烧伤感染的现状、对策与防治新动向

1 烧伤感染的现状2006年6月在昆山召开的第四届全国烧伤救治专题研讨会上,不同地区的烧伤中心或单位提供的微生物学调查资料中有不少共同点,其中很主要的一点就是:铜绿假单胞菌和金黄色葡萄球菌仍是烧伤检出菌中的主要细菌,也是我国近50年来大面积深度烧伤救治工作中难以清除的病原菌,不变中的变化是其耐药性不断增长。甲氧西林耐药金黄色葡萄球菌因被专门命名,人们对其认识较深刻,而革兰阴性杆菌耐药性的快速增长也不容忽视。革兰阴性杆菌对许多抗生素已由多重耐药性逐步发展为全耐药性;而且在多种新型抗生素的压力下,又筛选、激活了一些此前未被注意的机会致病菌。当前应特别注意的是鲍氏不动杆菌和嗜麦芽窄食单胞菌,它们正逐步成为医院感染的重要细菌。上述细菌毒力并非特别强,只因其存在天然耐药性,一旦过度繁殖,可能成为"无药可治"的难治菌。在此有必要强调,"医院感染"的含义是"患者住院后获得新的感     

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。     

多聚酶链反应检测细菌DNA对大鼠空、回肠吻合口瘘的早期诊断价值

目的:探讨PCR检测大鼠外周血及腹水中细菌DNA对空肠-空肠、回肠-回肠吻合口瘘的早期诊断价值。方法:健康Wistar雌性大鼠50只，随机分成5组，每组10只：A组为假手术组;B组为空肠-空肠吻合组;C组为空肠吻合口瘘组;D组为回肠-回肠吻合组;E组为回肠吻合口瘘组。采集手术前后外周血及术后腹水，抽提DNA, 比较lacZ基因和16SrRNA基因的PCR阳性率，并观察各组的病理学情况。结果:（1）C，E组术后外周血lacZ基因PCR阳性率与B，D组无显著性差异（P>0.05）;C，E组术后外周血16SrRNA基因PCR阳性率显著高于B，D组（P<0.05）。（2）C，E组腹水lacZ基因和16SrRNA基因PCR阳性率均显著高于B，D组（P<0.05）。（3）C，E组腹水lacZ基因阳性率显著高于外周血（P<0.05）;C，E组腹水16SrRNA基因阳性率与外周血无显著性差异（P>0.05）。结论:（1）PCR检测术后外周血16SrRNA基因对空、回肠吻合口瘘的早期诊断有一定意义;（2）检测术后腹水lacZ基因和16SrRNA基因对空肠-空肠、回肠-回肠吻合口瘘的早期诊断也有一定意义。     

Effect of early and late antibiotic treatment in experimental acute pancreatitis in rats

Background The clinical course in acute necrotizing pancreatitis is mainly determined by bacterial infection of pancreatic and peripancreatic necrosis. The effect of two antibiotic regimens for early and late treatment was investigated in the taurocholate model of necrotizing pancreatitis in the rat. Materials and methods Seventy male Wistar rats were divided into five pancreatitis groups (12 animals each) and a sham-operated group (10 animals). Pancreatitis was induced by intraductal infusion of 3% taurocholate under sterile conditions. Animals received two different antibiotic regimes (20 mg/kg imipenem or 20 mg/kg ciprofloxacin plus 20 mg/kg metronidazole) early at 2, 12, 20, and 28 h after induction of pancreatitis or late at 16 and 24 h after induction of pancreatitis or no antibiotics (control). Animals were examined after 30 h for pancreatic and extrapancreatic infection. Results Early and late antibiotic treatment with both regimes could significantly reduce pancreatic infection from 58 to 8–25%. However, extrapancreatic infection was only reduced by early antibiotic therapy. While quinolones also reduced bacterial counts in small and large bowel, imipenem did not. Conclusions In our animal model of necrotizing pancreatitis, early and late treatment with ciprofloxacin/metronidazole and imipenem reduce bacterial infection of the pancreas. Extrapancreatic infection, however, is reduced significantly only by early antibiotic treatment. The effectivity of early antibiotic treatment in the clinical setting should be subject to further investigation with improved study design and sufficient patient numbers.     

