2010年CMSS对革兰阴性杆菌耐药性监测报告

目的 监测2010年中国革兰阴性杆菌的耐药性.方法 收集2010年9-12月全国13家教学医院的1 259株非重复的革兰阴性杆菌.菌株经中心实验室复核后,采用琼脂稀释法测定美罗培南等广谱抗菌药物的MIC.药敏结果判断采用CLSI 2011年M100-S21标准.结果 14种抗菌药物对845株肠杆菌科细菌的抗菌活性,敏感性依次为美罗培南829株(98.1％)、阿米卡星794株(94.0％)、亚胺培南761株(90.0％)、哌拉西林/他唑巴坦739株(87.5％)、头孢吡肟701株(83.0％)、厄他培南696株(82.4％)、头孢哌酮/舒巴坦678株(80.3％)、黏菌素637株(75.4％)、头孢他啶591株(70.0％)、环丙沙星499株(59.1％)、头孢西丁463株(54.8％)、头孢曲松452株(53.5％)、头孢噻肟442株(52.3％)、米诺环素435株(51.5％).大肠埃希菌中ESBL的发生率为61.3％ (106/173),高于肺炎克雷伯菌[41.2％ (70/170)].大肠埃希菌对美罗培南、亚胺培南、阿米卡星、哌拉西林/他唑巴坦保持较好的敏感性,而对环丙沙星、头孢曲松和头孢噻肟的耐药率较高.肺炎克雷伯菌对美罗培南、亚胺培南、阿米卡星和黏菌素的敏感率均保持在90％以上,而对头孢曲松和头孢噻肟的耐药率较高.阴沟肠杆菌、产气肠杆菌、弗劳地柠檬酸菌,对美罗培南、阿米卡星、头孢吡肟、头孢哌酮/舒巴坦、亚胺培南、哌拉西林/他唑巴坦、厄他培南的敏感率都保持在80.0％以上.对于铜绿假单胞菌敏感性较高的药物为黏菌素(98.4％,182株)、阿米卡星(85.9％,159株)、哌拉西林/他唑巴坦(80.0％,148株)、头孢他啶(79.5％,147株)、美罗培南(74.1％,137株)、环丙沙星(74.1％,137株)、头孢吡肟(73.5％,136株)、亚胺培南(71.9％,132株)和头孢哌酮/舒巴坦(70.8％,131株).鲍曼不动杆菌对碳青霉烯类的敏感率小于37.0％,对米诺环素敏感率为47.8％.97.8％(176株)的鲍曼不动杆菌对黏菌素敏感,泛耐药鲍曼不动杆菌和铜绿假单胞菌发生率分别为60.1％(108株)和18.9％(35株).结论 碳青霉烯类对肠杆菌科仍保持高活性,但鲍曼不动杆菌和铜绿假单胞菌的耐药性增加,鲍曼不动杆菌对碳青霉烯类的耐药性显著增加.     

