scholarly journals Temperate bacteriophages of Escherichia coli O119:B14

1970 ◽  
Vol 68 (3) ◽  
pp. 447-455
Author(s):  
S. S. Kasatiya
Keyword(s):  
Escherichia Coli ◽  
Indicator Strain ◽  
Temperate Phage ◽  
Biochemical Reactions ◽  
Serotype A ◽  
E Coli ◽  
Cross Reactions ◽  
Definite Relationship ◽  
Lysogenic Strain ◽  
Flagellar Antigens

SUMMARYLysogeny was detected in 98·8 % of the 343 Escherichia coli O119: B14 strains. A suitable indicator strain E. coli KS was selected to demonstrate the presence of temperate phages in this serotype. A great diversity in the temperate population was observed based on their lytic patterns and neutralization studies. No definite relationship could be established between the biochemical reactions and the flagellar antigens of the lysogenic strain and its temperate phage though some temperate phages released by E. coli O119:B14 strains with certain flagellar antigens did give specific lytic patterns and were serologically identical. Lysogenic strains, which did not release temperate phages spontaneously, were u.v. in-ductible. Cross-reactions with lysogenized colonies which were immune to corresponding phages also confirmed diversity of temperate phages in E. coli O119: B 14.

scholarly journals Serotype-related enterotoxigenicity inEscherichia coliO6.H16 and O148.H28

1977 ◽  
Vol 79 (3) ◽  
pp. 395-403 ◽  
Author(s):  
Sylvia M. Scotland ◽  
Roger J. Gross ◽  
Bernard Rowe
Keyword(s):  
Escherichia Coli ◽  
Restricted Range ◽  
E Coli ◽  
Single Colony ◽  
Flagellar Antigens

SUMMARYThe ability of certainEscherichia colistrains to produce enterotoxin is determined by transmissible plasmids. It is therefore possible that anyE. colistrain might be able to acquire such a plasmid and that the correlation between enterotoxigenicity and serotype might be random. However, recent studies show that the enterotoxigenic strains so far described belong to a restricted range of serotypes. Enterotoxigenic strains ofE. coliO6.H16 andE. coliO148.H28 have been associated with outbreaks of diarrhoea in several countries, therefore strains ofE. colibelonging to these serotypes were selected for further study.Twenty-three strains ofE. coliO6.H16 and 14 strains ofE. coliO148.H28 were examined; 20 strains ofE. coliO6.H16 and all 14 strains ofE. coli0148.H28 were enterotoxigenic but strains ofE. coliO6 with flagellar antigens other than H16 and strains ofE. coliO148 with flagellar antigens other than H28 were not enterotoxigenic. The examination of single colony subcultures derived from theE. coliO6.H16 strains showed that in some strains loss of enterotoxigenicity had occurred in a proportion of colonies.

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 Molecular Serotyping of Escherichia coli O26:H11

2005 ◽  
Vol 71 (8) ◽  
pp. 4941-4944 ◽  
Author(s):  
Lisa M. Durso ◽  
James L. Bono ◽  
James E. Keen
Keyword(s):  
Escherichia Coli ◽  
Traditional Methods ◽  
E Coli ◽  
Molecular Serotyping ◽  
Flagellar Antigens

ABSTRACT Serotyping is the foundation of pathogenic Escherichia coli diagnostics; however, few laboratories have this capacity. We developed a molecular serotyping protocol that targets, genetically, the same somatic and flagellar antigens of E. coli O26:H11 used in traditional serotyping. It correctly serotypes strains untypeable by traditional methods, affording primary laboratories serotyping capabilities.

scholarly journals Assessment of genotoxicity and cytotoxicity of "lixeira" (Curatella americanaL.) λ using the prophage induction test (SOS inductest)

2009 ◽  
Vol 45 (3) ◽  
pp. 491-496
Author(s):  
Juliana Brandstetter Vilar ◽  
Laryssa Silva de Andrade ◽  
Kaio Ramos Leite ◽  
Heleno Dias Ferreira ◽  
Lee Chen Chen
Keyword(s):  
Folk Medicine ◽  
Ethanolic Extract ◽  
Stem Bark ◽  
Indicator Strain ◽  
Prophage Induction ◽  
E Coli ◽  
Lysogenic Strain ◽  
Genotoxic Potential ◽  
Curatella Americana L ◽  
Curatella Americana

Curatella americana L., commonly known as "lixeira" in Brazil, has been used in folk medicine to treat ulcers and inflammations. The purpose of the present work was to evaluate the cytotoxic and genotoxic potential of the ethanolic extract of C. americana stem bark using the prophage λ induction test (SOS inductest). To evaluate the cytotoxicity of this plant, after treatment with different concentrations of the extract, Escherichia coli WP2s(λ) cultures were diluted in M9 buffer, inoculated into LB plates, and incubated for 24 h at 37 °C. To assess genotoxicity, the lysogenic strain E. coli WP2s(λ) was treated with different concentrations of the extract. Then, the lysogenic strain was added to the indicator strain (RJF013), LB(1/2)(malt/amp), seeded into plates with the matches, and incubated for 24 h at 37 °C. After this period, the total number of colonies and the number of plaques were counted to evaluate C. americana cytotoxicity and genotoxicity, respectively. Our results showed that although the extract of "lixeira" did not modify the survival of bacteria (p > 0.05), it caused a significant increase in prophage λ induction, especially at the higher concentrations (p<0.05). Therefore, we conclude that the ethanolic extract of C. americana stem bark did not present cytotoxic effect, but some genotoxic potential was observed.

