血培养阳性混合菌感染的病原菌分布及耐药性分析

目的探讨血培养阳性混合菌感染的病原菌的分布及对常用抗菌药物的耐药情况,以指导临床合理用药。方法收集2010~2013年首都医科大学附属北京友谊医院临床床检验中心分离血培养阳性的混合菌感染病原菌,病原菌鉴定采用生物梅里埃VITEKcompact2自动鉴定系统,药敏试验采用肉汤微量稀释法。结果血培养阳性的混合菌感染病例共分离原菌102株共51组混合菌每组均为两种菌,混合感染菌株组合前3位的分别是大肠埃希菌+屎肠球菌8例(15.7%),大肠埃希菌+肺炎克雷伯菌、大肠埃希菌+金黄色葡萄球菌和铜绿假单胞菌+金黄色葡萄球菌各3例(5.9%)。鲍曼不动杆菌+大肠埃希菌、鲍曼不动杆菌+屎肠球菌,大肠埃希菌+铜绿假单胞菌、粪肠球菌+铜绿假单胞菌,屎肠球菌+肺炎克雷伯菌各2例(3.9%)。革兰阴性杆菌60株(58.8%),革兰阳性球菌38株(37.3%),真菌4株(3.9%)。前5位的菌分别是大肠埃希菌21株(20.6%),屎肠球菌16株(15.7%),铜绿假单胞菌10株(9.8%),鲍曼不动杆菌9株(8.8%),肺炎克雷伯菌和金黄色葡萄球菌各8株(8.1%)。耐甲氧西林金黄色葡萄球菌(MRSA)的检出率为75%,耐万古霉素屎肠球菌(VRE)为18.8%。结论血培养阳性混合菌感染以革兰阳性菌合并革兰阴性菌和两种革兰阴性菌合并感染两种组合为主,革兰阴性菌所占比率高于革兰阳性菌,病原菌的耐药情况比较严重,应定期对病原菌的耐药性进行监测,以便指导临床合理应用抗生素。     

枸杞子浸出液对临床分离耐药菌体外抗菌活性的研究

目的探讨枸杞子浸出液对临床分离耐药菌(金黄色葡萄球菌、大肠埃希菌、粪肠球菌、肺炎克雷伯菌、白色念珠菌)的体外抑菌作用。方法制备不同浓度枸杞子浸出液,采用稀释法测定浸出液对临床分离耐药菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。结果不同浓度枸杞子浸出液对耐药菌均有一定程度抑菌效果,对金黄色葡萄球菌、大肠埃希菌和粪肠球菌的抑菌作用强,对肺炎克雷伯菌和白色念珠菌的相对较弱。结论枸杞子不同浓度浸出液对临床分离耐药菌有明显的体外抑菌效果,为进一步全面开发枸杞子药物价值提供依据。     

腹膜透析院内腹腔感染患者菌群分布、耐药性及相关因素分析

目的探讨腹膜透析院内腹腔感染患者菌群分布、药敏结果及危险因素,并且制订相应的措施。方法选取2018年3月至2019年3月在该院进行治疗的53例腹膜透析院内腹腔感染患者为腹腔感染组,选取同期来该院进行腹膜透析未发生腹腔感染患者67例为对照组,检测腹腔感染组患者菌群分布及药敏结果,对腹腔感染的相关因素进行分析。结果53例腹腔感染组患者中分离出病原菌76株,其中革兰阴性菌41株(53.95%),革兰阳性菌32株(42.11%),真菌3株(3.95%);主要病原菌为大肠埃希菌(15.79%)、肺炎克雷伯菌(13.16%)、屎肠球菌(13.16%)、粪肠球菌(11.84%)、金黄色葡萄球菌(25.83%);大肠埃希菌和肺炎克雷伯菌等革兰阴性菌对头孢哌酮/舒巴坦、亚胺培南、美罗培南较为敏感,耐药率≤20%;屎肠球菌、粪肠球菌、金黄色葡萄球菌等革兰阳性菌对万古霉素、利奈唑胺较为敏感,耐药率≤20%;腹膜透析院内感染患者年龄、透析时长、原发病与发生腹腔感染具有相关性(P<0.05)。结论造成腹膜透析院内腹腔感染的主要病原菌为大肠埃希菌、肺炎克雷伯菌、屎肠球菌、粪肠球菌和金黄色葡萄球菌,临床上可根据药敏试验结果选择相应的抗菌药物。患者年龄、透析时长、原发病与腹膜透析患者发生腹腔感染有关。     