2003-2004年中国十家教学医院革兰阴性杆菌的耐药分析

目的连续监测2003-2004年中国不同地区十家教学医院临床分离的革兰阴性杆菌的耐药性。方法非重复的1760株革兰阴性杆菌中，2003年871株，2004年889株。菌株经中心实验室复核后，采用琼脂稀释法测定美罗培南等数十种广谱抗菌药物的最低抑菌浓度（MICs），数据分析采用WHONET－5．3软件。结果10种抗菌药物对于1115株肠杆菌科细菌的抗菌活性，敏感率依次为：美罗培南、亚胺培南（敏感率99％）〉哌拉西彬三唑巴坦（86．3％）〉阿米卡星（81．8％）〉头孢吡肟（76．5％）、头孢哌酮／舒巴坦（75．1％）〉头孢他啶（74．8％）〉头孢噻肟（54．8％）、头孢曲松（51．8％）〉环丙沙星（48．6％）；美罗培南、亚胺培南的MIC。分别为0．125μg/ml、1μg/ml。超广谱B内酰胺酶（ESBL）的发生率，大肠埃希菌（56．8％）高于肺炎克雷伯菌（42．3％）和奇异变形杆菌（12．1％）。对于大肠埃希菌，抗菌活性在80％以上的药物除碳青霉烯类之外，还有哌拉西林／三唑巴坦（93．4％）、头孢他啶（86％）和阿米卡星（83．3％）；肺炎克雷伯菌对哌拉西林／三唑巴坦的敏感性为84．6％，头孢他啶的敏感性从82．3％降至69．9％，低于头孢吡肟（77．2％）。50％以上的阴沟肠杆菌对头孢他啶、头孢噻肟、头孢曲松耐药。阴沟肠杆菌、产气肠杆菌、弗劳地枸橼酸菌和黏质沙雷菌对哌拉西林／三唑巴坦的敏感率（67．7％-96．4％）略高于头孢吡肟（68．8％-77．5％）及头孢哌酮／舒巴坦（59．7％-87．5％）。这4种菌对阿米卡星的敏感率（70％-83．7％）高于环丙沙星（48．1％-79．5％）。所有摩根摩根菌和普通变形杆菌对美罗培南、亚胺培南敏感，头孢吡肟、头孢哌酮／舒巴坦、哌拉西林／三唑巴坦的敏感性在90％以上。绿脓假单胞菌对美罗培南的敏感性最高（84％），其次是阿米卡星、哌拉西林／三唑巴坦、头孢他啶和亚胺培南（72．5％-76．6％）。多重耐药的鲍曼不动杆菌从2003年的33％升至2004年的48％，2004年此菌对碳青霉烯类的耐药率增至18％。对于洋葱伯克霍尔德菌，敏感性最高的药物是美罗培南（64．9％）、头孢哌酮／舒巴坦（63．2％）、头孢他啶（59．6％）、哌拉西林／三唑巴坦（56．1％）和头孢毗肟（52．6％）。结论碳青霉烯类对肠杆菌科仍保持高活性，但非发酵糖菌，特别是鲍曼不动杆菌的耐药性明显增加，值得关注。对于常见的革兰阴性杆菌，美罗培南比亚胺培南的抗菌活性强4—16倍。     

2010年某院主要病原菌耐药监测分析

目的回顾性分析2010年绵阳市第三人民医院临床分离病原菌的耐药状况。方法常规方法培养分离医院内感染病原菌,并应用半自动细菌鉴定分析仪鉴定到种,采用纸片扩散法(K-B法)对临床分离株进行药敏试验。采用WHONET5.4软件进行数据分析。结果共分离病原菌1 105株,其中革兰阴性菌781株,革兰阳性菌324株。大肠埃希菌产超广谱β-内酰胺酶菌株检出率为48.7%,尚未发现对亚胺培南、美洛培南和厄他培南耐药的菌株。药敏试验结果显示,大肠埃希菌和克雷伯菌属对哌拉西林/三唑巴坦和头孢哌酮/舒巴坦、阿米卡星、头孢西丁保持高度敏感。鲍曼不动杆菌对头孢哌酮/舒巴坦和米诺环素耐药率分别为50.0%和62.0%,对亚胺培南和美洛培南耐药率高达66.0%。铜绿假单胞菌对左氧氟沙星的耐药率达52.5%。革兰阳性球菌中,耐甲氧西林金黄色葡萄球菌的发生率为12%。结论大肠埃希菌、鲍曼不动杆菌、铜绿假单胞菌、肺炎克雷伯菌等仍是医院感染主要病原菌。碳青霉烯类药物、阿米卡星、头孢西丁、哌拉西林/三唑巴坦、头孢哌酮/舒巴坦对肠杆菌科细菌的抗菌活性仍处于比较高的水平。头孢哌酮/舒巴坦和碳青霉烯类药物对非发酵菌具有较好的抗菌活性。因此,临床微生物室应加强对多重耐药菌的监测,为临床合理使用抗菌药物提供依据。     

不发酵糖革兰阴性杆菌的耐药性监测

目的 了解我院2007年-2008年分离的不发酵糖菌感染的耐药状况.方法 纸片扩散法(Kirby-Baure)测定该菌对美罗培南等10余种广谱抗菌药物的耐药性.判断标准参照2006年版CLSI文件.结果 不发酵糖菌在ICU、呼吸科、神经外科、神经内科患者中检出率高.2008年所有不发酵糖菌对抗菌药物的耐药率均高于2007年.铜绿假单胞菌对美罗培南最敏感(87.3%),其次阿米卡星(77.8%)、哌拉西林-他唑巴坦(76.2%)、头孢他啶(74.6%)、亚胺培南(71.4%),鲍曼不动杆菌对美罗培南的敏感率在82.1%,其次是亚胺培南(78.6%)、哌拉西林-他唑巴坦(55.4%)、头孢哌酮-舒巴坦(53.6%)、阿米卡星(51.8%),其他抗菌药物的敏感率均＜50%.耐亚胺培南的鲍曼不动杆菌有上升趋势,而且对头孢哌酮-舒巴坦以外抗菌药物的耐药率均在70%以上.结论 美罗培南对铜绿假单胞菌和洋葱伯克霍尔德菌的抗菌活性最强,美罗培南和亚胺培南对鲍曼不动杆菌的抗菌活性相仿,该菌对碳青霉烯类抗生素耐药率有所上升.     

