scholarly journals Arginine within a specific motif near the N‐terminal of FimY is critical for the maximal production of type 1 fimbriae in Salmonella enterica serovar Typhimurium

2019 ◽  
Vol 8 (9) ◽  
Author(s):  
Nan‐Ling Kuan ◽  
Kuang‐Sheng Yeh
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Type 1 Fimbriae ◽  
Serovar Typhimurium ◽  
Maximal Production

scholarly journals Type 1 Fimbriae of Salmonella enterica Serovar Typhimurium Bind to Enterocytes and Contribute to Colonization of Swine In Vivo

2003 ◽  
Vol 71 (11) ◽  
pp. 6446-6452 ◽  
Author(s):  
Carrie Althouse ◽  
Sheila Patterson ◽  
Paula Fedorka-Cray ◽  
Richard E. Isaacson
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Phase Variation ◽  
Gene Encoding ◽  
Type 1 Fimbriae ◽  
Systemic Spread ◽  
Serovar Typhimurium ◽  
Asymptomatic Infections

ABSTRACT Salmonella enterica serovar Typhimurium strain 798 is a clinical isolate from a pig and is known to be able to cause persistent, asymptomatic infections. This strain also is known to exist in two phenotypes (adhesive and nonadhesive to enterocytes) and can switch between the two phenotypes at a rate consistent with phase variation. Cells in the adhesive phenotype are more readily phagocytosed by leukocytes than nonadhesive cells. Once in a leukocyte, adhesive-phase cells survive while nonadhesive-phase cells die. In the present study, nonadhesive mutants were obtained with the transposon TnphoA. A nonadhesive mutant was selected for study and was shown by electron microscopy not to produce fimbriae. The gene encoding the adhesin was cloned and sequenced. Based on its sequence, the adhesin was shown to be FimA, the major subunit of type 1 fimbriae. The nonadhesive mutant was attenuated in its ability to colonize both mouse and pig intestines, but remained capable of systemic spread in mice. The nonadhesive mutant was phagocytosed to the same extent as parental cells in the adhesive phase and then survived intracellularly. These results demonstrated that type 1 fimbriae were important for attachment to enterocytes and promoted intestinal colonization. However, they were not important in promoting phagocytosis or intracellular survival.

scholarly journals FimA, FimF, and FimH Are Necessary for Assembly of Type 1 Fimbriae on Salmonella enterica Serovar Typhimurium

2012 ◽  
Vol 80 (9) ◽  
pp. 3289-3296 ◽  
Author(s):  
Sarah A. Zeiner ◽  
Brett E. Dwyer ◽  
Steven Clegg
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Food Poisoning ◽  
Enteric Bacteria ◽  
Transcriptional Unit ◽  
Content Type ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
Serovar Typhimurium

ABSTRACTSalmonella entericaserovar Typhimurium is a Gram-negative member of the familyEnterobacteriaceaeand is a common cause of bacterial food poisoning in humans. The fimbrial appendages are found on the surface of many enteric bacteria and enable the bacteria to bind to eukaryotic cells.S. Typhimurium type 1 fimbriae are characterized by mannose-sensitive hemagglutination and are assembled via the chaperone/usher pathway.S. Typhimurium type 1 fimbrial proteins are encoded by thefimgene cluster (fimAICDHFZYW), withfimAICDHFexpressed as a single transcriptional unit. The structural components of the fimbriae are FimA (major subunit), FimI, FimH (adhesin), and FimF (adaptor). In order to determine which components are required for fimbrial formation inS. Typhimurium, mutations infimA,fimI,fimH, andfimFwere constructed and examined for their ability to produce surface-assembled fimbriae.S. Typhimurium SL1344ΔfimA, -ΔfimH, and -ΔfimFmutants were unable to assemble fimbriae, indicating that these genes are necessary for fimbrial production inS. Typhimurium. However, SL1344ΔfimIwas able to assemble fimbriae. InEscherichia colitype 1 and Pap fimbriae, at least two adaptors are expressed in addition to the adhesins. However,E. colitype 1 and Pap fimbriae have been reported to be able to assemble fimbriae in the absence of these proteins. These results suggest differences between theS. Typhimurium type 1 fimbrial system and theE. colitype 1 and Pap fimbrial systems.

scholarly journals FimY Does Not Interfere with FimZ-FimW Interaction during Type 1 Fimbria Production by Salmonella enterica Serovar Typhimurium

2013 ◽  
Vol 81 (12) ◽  
pp. 4453-4460 ◽  
Author(s):  
Sarah A. Zeiner ◽  
Brett E. Dwyer ◽  
Steven Clegg
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Response Regulator ◽  
Response Regulators ◽  
Content Type ◽  
Component Systems ◽  
The Family ◽  
Serovar Typhimurium ◽  
Two Component Systems

ABSTRACTThe production of type 1 fimbriae inSalmonella entericaserovar Typhimurium is controlled, in part, by three proteins, FimZ, FimY, and FimW. Amino acid sequence analysis indicates that FimZ belongs to the family of bacterial response regulators of two-component systems. In these studies, we have demonstrated that introducing a mutation mimicking phosphorylation of FimZ is necessary for activation of its target gene,fimA. In addition, the interaction of FimZ with FimW, a repressor offimAexpression, occurs only when FimZ is phosphorylated. Consequently, the negative regulatory effect of FimW is most likely due to downmodulation of the active FimZ protein. FimY does not appear to function as a response regulator, and its activity can be lost by mimicking the phosphorylation of FimY. Overproduction of FimY cannot alleviate the nonfimbriate phenotype in a FimZ mutant, whereas high levels of FimZ can overcome the nonfimbriate phenotype of a FimY mutant. It appears that FimY acts upstream of FimZ to activatefimAexpression.

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 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.

scholarly journals Contribution of the SirA regulon to biofilm formation in Salmonella enterica serovar Typhimurium

Microbiology ◽  
2006 ◽  
Vol 152 (11) ◽  
pp. 3411-3424 ◽  
Author(s):  
Max Teplitski ◽  
Ali Al-Agely ◽  
Brian M. M. Ahmer
Keyword(s):  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Bacterial Species ◽  
Virulence Gene ◽  
Two Component System ◽  
Serovar Typhimurium ◽  
Regulatory Rnas

Orthologues of the Salmonella enterica serovar Typhimurium (S. typhimurium) BarA/SirA two-component system are important for biofilm formation and virulence in many γ-Proteobacteria. In S. typhimurium, SirA activates the csrB and csrC carbon storage regulatory RNAs and the virulence gene regulators hilA and hilC. The regulatory RNAs antagonize the activity of the CsrA protein, allowing translation of those same virulence genes, and inhibiting the translation of flagellar genes. In this report, it was determined that SirA and the Csr system also control the fim operon that encodes type 1 fimbriae. sirA orthologues in other bacterial species, and the fim operon of S. typhimurium, are known to play a role in biofilm formation; therefore, all members of the S. typhimurium sirA regulon were tested for in vitro biofilm production. A sirA mutant, a csrB csrC double mutant, and a fimI mutant, were all defective in biofilm formation. Conversely, inactivation of flhDC increased biofilm formation. Therefore, SirA activates csrB, csrC and the fim operon to promote biofilm formation. In turn, csrB and csrC promote the translation of the fim operon, while at the same time inhibiting the translation of flagella, which are inhibitory to biofilm formation.

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