29株耐亚胺培南和/或美罗培南鲍曼不动杆菌产碳青霉烯酶基因型检测

目的 了解临床分离耐亚胺培南和/或耐美罗培南鲍曼不动杆菌中产碳青霉烯酶的基因型别.方法 采用聚合酶链反应扩增IMP、VIM、OXA型碳青霉烯酶基因并测序.结果 29株对碳青霉烯类耐药的鲍曼不动杆菌中,以产OXA-24型和IMP型酶菌株最多,二者均占51.7％ (15/29).产OXA-24+ IMP型5株、OXA-24+ OXA-51+IMP型4株、VIM型4株、OXA-24+ OXA-58+ IMP型、OXA-23+ OXA-24+ IMP型各2株,OXA-23+IMP型、OXA-51+OXA-24型、OXA-24型、IMP型各1株,8株细菌PCR检测结果为阴性.结论 耐亚胺培南和/或美罗培南鲍曼不动杆菌主要产OXA-24型和IMP型碳青霉烯酶,部分菌株可同时产2种或以上碳青霉烯酶.     

皖北地区耐碳青霉烯鲍曼不动杆菌产金属β-内酰胺酶检测

目的了解皖北地区ICU病房内耐碳青霉烯鲍曼不动杆菌产金属β-内酰胺酶（metallo-β-lactamase,MBL）情况。方法收集皖北地区3家教学医院ICU病房中不动杆菌,K-B纸片扩散法检测其对碳青霉烯类抗生素耐药情况;PCR法检测blaIMP、blaVIM等MBL基因。结果共收集35株耐亚胺培南、美罗培南非重复分离鲍曼不动杆菌菌株,其中9株（25.7%）金属酶初筛阳性;PCR检测5株（5/35,14.3%）产IMP型MBL,1株（1/35,2.9%）VIM型MBL。结论在本地区耐碳青霉烯鲍曼不动杆菌中首次发现IMP和VIM型金属酶,提示产金属酶机制参与本地区鲍曼不动杆菌对碳青霉烯耐药,值得进一步关注。     

耐碳青霉烯类鲍曼不动杆菌OXA和NDM-1耐药基因的研究

目的检测江苏盛泽医院耐碳青霉烯类抗生素鲍曼不动杆菌的OXA和NDM-1耐药基因,分析耐碳青霉烯类抗菌药物的耐药机制。方法采用改良Hodge试验检测30株耐碳青霉烯类抗生素鲍曼不动杆菌产酶情况;用PCR的方法检测OXA-23、OXA-24、VIM、IMP和NDM-1碳青霉烯酶耐药基因。结果 30株分离菌中25株菌改良Hodge试验阳性,22株携带OXA-23型碳青霉烯酶耐药基因,未扩增出NDM-1碳青霉烯酶耐药基因。结论本院耐碳青霉烯类抗生素鲍曼不动杆菌的耐药机制主要是携带OXA-23型碳青霉烯酶基因。     

鲍曼不动杆菌中OXA碳青霉烯酶的表型筛选与PCR检测

摘要：目的 了解OXA碳青霉烯酶在暨南大学附属第一医院耐亚胺培南鲍曼不动杆菌中的流行状况,完善OXA碳青霉烯酶的分子流行病学资料。方法 采用改良Hodge试验筛选产碳青霉烯酶菌株,多重PCR法检测OXA碳青霉烯酶的编码基因（blaOXA-23-like、blaOXA-24-like、blaOXA-58-like和blaOXA-143）,利用生物信息学的方法对OXA亚型进行比对分析并制作分子进化树。结果 在157株耐亚胺培南鲍曼不动杆菌中Hodge试验筛选出碳青霉烯酶表型阳性菌株141株,PCR检测结果显示有132株携带OXA-23编码基因,未检测到OXA-24-like、OXA-58-like和OXA-143亚型。结论 产OXA-23碳青霉烯酶是该院鲍曼不动杆菌对亚胺培南耐药的主要机制之一。     