中国14家教学医院院内菌血症与肺炎和腹腔感染病原菌的抗生素耐药监测

目的 监测2006年10月-2007年10月我国不同地区14家教学医院分离的院内获得病原菌的分布和体外药物敏感性.方法 收集来自于院内菌血症、肺炎和腹腔感染患者标本的病原菌.菌株经中心实验室复核后,采用琼脂稀释法测定29种抗菌药物对菌株的MICs,数据输入WHONET5.4软件进行耐药性分析.结果 本研究共收集到2 660株病原菌.引起菌血症(BSI)的病原菌中分离率位于前3位的分别为大肠埃希菌(30.0%)、肺炎克雷伯菌(12.O%)和金黄色葡萄球菌(11.2%);引起院内获得性肺炎(HAP)的病原菌中分离率位于前3位的分别为铜绿假单胞菌(23.4%)、鲍曼不动杆菌(17.4%)和肺炎克雷伯菌(13.8%);引起腹腔感染(IAI)的病原菌中分离率位于前3位的分别为大肠埃希菌(38.8%)、肺炎克雷伯菌(10.2%)和铜绿假单胞菌(9.2%).对于大肠埃希菌和克雷伯菌,敏感性大于80%的药物包括替加环素(100%)、美罗培南(99.3%～100%)、亚胺培南(98.5%～100%)和哌拉西林/三唑巴坦(83.8%～95.1%),氟喹诺酮类药物的敏感性为12.4%～44.9%.对于肠杆菌属、柠檬酸杆菌属、沙雷菌属,替加环素的敏感性为99.2%-100%,亚胺培南和美罗培南的敏感性为96.6%-100%.另外,敏感性较高的抗菌药物还有阿米卡星(82.8%～96.6%)、哌拉西林/三唑巴坦(73.4%～93.1%)、头孢吡肟(69.O%～82.8%)和头孢哌酮/舒巴坦(72.6%～75.9%),氟喹诺酮类药物的敏感性为55.2%-82.8%.多苇耐药的铜绿假单胞菌和鲍曼不动杆菌的发生率分别为18.7%和54.O%.多黏菌素B对铜绿假单胞菌的敏感性最高(93.5%),其次为阿米卡星和哌拉西林/三唑巴坦(均为75.1%).多黏菌素B对鲍曼不动杆菌的敏感性最高(96.2%),其次为替加环素(92.1%)、亚胺培南(59.4%)、米诺环素(59.4%)和美罗培南(56.5%).金黄色葡萄球菌中MRSA的发生率为64.5%,凝同酶阴性葡萄球菌巾MRSCoN的发生率为82.8%.所有葡萄球菌对替加环素、万古霉素和替考拉宁的均敏感.本次监测中发现9株万古霉素耐药的肠球菌(VRE),VRE发生率为4.3%.结论 替加环素、碳青霉烯类、哌拉西林/三唑巴坦、阿米卡星和头孢吡肟对医院分离的肠杆菌科菌保持较高的抗菌活性;多黏菌素B对铜绿假单胞菌和鲍曼不动杆菌均体现出高抗菌活性,鲍曼不动杆菌对替加环素的敏感率达92.1%;替加环素、万古霉素和替考拉宁对院内革兰阳性球菌保持高的抗菌活性.     

