01)79064-7 |
| Popis: | SUMMARY Background: enteropathogenic Escherichia coli (EPEC) is the main etiological agent of infantile diarrhea in Brazil and other developing countries. Human milk IgA protects newborn intestinal mucosa by inhibiting bacterial adhesion to epithelial cells and this effect is shown by in vitro assays of EPEC adhesion to HEp-2 cultured cells. Bovine milk, if effective in promoting this protection, could be an useful tool in the absence of the natural breastfeeding, in high-risk nurseries or in hospital infections. Methods: the effect of colostrum, milk, and serum from dairy cows on the adherence to EPEC to HEp-2 cells was investigated. Colostrum from immunized and control animals and industrialized milk formulas were fractionated through a membrane device with a molecular weight cut off 10 kDa. The high molecular weight fraction (HMWF) of bovine colostrum was depleted of IgG through an affinity column and absorbed with an EPEC adherent strain. Antibodies were searched by ELISA and immunoblotting (IB). Results: colostrum and milk from EPEC-immunized animals showed and inhibitory activity on adherence similar to that of contol non-immunized animals. The inhibitory effect on adhesion was related to the HMWF. IgG-depleted colostrum partially retained the inhibitory effect, whereas IgG-rich eluate lost this property. The EPEC-absorbed fraction retained the inhibitory property. Industrialized milk formulas and respective HMWF also inhibited bacterial adherence. In IB assays, colostrum and milk samples from immunized animals recognized proteins of 30-40 kDa and 94 kDa, a molecular weight consistent with the adhesin intimin, in EPEC extracts. Conclusions: the inhibitory effect of EPEC adherence may be mediated by HMWF components, and IgG was not the only component responsible for this phenomenon. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|