1、革兰阳性球菌耐药与治疗倪语星上海交通大学医学院附属瑞金医院MDR细菌已成为全球关注的焦点 在全球范围内，“ESKAPE”耐药已成为导致患者发病及死亡的重要原因1“ESKAPE”耐药现象日益严重，但当前新型抗菌药物的研发逐渐减缓，未来可能面临无药可用的局面3新药数量1983-1987 1988-19921993-19971998-20022003-20071.Rice LB et al.The Journal of Infectious Diseases 2008;197:1079812.http:/www.who.int/world-health-day/zh/3.Boucher HW et
2、al.Clinical Infectious Diseases 2009;48:112我国主要的MDR致病菌 我国，“ESKAPE”耐药菌株检出率高检出率(%)产ESBL大肠埃希菌MRSA产ESBL肺炎克雷伯菌属不动杆菌属*铜绿假单胞菌*耐万古霉素屎肠球菌*在G-菌中的检出率朱德妹等.中国感染与化疗杂志.2011;11(5):321-32913967株株5380株株431株株1733株株1623株株呼吸道呼吸道 尿尿 液液粪粪 便便伤口伤口分泌物分泌物 血液血液 克雷伯菌属克雷伯菌属15.3%大肠埃希菌大肠埃希菌47.1%金葡菌金葡菌22.7%凝凝(-)葡萄球菌葡萄球菌50.2%志贺菌属志贺菌
3、属80.7%金葡菌金葡菌14.7%肠球菌肠球菌21.0%大肠埃希菌大肠埃希菌16.7%大肠埃希菌大肠埃希菌11.5%不动杆菌不动杆菌12.8%克雷伯菌克雷伯菌8.2%铜绿假单孢菌铜绿假单孢菌9.5%金葡菌金葡菌7.7%铜绿假单胞菌铜绿假单胞菌11.4%凝凝(-)葡萄球菌葡萄球菌5.8%克雷伯菌克雷伯菌 8.9%克雷伯菌克雷伯菌5.7%汪复,等.中国感染与化疗杂志.2010;10(5):325-334.各类标本中的主要病原菌？各类标本中的主要病原菌？血培养排名前10位的临床致病菌细菌名称正确污染率不确定金葡87.26.46.4大肠埃希菌99.30.00.7凝固酶阴性葡萄球菌12.481.95.8
4、肺克100.00.00.0肠球菌69.916.114.0绿脓96.41.81.8肺链100.00.00.0白念90.00.010.0草绿链38.049.312.7阴沟100.00.00.0一、药敏监测数据一、药敏监测数据ZAAPS监测项目简介监测项目简介 时间入选情况G+菌株2006年16个国家的50所医学研究中心共分离到4216株G+菌2007年23个国家的64所医学研究中心共分离到5591株G+菌不同国家不同国家MRSA耐药率耐药率 加拿大：55.7%拉丁美洲：平均为50.1%(29.0%-64.1%)欧洲：平均为28.2%(1.7%-56.2%)亚太地区：平均为44.2%(25.3%-6
5、8.0%)常用抗菌药物对金黄色葡萄球菌抗菌活性金黄色葡萄球菌(3000)MIC(g/mL)百分比(%)50%90%范围敏感/耐药利奈唑胺220.25-899.9/环丙沙星0.540.06-464.2/34.9左氧氟沙星0.540.5-465.2/34.6克林霉素0.2520.25-274.3/25.6替考拉宁222-8100.0/0.0TMP-SMX0.50.50.5-293.1/6.9万古霉素110.25-2100.0/0.0常用抗菌药物对CoNS的抗菌活性CoNS(716)MIC(g/mL)百分比(%)50%90%范围敏感/耐药利奈唑胺110.06-899.7/青霉素220.25-220.