2006年至2008年呼吸道铜绿假单胞菌药敏变化趋势

目的 了解近3年本院呼吸道铜绿假单胞菌药敏变化趋势,指导临床合理使用抗菌药物.方法 收集并分析2006年至2008年我院呼吸道标本铜绿假单胞菌药敏资料.结果 近3年来,对铜绿假单胞菌敏感率增幅排在前5位的抗菌药依次是头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、环丙沙星、左氧氟沙星、亚胺培南.2006年,对铜绿假单胞菌敏感率超过70%抗菌药为阿米卡星:2007年为亚胺培南、阿米卡星、氨曲南和环丙沙星;2008年为阿米卡星、亚胺培南、环丙沙星和左氧氟沙星.中介敏感比率呈上升趋势的抗菌药物有氨曲南、头孢哌酮/舒巴坦、头孢噻肟.3年来,中介敏感比率保持在10%以上的抗菌药物有关罗培南、头孢哌酮/舒巴坦、左氧氟沙星和头孢吡肟.耐药率降幅前5位依次为头孢哌酮/舒巴坦、头孢吡肟、哌拉西林/他唑巴坦、左氧氟沙星和环丙沙星.3年来,铜绿假单胞菌耐药率均低于20%抗菌药为阿米卡星;耐药率在20%～30%抗菌药为亚胺培南和美罗培南.结论 近3年头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、环丙沙星、左氧氟沙星、亚胺培南等对铜绿假单胞菌敏感性逐年增加.2008年,阿米卡星、亚胺培南、环丙沙星和左氧氟沙星等对铜绿假单胞菌存在较高敏感率.     

2008年中国15所教学医院医院感染患者分离的肠杆菌科细菌耐药性分析

目的监测2008年我国不同地区15所教学医院医院感染患者中分离的肠杆菌科细菌的耐药性。方法按设计方案收集非重复的1 357株医院感染患者中分离的肠杆菌科细菌。菌株经中心实验室复核后,采用琼脂稀释法测定15种抗菌药物的最低抑菌浓度(MIC),数据输入WHONET5.6软件进行统计分析。结果大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌敏感率较高的药物有美罗培南(97.6%～100%)、帕尼培南(79.8%～98.4%)、亚胺培南(64.9%～98.1%)、厄他培南(91.3%～97.4%)、哌拉西林-他唑巴坦(87.2%～97.4%)、头孢美唑(82.1%～97.0%)和阿米卡星(89.9%～93.8%)。肠杆菌属细菌敏感率较高的抗菌药物有美罗培南(98.7%)、帕尼培南(96.4%)、亚胺培南(95.4%)和阿米卡星(85.7%)。弗劳地枸橼酸杆菌和黏质沙雷菌敏感率较高的药物有碳青霉烯类抗生素(92.0%～100%)、哌拉西林-他唑巴坦(93.1%～99.1%)、阿米卡星(89.0%～94.3%)和头孢吡肟(86.2%～93.1%)。结论碳青霉烯类抗生素、哌拉西林-他唑巴坦和阿米卡星对医院分离的肠杆菌科细菌保持了较高的抗菌活性,头孢美唑对大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌表现出良好的抗菌活性。     

2009年广东省东莞市太平人民医院细菌耐药监测

目的 了解广东省东莞市太平人民医院2009年临床分离菌对常用抗菌药物的耐药情况.方法 采用纸片扩散法(K-B法)进行抗菌药物药敏试验,采用CLSI 2009年版判断标准,数据分析采用WHONET 5.4软件.结果 临床分离的1331株细菌中,革兰阴性菌占70.8% (943/1331),革兰阳性菌占29.2 % (388/1331).金葡菌和凝固酶阴性葡萄球菌分别为152株和123株,其中MRSA和MRCNS的检出率分别为27.6%和80.5l,未检出糖肽类抗生素耐药的革兰阳性球菌.肠杆菌科细菌对亚胺培南、美罗培南高度敏感,产ESBLs的大肠埃希菌和肺炎克雷伯菌的检出率分别为47.4 % (154/325)和38.5% (74/192).检出1株耐碳青霉烯类抗生素的阴沟肠杆菌.鲍曼不动杆菌对亚胺培南、美罗培南、头孢哌酮-舒巴坦和哌拉西林-他唑巴坦的耐药率均低于20 %.铜绿假单胞菌对亚胺培南、美罗培南、阿米卡星、头孢哌酮-舒巴坦和哌拉西林-他唑巴坦的耐药率均低于10%,嗜麦芽窄食单胞菌对磺胺甲噁唑-甲氧苄啶、左氧氟沙星和米诺环素的耐药率较低.结论 2009年该院临床分离菌以革兰阴性杆菌为主,所分离的革兰阴性杆菌对碳青霉烯类抗生素高度敏感,但已检出1株耐碳青霉烯类抗生素的阴沟肠杆菌.开展细菌耐药监测,对指导本单位合理应用抗菌药物有重要意义.     

