耐亚胺培南铜绿假单胞菌的临床分离及耐药机制分析

目的：了解我院耐亚胺培南铜绿假单胞菌（IRPA）的临床分布情况,并探讨其耐药机制。方法：对2009年1月～2010年12月我院住院患者临床分离的非重复性IRPA的数据资料进行统计分析,采用PCR方法检测金属酶基因和外膜通道蛋白基因。结果：从404株铜绿假单胞菌中共分离出100株IRPA,分离率为24.75%。其中90株（90.0%）IRPA来源于下呼吸道痰液标本;IRPA主要来源于重症医学科（ICU）;IRPA对阿米卡星最敏感率为73.0%（耐药率为27.0%）,其次是哌拉西林/他唑巴坦（敏感率为63.0%）,哌拉西林（敏感率为59.0%）,庆大霉素（敏感率为58.0%）,头孢他啶（敏感率为57.0%）,其余药物的敏感率均〈50.0%。仅1株IRPA检测出IMP基因阳性（1.0%）,测序为IMP-9型金属酶基因,其余金属酶基因均未检出;oprD2基因缺失的IRPA有65株（65.0%）。结论：我院IRPA主要是由于外膜通道蛋白oprD2缺失引起,且已有IMP-9型IRPA在我院流行,需引起重视。     

KPC-2基因在克雷伯菌属中传播机制研究

目的 研究克雷伯菌属对亚胺培南耐药机制以及KPC-2基因在克雷伯菌属中传播机制。方法 收集四川大学华西医院两个阶段（2009～2010年和2012～2013年）分离的对亚胺培南耐药的克雷伯菌属细菌。琼脂稀释法测定亚胺培南最低抑菌浓度(MIC),CARB ChromID平板和改良Hodges试验检测碳青霉烯耐药表型,PCR检测细菌的KPC-2基因表达。质粒接合试验检测质粒传播性。随机引物扩增多态性DNA（RAPD）方法和肠杆菌基因间重复一致序列聚合酶链反应（ERIC-PCR）技术分别用于分析质粒和菌株的同源性。结果 第一阶段筛选并确证耐亚胺培南的3株产酸克雷伯菌首先获得碳青酶烯类抗生素耐药性,第二阶段筛选并确证耐亚胺培南的7株肺炎克雷伯菌出现相同的获得性耐药。PCR显示10株细菌均携带KPC-2型基因。质粒接合试验显示产酸克雷伯菌中携带KPC-2基因的质粒可以传递到受体菌,且与KPC-2基因阳性的肺炎克雷伯菌中携带的质粒具有同源性。ERIC-PCR结果显示7株KPC-2基因阳性的肺炎克雷伯菌具有同源性。结论 四川大学华西医院分离的对亚胺培南耐药的肺炎克雷伯菌和产酸克雷伯菌主要耐药机制是产生KPC-2型碳青霉烯酶。产酸克雷伯菌中携带KPC-2基因质粒,该质粒具有传递性且与肺炎克雷伯菌携带质粒相同。肺炎克雷伯菌中耐药株的传播形式为同一克隆传播,而在克雷伯菌属中不同菌种间耐药传播途径为同一质粒的水平传播。     

