ID 106004
Author
Nakayama-Imaohji, Haruyuki Department of Immunology and Parasitology, Institute of Health Biosciences, the University of Tokushima Graduate School|Department of Molecular Bacteriology, Institute of Health Biosciences, the University of Tokushima Graduate School
Ichimura, Minoru Department of Immunology and Parasitology, Institute of Health Biosciences, the University of Tokushima Graduate School
Iwasa, Tomoya Department of Molecular Bacteriology, Institute of Health Biosciences, the University of Tokushima Graduate School
Okada, Natsumi Department of Molecular Bacteriology, Institute of Health Biosciences, the University of Tokushima Graduate School
Ohnishi, Yoshinari Department of Molecular Bacteriology, Institute of Health Biosciences, the University of Tokushima Graduate School Tokushima University Educator and Researcher Directory
Kuwahara, Tomomi Department of Molecular Bacteriology, Institute of Health Biosciences, the University of Tokushima Graduate School|Department of Molecular Microbiology, Faculty of Medicine, Kagawa University
Keywords
Bacteroides fragilis
sialidase
sialoglycoconjugate
colonization
mucin
Content Type
Journal Article
Description
Recent analysis of the whole genome sequence of Bacteroides fragilis revealed extensive duplication of polysaccharide utilization genes in this anaerobe. Here we analyzed a unique 27-kb gene cluster (sgu) comprised of the 13 sialoglycoconjugates-utilization genes, which include the sialidase gene (nanH1) in B. fragilis strain YCH46. The genes were tightly organized and transcribed polycistronically. Comparative PCR scanning demonstrated that the sgu locus was conserved among the Bacteroides strains tested. Based on the transcriptional profiles generated by reverse transcriptase PCR, the sgu locus can be classified into at least three regulatory units : 1) sialic acid- or sialooligosaccharide-inducible genes, 2) constitutively expressed genes that can be down-regulated by catabolite repression, and 3) constitutively expressed genes. In vitro comparison of the growth of a sgu locus deletion mutant (SGUM172941) with a wild type strain indicates that this locus is necessary for B. fragilis to efficiently utilize mucin as a carbon source. Furthermore, SGUM172941 was defective in colonization of the intestines of germfree mice under competitive conditions. These data indicate that the sgu locus in B. fragilis plays a crucial role in the utilization of host-derived sialoglycoconjugates and the stable colonization of this anaerobe in the human gut.
Journal Title
The journal of medical investigation : JMI
ISSN
13431420
NCID
AA11166929
Volume
59
Issue
1-2
Start Page
79
End Page
94
Sort Key
79
Published Date
2012-02
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Publisher
departments
Medical Sciences