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.

scholarly journals Isolation and Characterization of a New T-Even Bacteriophage, CEV1, and Determination of Its Potential To Reduce Escherichia coli O157:H7 Levels in Sheep

2006 ◽  
Vol 72 (9) ◽  
pp. 6405-6410 ◽  
Author(s):  
Raul R. Raya ◽  
Peter Varey ◽  
Rebecca A. Oot ◽  
Michael R. Dyen ◽  
Todd R. Callaway ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Oral Dose ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Isolation And Characterization ◽  
Unit Reduction

ABSTRACT Bacteriophage CEV1 was isolated from sheep resistant to Escherichia coli O157:H7 colonization. In vitro, CEV1 efficiently infected E. coli O157:H7 grown both aerobically and anaerobically. In vivo, sheep receiving a single oral dose of CEV1 showed a 2-log-unit reduction in intestinal E. coli O157:H7 levels within 2 days compared to levels in the controls.

scholarly journals Isolation and characterization of escherichia coli in ready-to-eat foods vended in Islamic University, Kushtia

1970 ◽  
Vol 18 ◽  
pp. 99-103 ◽  
Author(s):  
S Biswas ◽  
MAK Parvez ◽  
M Shafiquzzaman ◽  
S Nahar ◽  
MN Rahman
Keyword(s):  
Escherichia Coli ◽  
Pattern Analysis ◽  
University Campus ◽  
Rflp Pattern ◽  
E Coli ◽  
Fish Meat ◽  
Isolation And Characterization ◽  
Food Borne ◽  
Identification And Characterization

Context: Escherichia coli is shed in the feces of warm blooded animals and humans and thus potential for public health. Detection and characterization of E. coli in the ready-to-eat (RTE) foods concerns due to their presence indicates fecal contamination of the food.   Objective: To identify, characterize and RFLP pattern analysis of E. coli isolated from RTE foods vended in Islamic University campus, Kushtia.   Materials and Methods: Fifty samples from four types of consumed foods in six student halls of residence, some temporary restaurants of Islamic University, Kushtia were assessed for bacterial contamination by standard methods. Identification and characterization of E. coli isolates were performed using IMViC tests. Genomic DNA was used to perform RFLP pattern analysis.   Results: Thirty seven out of 50 (74%) examined samples of RTE foods had E. coli contamination. The highest number of E. coli was isolated from vegetable oriented RTE foods (90.90%) and fish, meat and cereals samples were also significantly E. coli positive. RFLP profiling of two E. coli isolates were observed.   Conclusion: The results of this study provide evidence that some RTE foods had unsatisfactory levels of contamination with E. coli. Thus street vended RTE food could be important potential vehicles for food-borne diseases. Molecular characterization may be exploited to identify food borne pathogen among different species.  Keywords: Ready-to-eat foods; Escherichia coli; RFLP pattern DOI: http://dx.doi.org/10.3329/jbs.v18i0.8783 JBS 2010; 18(0): 99-103

Occurrence and Characterization of Escherichia coli O157 and Other Serotypes in Raw Meat Products in Morocco

2008 ◽  
Vol 71 (10) ◽  
pp. 2082-2086 ◽  
Author(s):  
LUCIANO BENEDUCE ◽  
GIUSEPPE SPANO ◽  
ARI Q. NABI ◽  
FRANCESCO LAMACCHIA ◽  
SALVATORE MASSA ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Susceptibility Testing ◽  
Meat Products ◽  
Molecular Techniques ◽  
Escherichia Coli O157 ◽  
Raw Meat ◽  
E Coli ◽  
Meat Samples ◽  
The City

In this study, 100 raw meat samples were collected from 15 local Moroccan butcheries in five different areas of the city of Rabat during a period of 4 months. Overall, 7 of 15 butcheries from three areas of the city yielded strains of Escherichia coli O157. Single isolates from 9 (9%) of 100 raw meat samples were biochemically and serologically confirmed as E. coli O157. Using molecular techniques, two strains were positive for the Shiga toxin, with two additional strains containing an attaching-effacing gene. All potentially virulent serotypes isolated from these meat samples showed distinct pulsed-field gel electrophoresis profiles. Based on antibiotic susceptibility testing, more than 70% of the isolates were resistant to ampicillin and clavulanic acid–amoxicillin. Moreover, one strain was resistant to more than three antibiotics. Our study represents the first survey of E. coli O157 and related serotypes in raw meat products in Morocco.

