双语09-螺旋体.ppt

第1章其他原核细胞微生物第四节螺旋体spirochete,是一类细长、柔软、螺旋状、运动活泼的原核细胞型微生物。(thespirochetesareagroupofthin,soft,helical,activelymotileprokaryotes)基本结构与细菌相似，例如有细胞壁、原始核质，以二分裂方式繁殖和对抗生素等药物敏感等(thespirochetesinmanywaysarelikebacteria,whichpossessbasicstructuressuchascellwall,prokaryoticnucleoid,reproducebybinaryfission,andaresensitivetoantibiotics.),螺旋体的科family和属genus,螺旋体引起人类疾病病原体螺旋体科密螺旋体属(Treponema)梅毒苍白密螺旋体苍白亚种疏螺旋体属(Borrelia)莱姆病伯氏疏螺旋体流行性回归热回归热疏螺旋体钩端螺旋体科钩端螺旋体属(Leptospira)钩端螺旋体病问号状钩端螺旋体,名称螺旋数螺旋其他特点举例疏螺旋体3-10不规则回归热疏螺旋体伯氏疏螺旋体密螺旋体8-14规则，细密两端尖苍白密螺旋体苍白亚种钩端螺旋体规则，更细密两端钩状问号状钩端螺旋体,重要的螺旋体,一、苍白密螺旋体苍白亚种（梅毒螺旋体）T.pallidumsubsp.pallidum,814个致密而规则的小螺旋，两端尖直，运动活泼(8-14small,close,regularspirals,pointedends,activemotility)革兰染色阴性，但不易着染(G-,butnotbeeasilystainedbyordinarydyes)Fontana镀银染色法染成棕褐色(Fontanasilverimpregnationstainbrown),1生物学性状(biologicalcharacteristics)形态与染色(morphologyandstaining),不能在无活细胞的人工培养基（artificialmedia）中生长繁殖(cannotgrowincell-freemedia)在家兔上皮细胞培养中能有限生长，繁殖慢：30h/代。(limitedgrowthisachievedinculturedrabbitepithelialcells,butreplicationisslow,generationtime:30h),培养（culture）:,抵抗力（resistance）极弱(veryweak),对温度和干燥特别敏感。对常用化学消毒剂亦敏感，1%2%石炭酸（phenol）内数分钟就死亡。对青霉素、四环素、红霉素或砷剂均敏感。(easilyinactivatedbyheat(42),desiccation,cold,disinfectantsandsensitivetopenicillin,tetracycline,erythromycin,andarsenical,etc.),致病性（pathogenecity）与免疫性（immunity）,致病物质(Pathogenicfactors):外膜蛋白(Outermembraneproteins)黏附(adherencetohostcell)透明质酸酶(hyaluronidase)扩散(promotinginvasion)宿主细胞纤维粘连蛋白覆于其表面(Coatingofhostfibronectinprotectsagainstphagocytosis.)所致疾病-梅毒(syphilis)人是梅毒的唯一传染源(humansaretheonlysourceofinfection)获得性-性接触传播(acquiredsyphilis-sexualcontact)先天性-母体胎盘胎儿(congenitalsyphilis-pregnantwomanplacentafetus),免疫性(immunity)-感染性免疫(infectionimmunity)细胞免疫比体液免疫重要(cell-mediatedimmunityismoreimportantthanhumoralimmunityforthedisease),获得性梅毒acquiredsyphilis,期（初期）梅毒：感染性极强，破坏性小Primarysyphilis:veryhighlyinfectiousbutlittledestructive.Inabout3weeksafterinfection,hardchancredevelopsatthesiteofinfection,usuallyatexternalgenitalia.Thisprimarylesionalwayshealsspontaneously.感染后3周左右局部出现无痛性硬下疳，多见于外生殖器，一般48周后，常自愈。期梅毒：感染性强，破坏性小Secondarysyphilis:highlyinfectiousbutlittledestructive.Thisstageusuallybegins2to8weeksafterthechancreappears.Syphilisbacteriaenterthebloodandspreadthroughthebody,causingmanydifferentsymptoms,includingrash(syphilid),systemicLymphnodeenlargement发生于硬下疳出现后28周。