The hemolysin of escherichia coli

@article{Bhakdi2004TheHO,
  title={The hemolysin of escherichia coli},
  author={Sucharit Bhakdi and Nigel Mackman and Gianfranco Menestrina and Lindsay Gray and Ferdinand Hugo and Werner Seeger and I. Barry Holland},
  journal={European Journal of Epidemiology},
  year={2004},
  volume={4},
  pages={135-143}
}
Many strains of E. coli elaborate a hemolysin which is responsible for the zone of β-hemolysis surrounding bacterial colonies on blood agar. The significance of this cytolysin as a determinant of bacterial pathogenicity has been established in animal models with the use of genetically engineered, isogenic bacterial strains. An analogous role in human infections has been inferred from the high association of hemolysin production with disease. Studies at a molecular genetical level have defined 4… 

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References

SHOWING 1-10 OF 87 REFERENCES

Escherichia coli hemolysin is released extracellularly without cleavage of a signal peptide

TLDR
These studies demonstrated how hemolysin-associated 110- and 58-kilodalton polypeptides detected in the minicell background could be misinterpreted as a precursor-product relationship.

Purification of α-hemolysin from an overproducing E. coli strain

TLDR
α-hemolysin was purified from culture supernatants of strain SU100 by ammonium sulfate precipitation and gel filtration in Sephacryl S-200 in the presence of 6 M urea and, when subjected to electrophoretic analysis in denaturing conditions, a single 107 kdal polypeptide was observed.

Characterization of Escherichia coli hemolysins conferring quantitative differences in virulence

TLDR
The region conferring quantitative differences in extracellular hemolysin production and virulence was found to be within a region of less than 1 kilobase where the hly c cistron is encoded as well as the probable transcription initiation ares for the entire hemoly sin operon.

Properties of the Hemolytic Activities of Escherichia coli

TLDR
The kinetics of the lytic reaction are most consistent with the hypothesis that one molecule of cell-free hemolysin is sufficient to lyse one erythrocyte and that it is inactivated in the Lytic reaction.

Relation between the hemolytic property and iron metabolism in Escherichia coli

TLDR
The results suggest that hemolysin secretion in E. coli is related to the bacterial iron metabolism, and hemoly sin secretion is differentially regulated among E. Escherichia coli strains.

Synthesis and secretion of hemolysin by Escherichia coli

TLDR
Hemolytic Escherichia coli cells were found to synthesize and secrete significant amounts of hemolysin into a mineral salt-glucose medium containing hemoglobin, and it was concluded that two transport processes are involved in hemoly sin secretion.

Transport of hemolysin across the outer membrane of Escherichia coli requires two functions

TLDR
It is shown that the phenotypic appearance of colonies from hlyBb mutants is that of beta-hemolytic Escherichia coli strains, indicating that a substantial portion of hemolysin has already reached the outside of the outer membrane without being released into the medium.

Regulation of haemolysin synthesis in E. coli determined by HLY genes of human origin

TLDR
Data is presented indicating that the previously reported variation in haemolysin production in different media is entirely due to the instability of the haemoolysin itself.

Chemical and immunological analysis of the complex structure of Escherichia coli alpha-hemolysin

TLDR
Findings suggest several possible mechanisms for release of AH from the bacterial cell including release by outer membrane fragmentation, and the existence of AH complexed with lipopolysaccharide may have important implications in understanding its toxicity.

Molecular cloning and physical characterization of a chromosomal hemolysin from Escherichia coli

TLDR
Seventeen hemolytic E. coli isolates from human urinary tract infections were found to share similar DNA sequences with J96 hemolysin sequences, using a hemoly sin-specific restriction endonuclease fragment as a hybridization probe, suggesting that in the evolutionary sense the hemolySin-specific genetic sequences have only recently been introduced into the E. bacteria.
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