scholarly journals Development and Characterization of a Fluorescent-Bacteriophage Assay for Detection of Escherichia coli O157:H7

1999 ◽  
Vol 65 (4) ◽  
pp. 1397-1404 ◽  
Author(s):  
Lawrence Goodridge ◽  
Jinru Chen ◽  
Mansel Griffiths
Keyword(s):  
Escherichia Coli ◽  
Flow Cytometry ◽  
Immunomagnetic Separation ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Lower Detection ◽  
Unreliable Method ◽  
Direct Epifluorescent Filter Technique ◽  
Bacterial Concentrations

ABSTRACT In this paper we describe evaluation and characterization of a novel assay that combines immunomagnetic separation and a fluorescently stained bacteriophage for detection of Escherichia coliO157:H7 in broth. When it was combined with flow cytometry, the fluorescent-bacteriophage assay (FBA) was capable of detecting 104 cells/ml. A modified direct epifluorescent-filter technique (DEFT) was employed in an attempt to estimate bacterial concentrations. Using regression analysis, we calculated that the lower detection limit was between 102 and 103cells/ml; however, the modified DEFT was found to be an unreliable method for determining bacterial concentrations. The results of this study show that the FBA, when combined with flow cytometry, is a sensitive technique for presumptive detection of E. coliO157:H7 in broth cultures.

scholarly journals Isolation and characterization of the cytochrome domain of flavocytochrome b2 expressed independently in Escherichia coli

1992 ◽  
Vol 283 (1) ◽  
pp. 87-90 ◽  
Author(s):  
C E Brunt ◽  
M C Cox ◽  
A G P Thurgood ◽  
G R Moore ◽  
G A Reid ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Field ◽  
Cytochrome B5 ◽  
Microsomal Cytochrome ◽  
E Coli ◽  
Flavocytochrome B2 ◽  
Isolation And Characterization ◽  
Exchange Rate Constant ◽  
Microsomal Cytochrome B5

The cytochrome domain of flavocytochrome b2 (L-lactate dehydrogenase) was expressed in the bacterium Escherichia coli and a purification procedure was developed. When expressed in E. coli, the b2-cytochrome domain contains protohaem IX and has an electronic absorption spectrum identical with that of the cytochrome b2 ‘core’ produced by proteolytic cleavage of the enzyme isolated from yeast. The b2-cytochrome domain isolated from E. coli has an Mr of 10,500 and a redox potential of -31 +/- 2 mV. High-field n.m.r. studies indicate pKa values for the haem propionate groups to be 4.8 and 4.6, consistent with these groups being exposed to solvent rather than buried inside the protein. Using n.m.r. spectroscopy, we have determined an electron self-exchange rate constant for the b2-cytochrome domain of 2.3 x 10(6) M-1.s-1, which is more than two orders of magnitude larger than the value obtained for microsomal cytochrome b5, a homologue of b2-cytochrome domain.

scholarly journals First isolation of Escherichia coli O157:H7 from faecal and milk specimens from Anatolian water buffaloes (Bubalus bubalus) in Turkey

2008 ◽  
Vol 79 (4) ◽  
Author(s):  
E. Seker ◽  
H. Yardimci
Keyword(s):  
Escherichia Coli ◽  
Raw Milk ◽  
Escherichia Coli O157 ◽  
Water Buffaloes ◽  
E Coli ◽  
Milk Samples ◽  
Cultural Methods ◽  
Faecal Samples

Three hundred rectal faecal samples and 213 raw milk samples obtained from the tanks and containers were examined using standard cultural methods. Escherichia coli O157:H7 was isolated from 11 (3.7 %) of 300 faecal samples and 3 (1.4 %) of 213 raw milk samples. It was determined that 8 (73 %) of E. coli O157:H7 strains isolated from faecal samples originated from water buffaloes younger than 2 years of age and 3 (27 %) from 2-year-old and older water buffaloes. This is the 1st isolation of Escherichia coli O157:H7 from faecal and milk samples of water buffaloes in Turkey.

scholarly journals Isolation and characterization of a novel bacteriophage, Kapi1, capable of O-antigen modification in commensal Escherichia coli.

