泛耐药鲍曼不动杆菌菌血症危险因素及临床结局

目的　比较泛耐药鲍曼不动杆菌（pan-drug resistant Acinetobacter baumannii,PDRAB）菌血症与非泛耐药鲍曼不动杆菌（non-pan-drug resistant Acinetobacter baumannii,NPDRAB）菌血症的临床资料,探讨PDRAB菌血症的危险因素及其临床结局。方法　本研究为回顾性队列研究,纳入对象为2010年1月1日至2012年12月31日就诊于北京协和医院的鲍曼不动杆菌菌血症患者,采用统一的标准表格收集患者的临床资料和检验结果,以鲍曼不动杆菌血培养标本采集14 d内发生院内死亡为主要临床结局。 结果　共纳入52例鲍曼不动杆菌菌血症患者,平均年龄（54±20）岁,其中男性30例（57.7%）;平均急性生理与慢性健康状况Ⅱ（acute physiology and chronic health evaluation Ⅱ, APACHE Ⅱ）评分（21±9）分,平均序贯器官衰竭评估（sepsis-related organ failure assessment,SOFA）评分（10±5）分;鲍曼不动杆菌菌血症发生前,患者中位住院时间为12 d（7～20 d）;仅6例患者对碳青霉烯类药物敏感。33例患者感染NPDRAB,19 例感染PDRAB。在感染鲍曼不动杆菌前,PDRAB患者与NPDRAB患者比较,接受机械通气概率更大（94.7%比63.6%,P=0.031）,住院时间更长（中位住院时间17 d比10 d,P=0.025）。鲍曼不动杆菌菌血症患者14 d死亡率为67.3%（35/52）。多因素分析提示,脓毒性急性肾损伤（OR 7.9,95% CI 1.113～55.448,P=0.039）、不适当抗菌药物治疗（OR 9.4,95% CI 1.020～87.334,P=0.048）和降钙素原水平（OR 1.3,95% CI 1.332～1.088,P=0.005）是鲍曼不动杆菌菌血症患者14 d死亡的独立危险因素。结论　鲍曼不动杆菌具有多重耐药性,甚至对目前所有全身用抗菌药物均不敏感,感染患者死亡率较高。菌血症发生前接受机械通气和住院时间是PDRAB 菌血症的危险因素,但PDRAB感染本身不能作为判断患者预后不良的指标。不适当抗菌药物治疗、脓毒性急性肾损伤和降钙素原水平是鲍曼不动杆菌菌血症患者14 d死亡的独立危险因素。     

重症患者多重耐药鲍曼不动杆菌血流感染相关危险因素分析

目的:探究重症患者多重耐药鲍曼不动杆菌血流感染相关危险因素。方法:选取2016年1月～2018年9月ICU治疗的172例患者为研究对象,其中合并多重耐药鲍曼不动杆菌血流感染的60例患者为观察组,112例未发生多重耐药鲍曼不动杆菌血流感染患者为对照组。分析多重耐药鲍曼不动杆菌血流感染相关危险因素。结果:观察组患有恶性肿瘤率、APACHEⅡ评分≤19分率、血流感染前抗菌药物使用2种率、气管切开率、机械通气时间7 d率、气管插管率以及血流感染前ICU住院时间7 d率均高于对照组(P0.05);APACHEⅡ评分≤19分、机械通气时间7 d、合并恶性肿瘤、气管切开、气管插管以及血流感染前抗菌药物使用2种是多重耐药鲍曼不动杆菌血流感染的独立危险因素(P0.05)。结论:APACHEⅡ评分≤19分、机械通气时间7d、合并恶性肿瘤、气管切开、气管插管以及血流感染前抗菌药物使用2种是多重耐药鲍曼不动杆菌血流感染的独立危险因素。     