鲍曼不动杆菌的耐药情况及碳青霉烯酶基因检测

了解佳木斯大学附属第一医院鲍曼不动杆菌耐药性及碳青霉烯酶包括苯唑西林酶和金属酶相关耐药基因分布情况,为临床抗菌药物的合理选择提供依据。2013年9月至2014年12月使用VITEK-II全自动微生物鉴定/药敏测试系统筛选出佳木斯大学附属第一医院临床标本鲍曼不动杆菌69株;采用多重PCR方法检测鲍曼不动杆菌携带的碳青霉烯酶相关耐药基因16SrRNA、OXA-23、OXA-24、OXA-51、OXA-58、IMP、VIM、SIM,并对耐药基因扩增的阳性产物进行DNA 序列分析。69株AB对亚胺培南、美洛培南的耐药率分别为36.2%、37.68%,对其他抗菌药物的耐药率均高于50%。6种耐药基因的检测结果为69株(100%)携带OXA-51基因,32株(46.4%)携带OXA-23基因,17株(24.6%)携带OXA-24基因,5株(7.2%)携带OXA 58基因,1株（1.4%）携带IMP基因。25株碳青霉烯类药物耐药鲍曼不动杆菌中,22株(88%) 携带OXA-23,1株(4%)携带OXA-58,10株(40%)携带OXA-24,6株（24%）同时携带OXA-23、OXA-24。 DNA序列分析结果显示：OXA-23、OXA-24、OXA-51、OXA-58分别与NCBI的序列同源性均为99%。产OXA-23型碳青霉烯酶可能是佳木斯大学附属第一医院鲍曼不动杆菌对碳青霉烯酶类抗菌药物耐药的主要原因,另外佳木斯大学附属第一医院存在OXA-24型耐药基因鲍曼不动杆菌的区域性流行。     

426株鲍曼不动杆菌的耐药性分析与OXA-23型碳青霉烯酶检测

目的 了解暨南大学附属第一医院2009年至2011年鲍曼不动杆菌的分布特点和耐药状况,为临床合理使用抗生素提供依据,同时研究广州地区亚胺培南耐药鲍曼不动杆菌中OXA-23型碳青霉烯酶的分子流行病学特征.方法 利用梅里埃VITEK-2 Compact微生物分析仪鉴定细菌,K-B法进行药敏试验,采用WHONET 5.6软件统计分析药敏结果,PCR检测OXA-23型碳青霉烯酶的编码基因.结果 2009年至2011年临床分离出426株鲍曼不动杆菌,主要分离自呼吸科病房(119株,占27.9％)和ICU病房(107株,占25.1％),标本类型以痰液为主(361株,占84.7％),鲍曼不动杆菌对12种抗生素的耐药率总体呈逐年上升趋势,对亚胺培南的耐药率从13.2％上升到39.3％,在124株亚胺培南耐药鲍曼不动杆菌中PCR检出98株OXA-23型碳青霉烯酶阳性菌株.结论 鲍曼不动杆菌对各种抗菌药物的耐药性逐年增强,产OXA-23型碳青霉烯酶是其对亚胺培南耐药的主要机制之一.     

耐碳青霉烯类鲍曼不动杆菌OXA基因检测及同源性分析

目的 了解台州地区碳青霉烯类耐药鲍曼不动杆菌的耐药性、碳青霉烯酶基因型以及同源性.方法 63株碳青霉烯类耐药鲍曼不动杆菌经VITEK2 Compact进行细菌鉴定及药敏分析,用K-B法复核药敏结果,采用多重PCR扩增分析碳青霉烯酶的基因型;采用脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)分析其同源性.结果 63株菌株为多重耐药菌株,除多粘菌素、阿米卡星、头孢哌酮/舒巴坦外,对其他常用抗生素的耐药率均在70％以上.63株菌株检测出OXA-51基因60株(95.2％),OXA-23基因58株(92.1％),两个基因同时存在的有58株(92.1％).PFGE结果显示碳青霉烯类鲍曼不动杆菌主要分为5个克隆型,其中A、B两个为主型.结论 产OXA酶是台州地区耐碳青霉烯类鲍曼不动杆菌的主要耐药机制之一,其中OXA-23是主要的基因型.     

