第5章细菌感染的检查方法与防治原则.pptx

第5章细菌感染的检查方法Laboratory DiagnosisOutlinen nLaboratory diagnosis for Laboratory diagnosis for bacterial infectionsbacterial infectionsuuMorphological-microscopic Morphological-microscopic uuMolecularMolecularuuSerologicalSerologicaln nLaboratory diagnosis for Laboratory diagnosis for viral infectionsviral infectionsuuMorphological-electron microscopic Morphological-electron microscopic uuIsolation Isolation uuMolecular:nucleic acids and proteins Molecular:nucleic acids and proteins uuSerologicalSerologicaln nLaboratory diagnosis for Laboratory diagnosis for fungal infectionsfungal infectionsuuMorphological-microscopicMorphological-microscopicuuIsolationIsolationAssaysn nMorphologicalMorphological assays assaysuuLight or electron microscopiesLight or electron microscopiesn nIsolation and differentiationIsolation and differentiationn nSerologicalSerological assays assaysuuAntigen-antibody assays Antigen-antibody assays n nMolecularMolecular assays assaysuuMicroorganisms gene(DNA&RNA)Microorganisms gene(DNA&RNA)Principles for Specimen Collectionn nSterile manipulation,avoid contaminationSterile manipulation,avoid contaminationn nObtain a specimenObtain a specimen uufrom the infected sitefrom the infected siteuuaccording to the disease phaseaccording to the disease phaseuubefore administrating antibioticsbefore administrating antibioticsn nDouble sera for antibody detections,acute and recovery Double sera for antibody detections,acute and recovery phase eachphase eachuuPositive if the titer of the later specimen is above 4X to the first Positive if the titer of the later specimen is above 4X to the first specimenspecimenn nTransport,and store correctlyTransport,and store correctlyuuas soon as possibleas soon as possibleuuStore at-4Store at-4o oC for most bacterial specimens,but C for most bacterial specimens,but keep warm for keep warm for Neisseria meningitidisNeisseria meningitidis and and Neisseria gonorrhoeaeNeisseria gonorrhoeaeuuStore at-4Store at-4o oC -70C -70o oC for viral specimensC for viral specimensLaboratory Diagnosis for Bacterial Infectionsn nMorphological n nProtein and Nucleic acidsn nAntibodyBacteriological Diagnosisn nIdentifying the organismMorphological Morphological Isolation&cultureIsolation&cultureBiochemical reaction Biochemical reaction Serological assaysSerological assaysn nPathogenesis&antibiotics susceptibilityAnimal experimentAnimal experimentVirulence testVirulence testantibiotics susceptibility antibiotics susceptibility Diagnosis Strategy for Bacterial InfectionMorphologicaln nNon-stained microscopic observationuuDark-field microscopyDark-field microscopyuuObserving the movement of live bacteriaObserving the movement of live bacterian nStained microscopic observationsuuGram stainGram stainuuAcid-fast stainAcid-fast stainuuFluorescence stain Fluorescence stain Isolation&Culture:Colonyn nSizen nShapen nColorn nSurface featuresuuSmooth-RoughSmooth-Roughn nTransparencyn nHemolysisBiochemical Reactions Sugar Fermentation H Sugar Fermentation H2 2S Test Citrate utilizationS Test Citrate utilizationSerological Assaysn nDetection Detection antibodyantibody in the patients serum in the patients serumn nA A current infectioncurrent infection should be should beuuIgM positiveIgM positiveuuA 4-fold or greater rise on antibody titer between the acute serum A 4-fold or greater rise on antibody titer between the acute serum sample and the convalescent serum samplesample and the convalescent serum samplen nMajor Major drawbacksdrawbacksuuA single IgG antibody titer is difficult to interpret because it is unclear A single IgG antibody titer is difficult to interpret because it is unclear whether it represents a current or a previous infectionwhether it represents a current or a previous infectionuuthe convalescent sample is usually taken 10-14 days after the acute the convalescent sample is