Biofilm细菌生物膜适用医学生

细菌生物膜,内容适合医学院3-5年级学生使用,“InapaperinSciencein1999,wesaid65percentofalldiseasesinthedevelopedworldarebiofilms,”Costertonsaid.“NowtheNIHsays80percent.”,Biofilmsmatrix-enclosedmicrobialaccretions/逐渐生长/增加thatadheretobiologicalornon-biologicalsurfaces.,onacontactlens,onaspider,细菌生物膜广泛存在于自然环境中,细菌生物膜广泛存在于自然环境中Biofilmformationappearsearlyinthefossilrecord(3.25billionyearsago)andiscommonthroughoutadiverserangeoforganismsinboththeArchaea/单细胞生物andBacterialineages.Biofilmformationrepresentsaprotectedmodeofgrowththatallowscellstosurviveinhostileenvironmentsandalsodispersetocolonizenewniches.,回肠表面的细菌生物被膜,人体植入导管表面的细菌生物被膜,细菌生物膜广泛存在于自然环境中,真菌生物膜,BiofilmscanbeharmfulCathetersandprostheses(mayleadtosystemicinfection)Dentaldisease（牙菌斑、口腔味道？）Otitismedia/中耳炎,inflammatoryboweldisease/IBD,prostatitis/前列腺炎,sinusitis/鼻窦炎,etc.,生物膜与疾病（总结）,细菌生物膜进入体内的可能途径,细菌生物膜的基本性质,生物膜1978年由J.WilliamCosterton等通过电镜方法首次观察到Biofilm定义：指细菌自身产生的外部多糖基质、纤维蛋白质、脂蛋白等包裹着的菌细胞的结构。生物被膜是细菌的一种具有保护性的生长模式，是细胞间相互协调作用的复杂的多细胞群体，具有结构和代谢复杂性。形成生物被膜的黏附细菌群也可以释放出浮游细菌，是潜在的持续感染因素。,Biofilmsmatrix-enclosedmicrobialaccretions/逐渐生长/增加thatadheretobiologicalornon-biologicalsurfaces.古老：fossilrecord(3.25billionyearsago)Common：adiverserangeoforganismsArchaea/单细胞生物,bacteria，fungiRepresentsaprotectedmodeofgrowththatallowscellstosurviveinhostileenvironmentsCandispersetocolonizenewniches/可以释放出浮游细菌，生长迅速，是潜在感染因素,Biofilm特点总结,Biofilm的形成过程-体内过程,Biofilm的形成过程-从菌落角度,细菌的初始吸附与其鞭毛、菌毛有关,NatureRevMicro2010,像“铠甲”一样,生物膜的结构特点,化学组成水分（97%）胞外大分子吸附的营养物质及代谢产物、细菌裂解物蛋白质、DNA,细菌生物膜的结构特点,生物膜的结构特点成熟生物被膜模型由外到内依次为：生物被膜层（bulkofbiofilm）连接层（linkingfilm）条件层（conditioningfilm）基质层（substratum)细菌被大量的胞外多糖包绕形成微菌落，各微菌落之间充满水通道,是细菌获取营养和排除代谢废物的通道。,Allbiofilmshaveamatrix(EPS)toprotectagainsttheenvironmentandholdcoloniesinplaceDifferentspecies,differentbiofilmdevelopmentMixesofpolysaccharides,proteins,andnucleicacids,成分,TheBiofilmMatrix,NatRevMicro2010,成分,原理,1、EPS的存在可以阻止抗生素作用-细菌耐药性；2、抗免疫清除：屏蔽作用使吞噬细胞和杀伤细胞及其所分泌的酶不能发挥作用；3、细菌生活微环境改变：比如厌氧菌繁殖、H2S产生、pH改变（口臭、龋齿等）4、Quorumsensing：参阅,byBonnieBasler(普林斯顿大学),细菌生物膜与抗性和特点,细菌生物膜进入体内的可能途径,临床意义,医疗器械表面、插入导管、植入医疗器具/hipreplacement-是医原性感染的主要原因之一生物造成细菌对抗生素不敏感/耐药性P.N.R.Nair(2006)InternationalEndodonticJournal.Onthecausesofpersistentapicalperiodontitis:areview,临床意义,Apicalperiodontitisisachronicinflammatorydisorderofperiradiculartissuescausedbyaetiologicalagentsofendodonticorigin.Persistentapicalperiodontitisoccurswhenrootcanaltreatmentofapicalperiodontitishasnotadequatelyeliminatedintraradicularinfection.Problemsthatleadtopersistentapicalperiodontitisinclude:inadequateasepticcontrol,pooraccesscavitydesign,missedcanals,inadequateinstrumentation,debridementandleakingtemporaryorpermanentrestorations.Evenwhenthemoststringentproceduresarefollowed,apicalperiodontitismaystillpersistasasymptomaticradiolucencies/射线可透性,becauseofthecomplexityoftherootcanalsystemformedbythemainandaccessorycanals,theirramificationsandanastomoseswhereresidualinfectioncanpersist.,P.N.R.Nair(2006)InternationalEndodonticJournal.Onthecausesofpersistentapicalperiodontitis:areview,与口腔的关系,Further,thereareextraradicularfactorslocatedwithintheinflamedperiapicaltissuethatcaninterferewithpost-treatmenthealingofapicalperiodontitis.Thecauseshavenotbeenwellcharacterized,buttherearesixbiologicalfactorsthatleadtoasymptomaticradiolucenciespersistingafterrootcanaltreatment.(i)intraradicularinfectionpersistinginthecomplexapicalrootcanalsystem;(ii)extraradicularinfection,generallyintheformofperiapicalactinomycosis;(iii)extrudedrootcanalfillingorotherexogenousmaterialsthatcauseaforeignbodyreaction;(iv)accumulationofendogenouscholesterolcrystalsthatirritateperiapicaltissues;(v)truecysticlesions,and(vi)scartissuehealingofthelesion,Howarebiofilmsstudiedinthelab?,Single-speciesvs.Multi-speciesTransparentflowcellsBacteriaattachtoglassandnutrientsflowthroughthecellMicroscopyBacterialculture,生物被膜的观察研究方法扫描电镜:Co