鲍曼不动杆菌碳青霉烯酶基因分布与 耐药相关性研究

目的研究鲍曼不动杆菌碳青霉烯酶基因的分布与其耐药的相关性。方法收集2015年1月至2017年3月瑞安市两家市级医院的100株耐碳青霉烯类抗生素鲍曼不动杆菌,应用PCR技术检测碳青霉烯酶的相关基因,应用ERIC-PCR法对筛选结果阳性菌株进行DNA同源性分析。结果 100株耐碳青霉烯类抗生素鲍曼不动杆菌中,有50株携带OXA-51基因,26株携带OXA-23基因,同时携带OXA-51和OXA-23基因的有10株,未检出其他碳青霉烯酶基因。对筛选出的58株鲍曼不动杆菌进行同源性分析,得出的DNA指纹条带数为7条,其大小为200~2 000bp。根据片段数目和大小,分为A、B、C、D、E共5种基因型,分别有38、32、21、5、4个克隆株。结论本地区鲍曼不动杆菌对碳青霉烯类药物耐药的机制主要为携带OXA-23基因,克隆传播是主要的传播途径。     

耐亚胺培南鲍曼不动杆菌医院内感染流行的分子机制研究

目的研究耐亚胺培南鲍曼不动杆菌的耐药谱特征及其医院内感染流行和耐药性产生的分子机制,为临床防治提供依据.方法4株耐亚胺培南鲍曼不动杆菌分离自2002年10月至2003年1月外科重症监护病房的感染患者,采用纸片扩散法及E-test进行药物敏感性检测及MIC值测定,肠杆菌科基因组内重复一致序列聚集合酶链反应(ERIC-PCR)进行克隆株的DNA分型,耐药质粒转移及消除试验、等电聚焦电泳、PCR扩增β-内酰胺酶基因及其克隆测序以识别其耐药基因和进行质粒定位.结果4株菌除对头孢哌酮/舒巴坦复合制剂的MIC值较低外,对头孢菌素类、氨基糖甙类和氟喹喏酮类等抗生素均显示出了较高水平的多重耐药性;DNA分型证实为同一克隆株;产OXA-23型碳青霉烯酶和PER-1型超广谱β-内酰胺酶(ESBLs);OXA-23定位在质粒上,PER-1定位在染色体上.结论本组耐亚胺培南鲍曼不动杆菌为多重耐药株,同一克隆株在不同感染个体间的相互传播导致了本次医院内感染的流行,产OXA-23和PER-1型β-内酰胺酶是其耐药性产生的重要原因.     

分离自老年病房的鲍曼不动杆菌耐药机制初步研究*

目的:检测老年住院患者分离的鲍曼不动杆菌的主要耐药基因,并研究不同耐药基因型与耐药表型之间的对应关系。方法:用PCR方法检测分离自老年住院患者的不同标本来源的170例非重复鲍曼不动杆菌的耐药基因。检测的耐药基因包括D类碳青霉烯酶:bla_(OXA-51),bla_(OXA-23),bla_(OXA-24),bla_(OXA-58),B类金属碳青霉烯酶:bla_(VIM),bla_(IMP),bla_(SIM),bla_(GIM),bla_(DIM),bla_(NDM-1),以及A类超广谱β-内酰胺酶:blaKPC,共计11种。根据检测结果对菌株进行基因分型,并研究不同基因型与CRAB和CSAB这两种耐药表型之间的对应关系。结果:170株鲍曼不动杆菌的固有基因bla_(OXA-51)均为阳性,此外,主要检出基因为bla_(OXA-23),共124株。另外检测出blaKPC12株,bla OXA-58 6株,bla_(NDM-1)3株,bla_(SIM)2株,bla_(OXA-24)、bla_(VIM)和bla_(DIM)各1株,IMP和GIM未检出。根据检出耐药基因的不同组合,分为bla OXA-51+bla_(OXA-23)阳性为基础的A型(124株)及bla_(OXA-23)阴性为基础的B型(bla_(OXA-51),39株)、C型(bla_(OXA-51)+bla_(OXA-58),6株)、D型(bla_(OXA-51)+bla_(OXA-24),1株)共计四类基因型。从耐药表型来看,128株碳青霉烯耐药菌中有122株bla_(OXA-23)为阳性,在CRAB中占95.3%(122/128),42株碳青霉烯敏感株中,有40株bla_(OXA-23)为阴性,在CSAB中占95.2%(40/42)。结论:老年病房流行的耐碳青霉烯鲍曼不动杆菌的耐药基因型以bla_(OXA-23)阳性为主。其与鲍曼不动杆菌CRAB耐药表型、bla_(OXA-23)阴性与CSAB耐药表型之间有良好的对应关系。     

