LYSOGENY IN ENTEROPATHOGENIC ESCHERICHIA COLI: II. CHARACTERIZATION OF E. COLI BACTERIOPHAGE D-1

1961 ◽  
Vol 7 (6) ◽  
pp. 907-913
Author(s):  
John P. Glynn ◽  
W. Robert Bailey
Keyword(s):  
Escherichia Coli ◽  
Host Cell ◽  
Burst Size ◽  
Enteropathogenic Escherichia Coli ◽  
E Coli ◽  
Uv Induction ◽  
Normal Propagation

One of 20 strains of Escherichia coli O111:B4 was found to be lysogenic for a phage which showed activity on several O26:B6 strains. High titers of this phage were obtainable only by UV induction. Normal propagation procedures failed to provide a desirable yield of phage. The calculated burst size of this phage was approximately 36 particles per cell. Other characteristics of the phage, designated D-1 by the authors, are given. Its potentiality as a possible transducing agent was also investigated. Some evidence is offered for the suspected site of attachment on the host cell.

scholarly journals Molecular and phenotypic typing of enteropathogenic Escherichia coli isolated in childhood acute diarrhea in Abuja, Nigeria

2017 ◽  
Vol 11 (07) ◽  
pp. 527-535 ◽  
Author(s):  
Casmir Ifeanyichukwu Cajetan Ifeanyi ◽  
Nkiruka Florence Ikeneche ◽  
Bassey Enya Bassey ◽  
Stefano Morabito ◽  
Caterina Graziani ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acute Diarrhea ◽  
Antimicrobial Agents ◽  
Virulence Gene ◽  
Enteropathogenic Escherichia Coli ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Typical Epec ◽  
Marked Resistance

Introduction: Enteropathogenic Escherichia coli (EPEC) causes infectious diarrhea among children in developing countries. However, in Nigeria, due to limited laboratory resources, the genetic diversity of its virulence factors, which include intimin subtypes, remains undefined. Methodology: EPEC isolates from diarrheic children 60 months of age and younger in Abuja, Nigeria, were analyzed. Polymerase chain reaction (PCR) for EPEC virulence gene, Hep-2 cell adherence, and serotyping were performed. EPEC strains were further subtyped by PCR for the identification of intimin subtype genes α (alpha), β (beta), γ1 (gamma-1), and έ (epsilon). Antibiotic resistance and extended-spectrum beta-lactamase (ESBL) production was determined by Clinical and Laboratory Standards Institute guidelines. Results: Overall, 18 (4.5%) out of 400 children with acute diarrhea had EPEC infection.  Typical EPEC (tEPEC) strains were detected in 14 (3.5%), whereas 4 (1.1%) were atypical EPEC (aEPEC). A total of 15 (83.3%) of the EPEC isolated belonged to β intimin subtype gene, while the remaining 3 EPEC isolates possessed the intimin έ subtype. No α and γ intimin subtypes were detected. Traditional EPEC serotypes O114:H14 were detected only in tEPEC strains. Marked resistance to β-lactam agents were observed but no ESBL-producing tEPEC or aEPEC was detected. Conclusions: This is the first report of intimin subtype genes in Abuja, Nigeria. EPEC isolates of diverse serotypes resistant to β-lactam antimicrobial agents were observed. These data will be useful in facilitating the characterization of intimin variants of EPEC and some Shiga toxin-producing E. coli (STEC) in humans and other animal species.

scholarly journals Characterization of typical and atypical enteropathogenic Escherichia coli (EPEC) strains of the classical O55 serogroup by RAPD analysis

1999 ◽  
Vol 30 (4) ◽  
pp. 365-368 ◽  
Author(s):  
Dennys M. Girão ◽  
Sílvia Y. Bando ◽  
Valéria Brígido de C. Girão ◽  
Carlos A. Moreira-Filho ◽  
Sérgio Eduardo L. Fracalanzza ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Epidemiological Studies ◽  
Enteropathogenic Escherichia Coli ◽  
E Coli ◽  
Typical Epec ◽  
Rapd Method ◽  
Atypical Strains

The genetic diversity of 41 typical and atypical enteropathogenic Escherichia coli (EPEC) strains of the serogroup O55 was analyzed by using the random amplified polymorphic DNA (RAPD) method. All typical EPEC O55 strains were grouped in two clusters (A and C) and belonged to the serotype O55:H6, while cluster B included all atypical strains, which were of the serotype O55:H7. The three groups also included non-motile strains. RAPD may be a useful method for epidemiological studies on E. coli O55 infection.

scholarly journals Functional expression of the eukaryotic proton pump rhodopsin OmR2 in Escherichia coli and its photochemical characterization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masuzu Kikuchi ◽  
Keiichi Kojima ◽  
Shin Nakao ◽  
Susumu Yoshizawa ◽  
Shiho Kawanishi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Proton Pump ◽  
Expression System ◽  
Spectroscopic Characterization ◽  
Functional Expression ◽  
Proton Pumping ◽  
E Coli ◽  
Oxyrrhis Marina ◽  
Domains Of Life

AbstractMicrobial rhodopsins are photoswitchable seven-transmembrane proteins that are widely distributed in three domains of life, archaea, bacteria and eukarya. Rhodopsins allow the transport of protons outwardly across the membrane and are indispensable for light-energy conversion in microorganisms. Archaeal and bacterial proton pump rhodopsins have been characterized using an Escherichia coli expression system because that enables the rapid production of large amounts of recombinant proteins, whereas no success has been reported for eukaryotic rhodopsins. Here, we report a phylogenetically distinct eukaryotic rhodopsin from the dinoflagellate Oxyrrhis marina (O. marina rhodopsin-2, OmR2) that can be expressed in E. coli cells. E. coli cells harboring the OmR2 gene showed an outward proton-pumping activity, indicating its functional expression. Spectroscopic characterization of the purified OmR2 protein revealed several features as follows: (1) an absorption maximum at 533 nm with all-trans retinal chromophore, (2) the possession of the deprotonated counterion (pKa = 3.0) of the protonated Schiff base and (3) a rapid photocycle through several distinct photointermediates. Those features are similar to those of known eukaryotic proton pump rhodopsins. Our successful characterization of OmR2 expressed in E. coli cells could build a basis for understanding and utilizing eukaryotic rhodopsins.

