The effect of amikacin and imipenem alone and in combination against an extended-spectrum beta-lactamase-producing Klebsiella pneumoniae strain

In vitro and in vivo activities of amikacin and imipenem alone, and in combination, were studied against an extended-spectrum beta-lactamase-producing Klebsiella pneumoniae strain. The strain was in vitro susceptible to both antimicrobials at 10(5) and 10(7) CFU/mL. In time-kill studies amikacin, imipenem, and amikacin plus imipenem decreased the bacterial counts; difference between the bactericidal effects was not observed. Chequerboard technique showed no interaction between the tested drugs. Mice infected with 10(7) CFU/g of the K. pneumoniae were treated by amikacin (15 mg/kg every 8 h), imipenem (40 mg/kg every 4 h), or amikacin plus imipenem for 24 h. Blood bacterial counts in the group treated with amikacin plus imipenem did not differ significantly from the groups treated with amikacin or imipenem alone. Combination of amikacin and imipenem did not demonstrate any advantage over imipenem alone either in vitro or in vivo.     

Safety and efficacy of colistin compared with imipenem in the treatmentof ventilator-associated pneumonia: a matched case–control study

Objective Our study aimed to determine the efficacy and safety of colistin in the treatment of ventilator-associated pneumonia (VAP) caused by pan-drug-resistant Pseudomonas aeruginosa or Acinetobacter baumanii. Design Pairwise, retrospective exposed–unexposed study. Setting Combined medical and surgical intensive care unit of Habib Bourguiba University Hospital (Sfax, Tunisia). Patients Sixty patients with VAP caused by pan-drug-resistant A. baumanii or P. aeruginosa matched to 60 controls with VAP caused by A. baumanii or P. aeruginosa susceptible to imipenem. All patients had normal renal function at the onset of antibiotic therapy. Interventions Case patients were treated by colistin intravenously and control patients were treated by imipenem intravenously. Measurements and results Baseline characteristics were similar between the colistin and imipenem groups. The mean duration of antibiotic therapy for VAP was 9.5 ± 3.8 days (range 5–22 days) with colistin and 8.9 ± 2.8 days (range 5–20 days) with imipenem (p = 0.32). A favorable clinical response to antibiotic therapy for VAP occurred in 45 patients (75%) in the colistin group and in 43 patients (71.7%) in the imipenem group (p = 0.68). The time to resolution of infectious parameters after the initiation of antibiotic therapy was not statistically different between the two groups. During the antibiotic course, none of the patients in either group developed renal failure. Conclusions We conclude that colistin can be a safe and effective option in the treatments of VAP caused by pan-drug-resistant P. aeruginosa or A. baumanii.     

头孢匹肟和亚胺培南对肠杆菌属和产ESBLs的大肠埃希菌、肺炎克雷伯菌稳定性的研究

目的 调查2001～2003年头孢匹肟、亚胺培南对临床分离的肠杆菌属、产ESBLs肺炎克雷伯菌、大肠埃希菌的体外抗菌活性的变化，以了解头孢匹肟、亚胺培南两种抗生素的稳定性。方法采用Vitek-32全自动微生物分析仪GNS—120药敏卡测定头孢匹肟、亚胺培南等10种抗生素对699株临床分离株的最低抑菌浓度(MIC)，同时检测肺炎克雷伯菌、大肠埃希菌产ESBLs的检出率。结果三年中，对于肠杆菌属细菌，头孢他啶、头孢曲松的体外抗菌活性有下降的趋势，而亚胺培南、头孢匹肟、氨曲南、哌拉西林／他唑巴坦的活性较为稳定。2001～2003年产ESBLs大肠埃希菌的检出率为20．9～36．8％，上升较快，产ESBLs肺炎克雷伯菌的检出率为16．7％～28．8％。头孢曲松、庆大霉素、环丙沙星、头孢匹肟、头孢他啶、氨曲南对ESBLs阳性菌抑菌浓度明显高于ESBLs阴性菌，而亚胺培南对两组的抑菌浓度没有明显差异。结论对于肠杆菌属细菌和产ESBLs肺炎克雷伯菌、大肠埃希菌，亚胺培南、头孢匹肟与喹诺酮类、氨基糖苷类、磺胺类等抗生素相比有较强的抗菌活性，且稳定性高，喹诺酮类与氨基糖苷类抗生素交叉耐药明显，且有上升的趋势。     

Risk factors and molecular epidemiology of Acinetobacter baumannii bacteremia in neonates

Background

Acinetobacter baumannii infections in neonates are not uncommon but rarely studied.