The role of bla(OXA-like carbapenemase) and their insertion sequences (ISS) in the induction of resistance against carbapenem antibiotics among Acinetobacter baumannii isolates in Tehran hospitals

This study aimed to evaluate the occurrence and dissemination of bla(OXA-like) carbapenemase genes and their insertion sequences among Acinetobacter baumannii isolates, taken from different hospitals in Tehran city and also their roles in the induction of resistance to carbapenem drugs. A total number of 100 non duplicate Acinetobacter baumannii with different origins, were isolated from patients with proved nosocomial infections at eight university hospital in Tehran city. Antimicrobial susceptibility of these strains was done by E-test against 7 antimicrobial agents according to CLSI guideline. PCR of bla(OXA-51-like), bla(OXA-23-like), bla(OXA-24-like), bla(OXA-58-like), IS(ABA-1), IS(1133) was carried out by specialized primers and then these strains were typed by REP-fingerprinting. Colistin, imipenem and meropenem were the most sensitive antibiotics against Acinetobacter baumannii isolates with 96%, 51% and 51% sensitivity respectively. All the isolates had a bla(OXA-51-like) intrinsic to these species. The rates of bla(OXA-23), 23 and 58-like were 38%, 32% and 1% respectively. Coexistence of bla(OXA-51/23/24-like) was observed among 16% of these isolates. All bla(OXA-23-like) carbapenemase genes had only one IS(ABA1). REP fingerprinting showed 5 genotypes among carbapenem resistant isolates, 16 of them being genotype A. This study emphasized on the major role of bla(OXA-like) carbapenemase, particularly bla(OXA-23-like) carbapenemase and their IS(ABA1), in the dissemination of carbapenem resistant Acinetobacter baumannii. This study confirmed a presumptive role of IS element neighboring the carbapenemase gene in the elevation of resistance to carbapenem drug among Acinetobacter baumannii isolates for the first time in Iran.     

Gram-negative bacteriae with resistance to carbapenems

Clinically-significant Gram-negative species remain mostly Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii. Carbapenem molecules are often the last resort for treating infections due to multidrug resistant isolates. In Enterobacteriaceae, resistance to carbapenems may result from combined mechanisms of resistance associating b-lactamases with weak (if any) intrinsic carbapenemase activity and decreased outer membrane permeability, or from true carbapenemases. KPC-type enzymes (partially inhibited by clavulanic acid) have been identified mostly in Klebsiella pneumoniae, first in bacteria identified in the USA and then worldwide, and in many enterobacterial species. Carbapenem-hydrolyzing b-lactamases (CHBL) could be also metallo-b-lactamases (VIM, IMP, NDM-1, etc.) mostly in hospital-acquired K. pneumoniae. One of the latest reported CHBL in Enterobacteriaceae is OXA-48, identified mostly in Mediterranean countries. All these carbapenemase producers are difficult to detect in a clinical laboratory and may be the source of multidrug resistance leading to a therapeutic dead end. Whereas the main mechanism of resistance to imipenem in P. aeruginosa remains due to a modification of the outer membrane protein OprD, the landscape of CHBL in P. aeruginosa expanding worldwide is made of KPC, GES-related enzymes and metallo-b-lactamases (IMP, VIM, etc.). These enzymes are involved in multidrug resistance strains as a source of nosocomial outbreaks. In Acinetobacter baumannii, KPC and metallo-b-lactamases have been identified. However, the most frequent CHBL are oxacillinases (OXA-23, OXA-40, OXA-58, OXA-143) which are specific to that species. Novel carbapenemases are continuously being identified worldwide with exchange of the resistance genes between Enterobacteriaceae, P. aeruginosa and A. baumannii.     