6、4/79.6奎奴普丁-达托普丁0.250.50.25-298.9/0.6替考拉宁282-1697.5/0.3万古霉素120.12-899.0/0.02008年CHINET监测网各医院金葡菌MR菌株检出率医院金黄色葡萄球菌医院金黄色葡萄球菌MR株数/总株数（%）MR株数/总株数（%）华山医院421/54377.5 北京医院/214/279/76.7 瑞金医院375/56666.3 上海儿科医院/43/291/14.8 协和医院221/38058.7 上海儿童医院/68/353/20.4 同济医院257/41762.6 重庆医大一附院/8/18/44.4浙医一附院107/21450.0 甘肃省人民
7、医院/58/112/51.8 广州一附院79/12065.8 新疆医大一附院/65/146/44.5 总计1916/343955.7(14.8-77.5)55.7(14.8-77.5)两家儿童医院MRSA检出率低2008年CHINET监测网各医院凝固酶(-)葡萄球菌MR菌株检出率医院凝固酶阴性葡萄球菌医院凝固酶阴性葡萄球菌MR株数/总株数（%）MR株数/总株数（%）华山医院45/5188.2北京医院12/1675.0瑞金医院90/12174.4上海儿科医院/304/503/60.4协和医院186/22881.6上海儿童医院/302/327/92.4同济医院172/21181.5重庆医大一附院/
8、1/1/浙医一附院560/74775.0甘肃省人民医院/20/28/71.4广州一附院36/4481.8新疆医大一附院/16/21/76.2总计1744/229875.9(60.4-92.4)75.9(60.4-92.4)MSSA(1495株株)与与MRSA(1916株株)的耐药率（的耐药率（%）MRSA的耐药率MSSA仍有75，67菌株对SMZ/TMP、磷霉素敏感MSSA对内酰胺类、氟喹诺酮类、SMZ/TMP、利福平、磷霉素的耐药率MSCNS2.MRCNS耐药率MRSA，但仍有约90、65菌株对利福平、磷霉素敏感。3.无万古、替考拉宁、利奈唑胺耐药株2006-2010年监测数据 耐万古霉素的
9、粪肠球菌与屎肠球菌发生率极少细菌耐药率(%)1.汪复.2006年中国CHINET细菌耐药性监测.中国感染与化疗杂志 2008;8(1):1-9.2.汪复等.2007年中国CHINET细菌耐药性监测.中国感染与化疗杂志 2008;8(5):325-333.3.肖永红等.2006-2007年Mohnarin细菌耐药检测.中华医院感染学杂志 2008;18(8):1051-1056.4.汪复等.2008年中国CHINET细菌耐药性监测.中国感染与化疗杂志 2009;9(5):321-329.5.汪复等.2009年中国CHINET细菌耐药性监测.中国感染与化疗杂志 2010;10(5):325-334
10、.6.朱德妹,汪复,胡付品等.2010年中国CHINET细菌耐药性监测.中国感染与化疗杂志 2011;11(5):321-329.二、S.aureus and MRSA Methicillin resistant S.aureus Presence of a mecA gene Carried in a mobile genetic element(SCCmec)Most routine testing antibiotic sensitivity(MRSA id agar)LGA251MSSACLSI药敏指南药敏指南“金黄色葡萄球菌或所有凝固酶阴性葡萄球菌如对苯唑西林(或甲氧西林)耐药，则对
11、青霉素类、头孢菌素类、碳青霉烯类和含酶抑制剂的复方制剂均应报告耐药均应报告耐药，而不考虑其体外药敏结果”。Cefoxitin Disk Test for mecA-mediated Resistance in Staphylococci Breakpoints(mm)OrganismOld M100-S16 New M100-S17ResSuscResSuscS.aureusS.lugdunensis192021*22*CoNSNo change24252425OX-R=mecA=MRSA?Discovery of the new MRSA strains(LGA251)We found S.
