对产超广谱β-内酰胺酶细菌的检测和耐药性分析

目的 :了解临床病人标本中产超广谱 β-内酰胺酶 (ESBLs)细菌的检出率及耐药情况 ,以指导临床合理使用抗生素。方法 :用NCCLS规定的表型确证试验进行ESBLs的检测。结果 :ESBLs的总阳性率为 19.9% ,大肠埃希菌为 18. 1% ,肺炎克雷伯菌为 2 2 . 7%。产ESBLs菌对 8种抗生素的耐药率与不产ESBLs菌相比有显著差异 (P <0 0 5 ) ,对 3种抗生素 (亚胺培南、头孢哌酮 /舒巴坦、哌拉西林 /他唑巴坦 )的耐药率与不产ESBLs菌相比无显著差异。结论 :临床实验室应加强对ESBLs的检测 ,治疗产ESBLs菌引起的感染 ,应选用头霉素、碳青霉烯类及含酶抑制剂的复合抗生素。     

临床分离4364株细菌的分布特征和耐药性变迁分析

目的了解2003—2005年分离的4364株细菌的分布特征及耐药性变迁，为合理使用抗菌药物提供依据。方法大多数分离细菌的鉴定和药敏试验利用BD Phoenix仪，少数利用手工鉴定和K-B法药敏试验。数据分析用WHONET5．0软件。结果葡萄球菌对万古霉素和替考拉宁的敏感率一直为100％，对其他抗菌药物的耐药率大多逐年上升，甲氧西林耐药率也逐年上升，金黄色葡萄球菌从40．8％上升到61．6％，表皮葡萄球菌从69．7％上升到79．8％。G^-杆菌合计，大多数抗菌药物的耐药率逐年升高，耐药率一直低于30％的为美洛培南、亚安培南、头孢哌酮／舒巴坦、哌拉西林-他唑巴坦和头孢他啶。大肠埃希菌和肺炎克雷伯菌体外产ESBLs的检出率一直居高不下，为29．5％～45．5％。结论本院肠杆菌科产ESBLs比例、葡萄球菌甲氧西林耐药率和非发酵菌碳青霉烯类耐药率均较高，应加强抗菌药物的合理使用和采取有效的隔离措施以降低耐药率及多重耐药菌的扩散。     

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。     

头孢米诺和其他14种抗菌药物对产与不产超广谱β-内酰胺酶菌株抗菌活性比较

目的测定头孢米诺和其他14种抗菌药物对产与不产超广谱β-内酰胺酶(ESBLs)菌株的体外抗菌活性.方法采用琼脂稀释法测定头孢米诺和其他14种抗菌药物的最小抑菌浓度(MIC),纸片确证法检测ESBLs.结果对110株产ESBL的大肠埃希菌和肺炎克雷伯菌,未发现亚胺培南耐药的菌株,除亚胺培南外,头孢米诺比其他的13种抗生素有较低的耐药性,其耐药率为7.3%,MIC50和MIC90值范围分别为0.5～1 mg/L和2～32 mg/L;对40株不产ESBLs的大肠埃希菌和肺炎克雷伯菌、头孢米诺、头孢美唑、头孢他啶、头孢噻肟、头孢曲松、头孢哌酮、头孢吡肟及亚胺培南,有相似的体外抗菌活性,其敏感率均为100%,MIC50和MIC90值范围分别为0.032～0.5 mg/L和0.064～4 mg/L.结论对产ESBL的大肠埃希菌和肺炎克雷伯菌,未发现亚胺培南耐药的菌株,头孢米诺比其他β-内酰胺类,庆大霉素和氟喹诺酮类有较高的体外抗菌活性;对不产ESBLs的菌株,头孢米诺、头孢美唑、头孢他啶、头孢噻肟、头孢曲松、头孢吡肟及亚胺培南有相同的抗菌活性,没有耐药的菌株发现.     

Multidrug resistance mediated by co-carriage of extended-spectrum beta-lactamases,AmpC and New Delhi metallo-beta-lactamase-1 genes among carbapenem-resistant Enterobacteriaceae at five Indian medical centres

In this study, we evaluated the coexistence of extended-spectrum beta-lactamases (ESBL), AmpC and New Delhi metallo-beta-lactamase-1 (NDM-1) genes among carbapenem-resistant Enterobacteriaceae (CRE) recovered prospectively from patients at multiple sites. The study included 285 CRE strains from 2782 Gram-negative Bacilli collected from multiple centres during 2007–2010, of which 87 were characterised. Standard and reference laboratory methods were used for resistance determination. Detection of bla_NDM-1, bla_AmpC, bla_TEM, bla_SHV and bla_CTX-M was done by polymerase chain reaction. High levels of antimicrobial resistance observed among study isolates. Co-carriage of ESBLs, AmpC and NDM-1 was 26.3%. Nosocomial origin among the co-carriage isolates was 64.3%, with 9.2% associated mortality.     

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.     

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.     

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。