多重耐药鲍曼不动杆菌血流感染危险因素分析

目的探讨多重耐药(MDR)鲍曼不动杆菌血流感染的危险因素及影响鲍曼不动杆菌血流感染30 d预后的危险因素。方法采用病例对照的研究方法,回顾性分析2013年1月-2014年12月中国医科大学附属第一医院MDR鲍曼不动杆菌血流感染49例,以同时期敏感鲍曼不动杆菌血流感染29例作为对照,应用单因素分析及多因素logistic回归分析探讨MDR鲍曼不动杆菌血流感染的危险因素。将78例鲍曼不动杆菌血流感染患者按血培养标本采集后30 d内预后分为存活组(38例)和非存活组(40例),应用上述方法分析影响鲍曼不动杆菌血流感染30 d预后的危险因素。结果单因素分析发现,MDR鲍曼不动杆菌血流感染的危险因素包括:感染前应用碳青霉烯类药物、应用喹诺酮类药物、应用2类以上抗菌药物、接受机械通气、留置鼻胃管、留置中心静脉导管、入住ICU等;再进行logistic多因素回归分析,结果显示入住ICU(OR=7.118)、感染前应用2类以上抗菌药物(OR=8.073)是MDR鲍曼不动杆菌血流感染的独立危险因素。预后单因素分析结果提示影响鲍曼不动杆菌血流感染30 d预后的危险因素包括:入住ICU、机械通气、血培养提示MDR鲍曼不动杆菌感染等,再进行logistic多因素回归分析发现,MDR鲍曼不动杆菌感染(OR=5.837)、机械通气(OR=4.926)是影响鲍曼不动杆菌血流感染30 d预后的独立危险因素。结论感染前入住ICU、应用2类以上抗菌药物是MDR鲍曼不动杆菌血流感染的独立危险因素;MDR鲍曼不动杆菌感染、机械通气是影响鲍曼不动杆菌血流感染30 d预后的独立危险因素。     

ICU内鲍曼不动杆菌的耐药性和相关因素分析

目的分析重症监护室内鲍曼不动杆菌的耐药性及相关高危因素。方法选取2016年3月~2017年4月我院重症监护病房患者832例。收集患者的引流液、伤口分泌物、血液、尿液、痰液等标本,采集完成后送检验中心进行细菌培养及药敏试验,评估患者鲍曼不动杆菌感染情况及其耐药性,并评估感染鲍曼不动杆菌的高危因素。结果 832例患者中感染鲍曼不动杆菌者116例(13.9%),其中有100例感染者为鲍曼不动杆菌全耐药、广泛耐药、多重耐药,占86.2%,鲍曼不动杆菌主要分布于痰液83株,占71.6%,其次为尿液14株,占12.1%。鲍曼不动杆菌感染与患者应用广谱抗菌药物、应用激素、入住ICU时间、机械通气、昏迷、年龄等因素密切相关。结论重症监护室内鲍曼不动杆菌感染为全耐药、广泛耐药、多重耐药,与患者应用广谱抗菌药物、应用激素、入住ICU时间、机械通气、昏迷、年龄等因素密切相关。     

神经外科ICU患者鲍曼不动杆菌感染和耐药性

目的探讨神经外科ICU患者鲍曼不动杆菌感染情况以及对抗菌药物的耐药情况,为临床抗菌药物使用及医院感染控制提供依据。方法回顾性分析2016年1月至2016年12月本院神经外科ICU患者不同标本分离出的鲍曼不动杆菌分布情况及对18种抗菌药物耐药情况,并进行统计分析。结果 936例标本共检出鲍曼不动杆菌251株,占26.8%;251株鲍曼不动杆菌中多重耐药菌211株,占84%;药敏结果显示,所分离出的鲍曼不动杆菌对替加环素的耐药率最低2%,对其它抗菌药物耐药率较高。结论神经外科ICU患者的标本中分离出的鲍曼不动杆菌对大多数抗菌药物耐药,多重耐药鲍曼不动杆菌占有比例极高,临床应加强抗菌药物合理使用,加强病原学检测,重视消毒隔离,尽量减少侵入性操作,以减少鲍曼不动杆菌交叉感染及耐药菌产生。     