12、aureus that were highly resistant on one farm(ST425)(Oxacilin MIC=16mg/l,cefoxitin MIC=32mg/l)Looked for mecA gene negative results Sequenced whole genome to look for the reason Found a divergent mecA gene inside a new SCCmecImportance of the new MRSA Molecular tests(PCR&slide agglutination test)des
13、igned to detect MRSA give a negative result when tested on the new strain The new MRSA is moving between people and cattle Old MRSA was not found in dairy cows Divergent MRSA is found in S.aureus strains thought to be restricted to animals Geographical clustering of human and cow strains of the new
14、MRSA Divergent MRSA mecA gene has not been found in human strains Isolations of divergent MRSA appear to be increasingNew MRSA isolates by year0102030405060ScotlandEnglandDenmark19752002200420052006 2007 2008 2009 2010 2011CC130CC599ST425CC1943ST1021CC49HumanCattle SheepRatCatDogHorseG PigDeerSeal F
15、inchRabbit三、对糖肽类的耐药机制VRSA vanA gene positive Change of D-alanyl-D-alanyl-D-lactate 1000 fold decrease in affinity to vancomycin Typical MIC16mg/L to vancomycinVRSA USA 12 cases http:/www.cdc.gov/HAI/settings/lab/vrsa_lab_search_containment.html First discovered in 2002 8 from Michigan!2 most reccent
16、 from Delaware(2010)Iran-1 case THE-2,2005 India 6 cases From intensive care units in 2 tertiary hospitals in Hydrabad-2008VISA isolates Not a single mutation or acquisition of a single gene Complex!Involves a series of changes!Increased cell wall thickening,increased number of free D-alanyl-D-alani
17、n residues,reduced autolytic activity,mutations in regulators of cell wall synthesis(i.e.graRS,vraSR),change in transcription profile Typical MIC 4-8mg/LhVISA isolates susceptible by standard MIC testing but have subpopulations expressing reduced susceptibility Same types of resistance mechanisms as
18、 VISA isolates Typical MIC 1-2mg/LPopulation profile of initial isolate(6000)and after persistant bacteremia/vancomycin therapy(6001)Howden,AAC,2006JKD6001JKD6000ATCC25923Mu3987654321012345678Vancomycin g/mlLog 10 CFU/mlPrevalence of VISA/hVISA Highly variable prevalences are reported in the literat
19、ure including within countries Illustrated by data from Australia Melbourne(Austin)117 MRSA VISA 2 isolates(2%)Sydney 401 MRSA BSI hVISA 46(11.5%)(almost all ST239)VISA 2(0.5%)Australia general 532 SAB/202 MRSA hVISA 2 isolates 0.4%/1%VISA 0 isolatesHorne AAC,2009.Val Hal,Plosone.Homes,JID 2011.Summ
20、ary The prevalence of VRSA and VISA isolates are still low in most part of the world The prevalance of hVISA varies in general relatively low but can locally be up 50%of MRSA isolates There are increasing evidence that strains with MIC1mg/L are associated with pooer outcome but large definitive pros
21、pective studies is neededLinezolid-R S.aureus:Review April June 2008 12 patients with LRSA 6 VAP,3 bacteremia 1 predominant clone cfr mediated resistance Health care workers and environment NegClinical Outbreak of Linezolid-Resistant Staphylococcus aureus in an Intensive Care UnitSanchez M,JAMA 2010