2021 ◽  
Author(s):  
Kat Pick ◽  
Tracy Lyn Raivio
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Shigella Flexneri ◽  
Model System ◽  
Temperate Phage ◽  
Phage Displays ◽  
E Coli ◽  
O Antigen ◽  
Isolation And Characterization

In this study, we describe the isolation and characterization of novel bacteriophage Kapi1 (vB_EcoP_Kapi1) isolated from a strain of commensal Escherichia coli inhabiting the gastrointestinal tract of healthy mice. We show that Kapi1 is a temperate phage integrated into tRNA argW of strain MP1 and describe its genome annotation and structure. Kapi1 shows limited homology to other characterized prophages but is most similar to the phages of Shigella flexneri, and clusters taxonomically with P22-like phages. Investigation of the lifestyle of Kapi1 shows that this phage displays unstable lysogeny and influences the growth of its host. The receptor for Kapi1 is the lipopolysaccharide O-antigen, and we further show that Kapi1 alters the structure of its hosts O-antigen in multiple ways. We hope to use MP1 and Kapi1 as a model system to explore molecular mechanisms of mammalian colonization by E. coli and ask what the role(s) of prophages in this context might be.

scholarly journals Isolation and characterization of Escherichia coli phage and enhance its bactericidal activity that collaborative with kanamycin sulfate

2020 ◽  
Author(s):  
Liming Jiang ◽  
Rui Zheng
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Therapeutic Potential ◽  
Health Concern ◽  
Low Concentration ◽  
E Coli ◽  
Kanamycin Sulfate ◽  
Isolation And Characterization

Abstract Background: Escherichia coli is the most important and widespread bacteria in worldwide, which mainly found in contaminated food, human and animal faeces. Unfortunately, Some of E. coli strains are multidrug-resistant (MDR) pathogen leading significant public health concern globally. Biofilm is a multicellular community of microorganisms. Phages and their derivatives are ideal candidates for replacing or compensating for antibiotic problems in the future. Method: Here, we aimed to isolation and characterization of Escherichia coli phage and research its bactericidal activity that individually or collaborative with kanamycin sulfateResults: In this study, three virulent phages Flora, T4 and WJ were isolated from the laboratory and drug sample in Wuxi, China. It’s belonged to the Myoviridae family and optimum temperature is 42 ℃, optimum pH= 7, optimum MOI is 0.0001 and the genome size of Flora, T4 and WJ were 168, 909, 168903 and 168, 900 bp respectively. Flora has two exonuclease, whereas T4 and WJ have only one. Antibiotics have better bactericidal activity than phages in a low concentration medium of bacteria, nonetheless, phages have better bactericidal activity than antibiotics in a high concentration of bacteria, and that, collaboration of phages and antibiotics have better bactericidal activity effect than alone of phages or antibiotics in a low concentration medium of bacteria. Conclusion: The excellent performance of phage Flora for its therapeutic potential on clinic. The data of this study provided the strong evidence that the application of phage could reduce the growth and biofilm of E. coli that are important to maintain public health. Keywords: Escherichia coli, phage, lytic spectrum, biofilm, antibiotic

scholarly journals Isolation and Characterization of Sorbitol-Fermenting Shiga Toxin (Verocytotoxin)-Producing Escherichia coli O157:Hßtrains in the Czech Republic

1998 ◽  
Vol 36 (7) ◽  
pp. 2135-2137 ◽  
Author(s):  
Martina Bielaszewska ◽  
Herbert Schmidt ◽  
Mohamed A. Karmali ◽  
Rasik Khakhria ◽  
Jan Janda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Czech Republic ◽  
Shiga Toxin ◽  
Escherichia Coli O157 ◽  
The Czech Republic ◽  
Isolation And Characterization ◽  
First Finding ◽  
Uremic Syndrome ◽  
Genotypic Characteristics

Two sorbitol-fermenting (SF) Shiga toxin-producingEscherichia coli (STEC) O157:H− strains were isolated from patients with hemolytic-uremic syndrome in the Czech Republic in 1995. Their phenotypic and genotypic characteristics and genomic DNA fingerprints were identical or closely related to those of SF STEC O157:H− strains isolated in Germany in 1988 to 1997. This indicates that the Czech isolates belong to the SF STEC O157 clone which is widespread in Germany. It is the first finding of the clone outside Germany.

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