scholarly journals Complex Interplay between Type 1 Fimbrial Expression and Flagellum-Mediated Motility of Uropathogenic Escherichia coli

2007 ◽  
Vol 189 (15) ◽  
pp. 5523-5533 ◽  
Author(s):  
M. Chelsea Lane ◽  
Amy N. Simms ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Constitutive Expression ◽  
Complex Interplay ◽  
Phenotypic Effect ◽  
Upec Strain ◽  
Partial Restoration ◽  
Type 1 Fimbriae ◽  
K 12 ◽  
The Relationship

ABSTRACT Type 1 fimbriae and flagella have been previously shown to contribute to the virulence of uropathogenic Escherichia coli (UPEC) within the urinary tract. In this study, the relationship between motility and type 1 fimbrial expression was tested for UPEC strain CFT073 by examining the phenotypic effect of fimbrial expression on motility and the effect that induction of motility has on type 1 fimbrial expression. While constitutive expression of type 1 fimbriae resulted in a significant decrease in motility and flagellin expression (P < 0.0001), a loss of type 1 fimbrial expression did not result in increased motility. Additionally, hypermotility and flagellar gene over- and underexpression were not observed to affect the expression of type 1 fimbriae. Hence, it appeared that the relationship between type 1 fimbrial expression and motility is unidirectional, where the overexpression of type 1 fimbriae dramatically affects motility and flagellum expression but not vice versa. Moreover, the constitutive expression of type 1 fimbriae in UPEC cystitis isolate F11 and the laboratory strain E. coli K-12 MG1655 also resulted in decreased motility, suggesting that this phenomenon is not specific to CFT073 or UPEC in general. Lastly, by analyzing the repression of motility caused by constitutive type 1 fimbrial expression, it was concluded that the synthesis and presence of type 1 fimbriae at the bacterial surface is only partially responsible for the repression of motility, as evidenced by the partial restoration of motility in the CFT073 fim L-ON ΔfimAICDFGH mutant. Altogether, these data provide further insight into the complex interplay between type 1 fimbrial expression and flagellum-mediated motility.

scholarly journals Multiple Genes Repress Motility in Uropathogenic Escherichia coli Constitutively Expressing Type 1 Fimbriae

2008 ◽  
Vol 190 (10) ◽  
pp. 3747-3756 ◽  
Author(s):  
Amy N. Simms ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Mismatch Repair ◽  
Constitutive Expression ◽  
Mismatch Repair Gene ◽  
Repair Gene ◽  
Upec Strain ◽  
Type 1 Fimbriae ◽  
Multiple Genes ◽  
Strain Cft073

ABSTRACT Two surface organelles of uropathogenic Escherichia coli (UPEC), flagella and type 1 fimbriae, are critical for colonization of the urinary tract but mediate opposite actions. Flagella propel bacteria through urine and along mucus layers, while type 1 fimbriae allow bacteria to adhere to specific receptors present on uroepithelial cells. Constitutive expression of type 1 fimbriae leads to repression of motility and chemotaxis in UPEC strain CFT073, suggesting that UPEC may coordinately regulate motility and adherence. To identify genes involved in this regulation of motility by type 1 fimbriae, transposon mutagenesis was performed on a phase-locked type 1 fimbrial ON variant of strain CFT073 (CFT073 fim L-ON), followed by a screen for restoration of motility in soft agar. Functions of the genes identified included attachment, metabolism, transport, DNA mismatch repair, and transcriptional regulation, and a number of genes had hypothetical function. Isogenic deletion mutants of these genes were also constructed in CFT073 fim L-ON. Motility was partially restored in six of these mutants, including complementable mutations in four genes encoding known transcriptional regulators, lrhA, lrp, slyA, and papX; a mismatch repair gene, mutS; and one hypothetical gene, ydiV. Type 1 fimbrial expression in these mutants was unaltered, and the majority of these mutants expressed larger amounts of flagellin than the fim L-ON parental strain. Our results indicate that repression of motility in CFT073 fim L-ON is not solely due to the constitutive expression of type 1 fimbriae on the surfaces of the bacteria and that multiple genes may contribute to this repression.

scholarly journals Decreased Expression of Type 1 Fimbriae by apstMutant of Uropathogenic Escherichia coli Reduces Urinary Tract Infection