某医院ICU住院患者鲍曼不动杆菌感染情况调查

摘要 目的 〖HT5"SS〗了解医院重症监护病房（ICU）住院患者鲍曼不动杆菌医院感染情况及其耐药性,为临床合理预防和治疗鲍曼不动杆菌感染提供指导。方法 采用回顾性调查方法,对江苏省某医院ICU住院鲍曼不动杆菌感染患者情况及其耐药性进行调查。结果 从该医院ICU住院患者送检标本中共分离出63株鲍曼不动杆菌,分属63例患者的标本,含泛耐药菌株29例,占分离菌株的74.6%。有85.7%的鲍曼不动杆菌分离自痰液标本,主要感染部位为下呼吸道,其次是菌血症和泌尿道感染。所分离的鲍曼不动杆菌对复方新诺明和喹诺酮类抗菌药物耐药率较低,对头孢类抗菌药物和氨曲南耐药率均高于90%。结论 该医院ICU鲍曼不动杆菌感染以下呼吸道感染和菌血症最为多见,多数送检样本中出现泛耐药鲍曼不动杆菌菌株,患者间存在交叉感染可能,临床合理选择抗菌药物治疗的同时需加强消毒工作。     

2010年中国CHINET鲍曼不动杆菌耐药性监测

目的了解2010年中国不同地区14所教学医院临床分离鲍曼不动杆菌的耐药性。方法收集14所教学医院临床分离的非重复不动杆菌属共5 523株,其中鲍曼不动杆菌4 949株,按照统一方案,在各监测点采用纸片扩散法进行药敏试验,试验结果按照CLSI 2010年版标准判读,采用WHONET 5.4软件进行数据分析。结果鲍曼不动杆菌对头孢哌酮-舒巴坦和米诺环素耐药率最低,分别为33.6%和35.4%。对碳青霉烯类抗生素亚胺培南和美罗培南的耐药率分别为62.1%和63.6%,对其他监测的抗菌药物的耐药率均达56.2%以上。不同医院分离菌对抗菌药物的耐药率不同,其中以ICU分离菌耐药率最高,急诊次之,内科最低。门诊与住院患者分离菌对亚胺培南和美罗培南的耐药率分别为48.3%/50.8%和62.3%/63.8%,且住院患者分离菌对抗菌药物的耐药率高于门诊患者(米诺环素除外)。全国14所教学医院药敏试验结果显示多重耐药(MDR)及泛耐药(PDR)鲍曼不动杆菌分别达55.0%(2 720/4 949)和21.4%(1 058/4 949)。2010年鲍曼不动杆菌耐药率与往年相比,呈上升趋势,尤以对头孢哌酮-舒巴坦、碳青霉烯类抗生素耐药率升高显著。结论鲍曼不动杆菌对各抗菌药物的耐药性仍呈上升趋势。头孢哌酮-舒巴坦和米诺环素对鲍曼不动杆菌仍具有较好的体外抗菌活性。不同医院、不同科室鲍曼不动杆菌对抗菌药物的耐药率存在显著差异。     

血培养鲍曼不动杆菌阳性的临床分析

目的调查鲍曼不动杆菌引起的菌血症的临床分布特征和耐药性特点.方法回顾性临床研究分析2004年3月至2004年12月住院病人血液中分离的鲍曼不动杆菌的临床资料,并用Whonet5.3软件对鲍曼不动杆菌的药敏进行统计分析.结果所有送检病人中有31例血液培养出鲍曼不动杆菌,有8例(25.8%)是污染,其余23例(74.2%)确定为菌血症,主要分布在肝移植病房和ICU,死于鲍曼不动杆菌菌血症的有7例(30.4%),1例未愈,15例(65.2%)治愈.鲍曼不动杆菌对多种抗菌药物耐药,对亚胺培南、哌拉西林/他唑巴坦、头孢哌酮/舒巴坦的耐药率分别为55.6%、44.4%、42.6%的高耐药率.结论由于病人基础疾病严重,住院时间长,呼吸机、免疫抑制剂的使用,各种导管和侵入性操作是感染血液的危险因素,广谱抗生素的大量使用产生了多重耐药菌株,增加了患者的危险性,提示应高度重视并积极采取相应的防范措施,控制该菌耐药率的上升和多重耐药菌株的产生,预防医院感染.     