亚胺培南耐药的铜绿假单胞菌中Ⅰ类整合酶基因的研究

目的了解我院临床分离的耐亚胺培南（IMP）的铜绿假单胞菌（PA）中Ⅰ类整合酶基因（intIl）和耐消毒剂-磺胺相关基因（qacE△1-sulI）的存在状况,追溯我院耐亚胺培南铜绿假单胞菌（IRPA）的来源及其耐药机理。方法采用VITEK-AMS60全自动微生物仪进行菌株鉴定和药敏试验,随机挑选自临床分离的60株铜绿假单胞菌（其中30株IMP耐药的PA,30株IMP敏感的PA）。采用聚合酶链反应（PCR）技术及序列分析法检测I类整合子遗传标记（intI1和qacE△1-sulI）基因。结果IMP耐药组对抗生素的耐药率明显高于IMP敏感组;30株IMP耐药的PA中有23株（76．7％）intI1阳性。11株（36．7％）qacE△1一sulI阳性;另30株IMP敏感的PA中有12株（40．O％）intll阳性,3株（10．0％）qacE△1-sulI阳性．阳性基因主要来自神经外科,其次是神经内科和外科ICU病房。结论I类整合子遗传标记基因（intIl和qacE△l-sulI）与PA的耐药和多重耐药具有相关性,特别是IRPA中intIl基因携带率很高,提示intIl基因可能是PA耐IMP及多重耐药的一个重要原因．临床应合理使用抗生素,减少耐药菌株的产生,同时对重点科室的感染控制措施。加强对耐药基因在病原菌种属间传播和扩散的监测工作．     

亚胺培南/西司他丁钠对重症感染的疗效观察

目的观察亚胺培南/西司他丁钠在重症感染中的疗效. 方法将重症感染80例分两组,即亚胺培南/西司他丁钠组48例和对照组32例;分析病情、病种分布、治疗转归、细菌培养. 结果观察组机械通气34例41例次,死亡10例; 对照组机械通气9例11例次,死亡9例;观察组较对照组更严重,呼吸机应用例数明显高于对照组,P<0.05;亚胺培南/西司他丁钠组有效率87.5%,对照组有效率68.8%,差异有显著性;用药后真菌培养观察组11株,对照组10株,两组差异无显著性. 结论重症感染经验性治疗将亚胺培南/西司他丁钠作为起始用药,可防止病情迅速恶化,随后根据病原学及临床效果降阶梯换用针对性抗生素有良好效果.     

血必净注射液联合亚胺培南治疗肝硬化并发自发性细菌性腹膜炎的临床研究

目的探究血必净注射液联合亚胺培南治疗肝硬化并发自发性细菌性腹膜炎的临床疗效。方法选取2013年8月—2015年8月黄河三门峡医院消化内科收治的肝硬化并发自发性细菌性腹膜炎患者88例,随机分为对照组和治疗组,每组各44例。对照组患者腹腔穿刺放液≤2 000 m L/d,放液后给予注射用亚胺培南西司他丁钠0.5 g/次,1次/d,同时静脉滴注注射用亚胺培南西司他丁钠,0.5 g加入到0.9%生理盐水100 m L中,3次/d。治疗组在对照组治疗基础上静脉滴注血必净注射液,50 m L加入到0.9%生理盐水100 m L中,1次/d。两组均连续治疗7 d。观察两组的临床疗效,比较两组发热、腹胀、腹痛、腹部压痛和反跳痛等临床症状消失时间。观察两组并发症的发生率,同时比较两组治疗前后白细胞(WBC)、C反应蛋白(CRP)、降钙素原(PCT)、肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)的变化。结果治疗后,对照组和治疗组的总有效率分别为75.00%、90.91%,两组比较差异有统计学意义(P0.05)。治疗组发热、腹胀、腹痛、腹部压痛和反跳痛等临床症状消失时间均显著短于对照组,两组比较差异具有统计学意义(P0.05)。两组WBC、CRP、PCT、TNF-α、IL-6均较治疗前显著降低,同组治疗前后差异具有统计学意义(P0.05);且治疗7 d后治疗组这些观察指标显著低于对照组,两组比较差异具有统计学意义(P0.05)。对照组和治疗并发症的总发生率分别为18.18%、4.55%,两组比较差异具有统计学意义(P0.05)。结论血必净注射液联合亚胺培南治疗肝硬化并发自发性细菌性腹膜炎的临床疗效显著,可以显著缓解临床症状,降低并发症的发生率,还可以降低血清炎症因子的表达,具有一定的临床推广应用价值。     

