全耐药鲍氏不动杆菌的随机扩增DNA多态性分析

目的 通过全耐药鲍氏不动杆菌随机扩增DNA多态性(RAPD)基因分型同源性分析,以用于医院感染的追踪控制和流行病学的调查研究.方法 收集8个月内从医院分离的15株全耐药鲍氏不动杆菌,提取DNA后进行RAPD分型,同时进行抗菌药物敏感试验和流行病学分析.结果 15株全耐药菌株被分为6个RAPD型,其中ICU1、ICU2分别存在两株克隆株,从ICU1转入外科病区的患者,同源件与其完全相同,全敏感菌株与全耐药菌株的同源性差异性很明显.结论 ICU存在全耐药鲍氏不动杆菌的局部流行.     

全耐药鲍氏不动杆菌肺部感染的临床分析

目的探讨全耐药鲍氏不动杆菌（PRAB）肺部感染的临床特点以及感染危险因素。方法对2004年6月-2005年8月间，医院住院治疗的83例PRAB肺部感染患者和80例一般鲍氏不动杆菌肺部感染患者的临床特征及其危险因素进行分析比较。结果PRAB肺部感染患者病死率（46．99％）显著高于非PRAB感染者（35．00％），其平均住院（54.53d）和住ICU时间（46．69d）显著大于后者（24．70d和41．87d），且其抗茵药物使用时间（49．02d）与种类（4．75种）也显著大于或多于后者（38．7d和3.45种）。结论PRAB感染已成为严重影响患者预后的难题，积极加强行之有效的预防措施是降低其发生的关键。     

Antibiotic Resistance of Acinetobacter baumannii in Iran: A Systemic Review of the Published Literature

Objectives

Acinetobacter baumannii is a bacterium responsible for health care-associated infections, and it frequently develops multiple drug resistance (MDR). The prevalence of antibiotic-resistant A. baumannii in Iran has increased, and this may cause significant clinical problems. Therefore, in order to elucidate the development of antibiotic resistance, we performed a systematic review of the literature published on antibiotic-resistant A. baumannii reported in Iran.

Methods

Thirty-six publications that met the criteria for inclusion were reviewed from an initial 87 papers. Selected papers published between 2008 and September 2014, were categorized on the basis of the sample collecting year been between 2001 and 2013.

Results

Analysis of data revealed that, in general, there was an increase in antimicrobial resistance. During the initial time point of these studies (2001–2007) there was a high rate of resistance to all antibiotics, with the exception of carbapenems, lipopeptides, and aminoglycosides that had a low resistance rate in comparison with the others. Also, the resistance rate was increased in one group of these three antimicrobial groups from 2010 to 2013. In particular, there was an increase in resistance to carbapenems (imipenem and meropenem) from 2010–2011 and 2012–2013, whereas no significant change in the resistance rate of the other two antimicrobial groups (lipopeptides and aminoglycosides) during the study time was observed, although we did observe certain trends in amikacin (aminoglycoside group antibiotic) between 2011–2012 and 2012–2013.

Conclusion

These findings indicate that antimicrobial resistance of A. baumannii in Iran has increased, which may very well affect the antimicrobial resistance of this organism worldwide. Based on these results, novel prevention and treatment strategies against A. baumannii infections are warranted. Furthermore, these data may assist in revising treatment guidelines and regional policies in care units to slow the emergence of antimicrobial resistance.     

鲍氏不动杆菌医院感染的耐药性调查

目的 探讨鲍氏不动杆菌(ABA)医院感染现状及对抗菌药物的耐药性,为临床医师合理使用抗菌药物提供试验依据.方法 2006年1月-2010年12月从住院患者感染性标本中分离出225株ABA,细菌培养与鉴定严格按《全国临床检验操作规程》进行;药敏试验采用K-B法进行,依据CLSI最新折点判读结果.结果 ABA在呼吸道标本中检出率居第1位,达73.8％,ABA对常用抗菌药物产生了不同程度的耐药性,对碳青霉烯类抗菌药物亚胺培南、美罗培南耐药率分别为4.4％和5.8％,且发现ABA泛耐药菌株,检出率为1.3％.结论 各级医院务必重视ABA耐药性的监测工作,预防与控制多药耐药ABA医院感染的发生暴发流行.     