下呼吸道感染常见病原菌及药敏分析

目的回顾分析院内下呼吸道感染病原菌的分布及耐药情况,为临床选用抗菌药物提供参考依据。方法收集住院下呼吸道感染患者痰标本分离的病原菌,采用纸片扩散法行药敏试验。结果分离出819株病原菌,其中革兰阴性杆菌574株,占70.1%,革兰阳性球菌154株,占18.8%,真菌91株,占11.1%。革兰阴性杆菌中前3位依次为：铜绿假单胞菌308株,占53.7%,鲍曼不动杆菌140株,占24.4%,大肠埃希菌56株,占9.8%;革兰阳性球菌中前3位为：金黄色葡萄球菌84株,占54.5%,溶血葡萄球菌42株,占27.3%,表皮葡萄球菌21株,占13.6%。耐药性分析：铜绿假单胞菌对头孢曲松耐药率最高,对阿米卡星、头孢吡肟、亚胺培南、美洛培南、哌拉西林/三唑巴坦耐药率较低。鲍曼不动杆菌对头孢曲松耐药率高,对阿米卡星、亚胺培南、美洛培南、哌拉西林/三唑巴坦耐药率低。大肠埃希菌对环丙沙星耐药率高,对阿米卡星、氨苄西林/舒巴坦、头孢他啶、亚胺培南、美洛培南、哌拉西林/三唑巴坦耐药率较低。结论革兰阴性杆菌是下呼吸道感染的常见病原菌,最常见为铜绿假单胞菌;药敏结果表明细菌耐药性较高,应加强病原菌检测及耐药性监测,合理使用抗菌药物。     

某地区2011～2015鲍曼不动杆菌耐药监测

目的探讨平谷地区临床分离鲍曼不动杆菌的耐药情况,指导临床合理应用抗菌药物。方法回顾性分析2011~2015年临床分离鲍曼不动杆菌的耐药情况。结果 2011~2015年临床分离鲍曼不动杆菌1 744株。呼吸道标本96.1%、尿液1.1%、血液0.9%、伤口0.5%、脓液0.3%、胆汁0.2%、导管0.1%、其他分泌物0.7%。庆大霉素、妥布霉素、阿米卡星耐药率小于45.7%。哌拉西林/他唑巴坦小于49.0%、氨苄西林/舒巴坦小于52.0%,亚胺培南小于50.0%,头孢他啶、头孢吡肟接近50.0%。头孢哌酮/舒巴坦由6.1%上升至57.1%。美罗培南由34.3%上升至85.7%。结论该院鲍曼不动杆菌感染病例逐年减少。病原菌主要来自呼吸道、泌尿道、血液、胆汁等。对庆大霉素、妥布霉素、阿米卡星、哌拉西林/他唑巴坦、氨苄西林/舒巴坦、头孢他啶、头孢吡肟、环丙沙星、亚胺培南耐药率呈逐年上升趋势。对头孢哌酮/舒巴坦、美罗培南、复方新诺明耐药率显著升高。对米诺环素、替加环素耐药率逐年下降。     

Geographic variations in activity of broad-spectrum beta-lactams against Pseudomonas aeruginosa: summary of the worldwide SENTRY Antimicrobial Surveillance Program (1997-2000)

With reports of increasing resistance to antimicrobial agents among Pseudomonas aeruginosa clinical isolates worldwide, the activities of cefepime and eight other broad-spectrum beta-lactams against 6969 isolates collected during 1997-2000 from the four regions of the SENTRY Antimicrobial Surveillance Program. P. aeruginosa isolates were tested by the reference broth microdilution method against nine beta-lactam antimicrobial agents (aztreonam, cefepime, ceftazidime, imipenem, meropenem, piperacillin +/- tazobactam, ticarcillin +/- clavulanate), three aminoglycosides (amikacin, gentamicin, tobramycin), and two fluoroquinolones (ciprofloxacin, levofloxacin). The strains were contributed by more than 100 medical centers. National Committee for Clinical Laboratory Standards criteria were used to identify susceptible and resistant isolates. P. aeruginosa strains from Latin America were generally the most resistant to all classes of antimicrobials, compared with strains from other regions. The beta-lactams exhibited a wide range of potency, with carbapenems most active (meropenem, 80-91% susceptible; imipenem, 76-88% susceptible). Piperacillin/tazobactam was the most active penicillin (77-80% susceptible), and cefepime (67-83% susceptible) had an average 2% (range, 0.7-3.5%) greater susceptibility rate than ceftazidime (66-80% susceptible) across all regions. The rank order of beta-lactam activity according to percent resistant isolates in North American P. aeruginosa strains was: meropenem (4.8% resistant) > cefepime (6.8%) > imipenem (8.6%) > piperacillin/tazobactam (10.3%) > piperacillin (12.9%). Only 2.3% and 6.5% of isolates were resistant to amikacin or tobramycin, respectively, and nearly 16% of P. aeruginosa strains were resistant to ciprofloxacin. Compared with other geographic regions, strains of P. aeruginosa remain most susceptible in North America. In all regions, aminoglycosides in combination with carbapenems, cefepime, or piperacillin/tazobactam would provide more potential antipseudomonal activity than fluoroquinolone combinations for wide-spectrum empiric regimens.     