2015年四川省儿童患者病原菌分布与耐药性监测

目的分析2015年四川地区儿童患者病原菌的分布及药敏情况。方法采用仪器结合手工的方法对细菌进行鉴定及药敏实验,并用WHONET5.6软件进行统计分析。结果四川地区儿童患者病原菌主要来源于痰液(70.6%)、血液(7.7%)及分泌物(6.3%)。阳性球菌主要以金黄色葡萄球菌(17.93%)、肺炎链球菌(15.09%)为主,阴性杆菌主要以大肠埃希菌(15.17%)、流感嗜血杆菌(14.51%)及肺炎克雷伯菌(9.68%)为主。全省耐甲氧西林金黄色葡萄球菌(MRSA)检出率是23.2%,未发现万古霉素、利奈唑胺、替考拉宁、替加环素耐药的金黄色葡萄球菌;产超广谱β-内酰胺酶(ESBLs)的大肠埃希菌和肺炎克雷伯菌的检出率分别为47.3%和39.4%。流感嗜血杆菌及卡它莫拉菌对三代以上的头孢菌素及喹诺酮类药物比较敏感。屎肠球菌对药物的耐药情况比粪肠球菌严重,耐万古霉素(VRE)的屎肠球菌的检出率达到1.5%,两者都出现对利奈唑胺的耐药株。结论四川地区儿童患者以呼吸道感染为主,阳性球菌主要是金黄色葡萄球菌和肺炎链球菌,阴性杆菌主要是大肠埃希菌,流感嗜血杆菌及肺炎克雷伯菌。不同地区细菌耐药性有一定的差异,由于儿科用药的特殊性,应加强临床用药指导,合理使用抗生素,防止耐药菌的产生和扩散。     

老年细菌性阴道炎患者致病菌分布与耐药性调查与分析

目的 分析老年细菌性阴道炎患者致病菌分布及耐药现状,为临床治疗提供依据.方法 回顾性分析2008～2010年于本院确诊的老年细菌性阴道炎患者送检的阴道分泌物标本致病菌分离、培养、鉴定及药敏试验结果.结果 主要病原菌依次为凝固酶阴性葡萄球菌(26.2%)、金黄色葡萄球菌(22.8%)、大肠埃希菌(20.5%)、肺炎克雷伯菌(14.7%)和屎肠球菌(12.1%).耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)检出率分别为46.8%、35.2%;超广谱β内酰胺酶(ESBLs)阳性大肠埃希菌和肺炎克雷伯菌分别为23.9%、23.5%.葡萄球菌对青霉素、红霉素耐药率较高,屎肠球菌对青霉素耐药率相对较低;MRSA、MRCNS及ESBLs阳性大肠埃希菌和肺炎克雷伯菌多药耐药现象严重.结论 革兰阳性球菌为老年细菌性阴道炎主要致病菌,其中肠球菌耐药性较轻,革兰阴性杆菌检出率相对较低.     

梧州地区细菌感染性疾病常见病原菌耐药性监测

目的 了解本地区细菌感染性疾病常见病原菌对各类抗菌药物的耐药状况,为临床合理用药提供依据.方法 根据美国国家临床实验室标准化委员会(NCCLS)推荐的抗菌药物分组原则选择抗菌药物,并采用琼脂纸片扩散法对常见病原菌进行药敏实验.结果 常见病原菌依次为大肠埃希菌、肺炎克雷伯菌、金黄色葡萄球菌、铜绿假单胞菌、鲍曼不动杆菌、粪肠球菌、溶血葡萄球菌、阴沟肠杆菌和表皮葡萄球菌.耐甲氧西林的金黄色葡萄球菌、溶血葡萄球菌和表皮葡萄球菌分别为34.5%、83.3%和66.7%,溶血葡萄球菌和表皮葡萄球菌对庆大霉素、四环素、环丙沙星和复方新诺明的耐药性强于金黄色葡萄球菌.粪肠球菌对青霉素类保持高度敏感,对氨苄西林和高水平庆大霉素的耐药率分别为3.5%和21.1%.大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌产超广谱β-内酰胺酶(ESBLs)率分别为21.7%、23.9%和14.6%,大肠埃希菌和肺炎克雷伯菌对青霉素类、头孢菌素、氨基糖甙类和氯霉素的耐药性均低于阴沟肠杆菌.鲍曼不动杆菌对哌拉西林、头孢他啶、亚胺培南、阿米卡星和环丙沙星的耐药性比铜绿假单胞菌更强.结论 及时掌握常见病原菌耐药特点和耐药菌株(MDR)发展趋势对制定各种感染的经验治疗方案和指导临床合理应用抗菌药物具有重要参考意义.     