ICU鲍氏不动杆菌医院感染耐药性分析

目的 探讨ICU鲍氏不动杆菌(ABA)医院感染的分布特征及耐药性,为指导临床合理选用抗菌药物提供依据.方法 对2010年1-12月ICU分离出的87株医院感染鲍氏不动杆菌分布及耐药性进行统计分析.结果 鲍氏不动杆菌在ICU的检出率较高,其中90.80％的标本来源于下呼吸道;该菌多药耐药现象严重,87株鲍氏不动杆菌耐药率最低的是多黏菌素为5.75％,对亚胺培南和美罗培南的耐药率达75.86％,对头孢三代、头孢四代、阿米卡星耐药率分别为87.36％、83.91％、80.46％,对哌拉西林/他唑巴坦、庆大霉素、替卡西林/克拉维酸、环丙沙星耐药率均＞90.0％;泛耐药鲍氏不动杆菌(PDRAB)检出17株,占19.54％.结论 ICU医院感染鲍氏不动杆菌耐药严重,医院应加强对ABA耐药性的监测,实施有效的预防控制措施,尽量减少和延缓耐药株和泛耐药株的产生,防止多药耐药ABA医院感染暴发流行.     

多种抗菌药物对医院感染鲍氏不动杆菌的耐药性差异分析

目的 探讨医院感染临床标本中鲍氏不动杆菌(ABA)的分布特征及耐药率,对预防控制突发细菌感染起着重要的作用.方法 回顾性分析医院2010年11月-2011年10月从住院患者各类感染标本中分离出的ABA感染情况及其耐药性.结果 391株ABA的分布以痰标本为主,占72.9％,其次为血液,占27.0％,支气管肺泡灌洗液,占17.0％；分布以神经内科、综合ICU和呼吸内科为主,分别占32.2％、23.8％和13.0％；该菌对氨苄西林、哌拉西林、头孢吡肟、头孢噻肟、左氧氟沙星、磺胺甲噁唑/甲氧苄啶的耐药率均＞71.0％,而且多药耐药率较高,对亚胺培南和美罗培南的耐药率仅为2.8％和3.3％.结论 ABA是医院感染的重要条件致病菌,其对抗菌药物耐药率高,应合理使用抗菌药物,注重检测和预防控制感染的发生.     

Prevalence and in vitro antimicrobial susceptibility patterns of Acinetobacter baumannii strains in a Moroccan university hospital

OBJECTIVE: The aim of this study was to identify the clinical presentations and the current antimicrobial susceptibility of Acinetobacter baumannii. RESULTS: We identified 754 strains especially from intensive care units (50.53%) between January 2003 and December 2005. Bronchial swabs and blood culture were prevalent. High-level resistance to betalactamines was noted: 91% to cefotaxime, 50.3% to ceftazidime, and 42.6% to imipenem. Aminoside resistance varied from 17.9% for netilmicine to 72.1% for gentamycin. The resistance rate to ciprofloxacine was 65.8%, and to trimethoprime-sulfamethoxazole 75.8%. In intensive care units, the antimicrobial resistance rate of A. baumannii was higher (p<0.05). CONCLUSION: The resistance of A. baumannii to current antibiotics is alarming especially in intensive care units. An effective strategy against nosocomial infection is still necessary.     

医院感染鲍氏不动杆菌毒力相关因素的研究

目的 研究医院感染鲍氏不动杆菌的毒力相关因素,评估其致病力的强弱.方法 收集医院感染患者标本中分离的鲍氏不动杆菌共135株,对其进行蹭行运动、明胶酶,生物被膜和甘露糖抵抗的红细胞凝集作用的研究.结果 鲍氏不动杆菌的蹭行直径≤10mm平均为4.50 mm;135株鲍氏不动杆菌均未检出明胶酶活性;其中有15株形成生物被膜,检出率为11.11％;D-甘露糖存在条件下,37株鲍氏不动杆菌与O型红细胞发生凝集,发生率为27.41％,83株与AB型红细胞发生凝集,发生率为61.48％,无D-甘露糖存在条件下,10株与O型红细胞发生凝集,发生率为7.40％,所有菌株均与AB型红细胞未发生凝集.结论 引起医院感染的鲍氏不动杆菌的毒力总体较弱,但多种因素影响鲍氏不动杆菌在体内的定植和感染,仍需长期监测,防止强毒力株的产生及播散.     