血培养鲍曼不动杆菌阳性的临床分析

目的调查鲍曼不动杆菌引起的菌血症的临床分布特征和耐药性特点。方法回顾性临床研究分析2004年3月至2004年12月住院病人血液中分离的鲍曼不动杆菌的临床资料,并用Whonet5.3软件对鲍曼不动杆菌的药敏进行统计分析。结果所有送检病人中有31例血液培养出鲍曼不动杆菌,有8例(25.8%)是污染,其余23例(74.2%)确定为菌血症,主要分布在肝移植病房和ICU,死于鲍曼不动杆菌菌血症的有7例(30.4%),1例未愈,15例(65.2%)治愈。鲍曼不动杆菌对多种抗菌药物耐药,对亚胺培南、哌拉西林/他唑巴坦、头孢哌酮/舒巴坦的耐药率分别为55.6%、44.4%、42.6%的高耐药率。结论由于病人基础疾病严重,住院时间长,呼吸机、免疫抑制剂的使用,各种导管和侵入性操作是感染血液的危险因素,广谱抗生素的大量使用产生了多重耐药菌株,增加了患者的危险性,提示应高度重视并积极采取相应的防范措施,控制该菌耐药率的上升和多重耐药菌株的产生,预防医院感染。     

综合监护病房泛耐药鲍曼不动杆菌医院感染危险因素及疾病转归分析

摘要 目的 探讨某院综合监护病房泛耐药鲍曼不动杆菌(XDRAB)医院感染的危险因素及疾病转归情况。方法 选取2018—2020年在该院综合监护病房内发生XDRAB感染患者62例为感染组,同期未发生医院感染患者62例为对照组,利用回顾性研究分析2组患者医院感染危险因素及疾病转归情况并进行分析。结果 呼吸系统感染占75.8%,其次为血液系统感染,占11.3%。单因素分析和多因素Logistic回归分析显示,住ICU＞7 d、机械通气＞4 d和抗菌药物使用＞14 d是ICU患者感染XDRAB的独立危险因素(P＜0.05)。XDRAB感染组医疗费用比未感染组多158 436.5元(P＜0.01)。感染组患者死亡率(17.74%)明显高于未感染组(1.61%)(P＜0.01)。结论 ICU XDRAB院内感染以呼吸系统感染为主,住ICU＞7 d、机械通气＞4 d和抗菌药物使用＞14 d是ICU患者发生XDRAB医院感染的独立危险因素。     

分离自ICU临床标本鲍曼不动杆菌耐药性及多药耐药株感染危险因素分析

目的 分析分离自重症监护病房(ICU)标本鲍曼不动杆菌(AB)的耐药性及多药耐药AB(MDRAB)感染危险因素.方法 回顾性分析本院2009年分离自ICU标本的171株AB的耐药性,确定MDRAB、泛耐药(PDR)株及碳青霉烯类耐药株;以非多药耐药AB(NMDRAB)为对照菌株,对MDRAB感染危险因素进行分析.结果 171株AB中,63.7%(115/171)为MDRAB、34.5%(59/171)为PDRAB、60.2%(103/171)为碳青霉烯耐药菌株.MDRAB对除多黏菌素B、头孢哌酮/舒巴坦、亚胺培南以外的抗菌药物的耐药率均超过95%.17个与MRDAB感染可能相关的危险因素中,住院时间超过15 d、机械通气治疗、多部位标本分离出AB、碳青霉烯类抗菌药物治疗和神经损伤为独立危险因素;头孢菌素类、喹诺酮类抗菌药物的使用和伴有慢性阻塞性肺病是MDRAB感染的潜在危险因素.MDRAB感染或定植的致死率高于NMDRAB(P<0.05).结论 分离自ICU标本的AB中,MDRAB检出率较高,耐药性强;MDRAB感染或定植致死率高.MDRAB感染与多个独立危险因素有关,加强对独立危险因素的控制有助于预防MDRAB感染的扩散.     