usually taken 10-14 days after the acute sample.By this time,the patient has often recovered and the diagnosis sample.By this time,the patient has often recovered and the diagnosis becomes a retrospective onebecomes a retrospective onen nSome Some exceptionsexceptionsuuIn certain diseases,a single titer of sufficient magnitude can be used In certain diseases,a single titer of sufficient magnitude can be used as presumptive evidence of a current infectionas presumptive evidence of a current infectionAnimal experimentn nAnimalsAnimalsMouseMouseGuinea PigGuinea Pig Rabbit Dog MonkeyRabbit Dog Monkeyn nInoculation routesInoculation routesIntradermal SubcutaneousIntradermal SubcutaneousIntraperitonealIntraperitoneal IntravenousIntravenousIntracranial/intracerebral IntraspinalIntracranial/intracerebral IntraspinalIntranasal LavageIntranasal LavageVirulence Testn nMedian lethal dose,Median lethal dose,LD50LD50n nMedian infective dose,Median infective dose,ID50ID50n nElek PlateElek PlateuuDiphtherotoxin Diphtherotoxin FFCorynebacterium diphtheriaeCorynebacterium diphtheriaeuuEnterotoxinEnterotoxinFFenterotoxigenic enterotoxigenic E.coliE.coliAntibiotic Susceptibility Testn nMethodMethodMIC&MBCn nMinimum Inhibitory ConcentrationMinimum Inhibitory Concentration，MICMICn nMinimum Bactericidal ConcentrationMinimum Bactericidal Concentration，MBCMBCn nBactericidal drugsBactericidal drugs usually have an MBC equal usually have an MBC equal or very similar to the MICor very similar to the MICn nBacteriostatic drugsBacteriostatic drugs usually have an MBC usually have an MBC significantly higher than the MIC significantly higher than the MIC Bacterial Proteins,DNA&RNAn nAntigens(Proteins)uuKnown antibodiesKnown antibodiesuuAgglutination,coagulation,precipitation,Agglutination,coagulation,precipitation,ELISA,Immunofluorescence,ELISA,Immunofluorescence,radioimmunoassayradioimmunoassayn nDNA&RNAuuPCRPCRuuNucleic acid hybridizationNucleic acid hybridizationDetection of Bacterial Antigensn nPrecipitation testn nCoagglutination testn nImmunoflorecence,IFn nMcAb techniqueBacterial DNA&RNA n nPCRn nDNA probe&hybridizationuuDNA hybridization(southern blot)DNA hybridization(southern blot)n nPlasmid fingerprint analysisuuRestrict multimorphologic analysisRestrict multimorphologic analysisPCRGene Chip/microarrayDiagnosis Strategy for Bacterial InfectionSection BPrevention and treatmentPreventionPreventionPassiveimmunityActiveimmunityVaccinesAdjuvantsHumanImmune-globulinAnimal sera and antitoxinsThe difference of artificial active and passive immunityActive immunityItemsPassive immunityImmuno substanceTime for responseDurationMain usageAntigenAntibody or cytokineSlow,24 weeksFast,just when the substance injectedLong,several months several yearsShort,23 weeksPreventionPrevention and emergency treatmentVaccinesVaccinesLive(attenuated)vaccinesInactivated vaccinesSubunit vaccinesPlant vaccinesTherapeutic vaccinesDNA vaccinesArtificial passive immunityn nAntitoxin(抗毒素抗毒素)n nantisera（抗血清）（抗血清）n nImmunoglobulin（免疫球蛋白）（免疫球蛋白）n nCytokine(细胞因子）细胞因子）Antimicrobial chemotherapyn nChemotherapy as a science began with Paul Chemotherapy as a science began with Paul Ehrlich in the first decade of the 20th Ehrlich in the first decade of the 20th century.Ehrlich formulated the principles of century.Ehrlich formulated the principles of selective toxicity and recognized the specific selective toxicity and recognized the specific chemical relationships between microbial chemical relationships between microbial pathogens and drugs,the development of pathogens and drugs,the development of drug resistance,and the role of combined drug resistance,and the role of combined therapy.Ehrlichs experiments led to the therapy.Ehrlichs experiments led to the arsphenamines(arsphenamines(胂凡纳明胂凡纳明胂凡纳明胂凡纳明 )for syphilis,the)for syphilis,the first planned chemotherapy.first planned chemotherapy.