285例泌尿系感染患儿的病原菌监测及耐药性分析

目的了解小儿泌尿系感染常见病原菌分布及其耐药情况。方法对本院分离的285例尿培养阳性患儿病原菌构成比及耐药性进行分析。结果 285株细菌中,革兰阴性杆菌174株(61.05%),革兰阳性球菌98株(34.39%),真菌(4.56%),前5位致病菌分别为大肠埃希菌(38.60%)、屎肠球菌(15.09%)、粪肠球菌(14.39%)、肺炎克雷伯菌(12.63%)、表皮葡萄球菌(3.86%)。大肠埃希菌和肺炎克雷伯菌产超广谱β-内酰胺酶(ESBLs)较高,其对亚胺培南美和罗培南无耐药,耐药率较低的依次为呋喃妥因、哌拉西林/他唑巴坦、阿米卡星和左氧氟沙星,产ESBLs菌株的耐药性高于不产ESBLs的菌株。屎肠球菌、粪肠球菌及表皮葡萄球菌对万古霉素和替考拉宁无耐药,其次对呋喃妥因和利福平的耐药率较低。结论本院小儿尿路感染病原菌以大肠埃希菌为主,细菌耐药性严重,临床治疗小儿泌尿系感染应根据药敏结果选择用药,避免滥用抗菌药物。     

糖尿病肾病患者尿路感染病原菌的分布及耐药性分析

目的对糖尿病肾病患者尿路感染病原菌的分布及耐药性进行分析。方法我院肾内科2013年1月-2015年1月收治的糖尿病肾病尿路感染患者140例,无菌采集患者中段尿标本进行病原菌分离及药敏试验。结果 140例糖尿病肾病(DN)共分离170株菌株,其中革兰阴性杆菌93株,以大肠埃希菌、肺炎克雷伯菌为主;革兰阳性球菌65株,以粪肠球菌、表皮葡萄球菌为主;真菌共分离到12株白念珠菌。68株大肠埃希菌中对亚胺培南(0%)、头孢哌酮-舒巴坦(5.88%)哌拉西林(17.6%)耐药率较低;12株肺炎克雷伯菌对亚胺培南(0%)、头孢哌酮-舒巴坦(8.33%)耐药率较低。革兰阴性杆菌中大肠埃希菌和肺炎克雷伯菌对青霉素、头孢类、喹诺酮类等抗菌药物均有较高的耐药率;革兰阳性球菌中的粪肠球菌和表皮葡萄球菌对万古霉素和呋喃妥因耐药率较低。结论糖尿病肾病尿路感染患者尿培养病原菌中革兰阴性杆菌以大肠埃希菌、肺炎克雷伯菌为主;革兰阳性球菌以粪肠球菌、表皮葡萄球菌为主,多数分离菌株具有较高的耐药率,临床应根据培养和药敏结果选择经济有效、肾毒性小、合理安全的抗生素进行治疗。     

不同临床标本病原菌分布及耐药性分析

目的 比较不同临床标本病原菌分布及耐药性分析,为临床治疗提供参考。方法 选取2012年10月至2013年10月大良医院收取的血液、尿液和伤口分泌物标本,进行病原菌培养和药物敏感试验。结果 血液标本检出病原菌279株,其中,大肠埃希菌占28.67%,肺炎克雷伯菌占12.19%,凝固酶阴性葡萄球菌占13.62%,金黄色葡萄球菌占9.68%,粪肠球菌占8.60%;尿液标本检出病原菌574株,其中,大肠埃希菌占38.68%,念珠菌占18.64%,铜绿假单胞菌占7.84%,肺炎克雷伯菌占7.49%,粪肠球菌占3.66%;伤口分泌物标本检出病原菌292株,其中,金黄色葡萄球菌占17.12%,大肠埃希菌占14.38%,凝固酶阴性葡萄球菌占10.27%,铜绿假单胞菌占7.53%,粪肠球菌占5.48%。不同标本病原菌分布及耐药性不同。结论 临床选用抗菌药物时,应加强耐药性监测,综合考虑各种因素。     

