Although multiple studies have focused on Helicobacter pylori, little is known about the mucosa-associated flora of the colon.
The aim of this study was to detect bacteria directly in colonic mucosa from patients screened for colorectal cancer.
Bacteria were quantified with the polymerase chain reaction and identified by comparative sequence analysis in colonoscopic biopsy specimens from 31 asymptomatic and 34 symptomatic controls with normal colonoscopic findings, 29 patients with colonic adenoma, and 31 patients with colorectal carcinoma.
In 41 patients, intra-and extracellular location of bacteria was confirmed with the gentamicin protection assay.
No bacteria were detected in biopsy specimens from 97% of asymptomatic and 69% of symptomatic controls.
In contrast, bacterial concentrations of 103-105 colony-forming units per microliter were detected in biopsy specimens from both malignant and macroscopically normal tissue in 90% and 93% of patients with adenoma and carcinoma, respectively.
E. coil and coli-like bacteria were shown to colonize the colonic mucosa in 82% of these patients.
The gentamicin protection assay indicated that E. coil was partially intracellular in 87% of patients with adenoma and carcinoma and in none of the controls.
The colonic mucosa of patients with colorectal carcinoma but not normal colonic mucosa is colonized by intracellular E. coli.
Mots-clés Pascal : Carcinome, Côlon, Rectum, Escherichia coli, Enterobacteriaceae, Bactérie, Dépistage, Association, Colonoscopie, Biopsie, Evaluation, Autriche, Europe, Homme, Muqueuse, Tumeur maligne, Appareil digestif pathologie, Intestin pathologie, Côlon pathologie, Rectum pathologie, Bactériose, Infection, Endoscopie
Mots-clés Pascal anglais : Carcinoma, Colon, Rectum, Escherichia coli, Enterobacteriaceae, Bacteria, Medical screening, Association, Colonoscopy, Biopsy, Evaluation, Austria, Europe, Human, Mucosa, Malignant tumor, Digestive diseases, Intestinal disease, Colonic disease, Rectal disease, Bacteriosis, Infection, Endoscopy
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0397189
Code Inist : 002B13B01. Création : 25/01/1999.