scholarly journals The high-adhesive properties of the FimH adhesin of Salmonella enterica serovar Enteritidis are determined by a single F118S substitution

Microbiology ◽  
2010 ◽  
Vol 156 (6) ◽  
pp. 1738-1748 ◽  
Author(s):  
Krzysztof Grzymajło ◽  
Marta Kuźmińska-Bajor ◽  
Jakub Jaworski ◽  
Piotr Dobryszycki ◽  
Maciej Ugorski
Keyword(s):  
Salmonella Enterica ◽  
Site Directed Mutagenesis ◽  
Chimeric Proteins ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Adhesive Properties ◽  
Type 1 Fimbriae ◽  
Rnase B ◽  
Donor Strand Exchange ◽  
First Time

The binding properties of low- and high-adhesive forms of FimH adhesins from Salmonella enterica serovars Enteritidis and Typhimurium (S. Enteritidis and S. Typhimurium) were studied using chimeric proteins containing an additional peptide that represents an N-terminal extension of the FimF protein. This modification, by taking advantage of a donor strand exchange mechanism, closes the hydrophobic groove in the fimbrial domain of the FimH adhesin. Such self-complemented adhesins (scFimH) did not form aggregates and were more stable (resistant to proteolytic cleavage) than native FimH. High-adhesive variants of scFimH proteins, with alanine at position 61 and serine at position 118, were obtained by site-directed mutagenesis of fimH genes from low-adhesive variants of S. Enteritidis and S. Typhimurium, with glycine at position 61 and phenylalanine at position 118. Direct kinetic analysis using surface plasmon resonance (SPR) and glycoproteins carrying high-mannose carbohydrate chains (RNase B, horseradish peroxidase and mannan-BSA) revealed the existence of high- and low-adhesive allelic variants, not only in S. Typhimurium but also in S. Enteritidis. Using two additional mutants of low-adhesive FimH protein from S. Enteritidis (Gly61Ala and Phe118Ser), SPR analysis pointed to Ser118 as the major determinant of the high-adhesive phenotype of type 1 fimbriae from S. Enteritidis. These studies demonstrated for the first time that the functional differences observed with whole fimbriated bacteria could be reproduced at the level of purified adhesin. They strongly suggest that the adhesive properties of type 1 fimbriae are determined only by structural differences in the FimH proteins and are not influenced by the fimbrial shaft on which the adhesin is located.

scholarly journals Characterization of FimH Adhesins Expressed by Salmonella enterica Serovar Gallinarum Biovars Gallinarum and Pullorum: Reconstitution of Mannose-Binding Properties by Single Amino Acid Substitution

2005 ◽  
Vol 73 (9) ◽  
pp. 6187-6190 ◽  
Author(s):  
Dagmara Kisiela ◽  
Anna Sapeta ◽  
Maciej Kuczkowski ◽  
Tadeusz Stefaniak ◽  
Alina Wieliczko ◽  
...  
Keyword(s):  
Colon Carcinoma ◽  
Salmonella Enterica ◽  
Human Colon ◽  
Site Directed Mutagenesis ◽  
Single Amino Acid ◽  
Binding Properties ◽  
Type 1 Fimbriae ◽  
Serovar Typhimurium ◽  
High Mannose

ABSTRACT Recombinant FimH adhesins of type 1 fimbriae from Salmonella enterica serovar Gallinarum biovars Gallinarum and Pullorum, in contrast to those of Salmonella enterica serovar Typhimurium, did not bind to high-mannose oligosaccharides or to human colon carcinoma HT-29 cells. However, mutated FimH proteins from biovar Gallinarum and biovar Pullorum, in which the isoleucine at position 78 was replaced by the threonine found in S. enterica serovar Typhimurium, bound well to glycoproteins carrying high-mannose oligosaccharides and colon carcinoma cells. The loss of sugar-binding properties by biovar Gallinarum and biovar Pullorum FimH adhesins, which are a part of the type 1 fimbriae, is most probably the result of a single T78I mutation, as was proven by site-directed mutagenesis of FimH proteins.

scholarly journals Expression of type 1 fimbriae (SEF 21) of Salmonella enterica serotype Enteritidis in the early colonisation of the rat intestine

2001 ◽  
Vol 50 (2) ◽  
pp. 191-197 ◽  
Author(s):  
PATRICK J. NAUGHTON ◽  
GEORGE GRANT ◽  
SUSAN BARDOCZ ◽  
EMMA ALLEN-VERCOE ◽  
MARTIN J. WOODWARD ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Rat Intestine ◽  
Type 1 Fimbriae ◽  
Salmonella Enterica Serotype Enteritidis

scholarly journals Inactivation of ibeA and ibeT Results in Decreased Expression of Type 1 Fimbriae in Extraintestinal Pathogenic Escherichia coli Strain BEN2908

2008 ◽  
Vol 76 (9) ◽  
pp. 4129-4136 ◽  
Author(s):  
Mélanie A. M. Cortes ◽  
Julien Gibon ◽  
Nathalie K. Chanteloup ◽  
Maryvonne Moulin-Schouleur ◽  
Philippe Gilot ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Wild Type Strain ◽  
Coli Strain ◽  
Wild Type ◽  
Adhesive Properties ◽  
Type 1 Fimbriae ◽  
Pathogenic Escherichia Coli ◽  
Genes Encoding