2012 ◽  
Vol 80 (8) ◽  
pp. 2802-2815 ◽  
Author(s):  
Sébastien Crépin ◽  
Sébastien Houle ◽  
Marie-Ève Charbonneau ◽  
Michaël Mourez ◽  
Josée Harel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Bacterial Virulence ◽  
Pho Regulon ◽  
Upec Strain ◽  
Content Type ◽  
Type 1 Fimbriae ◽  
Genes Encoding ◽  
Tract Infections

ABSTRACTThepstSCAB-phoUoperon encodes the phosphate-specific transport system (Pst). Loss of Pst constitutively activates the Pho regulon and decreases bacterial virulence. However, specific mechanisms underlying decreased bacterial virulence through inactivation of Pst are poorly understood. In uropathogenicEscherichia coli(UPEC) strain CFT073, inactivation ofpstdecreased urinary tract colonization in CBA/J mice. Thepstmutant was deficient in production of type 1 fimbriae and showed decreased expression of thefimAstructural gene which correlated with differential expression of thefimB,fimE,ipuA, andipbAgenes, encoding recombinases, mediating inversion of thefimpromoter. The role offimdownregulation in attenuation of thepstmutant was confirmed using afimphase-locked-on derivative, which demonstrated a significant gain in virulence. In addition, thepstmutant was less able to invade human bladder epithelial cells. Since type 1 fimbriae contribute to UPEC virulence by promoting colonization and invasion of bladder cells, the reduced bladder colonization by thepstmutant is predominantly attributed to downregulation of these fimbriae. Elucidation of mechanisms mediating the control of type 1 fimbriae through activation of the Pho regulon in UPEC may open new avenues for therapeutics or prophylactics against urinary tract infections.

scholarly journals Escherichia coli type-1 fimbriae are critical to overcome initial bottlenecks of infection upon low-dose inoculation in a porcine model of cystitis

Microbiology ◽  
2021 ◽  
Vol 167 (10) ◽  
Author(s):  
Kristian Stærk ◽  
Rasmus Birkholm Grønnemose ◽  
Thomas Kastberg Nielsen ◽  
Nicky Anúel Petersen ◽  
Yaseelan Palarasah ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Porcine Model ◽  
Post Inoculation ◽  
Upec Strain ◽  
Content Type ◽  
Type 1 Fimbriae ◽  
Susceptibility To Infection ◽  
General Importance

Most uropathogenic Escherichia coli (UPEC) express type-1 fimbriae (T1F), a key virulence factor for urinary tract infection (UTI) in mice. Evidence that conclusively associates this pilus with uropathogenesis in humans has, however, been difficult to obtain. We used an experimental porcine model of cystitis to assess the role of T1F in larger mammals more closely related to humans. Thirty-one pigs were infected with UPEC strain UTI89 or its T1F deficient mutant, UTI89ΔfimH, at inoculum titres of 102 to 108 colony forming units per millilitre. Urine and blood samples were collected and analysed 7 and 14 days post-inoculation, and whole bladders were removed at day 14 and analysed for uroepithelium-associated UPEC. All animals were consistently infected and reached high urine titres independent of inoculum titre. UTI89ΔfimH successfully colonized the bladders of 1/6 pigs compared to 6/6 for the wild-type strain. Intracellular UPEC were detectable in low numbers in whole bladder explants. In conclusion, low doses of UPEC are able to establish robust infections in pigs, similar to what is presumed in humans. T1F are critical for UPEC to surpass initial bottlenecks during infection but may be dispensable once infection is established. While supporting the conclusions from mice studies regarding a general importance of T1F in successfully infecting the host, the porcine UTI models’ natural high, more human-like, susceptibility to infection, allowed us to demonstrate a pivotal role of T1F in initial establishment of infection upon a realistic low-inoculum introduction of UPEC in the bladder.

scholarly journals Type 1 Fimbriation and Its Phase Switching in Diarrheagenic Escherichia coli Strains

2001 ◽  
Vol 8 (3) ◽  
pp. 489-495 ◽  
Author(s):  
Ken-Ichiro Iida ◽  
Yoshimitsu Mizunoe ◽  
Sun Nyunt Wai ◽  
Shin-Ichi Yoshida
Keyword(s):  
Escherichia Coli ◽  
Invertible Element ◽  
Nucleotide Sequence Analysis ◽  
Phase Variable ◽  
Phase Switching ◽  
E Coli ◽  
Static Culture ◽  
Type 1 Fimbriae ◽  
K 12