Active and passive immunization against Acinetobacter baumannii using an inactivated whole cell vaccine

The treatment of infections caused by Acinetobacter baumannii has become increasingly complicated due to the emergence of highly resistant strains. In the present study we demonstrate that immunization with an inactivated whole cell vaccine elicits a robust antibody response that provides protection against challenge with multiple A. baumannii strains in a murine model of disseminated sepsis. In addition, we show that passive immunization with serum raised against inactivated cells protects mice from subsequent infection. These results demonstrate that active and passive immunization using an inactivated whole cell vaccine may be an effective approach for preventing infection by A. baumannii.     

医院感染鲍氏不动杆菌的临床分布及耐药性分析

目的了解医院感染鲍氏不动杆菌(ABA)的临床分布及对抗菌药物的耐药性,为临床医师抗感染治疗提供科学依据。方法 223株ABA分离自医院患者感染性标本,采用法国生物梅里埃公司API 20NE试剂条进行细菌鉴定;采用K-B法进行药敏试验,依据CLSI最新折点判读结果。结果 ABA主要分离自呼吸道标本,占70.9%;对常用抗菌药物均产生了严重的耐药性,对亚胺培南和美罗培南耐药率分别为23.8%、24.7%,ABA泛耐药菌株检出率为17.5%。结论 ABA主要分离自呼吸道,对抗菌药物耐药现象严重,各级医院应重视细菌耐药性监控工作,预防多药耐药ABA医院感染的暴发流行。     

神经内科患者医院感染鲍氏不动杆菌的耐药性调查分析

目的 研究神经内科住院患者医院感染鲍氏不动杆菌(ABA)的抗药性,为医师控制感染选择抗菌药物提供依据.方法 无菌手法收集神经内科住院患者感染性标本;ABA培养按照临床微生物学检验的常规操作方法进行,细菌采用MicroScan AutoSCAN4自动微生物鉴定系统进行鉴定;药敏试验采用WHO指定的纸片扩散法(K-B法),抑菌圈直径的测量和敏感、中介、耐药判断依据CLSI的最新折点分析,药敏数据统计运用WHONET5.5软件版本处理.结果 神经内科流行的182株ABA在呼吸道标本中检出118株,检出率达到64.8％;ABA对临床抗菌药物均产生了严重的抗药性,检出泛耐药菌株41株,检出率为22.5％;检出耐碳青霉烯类菌株43株,检出率为23.6％.结论 医院务必加大对《抗菌药物临床应用管理办法》的执行力,重视感染病原学检测的相关管理,培训提升临床医师抗菌药物处方水平,以扭转细菌耐药性不断增长的危险倾向.     

Investigation and management of an imipenem-resistant oxa-23 Acinetobacter baumannii outbreak in an intensive care unit

Objectives

The study objectives were to describe the investigation and management of an imipenem-resistant Acinetobacter baumannii outbreak that occurred in the 15-bed ICU of a tertiary care teaching hospital (Brest, France), during the summer 2008.

Patients and methods

Patients harboring an imipenem-resistant A. baumannii strain were defined as case patients. We described case occurrence and steps taken to control the outbreak: contact isolation, reinforcement of hygiene procedures, unit shutdown decision, unit disinfection, and reopening. We also made a case control study and a cost analysis of the outbreak management.

Results

During a 10-day period, five patients were positive for a single clone of imipenem-resistant oxa-23 A. baumannii. Four patients presented with ventilation-acquired pneumonia and one was asymptomatic. The first two patients died one day after the first swab which led to the identification of A. baumannii. No additional case was noted in the ICU or in other hospital units after deciding to close the ICU. The cost of outbreak management was estimated at 264,553 euros. The case control study identified several factors associated with infection or colonization: length of stay in the ICU, chronic respiratory disease, number of previous antibiotic classes used, duration of ventilation, prone position, echocardiography, and presence of a nasogastric tube.