肝硬化并发自发性细菌性腹膜炎病原菌的临床分布与耐药分析

目的 了解肝硬化并发自发性细菌性腹膜炎(SBP)患者感染病原菌的临床分布及耐药现状,为临床治疗提供依据.方法 对该院2005～2011年住院部肝病科诊断为肝硬化并发SBP患者送检的腹水标本分离培养鉴定的细菌及耐药性进行回顾性分析.结果 肝硬化并发SBP患者腹水中共分离菌株71株,检出率由高至低依次为大肠埃希菌(49.30%)、肺炎克雷伯菌(30.99%)、粪肠球菌(16.90%),其中超广谱β-内酰胺酶(ESBLs)阳性的大肠埃希菌和肺炎克雷伯菌分别为31.42%、40.91%.大肠埃希菌和肺炎克雷伯菌对哌拉西林、头孢菌素、环丙沙星耐药率较高,对阿米卡星、米诺环素耐药率相对较低,肠球菌对青霉素、氨苄西林耐药率相对较低,对红霉素耐药率较高.未发现耐万古霉素粪肠球菌.结论 革兰阴性杆菌为肝硬化并发SBP患者主要病原菌,革兰阳性球菌检出率相对较低,其中粪肠球菌耐药现象较轻.ESBLs阳性大肠埃希菌和肺炎克雷伯菌多药耐药现象严重.     

The rediscovery and isolation of TFPI

Summary.  Tissue factor pathway inhibitor (TFPI) is a multivalent Kunitz-type proteinase inhibitor that produces factor (F)Xa-dependent feedback inhibition of the factor VIIa/tissue factor (FVIIa/TF) catalytic complex that is responsible for the initiation of coagulation. Since 1985, when Rapaport and colleagues reported that the lipoprotein fraction of plasma contained a FXa-dependent inhibitor of FVIIa/TF, myriad articles have established its biochemical structure, its mechanism of action, and its physiological importance. This brief personal account reviews historical studies that established the existence of the inhibitor and the events that led to its initial isolation.     

Molecular mechanisms of mild and moderate hemophilia A

Summary.  Mutations responsible for mild/moderate hemophilia A were extensively characterized over the last 15 years and more than 200 mutations have been identified. However, most of the molecular mechanisms responsible for the reduced factor (F)VIII levels in patients' plasma were determined only recently. Recent progresses in the study of the FVIII molecule three-dimensional structure provided a major insight for understanding molecular events leading to mild/moderate hemophilia A. This allowed prediction of mutations impairing FVIII folding and intracellular processing, which result in reduced FVIII secretion. Mutations potentially slowing down FVIII activation by thrombin were also identified. A number of mutations were also predicted to result in altered stability of activated FVIII. Biochemical analyses allowed identification of mutations reducing FVIII production. Mutations impairing FVIII stability in plasma, by reducing FVIII binding to von Willebrand factor (VWF) were also characterized. Defects in FVIII activity, notably slow activation by thrombin, or abnormal interaction with FIXa, were also recently demonstrated. Biochemical analysis of FVIII variants provided information regarding the structure/function relationship of the FVIII molecule and validated predictions of the three-dimensional structure of the molecule. These observations also contributed to explain the discrepant activities recorded for some FVIII variants using different types of FVIII assays. Altogether, the study of the biochemical properties of FVIII variants and the evaluation of the effects of mutations in three-dimensional models of FVIII identified molecular mechanisms potentially explaining reduced FVIII levels for a majority of patients with mild/moderate hemophilia A. It is expected that these studies will improve diagnosis and treatment of this disease.     