22、Linezolid-R S.aureus outbreakK-217Clinical and Microbiological characteristics of Linezolid-Resistant Staphylococcus aureus(LRSA)April-June 2008From July 2001 to May 2011:22 publications,77 patientsMechanism of resistance was a RNA mutation in 37 cfr gene in 33 Both 1 Not reported 730 ICU-patients,1
23、7 patients on hospital words and 18 outpatientsLRSA caused 29 respiratory tract infections,mostly VAP,bacteremia in 7,and SSTI in 6.Six patients were colonized.M de la Torre,ICAAC,Chicagao 2011Mechanisms of Linezolid Resistance Binding to the Petidyl Transferase Center(PTC)on the ribosome Mutations
24、of 23S rRNA Ribosomal proteins L3 and L4 Cfr methyl transferase geneLong KS.AAC 2012.Resistance to Linezolid Caused by modifications at Its Binding Site on the RibosomeLR-MRSA outbreak:Results All LR-MRSA(patients and HCWs)were genotypically identical by PFGE The cfr gene was detected in all isolate
25、s None of the isolates showed mutations in the 235 rRNA subunitLR-MRSA outbreak:Linezolid Use05101520251601401201008060402002009JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecemberJanuaryFebruaryMarchAprilMayJuneLR-MRSAMRSADDDs LinezolidIncidence densityN patients and incidence
26、 density MRSA in PSICUDapto-Resistance:mechanisms Mutations in genes essential for Membrane phospholipid biosynthesis reduce the net-negative charge of the cell membrane.Electrorepulsion of DaptomycinWhole Genome Characterization of the Mechanisms of Daptomycin Resistance in Clinical and Laboratory
27、Derived Isolates of Staphylococcus aureusPeleg AY.PLoSone 2012.Dapto-Resistance:mechanismsCorrelation between nonsusceptibility to daptomycin is due to cell wall thickeningPeleg AY.PLoSone 2012.Daptomycin MIC increase among patients with methicillin-resistant Staphylococcus aureus persistent bactera
28、emia treated with daptomycin.Prospective study in 22 Spanish hospitals.O.Gasch*,M.Camoez,MA.Dominguez,B.Padilla Increase in MICs in sequential isolates both to Daptomycin and Vancomycin.Switch to another drug if BCs do not become negativeGash O.ECCMID 2012.四、VRE 肠球菌对万古霉素的耐药可分为低水平耐肠球菌对万古霉素的耐药可分为低水平耐药
29、（药（MIC，8-32mg/L）和高水平耐药（）和高水平耐药（MIC，64mg/L）。）。根据肠球菌对万古霉素和替考拉宁的不同根据肠球菌对万古霉素和替考拉宁的不同耐药水平及耐药基因，耐药水平及耐药基因，VRE分为四个表型，分为四个表型，分别是分别是VanA，VanB，VanC和和VanD。VRE的分型及其耐药表型的分型及其耐药表型 类型类型 万古霉素万古霉素 （g/ml）替考拉宁替考拉宁 VanA 641000 16512 VanB 41024 0.252 VanC 232 0.122 VanD 1664 24CLSI bp 2,4-8 16 8,16 32 chromID VRE粪肠球菌屎肠
30、球菌 VRE筛选试验阳性必须做筛选试验阳性必须做MIC确认，并观确认，并观察动力和色素鉴别菌种，以区分获得性察动力和色素鉴别菌种，以区分获得性耐药（耐药（VanA和和VanB）及某些菌种存在的）及某些菌种存在的固有的中介（固有的中介（8-16）耐药（）耐药（VanC），后），后者在感染控制中的意义与者在感染控制中的意义与VRE不同。不同。肠球菌的治疗 粪肠球菌：氨苄西林加减庆大霉素 重症，HLAR：万古霉素 屎肠球菌：庆大霉素 重症，HLAR：万古霉素 VRE：VanA：替考拉宁，其他：利奈唑胺 泌尿道感染：呋喃妥因五、经验治疗以下情况高度提示革兰阳性球菌感染 血流感染，包括导管相关的血流感染，菌血症，脓毒症，细菌性心内膜炎 皮肤软组织感染，包括伤口和创面感染 手术部位感染，包括植入物感染 骨和关节感染，骨髓炎以下情况有可能革兰阳性球菌感染 HAP（MRSA）VAP（MRSA）复杂UTI（MRSA，肠球菌）革兰阳性球菌感染？葡萄球菌占革兰阳性球菌感染第一位 金黄色葡萄球菌占葡萄球菌感染第一位 MRSA占金黄色葡萄球菌5060%以下情况考虑糖肽类治疗 脓毒症 骨、关节感染 手术部位感染 血流感染：菌血症、心内膜炎 导管相关感染 院内肺炎 复杂性尿路感染