国产与进口头孢他啶治疗小儿细菌性下呼吸道感染的成本-效果分析

目的对国产与进口头孢他啶治疗小儿细菌性下呼吸道感染进行成本—效果分析。方法对我院2008年10月-2009年10月间患小儿细菌性下呼吸道感染且单用头孢他啶治疗的住院患者136例进行回顾性分析,根据药品不同产地将其分为A、B两组,A组给与头孢他啶（国产）60mg/（kg·d）,分2次静脉滴注;B组给与头孢他啶（进口）60mg/（kg·d）,分2次静脉滴注,两组疗程均为7d,分别计算两组病人治疗后的细菌清除率、不良反应发生率,两组的治疗有效率和总成本,计算成本-效果比。结果疗程结束后A、B两组的药物治疗成本分别为：A组236.4元、B组982.5元,组间比较存在显著性差异（P〈0.05）;治疗有效率分别为：91.30%、94.03%;A、B两组的细菌清除率分别为：86.36%、90.70%;两组不良反应发生率分别为：5.80%、2.99%,组间比较差异均无显著性（P〈0.05）;两组成本-效果比分别为：2.59、10.45。结论国产头孢他啶的成本-效果比优于进口头孢他啶,为较佳的治疗方案。     

Cerebrospinal fluid-filtration reduces TNF alpha in bacterial meningitis-CSF

A 37 year old male was admitted with the diagnosis of bacterial meningitis. Pneumococci were seen in the Gram stain of the cerebrospinal fluid. The clinical condition did not suggest severely raised intracranial pressure, there were no localizing signs and symptoms. CSF was turpid, with 20.100/3/mm³, mainly polymorphonuclear cells. Tumor necrosis factor alpha in CSp was greatly increased with 813 pg/ml. Parallel to the application of intravenous Penicillin G a CSF filtration was carried out. Within 214 h 225 ml CSF were filtrated through a Pall-filter, using a bidirectional pump. Cell count dropped to 720/3 cells/mm³, TNF-alpha to 39 pg/ml. The clinical course was uneventful, on day 12 the patient could be discharged without sequelae. CSF filtration may be a highly effective method to reduce from the CSF pathogenetically important cytokines, such as TNF-alpha, being responsible for intrathecal/meningeal inflammatory processes and triggered by cell-wall components of bacteria, e.g. pneumococci.     

Use of the microorganism Bacillus stearothermophilus as a model to evaluate toxicity of the lipophilic environmental pollutant endosulfan

Microorganisms are very powerful tools for the supply of information about the toxic effects of lipophilic compounds, since an impairment of cell growth usually occurs as a result of perturbations related, in most cases, with the partition of toxicants in membranes. The thermophilic eubacterium Bacillus stearothermophilus has been used as a model system to identify α- and β-endosulfan interactions with the membrane possibly related with the insecticide toxicity. Two approaches have been pursued: (a) bacterial growth is followed and the effects of endosulfan isomers determined; (b) biophysical studies with the fluorescent fluidity probe 1,6-diphenyl-1,3,5-hexatriene (DPH) were performed to assess the effects of α- and β-endosulfan on the organization of the membrane lipid bilayer. The effects on growth were quantitatively evaluated by determination of growth parameters, namely the lag phase, the specific growth rate and the cell density reached by cultures in the stationary phase. Growth inhibition by α and β-endosulfan dependent on the concentration is diminished or removed by the addition of 2.5 m Ca²⁺ to bacterial cultures. Fluorescence DPH polarization consistently showed opposite effects of Ca²⁺ and α- and β-endosulfan on the physical state of bacterial polar lipid dispersions.     