ABSTRACT IbeA in extraintestinal pathogenic Escherichia coli (ExPEC) strains was previously described for its role in invasion. Here we investigated the role of IbeA and IbeT, encoded by a gene located downstream of ibeA, in the adhesion of the avian ExPEC strain BEN2908 to human brain microvascular endothelial cells (HBMEC). The ΔibeA mutant was less adhesive to HBMEC than the wild-type strain BEN2908 was. Because strain BEN2908 also expresses type 1 fimbriae, we measured the adhesion specifically due to IbeA by comparing the adhesive properties of a Δfim derivative of strain BEN2908 to those of a double Δfim ΔibeA mutant. No differences were observed, indicating that the reduction of adhesion in BEN2908 ΔibeA could be due to a decrease in type 1 fimbria expression. We indeed showed that the decreased adhesion of BEN2908 ΔibeA was correlated with a decrease in type 1 fimbria expression. Accordingly, more bacteria had a fim promoter orientated in the off position in a culture of BEN2908 ΔibeA than in a culture of BEN2908. Expression of fimB and fimE, two genes encoding recombinases participating in controlling the orientation of the fim promoter, was decreased in BEN2908 ΔibeA. A reduction of type 1 fimbria expression due to a preferential orientation of the fim promoter in the off position was also seen in an ibeT mutant of strain BEN2908. We finally suggest a role for IbeA and IbeT in modulating the expression of type 1 fimbriae through an as yet unknown mechanism.

scholarly journals Surface Interactions between Escherichia coli and Hemocytes of the Mediterranean Mussel Mytilus galloprovincialis Lam. Leading to Efficient Bacterial Clearance

2001 ◽  
Vol 67 (1) ◽  
pp. 464-468 ◽  
Author(s):  
Laura Canesi ◽  
Carla Pruzzo ◽  
Renato Tarsi ◽  
Gabriella Gallo
Keyword(s):  
Escherichia Coli ◽  
Mytilus Galloprovincialis ◽  
Inhibitory Effect ◽  
Culturable Bacteria ◽  
Adhesive Properties ◽  
Type 1 Fimbriae ◽  
In Vivo Experiments

ABSTRACT The role of type 1 fimbriae in the interactions betweenEscherichia coli and Mytilus galloprovincialisLam. hemocytes was evaluated. The association of fimbriated strain MG155 with hemocyte monolayers at 18°C was 1.5- and 3- to 4-fold greater than the association of unfimbriated mutant AAEC072 in artificial seawater and in hemolymph serum, respectively. Such differences were apparently due to different adhesive properties since MG155 adhered more efficiently than AAEC072 when hemocytes were incubated at 4°C to inhibit the internalization process. Hemolymph serum increased both association and adherence of MG155 two- to threefold but did not affect association and adherence of AAEC072. MG155 was also 1.5- to 1.7-fold more sensitive to killing by hemocytes than AAEC072, as evaluated by the number of culturable bacteria after 60 and 120 min of incubation. The role of type 1 fimbriae in MG155 interactions with hemocytes was confirmed by the inhibitory effect ofd-mannose. In in vivo experiments MG155 cells were cleared from circulating hemolymph more rapidly than AAEC072 cells were cleared. These results confirm that surface properties are crucial in influencing bacterial persistence and survival within mussel hemolymph.

scholarly journals The Leucine-Responsive Regulatory Protein, Lrp, Activates Transcription of the fim Operon in Salmonella enterica Serovar Typhimurium via the fimZ Regulatory Gene

2007 ◽  
Vol 190 (2) ◽  
pp. 602-612 ◽  
Author(s):  
Kirsty A. McFarland ◽  
Sacha Lucchini ◽  
Jay C. D. Hinton ◽  
Charles J. Dorman
Keyword(s):  
Gene Expression ◽  
Salmonella Enterica ◽  
Regulatory Protein ◽  
Regulatory Region ◽  
Upstream Region ◽  
Positive Contribution ◽  
Type 1 Fimbriae ◽  
Regulatory Cascade ◽  
Serovar Typhimurium

ABSTRACT The fim operon of Salmonella enterica serovar Typhimurium encodes type 1 fimbriae. The expression of fim is controlled in response to environmental signals through a complex regulatory cascade involving the proteins FimW, FimY, and FimZ and a genetic locus, fimU, that encodes a rare arginine tRNA. We discovered that a knockout mutation in lrp, the gene that codes for the leucine-responsive regulatory protein (Lrp), inhibited fim transcription. The loss of fim gene expression was accompanied by a corresponding loss of the mannose-sensitive hemagglutination that is a characteristic of type 1 fimbriae. Normal type 1 fimbrial expression was restored following the introduction into the knockout mutant of a plasmid carrying a functional copy of the lrp gene. Electrophoretic mobility shift analysis revealed no interactions between purified Lrp protein and the regulatory region of the fimA, fimU, or fimW gene. Instead, Lrp produced protein-DNA complexes with the regulatory region of the fimZ gene, and the nature of these complexes was leucine sensitive. DNase I footprinting showed that Lrp binds within a region between −65 and −170 with respect to the fimZ transcription start site, consistent with the binding and wrapping of the DNA in this upstream region. Ectopic expression of the fimZ gene from an inducible promoter caused Lrp-independent type 1 fimbriation in serovar Typhimurium. These data show that Lrp makes a positive contribution to fim gene expression through direct interaction with the fimZ promoter region, possibly by antagonizing the binding of the H-NS global repressor protein.

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