Conclusion

This outbreak occurred during the summer period requiring the shutdown of the ICU and inducing a considerable cost. Rapid reactions of the ICU staff during the outbreak enabled to limit the epidemic.     

Outbreak of multidrug-resistant Acinetobacter baumannii in a Belgian university hospital after transfer of patients from Greece

Multidrug-resistant (MDR) Acinetobacter baumannii are emerging as important nosocomial pathogens. These organisms have a capacity for long-term survival in the hospital environment. The purpose of this study was to describe the course and control of an outbreak with MDR A. baumannii in a Belgian university hospital after transfer of two trauma patients from Greece. Wounds in both patients were colonised with MDR A. baumannii. Over an 11 month period from September 2004 to July 2005, carbapenem-non-susceptible A. baumannii (producing carbapenem-hydrolysing oxacillinase OXA-58) were isolated from 28 patients, despite early implementation of contact precautions. MDR A. baumannii was detected in routine clinical diagnostic samples from 26 patients and in screening specimens from an additional two patients. Twenty patients (71.4%) were colonised or infected during their stay in intensive care. Twenty-four (85.7%) respiratory samples were positive for MDR A. baumannii. Careful review of all procedures related to the respiratory tract did not identify a common route of transmission. Outbreak control required multiple interventions, including contact isolation of colonised and infected patients, monitoring the practice of personnel, screening of asymptomatic patients, use of isolation rooms and enhanced environmental disinfection. Introduction of single-use ventilator circuits was considered but the outbreak was controlled before implementation.     

VEB-1 Extended-spectrum beta-lactamase-producing Acinetobacter baumannii, France

VEB-1 extended-spectrum beta-lactamase-producing Acinetobacter baumannii was responsible for an outbreak in hospitals in France. A national alert was triggered in September 2003 when 4 hospitals reported clusters of A. baumannii infection with similar susceptibility profiles. Case definitions and laboratory guidelines were disseminated, and prospective surveillance was implemented; strains were sent to a single laboratory for characterization and typing. From April 2003 through June 2004, 53 hospitals reported 290 cases of A. baumannii infection or colonization; 275 isolates were bla(VEB-1)-positive and clonally related. Cases were first reported in 5 districts of northern France, then in 10 other districts in 4 regions. Within a region, interhospital spread was associated with patient transfer. In northern France, investigation and control measures led to a reduction of reported cases after January 2004. The national alert enabled early control of new clusters, demonstrating the usefulness of early warning about antimicrobial drug resist.     

医院感染鲍曼不动杆菌分子流行病学研究

目的 分析某医院不同科室来源的鲍曼不动杆菌菌株的同源性，了解鲍曼不动杆菌医院感染流行情况。方法 应用重复片段引物聚合酶链反应（PCR）的基因分型方法，对53株医院感染鲍曼不动杆菌进行基因分型。结果 53株鲍曼不动杆菌分为28个基因型，其中C型15株，分别分离自重症中心、心胸外科的重症监护病房（ICU）、烧伤整形外科、干部病房心内科、创伤手外科、呼吸内科、泌尿内科、儿科ICU、放疗科和血液科；E型和N型各4株，J型3株，O型、Q型和S型各2株，其余均为1株。从同一患者同一部位的不同时期分离出了不同基因型菌株。结论 该院鲍曼不动杆菌以C型菌株为主要的流行株；同一患者存在不同基因型鲍曼不动杆菌的感染。     

2011年鲍氏不动杆菌医院感染耐药性分析

目的 分析2011年鲍氏不动杆菌医院感染分布及耐药性,为临床治疗和医院感染控制提供依据.方法 对临床送检标本进行分离、培养,采用VITEK-32细菌鉴定仪对鲍氏不动杆菌进行鉴定,使用纸片扩散法测定菌株对抗菌药物的敏感性,所有数据应用WHONET5.5及SPSS13.0软件进行统计分析.结果 分离鲍氏不动杆菌188株,以痰中检出率最高,占79.3％;科室分布以ICU、呼吸科为主,分别占39.9％和12.2％;该菌对抗菌药物总耐药率以米诺环素最低,为14.9％,对其他常用抗菌药物的耐药率＞50.0％,而ICU除米诺环素外,对各类抗菌药物耐药率＞80.0％.结论 鲍氏不动杆菌耐药严重,集中分布于ICU,重视对鲍氏不动杆菌的耐药监测,采取有效措施避免和减少多药耐药的鲍氏不动杆菌传播.     

