60株肺炎克雷伯菌多重耐药性及主要耐药基因的研究

目的：了解临床分离的肺炎克雷伯菌耐药性及主要耐药基因存在状况。方法：采用Micmsean微生物鉴定仪，微量肉汤稀释法测定肺炎克雷伯菌对21种抗生素的敏感性。采用聚合酶链反应(PCR)及测序技术分析超广谱B内酰氨酶(ESBLs)，质粒介导的AmpC酶和氨基糖苷类修饰酶基因型。结果：肺炎克雷伯菌对亚胺培南全部敏感，对其他抗生素均有不同程度的耐药。60株全部扩增出TEM基因，有25株检出CTX-M-I群基因，有54株扩增出DHA基因，59株检出共3种氨基糖苷类修饰酶基因。且有22株同时携带2～6种耐药基因。对其中4株细菌进行基因型测序，证实CTX-M-I群扩增产物均为CTX-M-3；DHA扩增产物均为DHA-1；氨基糖苷类修饰酶基因分别为aac(3)-Ⅱ、aac(6′)-I和ant(3″)-I。其中CTX-M-3(AY635141)、DHA-1(AY635140)已注册GenBank(括号内为GenBank注册号)。结论：临床分离的肺炎克雷伯菌为多重耐药菌，同时存在2～6种耐药基因。     

超广谱β-内酰胺酶的流行状况及防治措施

超广谱β-内酰胺酶(extended-spectrum beta-lactamases,ESBLs)被证实对广谱的β-内酰胺酶类抗生素耐药,包括三代头孢菌素(如头孢他啶).ESBLs主要在常见的院内病原体(如大肠埃希菌、肺炎克雷伯菌)中被发现.因ESBLs表达导致的耐药性迅速增加,给公共卫生事业带来了严重和持续的威胁.本文综述了ESBLs的分类、产生菌、耐药机制、检测方法 发、流行趋势、危险因素及干预方法 发等.     

用VITEK检测细菌产超广谱β-内酰胺酶

目的 了解大肠埃希菌和肺炎克雷伯菌产超广谱β-内酰胺酶(ESBLs)菌株的构成比及耐药特征.方法 用VITEK-32、GNI 卡、GNS卡进行菌种鉴定、ESBLs检测和药敏试验.结果 363株大肠埃希菌和178株肺炎克雷伯菌ESBLs产生率分别为55.6%和20.8%;产ESBLs株对多种抗生素的耐药性明显高于非产ESBLs株;产ESBLs株对β-内酰胺类药物100.0%耐药;对碳青酶烯类药物100.0%敏感.结论 VITEK-32能快速完成大肠埃希菌和肺炎克雷伯菌的鉴定、ESBLs检测和药敏试验.     

产ESBLs肺炎克雷伯菌ESBLs基因与可移动遗传元件相关性分析

目的 了解产超广谱β-内酰胺酶(extended spectrum beta-lactamases, ESBLs)肺炎克雷伯菌(Klebsiella pneumoniae, Kpn)ESBLs基因与可移动遗传元件(mobile genetic elements, MGEs)标记基因的携带情况及其相关性。方法 收集从住院患者标本中分离出的产与非产ESBLs Kpn非重复菌株各100株，采用PCR检测细菌中4种ESBLs基因与8种MGEs标记基因，并作指标聚类分析。结果 产ESBLs Kpn中，ESBLs基因阳性率高达100%；MGEs标记基因以IS26、ISEcp1、traA、trbC和intI1基因为主，阳性率高于非产ESBLs Kpn(P<0.05)；ESBLs基因与MGEs标记基因的同时检出率明显高于非产ESBLs Kpn (P<0.05)；基因blaSHV-12、blaOXA-1与MGEs基因tnpU、tnp513、merA、intI1相关联，基因blaTEM-1、blaCTX-M-125与MGEs基因ISEcp1、IS26、traA相关联。产与非产ESBLs Kpn均没有只检出MGEs标记基因的菌株。结论 产ESBLs Kpn ESBLs基因和MGEs标记基因携带率高，两者存在相关性，可能是产ESBLs Kpn出现多重耐药的重要原因；MGEs标记基因在Kpn中可能不是单独存在的。     

Epidemiology,Risk Factors,and Outcome of Bloodstream Infection Within the First Year After Kidney Transplantation