鲍曼不动杆菌的感染调查和耐药性分析

目的探讨鲍曼不动杆菌感染的临床分布及药敏情况。方法对2009年1月-2011年12月的微生物送检标本进行统计分析,鲍曼不动杆菌2009年培养出19株,2010年29株(多重耐药菌株1株),2011年35株(多重耐药菌株2株),并对其分布的标本类型、科室及耐药情况进行分析。结果鲍曼不动杆菌在痰中检出率最高;科室分布依次为重症监护室(ICU)、神经外科、呼吸科;该菌对亚胺培南敏感性最高,对青霉素和头孢类抗生素耐药率均在55%以上。结论鲍曼不动杆菌感染患者的经验性抗生素治疗应根据其地区、医院最新的院内感染病原体分布及耐药性,合理选择抗生素;病情、高龄、免疫抑制剂、机械通气、多种侵入性操作及抗生素的使用为鲍曼不动杆菌医院感染危险因素;ICU存在多重耐药鲍曼不动杆菌的感染,应加以控制。     

多重耐药不动杆菌属血流感染74例临床分析

目的研究多重耐药不动杆菌血流感染的菌种分布特点、临床特征、抗菌治疗及其与预后的关系。方法回顾性分析复旦大学附属华山医院2005年1月—2011年12月不动杆菌血流感染患者的临床及微生物学资料。结果 74例不动杆菌血流感染患者入选,其中73例为医院感染,1例为社区获得性感染;原发性血流感染占51.4%（38/74）;继发性血流感染占48.6%（36/74）,继发于肺部感染最常见,占23.0%（17/74）。基础疾病以实体肿瘤最多见,占24.3%（18/74）,糖皮质激素应用、深静脉导管留置、手术及侵袭性操作是常见的诱发因素。发生血流感染后患者外周血白细胞总数及中性粒细胞比例较前升高,血清白蛋白水平下降,APACHEⅡ评分升高。74例血流感染患者中鲍曼不动杆菌感染65例,洛菲不动杆菌7例,琼氏不动杆菌1例,鲍曼不动杆菌和洛菲不动杆菌混合感染者1例;全因病死率为27.0%（20/74）。不动杆菌对头孢哌酮-舒巴坦耐药率最低,为20.0%（15/75）,对碳青霉烯类抗生素耐药率为40.0%～42.7%。患者预后与不动杆菌对抗菌药物的敏感性相关。对碳青霉烯类和含舒巴坦制剂不敏感菌株感染患者的病死率分别为46.9%（15/32）和40.0%（12/30）,显著高于敏感菌株感染患者的11.9%（5/42）和18.2%（8/44）。32例对碳青霉烯类不敏感菌株感染的患者中,20例接受了含舒巴坦制剂的抗菌药物,病死率为20.0%（4/20）,明显低于未使用含舒巴坦制剂药物患者的66.7%（8/,12）。结论不动杆菌血流感染绝大多数为医院感染,多发生于术后及重症患者。不动杆菌属对常用抗菌药物高度耐药,对碳青霉烯类和含舒巴坦制剂不敏感菌株感染患者病死率高,预后极差,应重视医院感染的防控。     

Molecular characterization of metallo-beta-lactamase-producing Acinetobacter baumannii and Acinetobacter genomospecies 3 from Korea: identification of two new integrons carrying the bla(VIM-2) gene cassettes

