第3章-消毒滅菌與病原微生物實(shí)驗(yàn)室生物安全課件

第3章消毒與滅菌與

病原微生物實(shí)驗(yàn)室生物安全§1常用術(shù)語§2.消毒滅菌的方法§3.消毒滅菌的運(yùn)用（自學(xué)）§4.影響消毒滅菌效果的因素

（自學(xué)）§5.病原微生物實(shí)驗(yàn)室生物安全復(fù)習(xí)題基本概念2.消毒(disinfection)1.滅菌(sterilization)3.防腐(antisepsis)5.無菌(asepsis)和無菌操作4.清潔(cleaning)SterilizationSterilizationisaprocessusedtoachievesterility,anabsolutetermmeaningtheabsenceofallviablemicro-organisms,includingviruses,bacteriaandtheirspores,andfungiandtheirspores.UsesofsterilizationSterilizationisrequiredforinstrumentsandmaterialsusedinproceduresthatinvolvedpenetrationintonormallysterilepartsofthebody,e.g.insurgicaloperations,intravenousinfusions,hypodermicinjectionsanddiagnosticaspirations.Itisalsorequiredformedia,reagentsandequipmentusedinlaboratorypractice.UseofdisinfectionDisinfectionisappliedincircumstancesinwhichsterilityisunnecessaryorsterilizingproceduresareimpracticable.AntisepsisAntisepsisisusedtodescribedisinfectionappliedtolivingtissuesuchasawound.Somewouldrestrictthetermantiseptictopreparationsappliedtoopenwoundsorabradedtissueandpreferthetermskindisinfectionfortheremovaloforganismsfromthehandsandintactskinsurfaces.CleaningCleaningisasoil-removingprocesswhichremovesmanymicro-organisms.Theyhavewideapplicationinthehospitalenvironmentandasthenecessaryprerequisitetosterilizationanddisinfection.Thedetergentsusedincleaninghavesomedisinfectionproperties,andthedilutioneffectofthoroughrinsingfurtherreducesthemicrobialload.Removalofdebrisdriedoninstrumentsorotheritemsthataredifficulttocleanmaybeenhancedbytheuseofultrasonicbaths.無菌操作：

防止微生物進(jìn)入人體或其它物品的操作方法。消毒滅菌的方法物理消毒滅菌法化學(xué)消毒滅菌法（自學(xué)）消毒滅菌方法的選擇考慮：待處理物品的性質(zhì)、可能污染的微生物、接觸者被感染的風(fēng)險(xiǎn)熱力消毒滅菌法輻射殺菌法濾過除菌法干燥與低溫抑菌法首選SterilizationanddisinfectionbyheatTheonlymethodofsterilizationthatisbothreliableandwidelyapplicableisbyheatingundercarefullycontrolledconditionsattemperaturesabove100℃toensurethatbacterialsporesarekilled.Heat:

Moistheat→usingsteamorwater.Itkillsmicro-organismsbycoagulatinganddenaturingtheirenzymesandstructuralproteins,aprocessinwhichwaterparticipates.

Dryheat→usingflameorhotair.Itkillsmicro-organismsbycausingadestructiveoxidationofessentialcellconstituents.Temperatureandtimeareinverselyrelated.MinimumrecommendedholdtimesforheatsterilizationProcessTemperature(℃)Holdtime(min)Dryheat1601201706018030Moistheat12115126101343Thosedonotincludetimeforheatinguporcoolingtheloadforsafehandling.Thusthetotalcycletimeforprocessingasterilizedarticlewillbemuchlonger.Saturatedsteamismoreefficientthandryheat

Thegreaterlethalactionofmoistheat.Steamisquickerinheatingupthearticletobesterilized.Whendrysaturatedsteammeetsacoolersurfaceitcondensesintoasmallvolumeofwaterandliberatestheheatofvaporization.

e.g.6litersofsteam(134℃)→10mlofwater→2162Jofheatenergy;6litersofair(134℃)→100Jofheatenergy;

（一）干熱滅菌法

1.焚燒：廢棄物、尸體

2.燒灼：接種環(huán)、試管口

3.干烤：160～170℃，2h.