BackgroundMulti-drug resistant organisms have been emerging among kidney transplant (KT) recipients with bloodstream infections (BSI). The investigation for epidemiology, risk factors and outcome of these infections following KT was initiated.Materials and MethodsA retrospective study of all adult KT recipients who developed a BSI within the first year after KT in 2016 at a single transplant center was conducted. The cumulative incidence of BSI was estimated with Kaplan-Meier methodology. Clinical characteristics and outcome were extracted. Risk factors were analyzed with Cox proportional hazards models.ResultsAmong 171 KT recipients, there were 26 (15.2%) episodes of BSI. Fifty-nine percent were men and the mean ± SD age was 43 ± 12 years. The cumulative incidence of BSIs was 10.1% at 1 month, 13.5% at 6 months, and 15.2% at 12 months. Gram-negative bacteria were responsible for 92% of BSIs, Escherichia coli was the most common pathogen (65%) followed by Klebsiella pneumoniae (11%). Among those, 71% were resistant to extended-spectrum cephalosporins. The genitourinary tracts were the predominant source of BSIs (85%). The second kidney transplantation (HR, 4.55; 95% CI, 1.24–16.79 [P = 0.02]) and receiving induction therapy (HR, 3.05; 95% CI, 1.15‐8.10 [P < 0.03]) were associated with BSI in a multivariate analysis. One patient (4%) developed allograft rejection, allograft failure and death from septic shock.ConclusionsOne out of six KT recipients could develop BSI from gram-negative bacteria within the first year after transplant, particularly in those that received the second transplantation or induction therapy.     

耐亚胺培南鲍曼不动杆菌医院感染聚集性病例分析

目的探讨耐亚胺培南鲍曼不动杆菌(IRAB)引起医院感染聚集性病例(NICC)的原因及耐药机制。方法对IRAB引起的NICC的临床资料、药敏结果进行分析。采用纸片扩散(K-B)法进行药敏试验,双纸片增效法检测金属β内酰胺酶(MBL)。结果 IRAB NICC均发生在5月,均曾入住过重症监护室(ICU);其中危重患者7例,发生医院感染前,9例患者均有使用3种以上抗菌药物史。MBL检测均为阳性;对临床常用治疗AB的药物均耐药。结论 IRAB NICC的发生与患者易感性、患有严重的基础疾病、高龄、隔离与消毒、病区医院感染监控、抗菌药物使用及AB的生物学特性等有关,碳青霉烯类耐药机制为产生了MBL。     

Characterization of cephalosporin-resistant clinical Enterobacteriaceae for CTX-M ESBLs in Bahrain

ObjectiveTo detect the presence of specific CTX-M class of extended spectyum β-lactamases (ESBLs) in a collection of cephalosporin-resistant Enterobacteriaceae isolates from Bahrain.MethodsA subset of 80 cephalosporin-resistant Enterobacteriaceae collected from Salmaniya Medical Complex, Bahrain, were characterized further for the presence of specific genogroups of CTX-M β-lactamases by multiplex- and monoplex- PCRs. The primers used for the multiplex and monoplex PCRs were of genogroups- 1, 2, 8, 9 and 25. Sequencing of the representative isolates was performed to find the circulating CTX-M-types.ResultsA total of 93.8% (75/80) isolates showed the amplicons corresponding to any of the genogroups (1, 2, 8, 9, 25) and the remaining 6.2% isolates turned out negative in multiplex PCR. Some of the isolates demonstrated multiple bands corresponding to the sizes of different genogroups. Further confirmation with respective monoplex PCR on these 75 isolates demonstrated that 93.3% (70/75) harbored CTX-M genogroup-1 and 6.7% (5/75) harbored genogroup-9. We did not find the presence of genogroups 2, 8, and 25 in these isolates by monoplex PCR. Sequencing results of genogroup-1 isolates demonstrated the presence of CTX-M-15-like ESBL, however, discrepant results were noticed in genogroup-9 isolates, sequencing showed them as CTX-M-55-like ESBL.ConclusionsThis is the first report from Bahrain characterizing the CTX-M genogroups of ESBLs and reporting the emergence of bla_CTX-M-55-like gene in this region.     

铜绿假单胞菌耐药性分析及分子流行病学研究简

目的 分析铜绿假单胞菌（PA）耐药现状及耐药基因情况.方法收集2009~2012年临床分离的PA 305株.K-B法进行药敏试验,并检出产ESBLs菌株及耐碳青霉烯的PA,用聚合酶链反应（PCR）对产ESBLs菌株进行TEM、SHV、CTX-M基因检测,对耐碳青霉烯PA进行VIM、IPM、OXA-23基因检测.结果 3年中PA对亚胺培南、美罗培南、头孢他啶、左氧的耐药率呈上升趋势,氨曲南、阿米卡星的耐药率呈下降趋势,305株PA中共检出48株产ESBLs,57株耐碳青霉烯.PCR检测出5株PA含TEM基因,2株含SHV基因.CTX-M、VIM、IPM、OXA-23基因检测均为阴性.结论 产ESBLs是我院耐药PA的重要原因,耐碳青霉烯的PA不含VIM、IPM、OXA-23基因.     

Amp C酶检测方法的探讨

目的 建立简便检测肠杆菌科细菌中Amp C酶的方法。方法 分别采用双纸片确证法和多剂量协同法检测35株大肠埃希菌和肺炎克雷伯菌,并用三维试验和Amp C酶酶量直接测定法进行对比,同时检测这些菌产ESBL的情况。结果 双纸片确证法检测出12株Amp C酶,不受ESBL的干扰,与直接酶量检测法完全一致,敏感性高于三维试验,多刑量协同法敏感性较差。结论 双纸片确证法可作为临床检测Amp C酶的方法。