Isolation and Characterization of Potential Probiotic Escherichia coli Strains from Rat Faecal Samples

2009 ◽  
Vol 5 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Prasant Kumar ◽  
S. Ferzin ◽  
S. Chintan ◽  
G. Naresh Kumar
Keyword(s):  
Escherichia Coli ◽  
Isolation And Characterization ◽  
Faecal Samples

Isolation and characterization of Escherichia coli O157:H7 and shiga toxin-converting bacteriophages from strains of human, bovine and porcine origin

2002 ◽  
Vol 2 (3) ◽  
pp. 29-38 ◽  
Author(s):  
E.E. Müller ◽  
M.B. Taylor ◽  
W.O.K. Grabow ◽  
M.M. Ehlers
Keyword(s):  
Escherichia Coli ◽  
Pcr Analysis ◽  
Sewage Sample ◽  
Natural Environments ◽  
Escherichia Coli O157 ◽  
Electron Microscopic ◽  
E Coli ◽  
Isolation And Characterization ◽  
Faecal Samples

Toxin-converting bacteriophages encoding the Stx2 gene were induced from strains of Escherichia coli O157:H7 isolated from sewage, bovine and porcine faeces. Toxin synthesis can be stimulated by the induction of integrated toxin-converting phages from the host E. coli O157:H7 organism by ultra-violet (UV) exposure. The UV-mediated DNA damage of E. coli O157:H7 triggers a bacterial SOS response resulting in phage release. Free ranging phages outside their E. coli O157:H7 hosts were detected but could not be isolated directly from environmental samples such as sewage and river water. E. coli O157:H7 colonies carrying the genes coding for Stx2 were isolated from 1 sewage sample (0.76% of positive samples), 8 cattle faecal samples (16.67% of positive samples) and 2 pig faecal samples (14.28% of positive samples). Characterization of E. coli O157:H7 was done by repetitive sequence analysis using ERIC-PCR to determine the relationships between the individual E. coli O157:H7 strains. The ERIC-PCR analysis revealed distinct patterns for all E. coli O157:H7 strains with some small differences between the strains. DNA sequencing of some of the E. coli O157:H7 positive isolates carrying the Stx2 genes were performed confirming the amplified DNA nucleotide sequences of Stx2. Electron microscopic analysis revealed, for the first time in South Africa, that Stx2-converting phages induced from E. coli O157:H7 have different morphologies to that of phage lambda which was previously described. The role of the induced integrated Stx2 phages in natural environments such as river and dam water remains unclear. With the induction of Stx2-converting phages from environmental E. coli O157:H7 isolates, it is now possible to determine the potential of these phages to convert non-pathogenic E. coli strains and other enterobacteriaciae into pathogenic strains.

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.

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