Seizures in the critically ill: the role of imipenem

PURPOSE: To determine the risk of seizures in critically ill patients receiving the antibiotic imipenem, a broad-spectrum antibiotic that has been associated with seizures. Reports generally have not considered other contributing factors such as dose, seizure history, and morbidity index of the underlying illness necessitating the antibiotic. METHODS: Charts of all patients in a 450-bed municipal hospital who received imipenem in a 6-month period, as determined by pharmacy records, were reviewed for dosage and duration of imipenem use, occurrence of seizures. and mortality outcome. Attention was paid to demographic features; pattern of seizure occurrence during, before, and after imipenem use; renal function; and correction for dosage based on size. RESULTS: Seventy-five charts were reviewed. Sixty-three patients had no seizures during the hospitalization, four had seizures while receiving imipenem, and eight had seizures during the hospitalization but before or after imipenem use. The incidence of seizures was 4/1,000 patient-days on, and 3.9/1,000 patient-days off imipenem (not significant). The risk of seizure in both groups was considerably higher in those patients with a history of seizures before hospitalization. The presence of other factors that could contribute to increased concentration of imipenem in the brain, such as renal failure or acute stroke, did not contribute to seizure incidence. Metabolic derangement, anoxia, and phenytoin discontinuation did contribute to seizure incidence. CONCLUSIONS: Seizure incidence is increased in all critically ill patients (16% of patients studied), but with no added risk during the period patients received imipenem. Determining the proper dose based on a patient's body mass, correction of dose in the presence of renal failure, and avoidance of excess of 2 g/day of imipenem removes any added risk for seizures from imipenem. Despite experimental data to suggest action of imipenem on the glutamate/N-methyl-d-aspartate receptor, or interference with binding to the gamma-aminobutyric acid receptor, and early clinical studies that warned against its use because of seizure risk, we found that careful use of this antibiotic is safe.     

汕头地区耐亚胺培南铜绿假单胞菌耐药分析

目的：了解汕头地区对亚胺培南耐药的铜绿假单胞菌（PA）的耐药情况及耐药机制。方法：收集临床分离耐亚胺培南的PA共141株,双纸片协同实验检测金属酶表型,PCR法检测外膜孔蛋白OprD2和金属β内酰胺酶（IMP、VIM、SPM）基因。结果：耐亚胺培南的铜绿假单胞菌均为多重耐药茵,对头孢哌酮／舒巴坦的耐药率较低,未发现产金属酶菌株,仅22株菌株扩增出OprD2基因。结论：头孢哌酮／舒巴坦可作为本地区临床治疗耐亚胺培南铜绿假单胞茵所致感染的首选经验用药,OprDa表达减少或不表达可能是临床分离铜绿假单胞茵对亚胺培南耐药的主要机制。     

Effects of some excitatory amino acid antagonists on imipenem-induced seizures in DBA/2 mice

The behavioural and convulsant effects of imipenem (Imi), a carbapenem derivative, were studied after intraperitoneal (i.p.) or intracerebroventricular (i.c.v.) administration in DBA/2 mice, a strain genetically susceptible to sound-induced seizures. The anticonvulsant effects of some excitatory amino acid antagonists and muscimol (Msc), a GABA_A agonist, against seizures induced by i.p. or i.c.v. administration of Imi were also evaluated. The present study demonstrated that the order of anticonvulsant activity in our epileptic model, after i.p. administration, was (+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)-cyclohepten-5,10-imine maleate (MK-801) > (±)(E)-2-amino-4-methyl-5-phosphono-3-pentenoate ethyl ester (CGP 39551) > 3-((±)-2-carboxypiperazin-4-yl)propenyl-1-phosphonic acid (CPPene) . 3-((±)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CCP) > 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(F)-quinoxaline (NBQX). Ifenprodil, a compound acting on the polyamine site of NMDA receptor complex was unable to protect against seizures induced by Imi, suggesting that the poliamine site did not exert a principal role in the genesis of seizures induced by Imi. In addition, the order of anticonvulsant potency in our epileptic model, after i.c.v. administration, was CPPene > MK-801 ? Msc ? (−)-2-amino-7-phosphonic acid (AP7) > γ-D-glutamylaminomethylsulphonate (γ-D-GAMS) > NBQX > kynurenic acid (KYNA) > 6-cyano-7-nitro-quinoxaline-2,3-dione (CNQX). The relationship between the different site of action and the anticonvulsant activity of these derivatives was discussed. Although the main mechanism of Imi induced seizures cannot be easily determined, potential interactions with the receptors of the excitatory amino acid neurotransmitters exists. In fact, antagonists of excitatory amino acids are able to increase the threshold for the seizures or to prevent the seizures induced by Imi. In addition, Imi acts on the central nervous system by inhibition of GABA neurotransmission and Msc, a selective GABA_A agonist, was able to protect against seizures induced by Imi.     