鲍曼不动杆菌耐药性监测与碳青霉烯酶基因型研究

目的：对鲍曼不动杆菌耐药性及碳青霉烯酶基因型进行研究,以指导临床合理应用抗生素。方法：收集青岛市海慈医疗集团2009年6月至2010年6月从临床分离的鲍曼不动杆菌60株,用琼脂稀释法测定最低抑菌浓度（M IC）,改良Hodge试验检测碳青霉烯酶,用PCR法检测OXA-23,OXA-24,OXA-58基因,并对PCR产物进行测序。结果：①鲍曼不动杆菌检出率前两位是ICU病房和呼吸科病房,分别占32.3%和27.4%,多重耐药鲍曼不杆菌阳性率最高的是ICU,为70.6%（12/17）,其次为呼吸科病房,为35.0%（7/20）,哌拉西林、哌拉西林/他唑巴坦、头孢曲松、头孢他啶、头孢吡肟、亚胺培南、美罗培南、庆大霉索、阿米卡星、环丙沙星、左氧氟沙星、加替沙星、头孢哌酮/舒巴坦、氨曲南耐药率分别为92.3%、55.4%、88.6%、86.3%、80.3%、30.0%、35.0%、76.6%、79.6%、75.1%、87.1%、48.3%、42.0%和79.6%.②在21株耐碳青霉烯类鲍曼不动杆菌,有14株碳青霉烯酶表型阳性,检出率为66.7%,有18株PCR扩增出OXA-23基因,检出率85.7%,全部菌株blaOXA-24及blaOXA-58PCR扩增均为阴性,PCR产物测序表明与鲍曼不动杆菌（AY795964.1）blaOXA-23基因序列100%同源。结论：鲍曼不动杆菌多重耐药性严重;表型和基因型检测证实本院临床分离鲍曼不动杆菌对碳青霉烯类耐药机制主要是产OXA-23型酶。     

Distribution of blaOXA genes among carbapenem-resistant Acinetobacter baumannii nosocomial strains in Poland

Acinetobacter baumannii is an important nosocomial pathogen occurring particularly in intensive care (ICU) as well as burn therapy units (BTU). A. baumannii strains have emerged as resistant to almost all antimicrobial agents, including carbapenems. b-lactamase-mediated resistance is the most common mechanism for carbapenem resistance in this species. Carbapenem-hydrolysing class D b-lactamases - OXA are widespread among A. baumannii strains. It is suggested that ISAba1 plays an important role in drug resistance. The aims of the study were detection of OXA encoding genes and presence of ISAba1. The study included the total of 104 isolates of carbapenem-resistant A. baumannii, obtained from patients hospitalized in ICU and BTU of Specialized Hospital in Krakow. Multiplex PCR was applied for detection of selected OXA carbapenemases encoding genes. PCR analysis showed the presence of bla OXA-51-like gene and ISAba1 in all isolates. 46 strains carried bla OXA-51-like and bla OXA-23-like genes while 48 bla OXA-51-like and bla OXA-40-like genes. 3 isolates carried: bla OXA-51-like , bla OXA-23-like and bla OXA-40-like genes. 7 strains encoded an OXA-51-like carbapenemase but were negative for enzymes belonging to the other families tested. Comparative analysis of ICU and BTU isolates revealed the dominance of: bla OXA-51-like and bla OXA-40-like among ICU while bla OXA-51-like and bla OXA-23-like in BTU.     

ICU耐碳青霉烯类鲍曼不动杆菌同源性研究

目的探讨重症监护病房（ICU）耐碳青霉烯酶鲍曼不动杆菌（CRAB）之间的同源性,并了解是否存在耐药菌株的克隆流行。方法收集宁波大学附属医院ICU 2010年2月至2011年5月分离到的CRAB 40株,常规药敏试验采用K-B法。用脉冲场凝胶电泳（PFGE）分析其耐药株的同源性。结果阿米卡星的敏感率最高为100%,其次米诺环素敏感率为50%;PFGE结果显示,40株CRAB菌株分为A、B、C三型,A型22株,主要分离时段为2010年2月～3月（16株）和2011年1月-2011年2月（6株）;B型16株,主要分离时段为2010年5月-6月（16株）,C型为C1亚型和C2亚型各1株为散发型。结论调查期间CRAB主要的PFGE基因型为A型和B型菌株克隆流行,流行相关的克隆株可在病区长期生存,从而引起病区持续感染,需要积极采取感染控制措施;同时不同时段主要流行株由克隆株A变为克隆株B,推测同一个病区的流行基因型可能存在流行变迁。     