In vitro activity of newer broad spectrum beta-lactam antibiotics against enterobacteriaceae and non-fermenters: a report from Austrian intensive care units. Austrian Carbapenem Susceptibility Surveillance Group.

We compared the in vitro activity of broad spectrum beta-lactam antibiotics against 573 gram-negative isolates (enterobacteriaceae and non-fermenters) collected between November 1996 and May 1997 from 9 laboratories serving intensive care units throughout Austria. MIC's (Minimal Inhibitory Concentration) were obtained with the E-test for meropenem, imipenem, ceftazidime, cefepime, cefpirome and piperacillin/tazobactam. Pseudomonas aeruginosa was the most frequently isolated organism (22%), followed by E. coli (19%), Klebsiella spp. (16%), and Enterobacter spp. (14%). Acinetobacter spp., Proteus spp., Serratia spp., Stenotrophomonas maltophilia, Citrobacter spp., Morganella morganii, Burkholderia cepacia and Salmonella enteritidis were isolated less frequently. Overall meropenem, imipenem and ceftazidime were the most active compounds in vitro, inhibiting 90%, 89%, and 87% of the isolates, respectively. Pseudomonas aeruginosa was inhibited by piperacillin/tazobactam in 89%, by cefepime in 87% and by ceftazidime in 85%. Imipenem, meropenem and cefpirome were less active (79%, 75% and 69% respectively). All E. coli strains were inhibited by meropenem, 99% were inhibited by imipenem, cefepime and cefpirome. Ceftazidime was active against 95% and piperacillin/tazobactam against 92% of E. coli. All Klebsiella spp. were inhibited by meropenem, cefepime and cefpirome. Imipenem inhibited 99% and ceftazidime 98% of the Klebsiella isolates. Piperacillin/tazobactam was active against 95% of Klebsiella spp. In vitro carbapenems are still the most active of all antibiotics tested. The relatively high resistance of Pseudomonas spp. and Acinetobacter spp. to carbapenems reflects the wide use of carbapenems during the last years. However, most bacterial isolates are still sensitive to the tested broad spectrum beta-lactams.     

In vitro killing of parenteral beta-lactams against standard and high inocula of extended-spectrum beta-lactamase and non-ESBL producing Klebsiella pneumoniae

Minimum inhibitory concentrations and time-kill curves were performed against 8 Klebsiella pneumoniae (4 non-extended-spectrum beta-lactamase[ESBL] and 4 ESBL) for piperacillin/tazobactam (40/5 microg/mL), cefepime (20 microg/mL), and meropenem (4 microg/mL) by using a standard and high inocula. Imipenem was evaluated only at the standard inoculum for the non-ESBL and ESBL isolates. Samples were withdrawn at 7 predetermined time-points over 24 hours and plated on trypticase soy agar plates. Minimum inhibitory concentrations were: piperacillin/tazobactam 4 to 8 microg/mL (ESBL and non-ESBL), cefepime 1 to 2 microg/mL (ESBL) and 0.06 to 0.125 microg/mL (non-ESBL), imipenem 0.125 to 0.25 microg/mL (ESBL and non-ESBL), and meropenem 0.03 to 0.06 microg/mL (ESBL and non-ESBL). Each antibiotic reached and maintained bactericidal killing (> or =3 log killing) for 24 hours against all non-ESBL isolates for both the standard and high inoculum. Cefepime, imipenem, and meropenem showed the same bactericidal activity against each ESBL isolate at the standard inoculum, whereas piperacillin/tazobactam showed bactericidal killing against only 1 ESBL isolate. At the high inoculum, cefepime and piperacillin/tazobactam were unable to maintain bactericidal activity against any of the ESBL isolates. Only meropenem was able to maintain bactericidal killing over 24 hours against the ESBL isolates at the high inoculum. In summary, meropenem and imipenem maintained bactericidal activity against non-ESBL and ESBL K. pneumoniae irrespective of the inoculum size. While piperacillin/tazobactam and cefepime are bactericidal against non-ESBL K. pneumoniae, their activity against ESBL K. pneumoniae is limited and based on the size of the inoculum. Until more data are available, piperacillin/tazobactam and cefepime should not be used for the treatment of ESBL K. pneumoniae.     