苍白亚种螺旋体血症，全身皮肤、粘膜常有梅毒疹，全身淋巴结肿大，有时亦累及骨、关节、眼及其他脏器。,期(晚期)梅毒)：感染性小，破坏性大tertiarysyphilis:littleinfectiousbuthighlydestructive.Tertiarysyphilisoccursfromasearlyastwoyearsaftertheinitialinfectionbutcantakeuptotenyearstomanifest.Virtuallyanytissueinthebodycanbedamagedthebasiclesionischronicgranulomaandlocalnecrosis.thelesionsprogressandsubsidealternatively,andfinallybecomelife-threatening(发生于感染2年以后，亦可长达1015年的。病变可波及全身组织和器官。基本损害为慢性肉芽肿，局部组织坏死。损害常进展和消退交替出现。皮肤、肝、脾和骨骼常被累及。可危及生命。),期（初期）梅毒primarysyphilis,期梅毒secondarysyphilis,期(晚期)梅毒tertiarysyphilis,主动脉瘤,gummaofhand,Charcotsjoints,先天性梅毒（胎传梅毒）(congenitalsyphilis),多发生于妊娠4个月之后经胎盘感染。(OftenOccursthroughtheplacentaafter4monthsofgestation)引起胎儿的全身性感染，导致流产、早产或死胎(Causesystemicinfectionoffetusabortion,prematurebirth,stillbirth)出生梅毒儿，呈现马鞍鼻、锯齿形牙、间质性角膜炎、先天性耳聋)等特殊体征(Manifestationsofsyphiliticinfants:saddlenose,Hutchinsonteeth,interstitialkeratitis,congenitaldeafness),Hutchinsonteeth,interstitialkeratitis,saddlenose,syphiliticinfant,三、微生物学检查法microbiologicaldiagnosis,1.标本(specimens)期梅毒-硬下疳渗出液(exudate)期梅毒-梅毒疹渗出液或局部淋巴结抽出液(aspirate)2.显微镜检查(microscopicexamination)-暗视野显微镜或荧光显微镜下找螺旋体（spirochaetearedemonstratedbydarkfieldorimmunofluorescencemicroscops）3.血清学诊断(serologicaltests)暗视野显微镜荧光显微镜,非特异性：非密螺旋体抗原试验:(Nonspecific-nontreponemalantigentests:)NonreactiveVDRL抗原(正常牛心肌的心脂质)+血清中的反应素(抗脂质抗体)(antigen-beefheartcardiolipin+reagin-antibodiestocardiolipin)reactiveVDRL方法:VDRL试验（venerealdiseaseresearchlaboratory)RPR试验(rapidplasmareagin)适用于大量过筛.注意假阳性。(thescreeningtestsaresubjecttofalse-positiveresults),特异性：密螺旋体抗原试验（Specific-treponemalantigentests:)抗原（Nichols株螺旋体）+螺旋体特异抗体(antigen+specificantibodiesagainstTreponemapallidum)优点：特异性强，可用作梅毒证实试验(advantages:excellentspecificity-usedasaconfirmationtestofofsyphilis)常用方法：FTA-ABS试验（间接荧光抗体检测）MHA-TP试验（微量间接血凝试验）。,preventionandcontrol,1toavoidsexualcontactwithsomeonewhohasasexuallytransmitteddisease,andsafesexwithcondomsishighlyrecommended.)避免不洁性行为，洁身自爱2vaccine-thereisnovaccineagainstsyphilis)疫苗:尚无3penicillin,asthetreatmentofchoice,isgivenaftertheaccuratediagnosisofsyphilis)梅毒确诊后，宜用青霉素等药物及早予以彻底治疗,三钩端螺旋体属Leptospira,问号状钩端螺旋体(L.interrogans)双曲钩端螺旋体(L.biflexa),螺旋细密、规则，形似细小珍珠排列的细链。