Investigation and management of an outbreak of multidrug-carbapenem-resistant Acinetobacter baumannii in Cambridge, UK

Multidrug-resistant Acinetobacter baumannii resistant to carbapenems (MRAB-C) has become endemic in many hospitals in the UK. We describe an outbreak of MRAB-C that occurred on two intensive care units using ORION criteria (Outbreak Reports and Intervention studies Of Nosocomial infection). All patients colonised or infected with MRAB-C were included. Enhanced infection control precautions were introduced in Phase 1 of the outbreak. The adult neurosciences critical care unit (NCCU) was partially closed in Phase 2 and strict patient segregation, barrier nursing and screening thrice weekly was introduced. When control was achieved, NCCU was reopened (Phase 3) with post-discharge steam cleaning and monthly cleaning of extract and supply vents. There were 19 cases, 16 on NCCU and three on the general intensive care unit (ICU). Mean age was 52 years, with six cases being female. All patients were mechanically ventilated and ten had either an extraventricular drain or intracranial pressure monitoring device in place. Four patients developed a bacteraemia, with one further case of ventriculitis. Nine patients had no clinical evidence of infection and four were identified initially on screening. Ten patients were treated; there were eight deaths. Environmental samples showed heavy contamination throughout NCCU. MRAB-C affects critically ill patients and is associated with high mortality. This outbreak was controlled by early involvement of management, patient segregation, screening of patients and the environment, and increased hand hygiene environmental cleaning and clinical vigilance. A multidisciplinary approach to outbreak control is mandatory.     

4起耐药鲍曼不动杆菌医院感染聚集性病例调查

目的探讨耐药鲍曼不动杆菌（DRAb）引起医院感染聚集性病例(NICC)的原因。方法对4起DRAb NICC的临床资料及流行病学调查结果进行分析和统计学描述。结果4起14例DRAb NICC均发生在气候炎热季节,分布于重症监护室（ICU）;其中危重患者10例（71.43%）,老年患者（＞65岁）6例（42.86%）;入住ICU时间的中位数为8 d;发生DRAb感染前局部生理屏障均受到破坏。12例（85.71%）为肺部感染(呼吸机相关性肺炎占 64.29%);11例（78.57%）为泛耐药Ab感染。发生医院感染前,9例（64.29%）患者有长期联合使用抗菌药物史;感染源2起是输入性的医院感染。结论DRAb NICC的发生与患者的易感性、隔离与消毒、病区医院感染监控、抗菌药物使用以及Ab的生物学特性等有关。     

Alterations of gyrA,gyrB, and parC and Activity of Efflux Pump in Fluoroquinolone-resistant Acinetobacter baumannii

Objectives

This study investigated the fluoroquinolone-resistant mechanism of 56 clinical cases of A baumannii infection from 23 non-tertiary hospitals, collected between 2004 and 2006.

Methods

Susceptibility testing was performed by broth microdilution and Epsilometer test. Analyses of quinolone resistance-determining region (QRDR) were done by sequencing. The activity of the efflux pump was measured using inhibitors.

Results

The sequences from selected 56 isolates were divided into seven groups (I-VII) on the basis of mutations in gyrA (S83L), parC (S80L, S80W and S84K) and gyrB (containing the novel mutations E679D, D644Y and A677V). The 27 isolates with triple mutations in gyrA, gyrB and parC (groups IV-VII) showed higher levels of resistance to ciprofloxacin (minimal inhibitory concentration [MIC] of 16-256 μg/mL) than the 26 isolates with double mutations in gyrA and parC (groups II and III, MIC of 8-64 μ g/mL; p < 0.05). Alterations in the efflux pump were observed in four isolates with the parC S80L mutation (group II) or E84K mutation (group VII), but no effect was observed in an isolate with the parC S80 W mutation (group III).

Conclusion

These results suggest that triple mutations in clinical isolates of A baumannii contribute to the development of high levels of resistance to fluoroquinolones and that mutations in parC S80L or E84K (groups II and VII) may contribute to alterations in efflux pump activity in A baumannii.