腹腔感染大肠埃希菌和肺炎克雷伯菌的耐药性监测

目的监测2008—2010年我国不同地区6所教学医院腹腔感染患者中分离的大肠埃希菌和肺炎克雷伯菌的体外药物敏感性。方法收集2008—2010年全国6所教学医院腹腔感染患者分离的大肠埃希菌和肺炎克雷伯菌。采用微量肉汤稀释法测定多种抗菌药物的最低抑菌浓度(MIC)。数据采用WHONET 5.6软件进行耐药性分析。结果 2008—2010年共收集到腹腔感染大肠埃希菌789株和肺炎克雷伯菌263株。对于大肠埃希菌,碳青霉烯类抗生素物具有高度体外抗菌活性(细菌对其敏感率96.7%～99.3%),哌拉西林-他唑巴坦(87.1%～93.2%)和阿米卡星(86.7%～89.8%)次之。细菌对头孢他啶的敏感率较高(48.5%～59.2%),2010年头孢曲松、头孢噻肟和头孢吡肟的敏感率仅为24.5%～32.8%。细菌对2种氟喹诺酮类药物的敏感率逐年降低,对氨苄西林-舒巴坦的敏感率最低,为12.4%～20.6%。大肠埃希菌中ESBLs的检出率逐年上升,从2008年的59.7%升至2010年的73.5%。厄他培南(90.4%～94.1%)、亚胺培南(95.1%～97.1%)、阿米卡星(79.2%～92.6%)和哌拉西林-他唑巴坦(80.2%～85.3%)对肺炎克雷伯菌保持了较高的抗菌活性。细菌对头孢他啶(66.3%～72.1%)和头孢吡肟(67.3%～79.1%)的敏感率略高于头孢噻肟(59.4%～61.8%)和头孢曲松(60.3%～60.6%)。细菌对2种氟喹诺酮类药物的敏感率从2008年的58.4%～60.4%到2010年的64.7%～72.1%。肺炎克雷伯菌中产ESBLs菌株的检出率略有下降,从2008年的37.6%至2010年的28.1%。产ESBLs菌株对厄他培南和亚胺培南保持了高的敏感率(88.5%～99.4%)。结论腹腔感染患者中分离的大肠埃希菌和肺炎克雷伯菌对碳青霉烯类抗生素、哌拉西林-他唑巴坦和阿米卡星保持了较高的体外敏感性。大肠埃希菌对第三代、第四代头孢菌素和氟喹诺酮类抗菌药物敏感性较低,提示临床上应谨慎使用。     

广州地区1998～2003年大肠埃希氏和肺炎克雷伯菌耐药性监测

目的：了解广州地区大肠埃希氏和肺炎克雷伯菌的耐药状况。方法：对12家医院1998～2003年从各种临床标本收集的1646株大肠埃希氏菌和1175株肺炎克雷伯菌，用K—B纸片法进行药敏试验，测定这些菌株对21种临床常用抗生素的耐药性。结果：只发现一株大肠埃希氏菌对亚胺培南耐药，对大肠埃希氏菌耐药率在10％以下的抗生素分别为哌拉西林／三唑巴坦（6．2％）、头孢他啶（6．6％）、头孢哌酮／舒巴坦（8．4％）和阿米卡星（8．3％），对肺炎克雷伯菌耐药率在10％以下的抗生素只有头孢舭肟（9．8％）和头孢哌酮／舒巴坦（9．3％）。环丙沙星对大肠埃希氏菌的耐药率在70％左右，而肺炎克雷伯菌只有30％左右，肺炎克雷伯菌对阿米卡星和头孢他啶的耐药率明显高于大肠埃希氏菌，在头孢西丁耐药菌株中这种差异更加突出。结论：5a监测中，两类细菌对临床常用大部分抗生素的耐药性没有明显改变，但对部分抗生素的耐药性各有特性，对本地区细菌进行系统、全面的耐药性监测是很有必要的。     