The promise and challenges of bioengineered recombinant clotting factors

The past 10 years of clinical experience have demonstrated the safety and efficacy of recombinant clotting factors. With the adoption of prophylactic strategies, there has been considerable progress in avoiding the complications of hemophilia. Now, insights from our understanding of clotting factor structure and function, mechanisms of hemophilia and inhibitors, gene therapy advances and a worldwide demand for clotting factor concentrates leave us on the brink of embracing targeted bioengineering strategies to further improve hemophilia therapeutics. The ability to bioengineer recombinant clotting factors with improved function holds promise to overcome some of the limitations in current treatment, the high costs of therapy and increase availability to a broader world hemophilia population. Most research has been directed at overcoming the inherent limitations of rFVIII expression and the inhibitor response. This includes techniques to improve rFVIII biosynthesis and secretion, functional activity, half-life and antigenicity/immunogenicity. Some of these proteins have already reached commercialization and have been utilized in gene therapy strategies, while others are being evaluated in pre-clinical studies. These novel proteins partnered with advances in gene transfer vector design and delivery may ultimately achieve persistent expression of FVIII leading to an effective long-term treatment strategy for hemophilia A. In addition, these novel FVIII proteins could be partnered with new advances in alternative recombinant protein production in transgenic animals yielding an affordable, more abundant supply of rFVIII. Novel rFIX proteins are being considered for gene therapy strategies whereas novel rVIIa proteins are being evaluated to improve the potency and extend their plasma half-life. This review will summarize the status of current recombinant clotting factors and the development and challenges of recombinant clotting factors bioengineered for improved function.     

von Willebrand factor and its propeptide: the influence of secretion and clearance on protein levels and the risk of venous thrombosis

BACKGROUND AND OBJECTIVES: Elevated levels of factor (F)VIII are associated with an increased risk of thrombosis. FVIII levels are determined mainly by von Willebrand factor (VWF). We have investigated the contribution of secretion and clearance rates to the elevated VWF antigen (VWF:Ag) and to the risk of thrombosis. VWF is secreted in equimolar amounts with its propeptide, which has a shorter half-life. VWF propeptide can be used as a measure of VWF secretion and allows estimation of the VWF half-life. METHODS AND RESULTS: We have measured VWF propeptide, VWF:Ag, FVIII:Ag and FVIII activity (FVIII:C) in the Leiden Thrombophilia Study. In controls, high VWF propeptide was associated with high VWF:Ag, FVIII:Ag and FVIII:C. In contrast to mature VWF:Ag, VWF propeptide was not influenced by blood groups. Using an ELISA-based assay we have shown that VWF propeptide lacks ABO antigens. Levels were higher in men and increased with age. A long VWF half-life was also associated with high VWF:Ag, FVIII:Ag and FVIII:C. The VWF half-life was influenced by blood group (10 h in O vs. 12 h in non-O individuals), but not by sex, and only slightly by age. VWF propeptide was higher in thrombosis patients than in controls. The VWF half-life was similar in patients and controls (11.4 and 11.1 h, respectively). CONCLUSIONS: Both secretion and clearance rates are important determinants of VWF and FVIII levels. However, mainly high VWF and FVIII levels caused by increased secretion seem to be associated with thrombosis. ABO blood group influences the clearance rates of VWF rather than VWF secretion rates.     

脑梗死患者血液vWF和VEGF含量的动态变化及临床意义

目的动态检测血浆血管性假性血友病因子（vWF）和血清血管内皮细胞生长因子（VEGF）含量，探讨脑梗死患者病情变化与血管内皮细胞功能的关系。方法对46例急性脑梗死患者和30例健康对照组血浆vWF和血清VEGF进行检测，观测脑梗死患者发病后第2、7、14天血浆vWF和血清VEGF含量，并分析它们与临床特征的关系。结果脑梗死患者第2、7、14天血浆vWF和血清VEGF含量高于健康对照组，并与患者神经功能评分和梗死面积相关。结论脑梗死患者血浆vWF和血清VEGF含量明显增高，提示vWF和VEGF参与了脑梗死早期的损伤与修复的病理变化过程。     

Structural and functional features of factor XI

Summary.  Factor XI (FXI) has structural and mechanistic features that distinguish it from other coagulation proteases. A relatively recent addition to vertebrate plasma coagulation, FXI is a homodimer, with each subunit containing four apple domains and a protease domain. The apple domains form a disk structure with binding sites for platelets, high molecular weight kininogen, and the substrate factor IX (FIX). FXI is converted to the active protease FXIa by cleavage of the Arg³⁶⁹−Ile³⁷⁰ bond on each subunit. This converts the catalytic domains to the active forms, and unmasks exosites on the apple domains required for FIX binding. FXI activation by factor XIIa or thrombin proceeds through an intermediate with only one activated submit (1/2-FXIa). 1/2-FXIa activates FIX in a similar manner to FXIa. While the importance of the homodimeric structure of FXI is not certain, it may represent a strategy for binding to FIX and a platelet surface simultaneously.     

