Back to Search
Start Over
Sialic acid and N-acetylglucosamine Regulate type 1 Fimbriae Synthesis.
- Source :
-
Microbiology spectrum [Microbiol Spectr] 2015 Jun; Vol. 3 (3). - Publication Year :
- 2015
-
Abstract
- Type 1 fimbriae of E. coli, a chaperon-usher bacterial adhesin, are synthesized by the majority of strains of the bacterium. Although frequently produced by commensal strains, the adhesin is nevertheless a virulence factor in Extraintestinal Pathogenic E. coli (ExPEC). The role of the adhesin in pathogenesis is best understood in Uropathogenic E. coli (UPEC). Host attachment and invasion by type 1 fimbriate bacteria activates inflammatory pathways, with TLR4 signaling playing a predominant role. In a mouse model of cystitis, type 1 fimbriation not only enhances UPEC adherence to the surface of superficial umbrella cells of the bladder urothelium, but is both necessary and sufficient for their invasion. Moreover the adhesin plays a role in the formation of transient intracellular bacterial communities (IBCs) within the cytoplasm of urothelial cells as part of UPEC cycles of invasion. The expression of type 1 fimbriation is controlled by phase variation at the transcriptional level, a mode of gene regulation in which bacteria switch reversibly between fimbriate and afimbriate phases. Phase variation has been widely considered to be a mechanism enabling immune evasion. Notwithstanding the apparently random nature of phase variation, switching of type 1 fimbrial expression is nevertheless controlled by a range of environmental signals that include the amino sugars sialic acid and N-acetylglucosamine (GlcNAc). Sialic acid plays a pivotal role in innate immunity, including signaling by the toll-like receptors. Here how sialic acid and GlcNAc control type 1 fimbriation is described and the potential significance of this regulatory response is discussed.
- Subjects :
- Acetylglucosamine genetics
Adhesins, Escherichia coli genetics
Adhesins, Escherichia coli metabolism
Animals
Bacterial Outer Membrane Proteins genetics
Cystitis microbiology
Escherichia coli Proteins genetics
Fimbriae Proteins biosynthesis
Fimbriae Proteins genetics
Fimbriae, Bacterial genetics
Gene Expression Regulation, Bacterial
Mice
N-Acetylneuraminic Acid genetics
Porins genetics
Receptors, Immunologic metabolism
Toll-Like Receptor 4 metabolism
Uropathogenic Escherichia coli genetics
Uropathogenic Escherichia coli metabolism
Urothelium microbiology
Virulence Factors genetics
Virulence Factors metabolism
Acetylglucosamine metabolism
Bacterial Adhesion physiology
Fimbriae, Bacterial metabolism
N-Acetylneuraminic Acid metabolism
Uropathogenic Escherichia coli pathogenicity
Subjects
Details
- Language :
- English
- ISSN :
- 2165-0497
- Volume :
- 3
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Microbiology spectrum
- Publication Type :
- Academic Journal
- Accession number :
- 26185091
- Full Text :
- https://doi.org/10.1128/microbiolspec.MBP-0015-2014