High level production of soluble single chain antibodies in small-scale Escherichia coli cultures

We have investigated the effect of growth and induction conditions on the production of soluble single-chain Fv antibody fragments in Escherichia coli under the control of wt lac promoter. The scFv was directed into the periplasmic space by a pelB leader sequence. Addition of sucrose to the medium gave a 15–25-fold increase in the yield of soluble scFv-phOx (3.0 mg/l) for bacterial shake-tube cultures and an increase of 80–150-fold (16.5 mg/l) for shake-flask cultures. Using flask culture in the presence of 0.4 M sucrose, a significant amount of scFv was released into the medium. We found that the scFv could be made to accumulate in the periplasm or be secreted into the medium by simply changing the incubation conditions and the concentration of the inducer. The ratio between soluble antibody fragments and insoluble scFv aggregates proved to be dependent on the strength of the promoter. Lowering the incubation temperature below 20°C had no effect on the yield of soluble antibody fragments in the periplasm, but they were no longer secreted into the medium. An example of high level production in shake-flask cultures and one-step purification by immobilized metal affinity chromatography (IMAC) is described for a soluble scFv specific for the T cell surface antigen CD3. The biological activity of the purified anti-CD3 scFv was demonstrated by flow cytometry. This method should be especially useful for the functional screening of a large number of clones in small-scale cultures.     

头孢托仑酯随机双盲对照治疗细菌性感染临床评价

为评价头孢托仑酯（ＭＥ１２０７）治疗细菌性感染的有效性和安全性，采用随机双盲对照试验和开放试验方法共治疗８０例患者，其中ＭＥ１２０７（Ａ药）与头孢克肟（Ｂ药）随机双盲各治疗２０例（呼吸系统和泌尿系统各１０对），ＭＥ１２０７开放试验治疗４０例（呼吸系统２０例、泌尿系统１０例、皮肤软组织感染１０例）。每日４００ｍｇ，疗程７～１４ｄ。ＭＥ１２０７痊愈率和有效率在对照试验中为８０％和９５％，在开放试验中为７５％和９２．５％，总痊愈率为７６．７％，总有效率为９３．３％，细菌培养阳性率为１００％，细菌清除率在对照试验和开放试验中分别为９５％和９２．５％。纸片法药敏试验中ＭＥ１２０７敏感株百分率为１００％，与头孢哌酮相同，而优于头孢克肟和头孢克洛，明显优于阿莫西林（４８．８％）。ＭＥ１２０７６０例中６例出现不良反应，表现为消化道反应３例，转氨酶升高２例，凝血酶原时间延长１例。与对照药头孢克肟相比在痊愈率、有效率、细菌清除率及不良反应发生方面均无显著性差异（Ｐ＞０．０５）。ＭＥ１２０７在每日４００ｍｇ剂量下治疗轻、中度细菌感染安全、有效。     

细菌性肝脓肿患者发生血小板减少影响因素研究

背景细菌性肝脓肿(PLA)是临床常见的内脏器官感染性疾病,既往PLA发生血小板减少的临床研究较少。目的 分析PLA患者发生血小板减少的流行病学和临床特征,并探讨发生血小板减少的影响因素。方法 纳入北京大学人民医院2011年1月至2020年12月161例因PLA住院的患者为研究对象。收集患者资料,包括年龄、性别、体质指数(BMI)、发病症状(发热、腹痛、恶心、呕吐)、既往病史信息(高血压、糖尿病、冠心病、肝胆疾病、恶性肿瘤);收集患者入院时辅助检查结果,包括白细胞计数、中性粒细胞绝对值、淋巴细胞绝对值(ALC)、单核细胞绝对值、血红蛋白、C反应蛋白(CRP)、降钙素原(PCT)、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、总胆红素(TBiL)、尿素氮(BUN)、肌酐(Scr)、白蛋白(ALB)、凝血酶原时间(PT)、活化部分凝血活酶时间、纤维蛋白原、D-二聚体(D-Dimer)、血小板计数(PLT);收集患者肝脓肿影像学检查(腹部CT或超声)结果(是否多个脓肿)、病原学检查结果(血培养、培养出肺炎克雷伯菌比例);收集患者的并发症情况及预后情况。根据外周血PLT是否<1...