Carbapenem-resistant Acinetobacter spp. used to be rare, but are increasingly isolated in Korea. Among 28 isolates of imipenem-resistant Acinetobacter spp. found in a Korean hospital in 1998 and 1999, 14 produced metallo-beta-lactamases. The bla(VIM-2) gene was detected, by PCR, in 11 and two isolates of Acinetobacter baumannii and Acinetobacter genomospecies 3, respectively, and bla(IMP-1) in one isolate of A. baumannii. The MICs of imipenem for the isolates were 8-32 mg/L. PFGE analysis of SmaI-digested genomic DNA gave identical patterns in eight of 11 bla(VIM-2)-positive A. baumannii isolates from respiratory specimens of ICU patients. The bla(VIM-2) gene cassettes in the isolates are identical to those from Pseudomonas aeruginosa isolates in Europe, but are inserted into new class I integrons In105 and In106. The attC site of the last cassette of the array in In106 is interrupted by the insertion of a putative class II intron. This is the first report of VIM-2 beta-lactamase-producing A. baumannii and Acinetobacter genomospecies 3. Production of the VIM-2 enzyme presents an emerging threat of carbapenem resistance among Acinetobacter spp. in Korea.     

外科ICU机械通气患者医院内气管支气管炎发生率、病原学和危险因素分析

目的　探讨机械通气患者并发医院内气管支气管炎(NTB)的发生率、病原学及危险因素。方法　应用队列研究方法回顾性分析我院2002年1月—2004年4月在外科ICU内机械通气患者的临床资料。结果　96例外科ICU内机械通气患者有43例(44.8%)发生NTB,NTB组和非NTB组患者在血浆白蛋白、鼻饲情况、机械通气天数、抗生素应用种数以及ICU内住院时间差别均有统计学意义。鼻饲的比值比(OR)为4.5(95%CI为1.7~11.7),血浆白蛋白减低的OR值为2.6(95%CI1.2~6.0)。机械通气并发NTB患者第1位致病菌是鲍曼不动杆菌(39.5%),其次是金黄色葡萄球菌(32.6%)。在机械通气<5 d并发NTB患者常见致病菌是鲍曼不动杆菌和耐甲氧西林金黄色葡萄球菌(MRSA),机械通气≥5 d并发NTB患者常见致病微生物为铜绿假单胞菌和鲍曼不动杆菌。结论　ICU内机械通气患者NTB的发病率较高,血浆白蛋白减低、鼻饲、机械通气时间和ICU内住院时间延长是NTB的重要危险因素。NTB患者应合理使用抗生素,以减少细菌产生耐药。鲍曼不动杆菌、MRSA和铜绿假单胞菌是机械通气并发NTB常见致病菌。     

Nosocomial bacteremia involving<Emphasis Type="Italic"> Acinetobacter baumannii</Emphasis> in critically ill patients: a matched cohort study

OBJECTIVE: To determine outcome and attributable mortality in critically ill patients with nosocomial bacteremia involving A. baumannii. DESIGN: A retrospective matched cohort study in which all ICU patients with microbiologically documented A. baumannii bacteremia were defined as cases. Matching of the controls was based on equivalent APACHE II score (+/-2 points) and diagnostic category. Control patients were required to have an ICU stay equivalent to or longer than the case prior to onset of the bacteremia. SETTING: The 54-bed ICU of the 1060-bed Ghent University Hospital. PATIENTS: 45 ICU patients with A. baumannii bacteremia and 90 matched control subjects without clinical or microbiological evidence of blood stream infection. MEASUREMENTS: Population characteristics and in-hospital mortality rates of patients with A. baumannii bacteremia and their controls were compared. Attributable mortality is determined by subtracting the crude mortality rate of the controls from the crude mortality rate of the cases. RESULTS: Patients with A. baumannii bacteremia had significantly more hemodynamic instability, longer ICU stay, and longer length of ventilator dependence than controls. In-hospital mortality rates for cases and controls were, respectively, 42.2% and 34.4%; thus the attributable mortality was 7.8%. CONCLUSION: In critically ill patients A. baumannii bacteremia is not associated with a significantly increased mortality rate.     