Antimicrobial susceptibility of 3931 organisms isolated from intensive care units in Canada: Canadian National Intensive Care Unit Study, 2005/2006

We tested the in vitro activity of 15 antimicrobials against Gram-positive cocci and 12 antimicrobials against Gram-negative bacilli versus 3931 isolates (20 most common organisms) obtained between September 1, 2005, and June 30, 2006, from 19 intensive care units (ICUs) across Canada. The most active (based upon MIC only) agents against methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus epidermidis were dalbavancin, daptomycin, linezolid, tigecycline, and vancomycin with MIC(90) (microg/mL) of 0.06 and < or =0.03, 0.25 and 0.12, 2 and 1, 0.5 and 0.5, and 1 and 2, respectively. The most active agents against vancomycin-resistant enterococci were daptomycin, linezolid, and tigecycline with MIC(90) (microg/mL) of 1, 4, and 0.12, respectively. The most active agents against Escherichia coli were amikacin, cefepime, meropenem, piperacillin/tazobactam, and tigecycline with MIC(90) (microg/mL) of 4, < or =1, < or =0.12, 8, and 0.5, respectively. The most active agents against extended-spectrum beta-lactamase-producing E. coli were meropenem and tigecycline with MIC(90) (microg/mL) of < or =0.12 and 1, respectively. The most active agents against Pseudomonas aeruginosa were amikacin, cefepime, meropenem, and piperacillin/tazobactam with MIC(90) (microg/mL) of 16, 32, 16, and 64, respectively. The most active agents against Stenotrophomonas maltophilia were tigecycline and trimethoprim/sulfamethoxazole with MIC(90) (microg/mL) of 4 and 4, respectively. The most active agents against Acinetobacter baumannii were fluoroquinolones (e.g., levofloxacin), meropenem, and tigecycline with MIC(90) (microg/mL) of 0.5, 1, and 2, respectively. In conclusion, the most active agents versus Gram-positive cocci and Gram-negative bacilli obtained from Canadian ICUs were daptomycin, linezolid, tigecycline, dalbavancin and amikacin, cefepime, meropenem, piperacillin/tazobactam, and tigecycline (not P. aeruginosa), respectively.     

In vitro evaluation of cefepime and other broad-spectrum beta-lactams in eight medical centers in Thailand. The Thailand Antimicrobial Resistance Study Group

The introduction of cephalosporins has had an important impact on the resistance rates to several clinically utilized beta-lactam antimicrobial agents. Most Thailand medical centers have not documented the levels of emerging resistant pathogens causing invasive infections. This study shows using reference-quality MIC techniques (Etest, AB BIODISK, Solna, Sweden), that carbapenem), "fourth-generation" cephalosporins (cefepime and cefpirome), and piperacillin/tazobactam were the most active agents tested against Gram-negative bacilli (Escherichia coli, Klebsiella spp., Enterobacter spp., Citrobacter spp., Serratia spp., indole-positive Proteae, Acinetobacter spp., Pseudomonas aeruginosa, and oxacillin-susceptible Staphylococcus spp. when compared to "third-generation" cephalosporins (ceftazidime and ceftriaxone). The rank order of activity for all species was imipenem (2.9% resistant) > cefepime (7.7%) > piperacillin/tazobactam (11.1%) > cefpirome (13.4%) > ceftriaxone (21.1%) > ceftazidime (29.9%). The incidence of extended spectrum beta-lactamase production among E. coli (15.7%) and K. pneumoniae (45.6%) was significant. Cefepime and imipenem were active against the majority of these isolates. The activity of cefepime was also shown to be very good against, 1) organisms capable of producing AmpC enzymes, 2) staphylococci species that were susceptible to oxacillin, and 3) many strains of nonfermentative Gram-negative bacilli. The prevalence of antimicrobial resistance in Thailand seems to be quite high among certain commonly encountered pathogens, and imipenem and cefepime have activity (susceptible and intermediate potency) against > 90% of these organisms.