老年人亚胺培南耐药铜绿假单胞菌耐药性研究

目的 明确我院老年病人临床分离铜绿假单胞菌的耐药性、同源性及耐碳青霉烯菌株的基因型。方法 收集我院2006年5月-2009年5月自临床老年病人分离的262株铜绿假单胞菌,纸片扩散法测定其对16种抗菌药物的耐药性;琼脂稀释法和E test法测定耐碳青霉烯菌株对14种抗菌药物的MIC值,PCR扩增及克隆测序分析金属酶基因型。脉冲场凝胶电泳(PFGE)分析携带金属酶基因型菌株的同源性。结果 262株铜绿假单胞菌中筛选到104株耐碳青霉烯。104株耐碳青霉烯铜绿假单胞菌对氨苄西林/舒巴坦、头孢哌酮/舒巴坦两个含舒巴坦制剂药物耐药率分别为78.9％和35.9％,对多黏菌素E耐药率最低为6.0％,对米诺环素耐药率58.3％,其余抗菌药物耐药率均大于70.0％;104株亚胺培南耐药铜绿假单胞菌中12株携带金属酶基因,10株检测到有携带VIM-2基因的1类整合子。PFGE分型中12株菌株属于5个克隆株。结论 在我院流行的亚胺培南耐药铜绿假单胞菌中,金属酶基因不是最主要的基因型,金属β-内酰胺酶均为VIM-2型金属酶,耐药基因盒分布于不同的1类整合子中,整合子播散是最主要的流行方式。     

碳青霉烯类抗生素诱导耐药铜绿假单胞菌外膜蛋白D2表达与编码基因多点突变

目的 探讨对碳青霉烯类抗生素耐药的铜绿假单胞菌编码外膜蛋白D2(OprD2)基因变异与OprD2表达的关系.方法 由临床分离敏感铜绿假单胞菌,使用不同浓度亚胺培南与美罗培南含药琼脂平板法筛选耐药菌株.应用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)、凝胶成像系统分析OprD2.应用聚合酶链反应及测序分析OprD2基因编码区.结果 人工诱导能产生出与临床分离株一样的对碳青霉烯类抗生素耐药的菌株.在SDS-PAGE图谱上亚胺培南与美罗培南耐药株与同源敏感株相比均有OprD2的减少.测序结果显示在多株耐药菌中,OprD2基因编码区3个基因位点同时出现碱基突变:在+84位点产生突变,胞嘧啶突变为胸腺嘧啶(C→T);在+401位点突变(C→A),造成第134位氨基酸苏氨酸突变为天冬氨酸(Thr→Asp);在+959位点突变(A→G),造成第320位氨基酸赖氨酸突变为精氨酸(Lys→Arg).结论 同时出现3个或更多的碱基点突变可能导致铜绿假单胞萧OprD2缺失或表达减少,可能是对碳青霉烯类抗生素产生耐药性的原因.