0000000000165102

AUTHOR

Manuel Blanco

showing 4 related works from this author

Assessment of Escherichia coli B with enhanced permeability to fluorochromes for flow cytometric assays of bacterial cell function.

2002

Background Flow cytometry has become a choice methodology for microbiological research. However, functional cytometric assays in live bacteria are still limited. This is due, in part, to the cell wall impairing penetration of vital dyes in bacteria, thus imposing permeabilization procedures. These manipulations may affect cell physiology, provoke cell aggregation or lysis, and they are time-consuming. Escherichia coli B strains have been used for mutagenic assays because of an altered lipopolysaccharide that provokes increased membrane permeability. We assessed the use of these strains as possible alternatives for flow cytometric assays to avoid the permeabilization steps. Methods Suspensio…

Cell Membrane PermeabilityMembrane permeabilityBiophysicsBiologymedicine.disease_causePathology and Forensic MedicineFlow cytometrychemistry.chemical_compoundEndocrinologymedicineEscherichia coliPropidium iodideFluorescein isothiocyanateEscherichia coliFluorescent Dyesmedicine.diagnostic_testStaining and LabelingCell BiologyHematologyFlow CytometryMolecular biologyCell aggregationStainingOxidative StresschemistryBiochemistryCytometryCytometry
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Nitic oxide promotes strong cytotoxicity of phenolic compounds against escherichia coli. The influence of antioxidant defenses

2003

[EN] The induction of mutagenic and cytotoxic effects by simple phenolics, including catechol (CAT), 3,4dihydroxyphenylacetic acid (DOPAC), hydroquinone (HQ), and 2,5-dihydroxyphenylacetic (homogentisic) acid (HGA), appears to occur through an oxidative mechanism based on the ability of these compounds to undergo autoxidation, leading to quinone formation with the production of reactive oxygen species. This is supported by the detection of such adverse effects in plate assays using Escherichia coli tester strains deficient in the OxyR function, but not in OxyR(+) strains. The OxyR protein is a redox-sensitive regulator of genes encoding antioxidant enzymes including catalase and alkyl hydro…

AntioxidantUltraviolet Raysmedicine.medical_treatmentCatecholsOxidative toxicityFree radicalsOxidative phosphorylationNitric OxideBiochemistryAntioxidantschemistry.chemical_compoundCaffeic AcidsQUIMICA ORGANICASuperoxidesPhysiology (medical)medicineEscherichia coliBIOQUIMICA Y BIOLOGIA MOLECULARHydrogen peroxidechemistry.chemical_classificationMelaninsReactive oxygen speciesbiologyHydroquinoneAutoxidationDose-Response Relationship DrugPhenolEscherichia coli ProteinsNitric oxideHydrogen PeroxideCatalaseFlow CytometryQuinoneHydroquinonesDNA-Binding ProteinsOxygenRepressor ProteinschemistryBiochemistryCatalaseMutationbiology.proteinQuinoneOxyROxidation-ReductionDNA DamageMutagensTranscription Factors
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Detection of oxidative mutagenesis by isoniazid and other hydrazine derivatives in Escherichia coli WP2 tester strain IC203, deficient in OxyR: stron…

1998

Abstract Strain IC203, deficient in the OxyR function, was sensitive to both cytotoxic and mutagenic effects of isoniazid (INH) whereas its parent, WP2 uvrA /pKM101, was resistant to these effects. Four other hydrazine compounds, hydrazine hydrate (HZH), phenylhydrazine (PHZ), hydralazine (HLZ) and nialamide (NLD), were mutagenic in WP2 uvrA /pKM101. Increases in mutagenicity were observed in IC203 for HZH and PHZ but not for HLZ and NLD. Growth inhibition zones by HZH, PHZ and NLD were larger in IC203 than in WP2 uvrA /pKM101. The enhancements in the effects of INH, HZH and PHZ in IC203 with respect to its oxyR + parent are considered to be caused by the production of reactive oxygen speci…

Health Toxicology and Mutagenesismedicine.disease_causechemistry.chemical_compoundSpecies SpecificityEscherichia coliIsoniazidGeneticsmedicineAnimalsEscherichia coliPhenylhydrazinechemistry.chemical_classificationReactive oxygen speciesbiologyMutagenicity TestsEscherichia coli ProteinsMutagenesisbiology.organism_classificationEnterobacteriaceaeRatsDNA-Binding ProteinsRepressor ProteinsLiverBiochemistrychemistryMutagenesisCatalasebiology.proteinbacteriaGrowth inhibitionReactive Oxygen SpeciesOxidation-ReductionCytosineMutagensTranscription FactorsMutation Research/Genetic Toxicology and Environmental Mutagenesis
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Functional assays of oxidative stress using genetically engineered Escherichia coli strains.

2003

Oxidative stress may be induced in bacteria by exogenous biocidal agents and is involved in endogenous metabolism. The oxyR operon is a main sensor of oxidative stress and oxyR-deficient bacteria show enhanced sensitivity to oxidative stress and increased accumulation of intracellular reactive oxygen species (ROS). Flow cytometric functional assays in bacteria are limited by the impaired penetration of vital dyes trough the cell wall. Escherichia coli B WP2 strains possess an altered cell-wall lipopolysaccharide that leads to increased membrane permeability. Flow cytometric analysis of WP2 strains is a convenient alternative for cytometric assays of bacterial function. This unit presents pr…

HistologyMembrane permeabilityLipopolysaccharideOperonBiologymedicine.disease_causeBiochemistryCell wallchemistry.chemical_compoundmedicineEscherichia coliEscherichia coliFluorescent DyesEscherichia coli ProteinsGeneral Medicinebiology.organism_classificationFlow CytometryDNA-Binding ProteinsRepressor ProteinsMedical Laboratory TechnologyOxidative StressBiochemistrychemistrybacteriaGenetic EngineeringReactive Oxygen SpeciesIntracellularBacteriaOxidative stressCurrent protocols in cytometry
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