油、粉末、炭鋼手術(shù)器械、實(shí)驗(yàn)用玻璃器皿

4.紅外線：醫(yī)療器械pathologicalwastematerialswastesharpneedlesInoculatingwires,loops,andpointsofforceps（二）濕熱滅菌法1.巴氏消毒法(pasteurization)61.1～62.8℃，30min或71.7℃,15-30s主要用于牛乳和酒類消毒

2.煮沸法:

煮沸100℃，5-10min,殺滅細(xì)菌繁殖體，細(xì)菌芽胞經(jīng)1-2h被殺死。常用于食具、刀剪等。如加入2%碳酸氫鈉……3.流動(dòng)蒸汽消毒法：一個(gè)大氣壓下100℃的水蒸汽消毒。細(xì)菌繁殖體15-30min.可被殺死，但芽胞不一定被全部殺滅4.間歇蒸汽消毒法(fractionalsterilization)：利用反復(fù)多次的流動(dòng)蒸汽間歇加熱消毒，100℃，15-30min.37℃過夜后,再蒸,如此反復(fù)3次.

如：血清培養(yǎng)基、含糖培養(yǎng)基血清凝固器5.高壓蒸汽滅菌法：用于所有耐高溫、耐濕物品103.4kPa(1.05kg/cm2)

121.3℃，15-20min.Atsea-level,boilingwateratatmosphericpressure(1bar)willproducesteamat98-100℃,2.4bar→125℃,3.0bar→134℃.1.紫外線（ultraviolet,UV）

波長240-300nm的紫外線具有殺菌作用以265-266nm最強(qiáng)。其主要作用于DNA，使一條DNA鏈上相鄰的兩個(gè)胸腺嘧啶共價(jià)結(jié)合形成二聚體，導(dǎo)致細(xì)菌變異和死亡。

Theshortestultravioletraysthatreachtheearth’ssurfaceinquantityhaveawavelengthofabout290nm.Moreeffectiveradiationof240-280nmisproducedbymercurylamps(ultravioletlamp).穿透力弱，故僅用于空氣（如手術(shù)室、傳染病房、無菌室）和不耐熱物品表面消毒。對芽胞無作用；可逆性。DonotlookdirectlyintotheUVlightduringoperationofthedevice.ExposuretoUVlight,evenforabriefperiod,candamageyoureyes.Expositionoftheskinwithultravioletradiation(UV)isthemaincauseofskincancerdevelopment.Theconsistentlyincreasingincidencesofskintumorsisassociatedwithrecreationalsunexposure.Epidemiologicaldataindicatethatexcessiveorcumulativesunlightexpositiontakeplaceyearsanddecadesbeforethetumoroccurs.2.電離輻射IonizingirradiationUses:Itisusedtosterilizelargeamountsofprepackedsingle-useitemssuchasplasticsyringesandlatexcathetersandsurgicalgloves.薄膜濾菌器濾過除菌：用于分離細(xì)菌生長過程產(chǎn)生的毒素或其它可溶性產(chǎn)物、制備不耐高溫的抗生素溶液、放射性藥物、血清等。濾膜孔徑≤0.45μm.濾過除菌不能除去大多數(shù)病毒和支原體

生物潔凈技術(shù)高效分子空氣過濾器（HEPAfilters）生物潔凈室冷凍真空干燥法：是目前保存菌種的最好方法。在低溫下快速將含菌樣凍結(jié)，并減壓抽真空，使水升華將樣品脫水干燥，形成完全干燥的固體菌塊。并在真空條件下立即融封，造成無氧真空環(huán)境，最后置于低溫下，使微生物處于休眠狀態(tài)，而得以長期保藏。

病原微生物的分類病原微生物實(shí)驗(yàn)室的分級(jí)高致病性病原微生物BSLBiosafetyLevel1(BSL-1)Laboratory

BiosafetyLevel2(BSL-2)Laboratory

SafetysuitsinthebiosafetylevelIIIfacilityBiosafetylevelIIIgloveboxEbolainfectionsperformedinabiosafetycabinetunderbiosafetylevel4conditionsTakingoutarackfromtheliquidnitrogentank,whichcontainsthevirusesforworkinbiosafetyle