Spheroplasts of enteropathogenic Escherichia coli. I. Biological characteristics

1968 ◽  
Vol 14 (6) ◽  
pp. 675-678 ◽  
Author(s):  
B. Diena ◽  
R. Wallace ◽  
L. Greenberg
Keyword(s):  
Escherichia Coli ◽  
Tissue Culture ◽  
Biological Characteristics ◽  
Enteropathogenic Escherichia Coli ◽  
E Coli ◽  
O Antigen ◽  
Pathogenic Serotypes

The properties of glycine-induced spheroplasts of six pathogenic serotypes of E. coli were investigated. Fimbriae and flagella appeared to be only partially synthesized as was the somatic O antigen. Cytopathogenicity of these spheroplasts for tissue culture was reduced and the infection of the monolayers was retarded as compared with the normal bacillary forms. Sensitivity to phage was almost completely lost, suggesting that glycine had either interfered with the synthesis of phage receptors or had altered the mucopeptide layerwhich is the substrate for phage enzymes. Alternatively, the phage may become a prophage inside the spheroplast with the loss of virulence.

Comparison of colony and stool blots for detection of enteropathogens by DNA probes

1991 ◽  
Vol 37 (5) ◽  
pp. 407-410
Author(s):  
Mônica A. M. Vieira ◽  
Beatriz E. C. Guth ◽  
Tânia A. T. Gomes
Keyword(s):  
Escherichia Coli ◽  
Key Words ◽  
Sensitivity And Specificity ◽  
Dna Probes ◽  
Type I ◽  
Enteropathogenic Escherichia Coli ◽  
Key Words Dna ◽  
E Coli ◽  
Heat Stable

DNA probes that identify genes coding for heat-labile type I (LT-I) and heat-stable type 1 (ST-I) enterotoxins, enteropathogenic Escherichia coli adherence factor (EAF), and Shigella-like, invasiveness (INV) are used to evaluate the sensitivity and specificity of stool blots in comparison with the sensitivity and specificity of colony blots in detecting enteropathoghens. The sensitivities of the probes in stool blots are 91.7% for the LT-I probe, 76.9% for the ST-I probes, 78.9% for the EAF probe, and 45.5% for the INV probe. The specificity of all probes is higher than 95%. In general, the stool blot method identifies as many if not more LT-I-, ST-I-, and EAF-producing E. coli infections than the colony blots. Key words: DNA probes, stool blots, enteropathogens, diagnosis.

Enteropathogenic Escherichia coli adherence to intestinal epithelial monolayers diminishes barrier function

1995 ◽  
Vol 268 (2) ◽  
pp. G374-G379 ◽  
Author(s):  
J. Spitz ◽  
R. Yuhan ◽  
A. Koutsouris ◽  
C. Blatt ◽  
J. Alverdy ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Host Cell ◽  
Barrier Function ◽  
Cell Function ◽  
Cytoskeletal Proteins ◽  
Calcium Stores ◽  
Intestinal Epithelial ◽  
Enteropathogenic Escherichia Coli ◽  
Wild Type ◽  
Cell Monolayers

The mechanism by which enteropathogenic Escherichia coli (EPEC) causes diarrhea remains elusive. Several alterations within the host cell have been demonstrated to occur following EPEC attachment including increases in intracellular Ca2+ concentration and rearrangement and phosphorylation of several cytoskeletal proteins. The consequences of these intracellular perturbations on host cell function, however, have not been determined. The aim of this study was to examine the effect of EPEC adherence on intestinal epithelial barrier function. T84 cell monolayers were infected with either wild-type EPEC or a nonadherent isogenic derivative. Transepithelial electrical resistance, a measure of barrier function, decreased 33.5 +/- 6.4% after a 6-h incubation with the wild-type strain. Electron microscopy revealed ultrastructurally normal cells, and lactate dehydrogenase release assays failed to demonstrate cytotoxicity. Dual 22Na+ and [3H]mannitol flux studies localized the permeability defect to tight junctions. In addition, cumulative flux of the paracellular marker mannitol was four- to fivefold greater across monolayers infected with wild-type EPEC. Sequestration of intracellular calcium stores by dantrolene completely abrogated the resistance drop associated with EPEC attachment. These data demonstrate that adherence of EPEC to intestinal epithelial cell monolayers disrupts tight junction barrier function via a calcium-requiring event.

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

scholarly journals Novel Hybrid of Typical Enteropathogenic Escherichia coli and Shiga-Toxin-Producing E. coli (tEPEC/STEC) Emerging From Pet Birds

2018 ◽  
Vol 9 ◽  
Author(s):  
Rosely Martins Gioia-Di Chiacchio ◽  
Marcos Paulo Vieira Cunha ◽  
Lilian Rose Marques de Sá ◽  
Yamê Minieiro Davies ◽  
Camila Bueno Pacheco Pereira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Enteropathogenic Escherichia Coli ◽  
E Coli ◽  
Pet Birds
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