耐亚胺培南绿脓假单胞菌的体外耐药监测与基因分型研究

目的 探讨对亚胺培南耐药的绿脓假单胞菌（IRPA）的耐约特征及流行现状，以利于医院感染的监测控制。方法 采用肠杆菌科基因间重复一致序列PCR（ERIC-PCR）方法对56株重症监护病房（ICU）分离的IRPA进行分子生物学分型；采用琼脂稀释法检测8种抗菌药物对IRPA的最低抑菌浓度（MIC）。结果 56株IRPA用ERIC方法分为33刊；IRPA对5种抗菌药物的耐药率≥50．0％。结论 IRPA的多重耐药性值得关注，ICU内IRPA存在散在的克隆流行态势，应注意监控IRPA在医院暴发流行。     

耐亚胺培南铜绿假单胞菌外膜蛋白D基因突变检测

目的探讨耐亚胺培南铜绿假单胞菌临床分离株外膜蛋白D（oprD）基因突变与耐药关系.方法应用随机扩增DNA多态性分析（RAPD）技术对10株耐亚胺培南铜绿假单胞菌临床分离株进行DNA分型,并对不同克隆耐药株oprD基因编码区进行全基因扩增测序和金属酶检测.结果 10株耐亚胺培南铜绿假单胞菌均不产金属酶,可分为4个不同克隆.与X63152序列比较,所有耐药菌株oprD基因发生显著变异,变异率大于50%.30、11、9、20、31号克隆株编码区276～387 bp之间发生多处点突变,其中308 bp G→C突变使其编码的苏氨酸被丝氨酸代替,344 bp C→A突变使其编码的赖氨酸被苏氨酸代替,393～412位有20 bp DNA片段缺失,其后的核苷酸序列发生移码突变.13、21号克隆株编码区264～273位有10 bp DNA片段缺失,产生移码突变,形成终止密码子TAA（319～321 bp）.1号克隆株和22号克隆株oprD基因分别发生大片段的碱基置换和多处点突变,变异率分别为54.03%和74.89%.结论耐亚胺培南铜绿假单胞菌临床分离株oprD基因变异具有多样性.     

神经科ICU鲍氏不动杆菌医院获得性肺炎调查分析

目的 分析神经科ICU病人下呼吸道鲍氏不动杆菌(Acinetobacter baumannii,ABA)医院获得性感染病原菌分布及耐药性变化趋势,指导医院感染防控及临床抗感染治疗。方法 回顾性分析青岛大学附属医院2008年1月至2015年12月共检出医院获得性肺部感染病原菌897株,统计分析ABA医院获得性下呼吸道感染分布及耐药性情况。结果 8年间总计117例病人分离培养下呼吸道ABA医院获得性肺炎菌株122株,占期间检出细菌株总数比例为9.21%。分离多耐药ABA菌株99株,占81.14%;泛耐药菌株11株,占9.02%。检出ABA对头孢哌酮/舒巴坦的敏感性较高,119株敏感,占97.54%。对亚胺培南、美罗培南和比阿培南的耐药率较高,分别为59.02%、59.84%和71.31%。结论 神经科危重病人下呼吸道医院获得性肺部感染ABA耐药现象日趋严重。必须加强医院感染防控,合理使用抗菌药物,加强ABA耐药性监测。     

2014—2018年耐碳青霉烯类肺炎克雷伯菌分离及耐药率分析#br#

目的 通过对耐碳青霉烯类肺炎克雷伯菌(carbapenem-resistant Klebsiella pneumoniae, CRKP)和非耐碳青霉烯类肺炎克雷伯菌的分离结果和耐药性分析,为临床提供合理治疗方案。方法 回顾性对比分析2014年1月—2018年12月分离出的284株CRKP和2272株非CRKP的标本来源、病区分布和耐药性。数据分析采用Whonet5.6统计软件,使用 SPSS 20.0软件进行差异显著性分析,耐药率比较采用χ2检验。结果 2014—2018年5年CRKP分离率分别为0、0.6%、0.2%、3.2%和26.5%,平均分离率为11.1%;病区分布主要为重症监护病房(ICU)、干部保健病房、神经内科、呼吸内科、肿瘤外科,构成比分别为33.8%、26.1%、8.8%、7.0%和4.9%。ICU的CRKP分离率明显高于非ICU(χ2=101.514, P<0.05),二者比较差异具有显著性。CRKP标本来源主要是痰液,构成比达到48.6%。CRKP出现多重耐药,CRKP对常用的革兰阴性抗菌药物头孢菌素类、氟喹诺酮类、碳青霉烯类耐药率均超过95%,对氨基糖苷类的耐药率也超过90%;而非CRKP耐药率较低,对所有11种抗菌药物耐药率<28.6%,非CRKP对11种抗菌药物的耐药率均低于CRKP,且差异有显著性(P<0.05)。结论 CRKP分离率和耐药率较高,CRKP的耐药率明显高于非CRKP,检验科应及时报告CRKP的分离和耐药情况,加强抗菌药物的管理,强化消毒、隔离等感染控制措施。     

Therapeutic drug monitoring of imipenem and the incidence of toxicity and failure in hospitalized patients: a retrospective cohort study

Objectives

Therapeutic drug monitoring (TDM) of beta-lactam antibiotics is increasingly employed to ensure adequate antibiotic exposure and slow emergence of resistance. Imipenem's therapeutic range has not been defined; we report plasma concentrations and clinical outcomes of patients receiving imipenem for bacterial infections.