The importance of colonization pressure in multiresistant Acinetobacter baumannii acquisition in a Greek intensive care unit

ABSTRACT: INTRODUCTION: We investigated the role of colonization pressure on multiresistant Acinetobacter baumannii acquisition and defined patient-related predictors for carriage at admission and acquisition during hospitalization in intensive care unit (ICU) patients. METHODS: This was a 12-month, prospective, cohort study of all patients admitted to a single ICU of a tertiary hospital. Screening samples were collected at ICU admission to identify imported carriers, and weekly during hospitalization to identify acquisition. Colonization pressure (carriers' patient-days × 100/all patients' patient-days) and the absolute number of carriers were calculated weekly, and the statistical correlation between these parameters and acquisition was explored. Multivariable analysis was performed to identify predictors for A. baumannii carriage at admission and acquisition during hospitalization. A. baumannii isolates were genotyped by repetitive-extragenic-palindromic polymerase chain reaction (PCR; rep-PCR). RESULTS: At ICU admission, 284 patients were screened for carriage. A. baumannii was imported in 16 patients (5.6%), and acquisition occurred in 32 patients (15.7%). Acquisition was significantly correlated to weekly colonization pressure (correlation coefficient, 0.379; P = 0.004) and to the number of carriers per week (correlation coefficient, 0.499; P <0.001). More than one carrier per week significantly increased acquisition risk (two to three carriers, odds ratio (OR), 12.66; P = 0.028; more than four carriers, OR, 25.33; P = 0.004). Predictors of carriage at admission were infection at admission (OR, 11.03; confidence interval (CI), 3.56 to 34.18; P < 0.01) and hospitalization days before ICU (OR, 1.09; CI, 1.01 to 1.16; P = 0.02). Predictors of acquisition were a medical reason for ICU admission (OR, 5.11; CI, 1.31 to 19.93; P = 0.02), duration of antibiotic administration in the unit (OR, 1.24; CI, 1.12 to 1.38; P < 0.001), and duration of mechanical ventilation (OR, 1.08; CI, 1.04 to 1.13; P = 0.001). All strains were multiresistant. Rep-PCR analysis showed one dominant cluster. CONCLUSIONS: Acquisition of multiresistant A. baumannii in ICU patients is strongly correlated to colonization pressure. High levels of colonization pressure and more than two carriers per week independently increase acquisition risk. Patient-related factors, such as infection at admission and long hospitalization before the ICU, can identify imported A. baumannii carriers. Medical patients with extended administration of antibiotics and long duration of mechanical ventilation in the ICU were the most vulnerable to acquisition.     

Multiple-drug-resistant bacteria in patients with severe acute exacerbation of chronic obstructive pulmonary disease: Prevalence, risk factors, and outcome