scholarly journals Rapid detection of plasmid-mediated high-level tigecycline resistance in Escherichia coli and Acinetobacter spp

2020 ◽  
Vol 75 (6) ◽  
pp. 1479-1483 ◽  
Author(s):  
Ze-Hua Cui ◽  
Wei-Na Ni ◽  
Tian Tang ◽  
Bing He ◽  
Zi-Xing Zhong ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacillus Stearothermophilus ◽  
Animal Health ◽  
Cost Effective ◽  
Inhibition Zone ◽  
Indicator Strain ◽  
Bromocresol Purple ◽  
E Coli ◽  
Acinetobacter Spp ◽  
High Level

Abstract Objectives The emergence and spread of plasmid-encoded tet(X3/X4) genes that confer high-level tigecycline and eravacycline resistance in Escherichia coli and Acinetobacter spp. pose serious threats to human and animal health. We developed a rapid and robust assay to detect Tet(X3/X4) in Gram-negative bacteria based on eravacycline degradation by the presence of the Tet(X) enzyme in the test strain. Methods This tetracycline inactivation method (TIM) is based on the degradation of eravacycline by the Tet(X3/X4)-producing strain, which results in reduced eravacycline activity against an acid-producing thermophile Bacillus stearothermophilus indicator strain. For Tet(X)-negative strains, eravacycline retains its antimicrobial activity. Coupled with a pH-sensitive dye (bromocresol purple), the reduced colorimetric inhibition zone can be measured to determine the production of Tet(X3/X4). One hundred and eighteen isolates, including 30 tet(X4)-positive E. coli, 30 tet(X3)-positive Acinetobacter spp. and 58 tet(X)-negative E. coli and Acinetobacter spp., were examined to evaluate the performance of this TIM. Results The sensitivity and specificity for E. coli carrying tet(X4) was 96.7% and 100%, respectively, and for Acinetobacter spp. carrying tet(X3) both were 100%. The TIM assay can be completed within 6.5 h. Conclusions The TIM is a simple, rapid and cost-effective method for the detection of plasmid-mediated high-level tigecycline resistance in E. coli and Acinetobacter spp.

scholarly journals New indicator Escherichia coli strain for rapid and accurate detection of supF mutations

2020 ◽  
Vol 42 (1) ◽  
Author(s):  
Ruriko Fukushima ◽  
Tetsuya Suzuki ◽  
Hiroyuki Kamiya
Keyword(s):  
Escherichia Coli ◽  
Mammalian Cells ◽  
Indicator Strain ◽  
Coli Strain ◽  
Chromosomal Dna ◽  
Amber Mutation ◽  
E Coli ◽  
Accurate Detection ◽  
Mutation Spectra ◽  
Forward Mutation

Abstract Background The supF gene of Escherichia coli is useful for forward mutation analysis in bacterial and mammalian cells used in mutagenesis and DNA repair studies. Indicator E. coli strains, such as KS40/pOF105, have been used to analyze supF mutations. However, KS40/pOF105 is not enough to select supF mutants on nutrient-rich agar plates. Therefore, in this study, a new indicator E. coli strain for rapid and accurate detection of supF mutations was developed. Results The gyrA and rpsL genes with an amber mutation were integrated into the chromosomal DNA of E. coli KS40 to produce a new indicator strain, RF01. RF01 cells transformed by the wild-type supF gene were sensitive to nalidixic acid and streptomycin on LB agar plates. supF mutant frequencies and mutation spectra in RF01 were similar to those in KS40/pOF105. In addition, some mutations in supF were only detected in RF01. Conclusion RF01 is a new and useful indicator E. coli strain for analyzing supF mutations.

scholarly journals Phage integration alters the respiratory strategy of its host

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Jeffrey N Carey ◽  
Erin L Mettert ◽  
Daniel R Fishman-Engel ◽  
Manuela Roggiani ◽  
Patricia J Kiley ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Laboratory Strain ◽  
Temperate Phage ◽  
Natural Isolate ◽  
Bet Hedging ◽  
Hedging Strategy ◽  
E Coli ◽  
Signal Transduction Protein ◽  
Host Genes ◽  
Host Regulation

Temperate bacteriophages are viruses that can incorporate their genomes into their bacterial hosts, existing there as prophages that refrain from killing the host cell until induced. Prophages are largely quiescent, but they can alter host phenotype through factors encoded in their genomes (often virulence factors) or by disrupting host genes as a result of integration. Here we describe another mechanism by which a prophage can modulate host phenotype. We show that a temperate phage that integrates in Escherichia coli reprograms host regulation of an anaerobic respiratory system, thereby inhibiting a bet hedging strategy. The phage exerts this effect by upregulating a host-encoded signal transduction protein through transcription initiated from a phage-encoded promoter. We further show that this phenomenon occurs not only in a laboratory strain of E. coli, but also in a natural isolate that contains a prophage at this site.

