scholarly journals Escherichia coli O157:H7 Curli Fimbriae Promotes Biofilm Formation, Epithelial Cell Invasion, and Persistence in Cattle

2020 ◽  
Vol 8 (4) ◽  
pp. 580 ◽  
Author(s):  
Haiqing Sheng ◽  
Yansong Xue ◽  
Wei Zhao ◽  
Carolyn J. Hovde ◽  
Scott A. Minnich
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Invasion ◽  
Base Pair ◽  
Biofilm Formation ◽  
Escherichia Coli O157 ◽  
Single Base ◽  
Single Base Pair ◽  
Epithelial Cell Invasion

Escherichia coli O157:H7 (O157) is noninvasive and a weak biofilm producer; however, a subset of O157 are exceptions. O157 ATCC 43895 forms biofilms and invades epithelial cells. Tn5 mutagenesis identified a mutation responsible for both phenotypes. The insertion mapped within the curli csgB fimbriae locus. Screening of O157 strains for biofilm formation and cell invasion identified a bovine and a clinical isolate with those characteristics. A single base pair A to T transversion, intergenic to the curli divergent operons csgDEFG and csgBAC, was present only in biofilm-producing and invasive strains. Using site-directed mutagenesis, this single base change was introduced into two curli-negative/noninvasive O157 strains and modified strains to form biofilms, produce curli, and gain invasive capability. Transmission electron microscopy (EM) and immuno-EM confirmed curli fibers. EM of bovine epithelial cells (MAC-T) co-cultured with curli-expressing O157 showed intracellular bacteria. The role of curli in O157 persistence in cattle was examined by challenging cattle with curli-positive and -negative O157 and comparing carriage. The duration of bovine colonization with the O157 curli-negative mutant was shorter than its curli-positive isogenic parent. These findings definitively demonstrate that a single base pair stably confers biofilm formation, epithelial cell invasion, and persistence in cattle.

scholarly journals Contribution of FliC to Epithelial Cell Invasion by Enterohemorrhagic Escherichia coli O113:H21

2006 ◽  
Vol 74 (12) ◽  
pp. 6999-7004 ◽  
Author(s):  
Shelley N. Luck ◽  
Luminita Badea ◽  
Vicki Bennett-Wood ◽  
Roy Robins-Browne ◽  
Elizabeth L. Hartland
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Invasion ◽  
Intestinal Epithelium ◽  
Enterohemorrhagic Escherichia Coli ◽  
Specific Antibodies ◽  
Epithelial Cell Invasion

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) O113:H21 can invade epithelial cells. In this study, we found that invasion but not adherence was inhibited by anti-FliCH21 specific antibodies. In addition, deletion of fliCH21 from EHEC O113:H21 resulted in an eightfold decrease in invasion that was restored upon transcomplementation with fliCH21 but not with fliCH6 . These results suggested that FliC plays an important role in the pathogenesis of infections caused by EHEC O113:H21 by allowing bacteria to penetrate the intestinal epithelium.

scholarly journals Epithelial Cell Adherence Mediated by the Enterotoxigenic Escherichia coli Tia Protein

2000 ◽  
Vol 68 (12) ◽  
pp. 6595-6601 ◽  
Author(s):  
Joseph G. Mammarappallil ◽  
Eric A. Elsinghorst
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Outer Membrane ◽  
Cell Invasion ◽  
Outer Membrane Proteins ◽  
Sodium Dodecyl ◽  
Enterotoxigenic Escherichia Coli ◽  
E Coli ◽  
Epithelial Cell Invasion

ABSTRACT In vitro studies have shown that enterotoxigenic Escherichia coli (ETEC) strains are capable of invading cultured epithelial cells derived from the human ileum and colon. Two separate invasion loci (tia and tib) have previously been isolated from the classical ETEC strain H10407 . The tialocus has been shown to direct the synthesis of Tia, a 25-kDa outer membrane protein. Tia is sufficient to confer the adherence and invasion phenotypes on laboratory stains of E. coli, suggesting that this protein is an adhesin and invasin. Here we report the purification of Tia and characterize its biological activity. Tia was purified by electroelution of outer membrane proteins that had been separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Purified Tia was labeled with biotin and then shown to bind to HCT8 human ileocecal epithelial cells in a specific and saturable manner. Polyclonal anti-Tia antiserum blocked this binding. These results show that Tia acts as an adhesin. Polyclonal anti-Tia antiserum also inhibited invasion of recombinant E. coli bearingtia clones, indirectly suggesting that Tia may also act as an invasin. We predict Tia to contain eight transmembrane amphipathic β-sheets with four loops that are exposed on the surface of the bacterial cell. A peptide corresponding to 19 residues in one of the four predicted surface-exposed loops inhibits Tia-mediated epithelial cell invasion. Seeding HCT8 cells on wells coated with purified Tia reduced Tia-mediated epithelial cell invasion. Together, these results indicate that Tia is an invasin and adhesin that binds a specific receptor on HCT8 cells.

scholarly journals Mutations in the csgD Promoter Associated with Variations in Curli Expression in Certain Strains ofEscherichia coli O157:H7

2001 ◽  
Vol 67 (5) ◽  
pp. 2367-2370 ◽  
Author(s):  
Gaylen A. Uhlich ◽  
James E. Keen ◽  
Robert O. Elder
Keyword(s):  
Escherichia Coli ◽  
Base Pair ◽  
Congo Red ◽  
Substrate Utilization ◽  
Ofescherichia Coli ◽  
Single Base ◽  
Curli Fiber ◽  
Single Base Pair ◽  
Red Dye ◽  
Promoter Mutations

ABSTRACT Single-base-pair csgD promoter mutations in human outbreak Escherichia coli O157:H7 strains ATCC 43894 and ATCC 43895 coincided with differential Congo red dye binding from curli fiber expression. Red phenotypecsgD::lacZ promoter fusions had fourfold-greater expression than white promoter fusions. Cloning the red variant csgDEFG operon into white variants induced the red phenotype. Substrate utilization differed between red and white variants.

scholarly journals Mechanisms of activation of the cryptic cel operon of Escherichia coli K12.

Genetics ◽  
1990 ◽  
Vol 124 (3) ◽  
pp. 473-482 ◽  
Author(s):  
L L Parker ◽  
B G Hall
Keyword(s):  
Escherichia Coli ◽  
Base Pair ◽  
Point Mutations ◽  
Insertion Sequences ◽  
Wild Type ◽  
Single Base ◽  
Escherichia Coli K12 ◽  
In The Wild ◽  
Single Base Pair ◽  
Strain Dependent

Abstract The cel (cellobiose utilization) operon of Escherichia coli K12 is not expressed in the wild-type organism. However, mutants that can express the operon and thereby utilize the beta-glucoside sugars cellobiose, arbutin and salicin are easily isolated. Two kinds of mutations are capable of activating the operon. The first involves mutations that allow the repressor to recognize the substrates cellobiose, arbutin and salicin as inducers. We have identified the sequence changes in five different active alleles and found those differences to be single base pair changes at one of two lysine codons in the repressor gene. The second kind of mutation involves the integration of the insertion sequences IS1, IS2 or IS5 into a 108-bp region 72-180 bp upstream of the start of transcription. Integration occurs at several different sites and in different orientations. Transcription of the cel operon begins at the same base pair in all mutants examined. Of 44 independent cel+ mutants, 27 were activated by point mutations and 17 were activated by insertion sequences. The preferred mechanism of activation appears to be strain dependent, since one of the parents yielded 94% insertionally activated alleles, while another yielded 100% point mutation activated alleles.

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