ABSTRACT Type 1 fimbriae can be expressed by most Escherichia coli strains and mediate mannose-sensitive (MS) adherence to mammalian epithelial cells. However, the role of type 1 fimbriae in enteric pathogenesis has been unclear. Expression of type 1 fimbriae inE. coli is phase variable and is associated with the inversion of a short DNA element (fim switch). Forty-six strains of diarrheagenic E. coli were examined for the expression of type 1 fimbriae. Only four of these strains were originally type 1 fimbriated. Seventeen strains, originally nonfimbriated, expressed type 1 fimbriae in association with off-to-on inversion of the fim switch, after serial passages in static culture. The switching frequencies of these strains, from fimbriate to nonfimbriate, were greater than that of the laboratory strain E. coli K-12. None of the 16 strains of serovar O157:H7 or O157:H− expressed type 1 fimbriae after serial passages in static culture. The nucleotide sequence analysis of thefim switch region revealed that all of the O157:H7 and O157:H− strains had a 16-bp deletion in the invertible element, and the fim switch was locked in the “off” orientation. The results suggest that expression of type 1 fimbriae may be regulated differently in different E. coli pathogens causing enteric infections.

scholarly journals Antigen 43 and Type 1 Fimbriae Determine Colony Morphology of Escherichia coli K-12

2000 ◽  
Vol 182 (4) ◽  
pp. 1089-1095 ◽  
Author(s):  
Henrik Hasman ◽  
Mark A. Schembri ◽  
Per Klemm
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Colony Morphology ◽  
Phase Variable ◽  
Habitat Specificity ◽  
Type 1 Fimbriae ◽  
Variable Surface ◽  
Antigen 43 ◽  
K 12

ABSTRACT Colony morphology has been used as an important identification and characterization criterion in bacteriology for many decades. However, the molecular mechanisms underlying the appearance of different colony types have been given little attention. The synthesis of O antigen is defunct in Escherichia coli K-12, and colonies should accordingly only appear to be rough. However, previous reports have noted the presence of different interchangeable colony morphology types. In this study we have addressed the influence of two phase-variable surface structures, antigen 43 and type 1 fimbriae, on colony morphology. Due to differential expression of these structures, four different colony phenotypes could be distinguished. By creating and studying defined mutants of the respective loci, i.e.,flu and fim, we conclude that the presence or absence of the corresponding gene products on the cells correlates with the observed colony morphology forms. Interestingly, the habitat specificity of bacteria under static liquid conditions seems to correlate with the colony phenotypes.

scholarly journals Reciprocal Packaging of the Main Structural Proteins of Type 1 Fimbriae and Flagella in the Outer Membrane Vesicles of “Wild Type” Escherichia coli Strains

2021 ◽  
Vol 12 ◽  
Author(s):  
Sarah A. Blackburn ◽  
Mark Shepherd ◽  
Gary K. Robinson
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Membrane Vesicle ◽  
Outer Membrane Vesicles ◽  
Wild Type ◽  
Protein Fusion ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
K 12

Fundamental aspects of outer membrane vesicle (OMV) biogenesis and the engineering of producer strains have been major research foci for many in recent years. The focus of this study was OMV production in a variety of Escherichia coli strains including wild type (WT) (K12 and BW25113), mutants (from the Keio collection) and proprietary [BL21 and BL21 (DE3)] strains. The present study investigated the proteome and prospective mechanism that underpinned the key finding that the dominant protein present in E. coli K-12 WT OMVs was fimbrial protein monomer (FimA) (a polymerizable protein which is the key structural monomer from which Type 1 fimbriae are made). However, mutations in genes involved in fimbriae biosynthesis (ΔfimA, B, C, and F) resulted in the packaging of flagella protein monomer (FliC) (the major structural protein of flagella) into OMVs instead of FimA. Other mutations (ΔfimE, G, H, I, and ΔlrhA–a transcriptional regulator of fimbriation and flagella biosynthesis) lead to the packaging of both FimA and Flagellin into the OMVs. In the majority of instances shown within this research, the production of OMVs is considered in K-12 WT strains where structural appendages including fimbriae or flagella are temporally co-expressed throughout the growth curve as shown previously in the literature. The hypothesis, proposed and supported within the present paper, is that the vesicular packaging of the major FimA is reciprocally regulated with the major FliC in E. coli K-12 OMVs but this is abrogated in a range of mutated, non-WT E. coli strains. We also demonstrate, that a protein of interest (GFP) can be targeted to OMVs in an E. coli K-12 strain by protein fusion with FimA and that this causes normal packaging to be disrupted. The findings and underlying implications for host interactions and use in biotechnology are discussed.

