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Characterization of adherent-invasive Escherichia coli isolated from pediatric patients with inflammatory bowel disease.
- Source :
-
Inflammatory bowel diseases [Inflamm Bowel Dis] 2012 May; Vol. 18 (5), pp. 913-24. Date of Electronic Publication: 2011 Oct 12. - Publication Year :
- 2012
-
Abstract
- Background: Crohn's disease (CD) and ulcerative colitis (UC), known as inflammatory bowel diseases (IBD), are characterized by an abnormal immunological response to commensal bacteria colonizing intestinal lumen and mucosa. Among the latter, strains of adherent-invasive Escherichia coli (AIEC), capable of adhering to and invading epithelium, and to replicate in macrophages, have been described in CD adults. We aimed at identifying and characterizing AIEC strains in pediatric IBD.<br />Methods: In all, 24 CD children, 10 UC, and 23 controls were investigated. Mucosal biopsies, taken during colonoscopy, were analyzed for the presence of AIEC strains by an adhesive-invasive test. Protein expression of the specific AIEC receptor, the carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6), was evaluated by western blot and immunohistochemistry, while tumor necrosis factor alpha (TNF-α) and interleukin (IL)-8 mRNA expression was detected by real-time polymerase chain reaction (PCR), after bacterial infection. Transmission electron microscopy and trans-epithelial electric resistance assays were performed on biopsies to assess bacteria-induced morphological and functional epithelial alterations.<br />Results: Two bacterial strains, EC15 and EC10, were found to adhere and invade the Caco2 cell line, similar to the well-known AIEC strain LF82 (positive control): they upregulated CEACAM6, TNF-α, and IL-8 gene/protein expression, in vitro and in cultured intestinal mucosa; they could also survive inside macrophages and damage the epithelial barrier integrity. Lesions in the inflamed tissues were associated with bacterial infection.<br />Conclusions: This is the first study showing the presence of adhesive-invasive bacteria strains in the inflamed tissues of children with IBD. Collective features of these strains indicate that they belong to the AIEC spectrum, suggesting their possible role in disease pathogenesis.<br /> (Copyright © 2011 Crohn's & Colitis Foundation of America, Inc.)
- Subjects :
- Adolescent
Animals
Antigens, CD genetics
Blotting, Western
Case-Control Studies
Cell Adhesion Molecules genetics
Cells, Cultured
Child
Colitis, Ulcerative immunology
Colitis, Ulcerative pathology
Crohn Disease immunology
Crohn Disease pathology
Escherichia coli genetics
Escherichia coli Infections immunology
Escherichia coli Infections pathology
Female
Fluorescent Antibody Technique
GPI-Linked Proteins genetics
GPI-Linked Proteins metabolism
Humans
Immunoenzyme Techniques
Interleukin-8 metabolism
Intestinal Mucosa immunology
Intestinal Mucosa microbiology
Macrophages immunology
Macrophages microbiology
Male
Mice
Organ Culture Techniques
RNA, Messenger genetics
Real-Time Polymerase Chain Reaction
Tumor Necrosis Factor-alpha pharmacology
Antigens, CD metabolism
Bacterial Adhesion
Cell Adhesion Molecules metabolism
Colitis, Ulcerative microbiology
Crohn Disease microbiology
Escherichia coli isolation & purification
Escherichia coli Infections microbiology
Subjects
Details
- Language :
- English
- ISSN :
- 1536-4844
- Volume :
- 18
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Inflammatory bowel diseases
- Publication Type :
- Academic Journal
- Accession number :
- 21994005
- Full Text :
- https://doi.org/10.1002/ibd.21899