一端或两端呈钩状。运动活泼,常使菌体呈C、S或8字型(fine,regularspirals;assumingtheappearanceofachainofbeads;oneortwoendsformingahook,activelymotile;bacterialbody-C,Sor8-shaped”),1.形态与染色morphologyandstaining,一、生物学性状Biologicalfeatures,革兰染色阴性，不易着染(G-,butdoesnotstainreadily)Fontana镀银染色法染成棕褐色(Fontanasilverimpregnationstainbrown),营养要求复杂，常用Korthof培养基(含10%兔血清)。(fastidiousnutritionalrequirements-Korthofmedia)适宜生长温度(optimaltemperature):2830钩端螺旋体在人工培养基中生长缓慢。(growslowlyinartificialmedia,generationtime:8-10h)液体培养基1周半透明云雾状生长(liquidmedia-semitransparent,cloudygrowth固体培养基2周透明、不规则的扁平细小菌落(solidmedia-transparent,irregular,flat,tinycolony)需氧或微需氧(aerobicormicro-aerobic),2.培养culture,3.抵抗力弱(resistance-weak),热抵抗力弱，601min即死亡。0.2%来苏、1:2000升汞、1%石炭酸经1030min被杀灭。对青霉素敏感。在湿土或水中可存活数月。(sensitivetoheat,lysol,MercuricBichloride,phenol,andpenicillin,etc.BUTsurviveinmoistsoilandwaterforseveralmonths),二、致病性与免疫性(pathogenecityandimmunity,致病物质-类似细菌内毒素与外毒素(Pathogenicfactorsareasfollows),1内毒素样物质(ELS)或称脂多糖样物质(LLS)2溶血素(hemolysin)3细胞毒性因子(CTF)4.细胞致病作用(CPE)物质,所致疾病,钩端螺旋体病-一种人畜共患传染病(zoonosis),传染源,传播途径,鼠和猪,经粘膜或破损皮肤进入;经胎盘垂直传播(verticaltransmission),发病机制,疾病特点,起病急、高热、乏力、全身酸痛、眼结膜充血、腓肠肌压痛、表浅淋巴结肿大,经粘膜或破损皮肤进入机体,transmission-of-leptospirosis,器官损害,免疫性,疾病后可获得抗同型钩体的持久免疫力(serovar-specificimmunityfollowsinfection),细胞免疫为主(cell-mediatedimmunity),Leptospirosisarea,Epidemiology,三、微生物学检查法,1.病原体检测(Pathogendetection)发病10天内取血液;1周后取尿液;有脑膜刺激者取脑脊液Specimens:blood-inthefirst10daysofthediseaseurine-afteroneweekofthediseaseCSF-ifMeningealirritationexists直接镜检(directmicroscopicexamination)分离与鉴定接种至Korthof培养基，置28孵育。阳性标本在2周内可见培养液呈轻度混浊暗视野显微镜检查有则用已知诊断血清鉴定其血清群和血清型。阴性标本:分离培养应连续观察4个月，仍无生长者。(isolationandidentification:Korthofmedia-incubationat28Positivespecimen:slightturbidityinliquidmediadarkfieldmicroscopicexaminationserologicaltestsNegativespecimen:continuousculturefor4months,动物接种(animalinoculation)幼龄豚鼠或金黄地鼠腹腔(peritonealcavityofguineapigorgoldenhamster)分子生物学方法(molecularbiologymethods),PCR或标记DNA探针(DNAmarkerprobe),2.血清学诊断serologicaldiagnosis,病初和发病后第34周各采血清一次。有脑膜刺激症状者采取脑脊液(specimens:sera-theearlyphaseofthedisease+the3rd-4thweekofthediseaseCSF-meningealirritation)方法:显微镜凝集试验(microscopicslideagglutinationtests,MAT)间接凝集试验(indirectagglutinationtest)以乳胶(聚苯乙烯)