OBJECTIVE: To determine prevalence, risk factors, and effect on outcome of multiple-drug-resistant (MDR) bacteria in patients with severe acute exacerbation of chronic obstructive pulmonary disease. DESIGN: Prospective, observational, cohort study. SETTING: Thirty-bed medical intensive care unit (ICU) in a university hospital. METHODS: All chronic obstructive pulmonary disease patients with acute exacerbation who required intubation and mechanical ventilation for >48 hrs were eligible during a 4-yr period. Patients with pneumonia or other causes of acute respiratory failure were not eligible. In all patients, quantitative tracheal aspirate was performed at ICU admission (positive at 10 colony-forming units [cfu]/mL). MDR bacteria were defined as methicillin-resistant Staphylococcus aureus, ceftazidime- or imipenem-resistant Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia, and extended-spectrum beta-lactamase-producing Gram-negative bacilli. All patients received empirical antibiotic treatment at ICU admission. Univariate and multivariate analyses were used to determine variables associated with MDR bacteria and variables associated with ICU mortality. RESULTS: A total of 857 patients were included, and 304 bacteria were isolated (>/=10 cfu/mL) in 260 patients (30%), including 75 MDR bacteria (24%) in 69 patients (8%). When patients with MDR bacteria were compared with patients without MDR bacteria, previous antimicrobial treatment (odds ratio [OR], 2.4; 95% confidence interval [95% CI], 1.2-4.7; p = .013) and previous intubation (OR, 31; 95% CI, 12-82; p < .001) were independently associated with MDR bacteria. When patients with bacteria other than MDR or patients with no bacteria were used as a reference group, these risk factors were still independently associated with MDR bacteria. Although ICU mortality rate was higher in patients with MDR bacteria than in patients without MDR bacteria (44% vs. 25%; p = .001; OR, 2.3; 95% CI, 1.4-3.8), MDR bacteria were not independently associated with ICU mortality. Inappropriate initial antibiotic treatment (88% vs. 5%; p = <.001; OR, 6.7; 95% CI, 3.8-12) and ventilator-associated pneumonia (23% vs. 5%; p = <.001; OR, 1.3; 95% CI, 1-1.8) rates were significantly higher in patients with MDR bacteria than in patients with bacteria other than MDR. Inappropriate initial antibiotic treatment was independently associated with increased ICU mortality (OR, 7.1; 95% CI, 1.9-30; p = .003). CONCLUSION: MDR bacteria are common in patients with acute exacerbation of chronic obstructive pulmonary disease requiring intubation and mechanical ventilation. Previous antimicrobial treatment and previous intubation are independent risk factors for MDR bacteria. Although MDR bacteria are not independently associated with ICU mortality, inappropriate initial antibiotic treatment is an independent risk factor for ICU mortality in these patients. Further studies are needed to determine whether broad-spectrum antibiotic treatment is cost-effective in these patients.     

Clinical characteristics and outcomes of patients with Burkholderia cepacia bacteremia in an intensive care unit

The purpose of this study was to investigate a cohort of patients with Burkholderia cepacia bacteremia in the intensive care unit (ICU) at our institution. A large outbreak of B. cepacia bacteremia involving 95 patients lasted for 4 years in an ICU in northern Taiwan. The clinical characteristics and antimicrobial treatment responses of these patients were analyzed. Minimal inhibitory concentrations were determined and pulse-field gel electrophoresis was performed for the 73 available isolates. Overall, the in-hospital mortality rate was 53.8% and the 14-day mortality rate was 16.8%. Most patients (95.6%) had several underlying diseases and all but 1 patient had tracheal intubation. Malignancy (37.5% versus 13.9%, P = 0.02) and higher Sequential Organ Failure Assessment (SOFA) scores at the onset of bacteremia (11.9 ± 4.7 versus 7.9 ± 3.6, P < 0.001) were significant risk factors for 14-day mortality. In contrast, treatment with ceftazidime (76.0% versus 43.7%, P = 0.02) and diabetes (51.9% versus 13.8%, P = 0.01) were associated with decreased mortality. In the multivariate analysis, malignancy and higher SOFA score were significant risk factors for mortality [odds ratio (OR) 12.45, 95% confidence interval (CI) 2.35-65.94; OR 1.20, 95% CI 1.00-1.45, respectively]. Meropenem, ceftazidime, and piperacillin-tazobactam were the most active agents (susceptible rate 100%, 97.3%, and 97.3%, respectively). Pulsed-field gel electrophoresis results indicated 49 of the 73 isolates could be classified as outbreak-related strains. There was no significant difference in the clinical characteristics and outcomes of patients with bacteremia due to outbreak-related and non-outbreak-related strains. In conclusion, malignancy and a higher SOFA score at onset of bacteremia predicted increased mortality, but the clinical presentation and outcome of patients with outbreak and non-outbreak strains were similar.