Divergent effects of cyclic adenosine 3',5'-monophosphate on formation of type 1 fimbriae in different K-12 strains of Escherichia coli.

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.

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

Journal of Bacteriology ◽

10.1128/jb.00434-07 ◽

2007 ◽

Vol 189 (15) ◽

pp. 5523-5533 ◽

Cited By ~ 71

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.

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

Journal of Bacteriology ◽

10.1128/jb.182.4.1089-1095.2000 ◽

2000 ◽

Vol 182 (4) ◽

pp. 1089-1095 ◽

Cited By ~ 71

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.

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

Frontiers in Microbiology ◽

10.3389/fmicb.2021.557455 ◽

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.

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

Microbiology ◽

10.1099/mic.0.28677-0 ◽

2006 ◽

Vol 152 (4) ◽

pp. 1143-1153 ◽

Cited By ~ 63

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.

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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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