Spread of a single clone Acinetobacter baumannii strain in an intensive care unit of a teaching hospital in Turkey

Acinetobacter baumannii is an important nosocomial pathogen, especially in immunocomprimised patients and those hospitalized in intensive care units. After the first isolation of A. baumannii strains from the bronchial aspirates of two patients in the intensive care unit (ICU) of our hospital as a pure culture, screening studies were performed to define possible source(s). A. baumannii strains isolated from bronchial aspirates and blood cultures of the patients in ICU were collected as a possible part of the outbreak. A total of 23 screening samples collected from equipment (7), hands (4) and gloves (2) of the staff, and from ten different body regions of the patients in the ICU were cultured. Antimicrobial susceptibility test of the isolates was performed by the standardized disk-diffusion method. All isolates were subtyped by antibiogram, arbitrarily primed polymerase chain reaction (AP-PCR) and pulsed-field gel electrophoresis (PFGE) typing methods. A total of 26 A. baumannii strains including eight clinical and 18 screening isolates were identified. All isolates were susceptible only to meropenem, tobramycin, and imipenem. There was at least a 96% resistance rate to the other antibiotics tested. Antibiogram typing showed that 24 of the 26 isolates were epidemiologically related, two were unique. AP-PCR yielded two types, one of which had 21 isolates, the other had five. PFGE fingerprinting revealed that all isolates were clonally related, including four closely related and 22 indistinguishable strains. Based on the results of PFGE which has been accepted as a reference method it can be concluded that A. baumannii strains isolated from our intensive care unit originated from a single type of strain.     

鲍曼不动杆菌对碳青霉烯类抗生素的耐药性分析

目的了解鲍曼不动杆菌的耐药情况,并检测耐碳青霉烯类鲍曼不动杆菌的耐药基因,为指导临床合理用药、控制院内感染提供依据。方法利用K-B法检测45株鲍曼不动杆菌临床分离株的耐药情况,通过改良Hodge试验、Carba NP试验和EDTA协同试验对多重耐药鲍曼不动杆菌的碳青霉烯酶进行表型检测,并采用PCR技术检测鲍曼不动杆菌携带OXA-23和NDM-1型耐药基因的情况。结果 45株鲍曼不动杆菌临床分离株中共筛出42株多重耐药菌株;利用改良Hodge试验和Carba NP试验检出36株碳青霉烯酶阳性菌株;采用PCR扩增出OXA-23,未扩增出NDM-1。结论鲍曼不动杆菌耐药情况严重,且耐药基因OXA-23携带率高,治疗时应根据药敏试验结果合理用药。     

鲍曼不动杆菌对碳青霉烯类抗生素的耐药性及其基因的分析

目的研究23株鲍曼不动杆菌对碳青霉烯类抗生素的耐药情况及对耐药基因分析,为临床用药提供依据。方法用珠海迪尔DL-96鉴定系统进行细菌鉴定及K-B法进行药敏试验,用碳青霉烯酶4种基因的特异性引物对其进行聚合酶链反应(PCR)扩增和基因型分析,并通过网上GenBank进行比对以确定编码酶基因的类型。结果 23株鲍曼不动杆菌对哌拉西林/他唑巴坦、左旋氧氟沙星、丁胺卡那霉素、多黏菌素B的耐药率分别为80%、45%、30%、10%,对其他抗生素的耐药率均在90%以上。携带D类碳青霉烯酶OXA-23基因有18株(78%),携带OXA-51基因有15株(65%),OXA-24、OXA-58基因引物PCR扩增为阴性,随机各抽取3株OXA-23基因阳性株进行测序后通过在网上GenBank比对与OXA-23标准株99%同源,OXA-51基因阳性株与OXA-51标准株98%同源。结论耐碳青霉烯类抗生素的鲍曼不动杆菌对多黏菌素的耐药率最低,其次是丁胺卡那霉素,其中以携带OXA-23型碳青霉烯酶基因为主,应引起临床高度关注,防止在院内广泛传播。