scholarly journals Involvement of Mismatch Repair in the Reciprocal Control of Motility and Adherence of Uropathogenic Escherichia coli

2012 ◽  
Vol 80 (6) ◽  
pp. 1969-1979 ◽  
Author(s):  
Lauren A. Cooper ◽  
Lyle A. Simmons ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Mismatch Repair ◽  
Upper Urinary Tract ◽  
Wild Type ◽  
Content Type ◽  
Partial Restoration ◽  
Type 1 Fimbriae ◽  
Tract Infections

ABSTRACTType 1 fimbriae and flagella, two surface organelles critical for colonization of the urinary tract by uropathogenicEscherichia coli(UPEC), mediate opposing virulence objectives. Type 1 fimbriae facilitate adhesion to mucosal cells and promote bacterial persistence in the urinary tract, while flagella propel bacteria through urine and along mucous layers during ascension to the upper urinary tract. Using a transposon screen of theE. coliCFT073fimlocked-ON (L-ON) mutant, a construct that constitutively expresses type 1 fimbriae and represses motility, we identified six mutants that exhibited a partial restoration of motility. Among these six mutated genes wasmutS, which encodes a component of the methyl-directed mismatch repair (MMR) system. When complemented withmutS in trans, motility was again repressed. To determine whether the MMR system, in general, is involved in this reciprocal control, we characterized the effects of gene deletions of other MMR components on UPEC motility. Isogenic deletions ofmutS,mutH, andmutLwere constructed in both wild-type CFT073 andfimL-ON backgrounds. All MMR mutants showed an increase in motility in the wild-type background, and ΔmutHand ΔmutSmutations increased motility in thefimL-ON background. Cochallenge of the wild-type strain with an MMR-defective strain showed a subtle but significant competitive advantage in the bladder and spleen for the MMR mutant using the murine model of ascending urinary tract infection after 48 h. Our findings demonstrate that the MMR system generally affects the reciprocal regulation of motility and adherence and thus could contribute to UPEC pathogenesis during urinary tract infections.

scholarly journals Demonstration of regulatory cross-talk between P fimbriae and type 1 fimbriae in uropathogenic Escherichia coli

Microbiology ◽  
2006 ◽  
Vol 152 (4) ◽  
pp. 1143-1153 ◽  
Author(s):  
Nicola J. Holden ◽  
Makrina Totsika ◽  
Eva Mahler ◽  
Andrew J. Roe ◽  
Kirsteen Catherwood ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Isolate ◽  
Regulatory Region ◽  
Clinical Isolates ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
Tract Infections ◽  
K 12 ◽  
The Impact

The majority of Escherichia coli strains isolated from urinary tract infections have the potential to express multiple fimbriae. Two of the most common fimbrial adhesins are type 1 fimbriae and pyelonephritis-associated pili (Pap). Previous research has shown that induced, plasmid-based expression of a Pap regulator, papB, and its close homologues can prevent inversion of the fim switch controlling the expression of type 1 fimbriae. The aim of the present study was to determine if this cross-regulation occurs when PapB is expressed from its native promoter in the chromosome of E. coli K-12 and clinical isolates. The regulation was examined in three ways: (1) mutated alleles of the pap regulatory region, including papB and papI, that maintain the pap promoter in either the off or the on phase were exchanged into the chromosome of both E. coli K-12 and the clinical isolate E. coli CFT073, and the effect on type 1 fimbrial expression was measured; (2) type 1 fimbrial expression was determined using a novel fimS : : gfp + reporter system in mutants of the clinical isolate E. coli 536 in which combinations of complete fimbrial clusters had been deleted; (3) type 1 fimbrial expression was determined in a range of clinical isolates and compared with both the number of P clusters and their expression. All three approaches demonstrated that P expression represses type 1 fimbrial expression. Using a number of novel genetic approaches, this work extends the initial finding that PapB inhibits FimB recombination to the impact of this regulation in clinical isolates.

Sign in / Sign up

Export Citation Format

Share Document