Presence of bacterial 16S ribosomal RNA gene segments in human intestinal lymph follicles.
Scand J Gastroenterol
; 35(8): 824-31, 2000 Aug.
Article
en En
| MEDLINE
| ID: mdl-10994621
BACKGROUND: There is currently no information regarding microbial agents inside the intestinal lymph follicles. METHODS: Biopsy or resected specimens, mostly from macroscopically normal areas, were sectioned with a cryostat. DNA was extracted from microdissected samples, exclusively from the lymph follicle. Amplification of DNA was performed using universal primers designed from conserved regions of bacterial 16S ribosomal RNA (rRNA). Several clones with inserts of around 400 base pairs were subjected to DNA sequence analysis followed by a database homology search. RESULTS: Bacterial 16S rRNA gene segments were detected in the lymph follicle in 2 of 14 (14%) non-inflammatory bowel disease (IBD) cases, 4 of 14 (28%) Crohn disease cases, and in 2 of 5 (40%) ulcerative colitis cases. Nineteen 16S rRNA gene segments were recognized in the eight positive cases. Five segments showed 100% identity to known bacterial 16S rRNAs, namely staphylococcus species, Streptococcus sanguis, and Paracoccus marcusii. However, the other 14 segments showed below 100% identity, indicating either the presence of unknown bacteria or of bacteria without known DNA data. No single identified or unidentified bacterium, characteristic of IBD, including Mycobacterium paratuberculosis and Listeria monocytogenes, was detected. CONCLUSIONS: The present study confirms the presence of bacterial 16S rRNA gene segments in human intestinal lymph follicles and paves the way for new investigations into the microbiology of the lymph follicle. Whether or not bacteria inside the lymph follicle is a primary stimulus in IBD has yet to be clarified.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Bacterias
/
ARN Bacteriano
/
ARN Ribosómico 16S
/
Enfermedades Inflamatorias del Intestino
/
Ganglios Linfáticos
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Límite:
Adolescent
/
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Scand J Gastroenterol
Año:
2000
Tipo del documento:
Article
País de afiliación:
Japón
Pais de publicación:
Reino Unido