Host Defence against Intraperitoneal Escherichia coli Infections in Mice

1982 ◽  
pp. 236-246
Author(s):  
S. Ahlstedt
Keyword(s):  
Escherichia Coli ◽  
Host Defence

scholarly journals Zebrafish nephrosin helps host defence against Escherichia coli infection

Open Biology ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. 170040 ◽  
Author(s):  
Qianqian Di ◽  
Qing Lin ◽  
Zhibin Huang ◽  
Yali Chi ◽  
Xiaohui Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Innate Immunity ◽  
Host Defence ◽  
Bacterial Burden ◽  
Wild Type ◽  
Lower Survival Rate ◽  
E Coli ◽  
Escherichia Coli Infection ◽  
Effective Models

Neutrophils play important roles in innate immunity and are mainly dependent on various enzyme-containing granules to kill engulfed microorganisms. Zebrafish nephrosin ( npsn ) is specifically expressed in neutrophils; however, its function is largely unknown. Here, we generated an npsn mutant ( npsn smu5 ) via CRISPR/Cas9 to investigate the in vivo function of Npsn. The overall development and number of neutrophils remained unchanged in npsn -deficient mutants, whereas neutrophil antibacterial function was defective. Upon infection with Escherichia coli , the npsn smu5 mutants exhibited a lower survival rate and more severe bacterial burden, as well as augmented inflammatory response to challenge with infection when compared with wild-type embryos, whereas npsn -overexpressing zebrafish exhibited enhanced host defence against E. coli infection. These findings demonstrated that zebrafish Npsn promotes host defence against bacterial infection. Furthermore, our findings suggested that npsn -deficient and -overexpressing zebrafish might serve as effective models of in vivo innate immunity.

Urinary tract infection

2010 ◽  
pp. 4103-4122
Author(s):  
Charles Tomson ◽  
Alison Armitage
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Transitional Cell ◽  
Host Defence ◽  
Common Condition ◽  
The United Kingdom ◽  
Increased Risk ◽  
Incomplete Bladder Emptying

Urinary tract infection (UTI) is a common condition, accounting for 1 to 3% of all primary care consultations in the United Kingdom. It affects patients of both sexes and all ages. The commonest organism causing uncomplicated community-acquired bacterial UTI is Escherichia coli. The occurrence and course of a UTI is influenced by the integrity of the host defence and by bacterial virulence factors. Disruption of the highly specialized transitional cell epithelium which lines the urinary tract, incomplete bladder emptying, anatomical abnormalities, and the presence of a foreign body, such as a urinary catheter, can all contribute to disruption of the host defence and increase the likelihood of infection. Sexual intercourse, use of condoms, and use of spermicides all increase the risk, and genetic factors influence the susceptibility of some people, e.g. girls with the P1 blood group are at increased risk of acute pyelonephritis. Bacterial characteristics that determine their ability to cause infection include specific mechanisms to adhere to the uroepithelium (‘pili’ or ‘fimbrias’ in the case of certain ...

Fifteen-minute consultation: Why and how do children get urinary tract infections?

2019 ◽  
Vol 104 (5) ◽  
pp. 244-247 ◽  
Author(s):  
Kjell Tullus
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Bacterial Virulence ◽  
Host Defence ◽  
Tract Infections

This paper describes urinary tract infections (UTI) from the perspective of a disturbed balance between bacterial virulence and host defence. In some children, a UTI is caused by a virulent Escherichia coli, while in other cases children with abnormal renal tracts can get infected by almost any bacteria. Such knowledge can help in guiding treatment, investigations and follow-up of a child with a UTI.

Virulence determinants of Escherichia coli: present knowledge and questions

1992 ◽  
Vol 38 (7) ◽  
pp. 747-752 ◽  
Author(s):  
Harry Smith
Keyword(s):  
Escherichia Coli ◽  
Biological Action ◽  
Host Defence ◽  
Virulence Determinants ◽  
E Coli ◽  
Bacterial Pathogenicity ◽  
Protein Toxins ◽  
State Of Research ◽  
Surface Adhesins

This paper describes the present state of research on the pathogenicity of Escherichia coli and points out the gaps in knowledge that should be filled in the future. First, the great versatility of E. coli in producing disease is noted, as well as the invaluable contributions that studies of it have made to the development of general knowledge on bacterial pathogenicity. Then, the biological requirements for pathogenicity: infection of mucous surfaces; penetration of those surfaces; multiplication in vivo; interference with host defence mechanisms; and damage to the host, are taken in turn, and an enquiry is made on how far studies have progressed toward identifying their molecular determinants and relating structure to biological action. Only for mucous surface adhesins and protein toxins are studies at the structure–function level. Some progress has been made on interference with host defence, but little is known about competition with commensals on mucous surfaces, invasion into the tissues, and growth in vivo. Key words: virulence determinants, Escherichia coli.

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

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
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).

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

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.

Infection of Escherichia coli with bacteriophages

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.

The Nature of the Intramembrane Particle

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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