The mannose-specific lectin activity of Escherichia coli type 1 fimbriae assayed by agglutination of glycolipid-containing liposomes, erythrocytes, and yeast cells and hydrophobic interaction chromatography

Type 1 fimbriae of Escherichia coli facilitate attachment to the host mucosa and promote biofilm formation on abiotic surfaces. The transcriptional regulator LrhA, which is known as a repressor of flagellar, motility and chemotaxis genes, regulates biofilm formation and expression of type 1 fimbriae. Whole-genome expression profiling revealed that inactivation of lrhA results in an increased expression of structural components of type 1 fimbriae. In vitro, LrhA bound to the promoter regions of the two fim recombinases (FimB and FimE) that catalyse the inversion of the fimA promoter, and to the invertible element itself. Translational lacZ fusions with these genes and quantification of fimE transcript levels by real-time PCR showed that LrhA influences type 1 fimbrial phase variation, primarily via activation of FimE, which is required for the ON-to-OFF transition of the fim switch. Enhanced type 1 fimbrial expression as a result of lrhA disruption was confirmed by mannose-sensitive agglutination of yeast cells. Biofilm formation was stimulated by lrhA inactivation and completely suppressed upon LrhA overproduction. The effects of LrhA on biofilm formation were exerted via the changed levels of surface molecules, most probably both flagella and type 1 fimbriae. Together, the data show a role for LrhA as a repressor of type 1 fimbrial expression, and thus as a regulator of the initial stages of biofilm development and, presumably, bacterial adherence to epithelial host cells also.

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Analysis of Escherichia coli Strains Causing Bacteriuria during Pregnancy: Selection for Strains That Do Not Express Type 1 Fimbriae

Infection and Immunity ◽

10.1128/iai.69.2.794-799.2001 ◽

2001 ◽

Vol 69 (2) ◽

pp. 794-799 ◽

Cited By ~ 9

Author(s):

J. C. Graham ◽

J. B. S. Leathart ◽

S. J. Keegan ◽

J. Pearson ◽

A. Bint ◽

...

Keyword(s):

Escherichia Coli ◽

Pregnant Women ◽

Regulatory Region ◽

Yeast Cells ◽

Virulence Determinants ◽

Type 1 Fimbriae ◽

Infected Urine ◽

Cytotoxic Necrotizing Factor 1

ABSTRACT Escherichia coli isolates from patients with bacteriuria of pregnancy were compared by PCR with isolates from patients with community-acquired cystitis for the presence of established virulence determinants. The strains from patients with bacteriuria of pregnancy were less likely to carry genes for P-family, S-family, and F1C adhesins, cytotoxic necrotizing factor 1, and aerobactin, but virtually all of the strains carried the genes for type 1 fimbriae. Standard mannose-sensitive agglutination of yeast cells showed that only 15 of 42 bacteriuria strains (36%) expressed type 1 fimbriae compared with 32 of 42 strains from community-acquired symptomatic infections (76%) (P < 0.01). This difference was confirmed by analysis of all isolates for an allele of the type 1 fimbrial regulatory region (fim switch), which negates type 1 fimbrial expression by preventing the fimswitch from being inverted to the on phase. This allele,fimS49, was found in 8 of 47 bacteriuria strains from pregnant women (17.0%) compared with 2 of 60 strains isolated from patients with cystitis (3.3%) (P < 0.05). Determination of the phase switch orientation in vivo by analysis of freshly collected infected urine from patients with bacteriuria showed that the fim switch was detectable in the off orientation in 17 of 23 urine samples analyzed (74%). These data indicate that type 1 fimbriae are not necessary to maintain the majority of E. coli bacteriurias in pregnant women since there appears to be selection against their expression in this particular group. This is in contrast to the considered role of this adhesin in community-acquired symptomatic infections. The lack of type 1 fimbria expression is likely to contribute to the asymptomatic nature of bacteriuria in pregnant women, although approximately one-third of the bacteriuria isolates do possess key virulence determinants. If left untreated, this subset of isolates pose the greatest threat to the health of the mother and unborn child.

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The mannose-specific lectin activity ofEscherichia colitype 1 fimbriae assayed by agglutination of glycolipid-containing liposomes, erythrocytes, and yeast cells and hydrophobic interaction chromatography

FEMS Microbiology Letters ◽

10.1111/j.1574-6968.1982.tb08653.x ◽

1982 ◽

Vol 14 (3) ◽

pp. 149-153 ◽

Cited By ~ 3

Author(s):

Lena Ã–hman ◽

Karl-Eric Magnusson ◽

Olle Stendahl

Keyword(s):

Hydrophobic Interaction ◽

Hydrophobic Interaction Chromatography ◽

Yeast Cells ◽

Lectin Activity

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A preparative hydrophobic interaction chromatography for purification of recombinant nucleocapsid protein of Nipah virus from clarified Escherichia coli homogenate

Separation and Purification Technology ◽

10.1016/j.seppur.2009.11.007 ◽

2010 ◽

Vol 71 (1) ◽

pp. 97-101 ◽

Cited By ~ 8

Author(s):

Fui Chin Chong ◽

Wen Siang Tan ◽

Dayang R.A. Biak ◽

Tau Chuan Ling ◽

Beng Ti Tey

Keyword(s):

Escherichia Coli ◽

Hydrophobic Interaction ◽

Nucleocapsid Protein ◽

Nipah Virus ◽

Hydrophobic Interaction Chromatography ◽

Recombinant Nucleocapsid Protein

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Role of the ceramide-signaling pathway in cytokine responses to P-fimbriated Escherichia coli.

Journal of Experimental Medicine ◽

10.1084/jem.183.3.1037 ◽

1996 ◽

Vol 183 (3) ◽

pp. 1037-1044 ◽

Cited By ~ 115

Author(s):

M Hedlund ◽

M Svensson ◽

A Nilsson ◽

R D Duan ◽

C Svanborg

Keyword(s):

Escherichia Coli ◽

Signaling Pathway ◽

Kinase Inhibitors ◽

Human Kidney ◽

Cytokine Response ◽

Protein Kinase Inhibitors ◽

E Coli ◽

Type 1 Fimbriae ◽

Outer Leaflet

Escherichia coli express fimbriae-associated adhesins through which they attach to mucosal cells and activate a cytokine response. The receptors for E. coli P fimbriae are the globoseries of glycosphingolipids; Gal alpha 1-->4Gal beta-containing oligosaccharides bound to ceramide in the outer leaflet of the lipid bilayer. The receptors for type 1 fimbriae are mannosylated glycoproteins rather than glycolipids. This study tested the hypothesis that P-fimbriated E. coli elicit a cytokine response through the release of ceramide in the receptor-bearing cell. We used the A498 human kidney cell line, which expressed functional receptors for P and type 1 fimbriae and secreted higher levels of interleukin (IL)-6 when exposed to the fimbriated strains than to isogenic nonfimbriated controls. P-fimbriated E. coli caused the release of ceramide and increased the phosphorylation of ceramide to ceramide 1-phosphate. The IL-6 response to P-fimbriated E. coli was reduced by inhibitors of serine/threonine kinases but not by other protein kinase inhibitors. In contrast, ceramide levels were not influenced by type 1-fimbriated E. coli, and the IL-6 response was insensitive to the serine/threonine kinase inhibitors. These results demonstrate that the ceramide-signaling pathway is activated by P-fimbriated E. coli, and that the receptor specificity of the P fimbriae influences this process. We propose that this activation pathway contributes to the cytokine induction by P-fimbriated E. coli in epithelial cells.

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