Virulence typing of Escherichia coli using microarrays

Abstract In Belgium, it is mandatory to report Shiga toxin-producing Escherichia coli (STEC) infections to the health inspection authorities. To facilitate the decision making regarding infection control measures, information about the risk factors for the development of the haemolytic uremic syndrome (HUS) can be helpful. We performed statistical analyses on a dataset of 411 Belgian STEC strains. Demographic and clinical patient characteristics as well as phenotypical and genotypical STEC strain characteristics were taken into account. Multivariate logistic regression models indicated that age categories ⩽5, 6–12 and ⩾75; the stx2 gene; and the eae gene were significant HUS development risk determinants. The stx2a subtype had the highest risk (OR 29.6, 95% CI 7.0–125.1), while all stx1 subtypes encompassed a significant lower risk (OR 0.3, 95% CI 0.1–0.5). Presence of the stx1 gene without stx2 encompassed a lower risk than the combined presence of stx1 and stx2, or stx2 solely. Based on these results, we propose a new virulence typing algorithm that will enable the National Reference Centre to provide the physicians and health inspection authorities with a risk classification for the development of HUS. We believe this will contribute to a more efficient STEC infection control management in Belgium.

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Development of three multiplex-PCR assays for virulence profiling of different iron acquisition systems in Escherichia coli

Iranian Journal of Microbiology ◽

10.18502/ijm.v12i4.3930 ◽

2020 ◽

Author(s):

Hamideh Kalateh Rahmani ◽

Gholamreza Hashemi Tabar ◽

Mahdi Askari Badouei ◽

Babak Khoramian

Keyword(s):

Escherichia Coli ◽

Multiplex Pcr ◽

Virulence Genes ◽

Current Knowledge ◽

Iron Acquisition ◽

E Coli ◽

Essential Nutrient ◽

Pcr Assays ◽

Virulence Typing ◽

Different Origin

Background and Objectives: Escherichia coli is responsible for various enteric and extraintestinal infections in animals and humans. Iron as an essential nutrient, has a proven role in pathogenicity of E. coli. Pathogenic E. coli benefits of having complicated systems for iron acquisition but our current knowledge is limited because of complexity of these systems. In the present study, three multiplex-PCR assays were developed to screen nine different virulence genes related to diverse iron acquisition systems in E. coli. Materials and Methods: The multiplex-PCR systems were designed and optimized in three panels. Each panel includes a triplex-PCR cocktail. The panels are as follow: panel 1: iroN, iutA and fecA; panel 2: fyuA, sitA and irp2; and panel 3: iucD, chuA and tonB. A total of 39 pathogenic E. coli was screened according to the designed multiplex-PCR. Results: In total, the top three frequent genes were tonB (100%), fecA (66.6%) and sitA (58.9%). With the exception of fecA and tonB, comparing the prevalence of genes among different origin of isolates (human, cattle, poultry and pigeon) showed significant associations (P < 0.05). Moreover, the iroN, sitA and iucD genes were significantly prevalent (P < 0.05) among members of extraintestinal pathogenic E. coli in comparison with the group of diarrheagenic E. coli. Conclusion: The current multiplex-PCR assays could be a valuable, rapid and economic tool to investigate diverse iron acquisition systems in E. coli for more precise virulence typing of pathogenic or commensal strains.

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Host characteristics and virulence typing of Escherichia coli isolated from diabetic patients

Gene Reports ◽

10.1016/j.genrep.2019.100371 ◽

2019 ◽

Vol 15 ◽

pp. 100371

Author(s):

Najar Peerayeh Shahin ◽

Eslami Majid ◽

Talebi Bezmin Abadi Amin ◽

Bakhshi Bita

Keyword(s):

Escherichia Coli ◽

Diabetic Patients ◽

Virulence Typing ◽

Host Characteristics

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Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081693 ◽

1978 ◽

Vol 36 (2) ◽

pp. 166-167 ◽

Cited By ~ 1

Author(s):

G. Stöffler ◽

R.W. Bald ◽

J. Dieckhoff ◽

H. Eckhard ◽

R. Lührmann ◽

...

Keyword(s):

Electron Microscopy ◽

Escherichia Coli ◽

Ribosomal Proteins ◽

Structural Organization ◽

Three Dimensional ◽

Ribosomal Subunit ◽

Spatial Arrangement ◽

Small Subunit ◽

Antibody Binding ◽

Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

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Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060490 ◽

1967 ◽

Vol 25 ◽

pp. 96-97

Author(s):

Manfred E. Bayer

Keyword(s):

Escherichia Coli ◽

Cell Wall ◽

Electron Microscope ◽

Uranyl Acetate ◽

E Coli ◽

Receptor Sites ◽

Rigid Cell Wall ◽

Host Cell Surface ◽

Bacterial Viruses ◽

Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

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Infection of Escherichia coli with bacteriophages

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063767 ◽

1969 ◽

Vol 27 ◽

pp. 370-371

Author(s):

Manfred E. Bayer

Keyword(s):

Escherichia Coli ◽

Nucleic Acid ◽

Cell Surface ◽

Virus Type ◽

Infection Process ◽

Adsorption Site ◽

The Other ◽

Specific Receptors ◽

Bacterial Receptors

The first step in the infection of a bacterium by a virus consists of a collision between cell and bacteriophage. The presence of virus-specific receptors on the cell surface will trigger a number of events leading eventually to release of the phage nucleic acid. The execution of the various "steps" in the infection process varies from one virus-type to the other, depending on the anatomy of the virus. Small viruses like ØX 174 and MS2 adsorb directly with their capsid to the bacterial receptors, while other phages possess attachment organelles of varying complexity. In bacteriophages T3 (Fig. 1) and T7 the small conical processes of their heads point toward the adsorption site; a welldefined baseplate is attached to the head of P22; heads without baseplates are not infective.

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The Nature of the Intramembrane Particle

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600003020 ◽

1980 ◽

Vol 38 ◽

pp. 688-691

Author(s):

A.J. Verkleij

Keyword(s):

Escherichia Coli ◽

Tight Junction ◽

Gap Junction ◽

The Other ◽

Fracture Face ◽

Band 3 Protein ◽

Satisfactory Explanation ◽

Freeze Fracturing ◽

Intramembrane Particle ◽

Luminal Membrane

Freeze-fracturing splits membranes into two helves, thus allowing an examination of the membrane interior. The 5-10 rm particles visible on both monolayers are widely assumed to be proteinaceous in nature. Most membranes do not reveal impressions complementary to particles on the opposite fracture face, if the membranes are fractured under conditions without etching. Even if it is considered that shadowing, contamination or fracturing itself might obscure complementary pits', there is no satisfactory explanation why under similar physical circimstances matching halves of other membranes can be visualized. A prominent example of uncomplementarity is found in the erythrocyte manbrane. It is wall established that band 3 protein and possibly glycophorin represents these nonccmplanentary particles. On the other hand a number of membrane types show pits opposite the particles. Scme well known examples are the ";gap junction',"; tight junction, the luminal membrane of the bladder epithelial cells and the outer membrane of Escherichia coli.

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