scholarly journals The properties of a temperate bacteriophage Wφ isolated from Escherichia coli strain W

1967 ◽  
Vol 9 (1) ◽  
pp. 135-139 ◽  
Author(s):  
S. W. Glover ◽  
G. Kerszman
Keyword(s):  
Escherichia Coli ◽  
Electron Microscope ◽  
Buoyant Density ◽  
Coli Strain ◽  
Temperate Phage ◽  
Temperate Bacteriophage ◽  
E Coli

Escherichia coli strain W was found to be lysogenic for a temperate phage Wφ. This phage, which plates on E. coli C, forms λ-like plaques 2–3 mm. diameter with turbid centres. It is serologically unrelated to λ but is closely related to P2 which it resembles in the electron microscope. Its buoyant density in CsCl has been measured and it is different from λ but similar to P2. E. coli C made lysogenic for Wφ restricts the growth of λ, and elsewhere (Kerszman, Glover & Aronovitch, 1967) it has been shown that the DNA of phage λ is degraded shortly after infection of bacteria lysogenic for Wφ. A mutant of Wφ has been isolated which has lost the property of restricting the growth of λ.

scholarly journals The serological relationship betweenYersinia enterocoliticaO9 andEscherichia coliO157 using sera from patients with yersiniosis and haemolytic uraemic syndrome

1991 ◽  
Vol 107 (2) ◽  
pp. 349-356 ◽  
Author(s):  
H. Chart ◽  
T. Cheasty ◽  
D. Cope ◽  
R. J. Gross ◽  
B. Rowe
Keyword(s):  
Escherichia Coli ◽  
Yersinia Enterocolitica ◽  
Haemolytic Uraemic Syndrome ◽  
Cross Reaction ◽  
Serological Relationship ◽  
E Coli ◽  
Cross Reactions ◽  
Hyperimmune Rabbit

SUMMARYSera from patients with yersiniosis. shown to contain antibodies toYersinia enterocoliticaO9; and sera from patients with haemolytic uraemic syndrome (HUS) caused byEscherichia coliO157, were used to investigate serological cross-reactions betweenY. enterocoliticaO9 andE. coliO157. Lipopolysaccharide (LPS) was isolated from strains ofY. enterocoliticaO9 andE. coliO157 and reacted with sera by immunoblotting and ELISA. Sera from patients with HUS contained antibodies to the LPS ofE. coliO157 only; 80% of sera from patients with yersiniosis contained antibodies to the LPS ofY. enterocoliticaO9 andE. coliO157. This one-way cross-reaction was also detected using hyperimmune rabbit antisera.

scholarly journals Isolation of Escherichia coli Bacteriophages from the Stool of Pediatric Diarrhea Patients in Bangladesh

2004 ◽  
Vol 186 (24) ◽  
pp. 8287-8294 ◽  
Author(s):  
Sandra Chibani-Chennoufi ◽  
Josette Sidoti ◽  
Anne Bruttin ◽  
Marie-Lise Dillmann ◽  
Elizabeth Kutter ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Low Frequency ◽  
Sewage Water ◽  
Indicator Strain ◽  
Cross Hybridization ◽  
Diagnostic Pcr ◽  
E Coli ◽  
Severe Diarrhea ◽  
Stool Samples ◽  
The Individual

ABSTRACT A 3-week coliphage survey was conducted in stool samples from 140 Bangladeshi children hospitalized with severe diarrhea. On the Escherichia coli indicator strain K803, all but one phage isolate had 170-kb genomes and the morphology of T4 phage. In spot tests, the individual T4-like phages infected up to 27 out of 40 diarrhea-associated E. coli, representing 22 O serotypes and various virulence factors; only five of them were not infected by any of these new phages. A combination of diagnostic PCR based on g32 (DNA binding) and g23 (major capsid protein) and Southern hybridization revealed that half were T-even phages sensu strictu, while the other half were pseudo-T-even or even more distantly related T4-like phages that failed to cross-hybridize with T4 or between each other. Nineteen percent of the acute stool samples yielded T4-like phages, and the prevalence was lower in convalescent stool samples. T4-like phages were also isolated from environmental and sewage water, but with low frequency and low titers. On the enteropathogenic E. coli strain O127:K63, 14% of the patients yielded phage, all of which were members of the phage family Siphoviridae with 50-kb genomes, showing the morphology of Jersey- and beta-4 like phages and narrow lytic patterns on E. coli O serotypes. Three siphovirus types could be differentiated by lack of cross-hybridization. Only a few stool samples were positive on both indicator strains. Phages with closely related restriction patterns and, in the case of T4-like phages, identical g23 gene sequences were isolated from different patients, suggesting epidemiological links between the patients.

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