多粘菌素耐藥基因mcr-1課件

Complexdisseminationofthediversifiedmcr-1-harbouringplasmidsinEscherichiacoliofdifferentsequencetypes

多粘菌素耐藥基因mcr-1質(zhì)粒的多樣性及復(fù)雜傳播機(jī)制王艷艷Emergenceofplasmid-mediatedcolistinresistancemechanismMCR-1inanimalsandhumanbeingsinChina:amicrobiologicalandmolecularbiologicalstudyYi-YunLiu*,YangWang*,TimothyRWalsh,Ling-XianYi,RongZhang,JamesSpencer,YoheiDoi,GuobaoTian,BaoleiDong,XianhuiHuang,Lin-FengYu,DanxiaGu,HongweiRen,XiaojieChen,LuchaoLv,DandanHe,HongweiZhou,ZisenLiang,Jian-HuaLiu,JianzhongShen目前發(fā)現(xiàn)多黏菌素耐藥機(jī)制two-componentsystems[pmrAB[6]andphoPQ[7])andtheregulatormgrBtheplasmid-mobilizedcolistinresistance(MCR-1)SincethefirstdiscoveryofMCR-1fromSouthernChina,inthelateof2015,thenewcolistinresistancegenehasspreadto5of7continentsnolessthansixspeciesofEnterobacteriaceae(E.coli,Enterobacteraerogenes,Enterobactercloacae,K.pneumonia,Salmonellaenterica,andShigellasomneiarerecipienthostsforthemcr-1-harbouringplasmidsMoreseriously,theMCR-1wasfoundtoco-localizewithtwotypesofnotoriousdrugresistantgenes(ESBLandNDM-1(and/oritsmutants).

菌株的收集與鑒定

主要內(nèi)容mcr-1基因所處的質(zhì)粒骨架呈現(xiàn)出多樣性與復(fù)雜性質(zhì)粒骨架上插入序列、轉(zhuǎn)座子等移動(dòng)元件的發(fā)現(xiàn)，表明其移動(dòng)散播機(jī)制的復(fù)雜性。檢測(cè)到的質(zhì)粒均位于E.coli中，對(duì)菌株進(jìn)行MLST分型發(fā)現(xiàn)其ST呈現(xiàn)出多樣化，具有11種序列型，并且發(fā)現(xiàn)了一種新的ST類型。通過構(gòu)建報(bào)告基因LacZ基因的融合，率先分析了mcr-1基因啟動(dòng)子的活性。MLST分型發(fā)現(xiàn)其ST呈現(xiàn)出多樣化β-GalactosidaseassaysThestrainsofE.colicarryingthechromosomePmcr-1-lacZtranscriptionalfusion(e.g.,FYJ853)weregrowninLBmedia,andmid-logphasecultureswerecollectedassayedforβ-galactosidaseactivityfollowinglysiswithSDS(sodiumdodecylsulfate)-chloroform.小結(jié)Insummary,itseemslikelythatcomplexdisseminationofthediversifiedmcr-1-harbouringplasmidsoccursamongstthevariousSTE.coliinhabitingthehealthyswinepopulations,inSouthernChina.Inparticular,ourfindingshighlightedtheurgentneedtoreconsidertheefficacy(safety)ofcolistinintheveterinaryuse,andformulateacomprehensivestrategytofightagain