Mechanisms of factor VIIa‐catalyzed activation of factor VIII

Summary. Background: Factor (F)VIIa, complexed with tissue factor (TF), is a primary trigger of blood coagulation, and has extremely restricted substrate specificity. The complex catalyzes limited proteolysis of FVIII, but these mechanisms are poorly understood. Objectives: In the present study, we investigated the precise mechanisms of FVIIa/TF‐catalyzed FVIII activation. Results: FVIII activity increased ～4‐fold within 30 s in the presence of FVIIa/TF, and then decreased to initial levels within 20 min. FVIIa (0.1 nm ), at concentrations present physiologically in plasma, activated FVIII in the presence of TF, and this activation was more rapid than that induced by thrombin. The heavy chain (HCh) of FVIII was proteolyzed at Arg⁷⁴⁰ and Arg³⁷² more rapidly by FVIIa/TF than by thrombin, consistent with the enhanced activation of FVIII. Cleavage at Arg³³⁶ was evident at ～1 min, whilst little cleavage of the light chain (LCh) was observed. Cleavage of the HCh by FVIIa/TF was governed by the presence of the LCh. FVIII bound to Glu‐Gly‐Arg‐active‐site‐modified FVIIa (K_d, ～0.8 nm ) with a higher affinity for the HCh than for the LCh (K_d, 5.9 and 18.9 nm ). Binding to the A2 domain was particularly evident. Von Willebrand factor (VWF) modestly inhibited FVIIa/TF‐catalyzed FVIII activation, in keeping with the concept that VWF could moderate FVIIa/TF‐mediated reactions. Conclusions: The results demonstrated that this activation mechanism was distinct from those mediated by thrombin, and indicated that FVIIa/TF functions through a ‘priming’ mechanism for the activation of FVIII in the initiation phase of coagulation.     

急性脑梗死患者止凝血相关因子变化的研究

目的　探讨脑梗死患者止凝血系统的改变及其临床意义。方法　检测 5 2例脑梗死患者和 5 5例正常人的外周血血管性血友病因子 (vWF)、因子Ⅷ活性 (FⅧ∶C)、血栓调节蛋白 (TM )、蛋白C(PC)、游离蛋白S(FPS)、组织纤溶酶原激活物 (t PA)、组织纤溶酶原激活剂抑制剂 (PAI 1)、β TG、PF4 的含量和血小板粘附试验(PAdT)及血小板聚集试验 (PAgT) ,并进行统计学分析。 结果　脑梗死组vWF、FⅧ :C、PC、PAI 1、β TG、PF4 、PAdT及PAgT较对照组增高 ,t PA下降 ,患者组TM及FPS含量与对照组无明显差异。 结论　提示脑梗死患者凝血活性增强、纤溶活性减低 ,血小板功能亢进     

重组色素上皮细胞衍生因子的制备及其对脑胶质瘤血管新生的影响

目的 用大肠杆菌表达色素上皮细胞衍生因子(PEDF)，及评价其在脑胶质瘤血管新生中的作用。方法 构建pET41／PEDF表达载体，用金属亲和层析(His Tag)和阴离子交换层析纯化重组蛋白，并以管腔形成试验验证重组蛋白活性。同时，采用酶联免疫吸附试验(ELISA)测定血管内皮细胞生长因子(VEGF)与血小板反应素-1(TSP-1)的变化。结果 用基因工程手段获得终产量为3．8mg／L，可抑制内皮细胞管腔形成的PEDF蛋白；PEDF可下调VEGF(减少1．8倍)和上调TSP-1(增高5．3倍)的表达。结论 PEDF可能是抑制脑胶质瘤新生血管形成的主要因素。