Isolation and characterization of a Tn5-induced tolQ mutant of Escherichia coli

1994 ◽  
Vol 40 (6) ◽  
pp. 503-507 ◽  
Author(s):  
C. Madrid ◽  
C. Badenas ◽  
A. Juárez
Keyword(s):  
Escherichia Coli ◽  
External Medium ◽  
Phenotypic Characterization ◽  
Phenotypic Properties ◽  
Isolation And Characterization ◽  
Filamentous Bacteriophages ◽  
Intracellular Compartments ◽  
Periplasmic Proteins ◽  
Leaky Mutants

Transposon mutagenesis was used to isolate an Escherichia coli mutant that released into the external medium a heterologous protein, the Aeromonas hydrophila aerolysin. Genetic mapping and phenotypic characterization of E. coli CM209 showed that Tn5 is inserted in the tolQ gene. This mutant strain released a significant amount of unprocessed (proaerolysin) protein into the external medium, together with other periplasmic proteins. Similar levels of the toxin were detected in the intracellular compartments of the parental and mutant strains. Whereas inactivation of the tolQ gene itself was responsible for some of the phenotypic properties of strain CM209, such as tolerance to group A colicins or to filamentous bacteriophages, the leaky phenotype was associated with a polar effect exerted by Tn5 on distal genes of the tolQRA cluster.Key words: Tn5, tolQ gene, aerolysin, leaky mutants.

Isolation and characterization of a novel Escherichia coli Kayfunavirus phage DY1

2021 ◽  
Vol 293 ◽  
pp. 198274
Author(s):  
Xiaoming Yuan ◽  
Shuhong Zhang ◽  
Juan Wang ◽  
Chun Li ◽  
Na Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Isolation And Characterization

scholarly journals Isolation and characterization of pathogenic Escherichia coli bacteriophages from chicken and beef offal

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Celosia Lukman ◽  
Christopher Yonathan ◽  
Stella Magdalena ◽  
Diana Elizabeth Waturangi
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
High Efficiency ◽  
Multiplicity Of Infection ◽  
Isolation And Characterization ◽  
Transmission Electron ◽  
Pathogenic Escherichia Coli ◽  
Family Based

Abstract Objective This study was conducted to isolate and characterize lytic bacteriophages for pathogenic Escherichia coli from chicken and beef offal, and analyze their capability as biocontrol for several foodborne pathogens. Methods done in this research are bacteriophage isolation, purification, titer determination, application, determination of host range and minimum multiplicity of infection (miMOI), and bacteriophage morphology. Results Six bacteriophages successfully isolated from chicken and beef offal using EPEC and EHEC as host strain. Bacteriophage titers observed between 109 and 1010 PFU mL−1. CS EPEC and BL EHEC bacteriophage showed high efficiency in reduction of EPEC or EHEC contamination in meat about 99.20% and 99.04%. The lowest miMOI was 0.01 showed by CS EPEC bacteriophage. CI EPEC and BL EPEC bacteriophage suspected as Myoviridae family based on its micrograph from Transmission Electron Microscopy (TEM). Refers to their activity, bacteriophages isolated in this study have a great potential to be used as biocontrol against several foodborne pathogens.

Isolation and characterization of the heat stable enterotoxin from a pathogenic bovine strain of Escherichia coli

1984 ◽  
Vol 9 (4) ◽  
pp. 399-414 ◽  
Author(s):  
Charles Gerday ◽  
Marianne Herman ◽  
Jacques Olivy ◽  
Nicole Gerardin-Otthiers ◽  
Dominique Art ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Heat Stable ◽  
Isolation And Characterization ◽  
Bovine Strain
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