重组含绿脓杆菌外毒素A受体结合区蛋白的表达、纯化、复性及细胞生物学活性研究

绿脓杆菌是烧伤及外科手术感染的主要病原菌之一,而绿脓杆菌外毒素A(PEA)是该菌的最主要的毒力因子之一,极微量的PEA便可引起肝、肾等组织细胞死亡,进而导致肝、肾等多器官功能衰竭,这是临床上绿脓杆菌感染后高死亡率的主要原因。同时,PEA还严重影响创口的愈合。目前临床上对于绿脓杆菌感染的控制以及对PEA毒血症的防治尚无有效的方法与手段。本实验是利用基因工程手段克隆表     

抗绿脓杆菌核糖核酸的免疫活性研究

在应用抗菌素比较容易地解决了各种细菌感染的治疗之后,临床上出现了“条件致病菌”的感染问题。在革兰氏阴性杆菌中,绿脓杆菌是分布广、自然抗药性发生率高的一类条件致病细菌。它所引起的感染性疾病,近来有逐年增加的趋势,已经成为死亡率较高的难治病之一。绿脓杆菌感染常在机体防御功能低下时发生。虽然临床上不断使用新的抗菌素,但如果机体条件不改善,疗效就受到一定限制。因此国内外都在研究应用各种免疫制剂治疗和予防绿脓杆菌的感染,以便给临床控制和治疗绿脓杆菌感染寻找新途径。鉴于免疫核糖核酸有特异促进噬菌细     

不同血清型的绿脓杆菌对抗生素的耐药性

目前治疗由绿脓杆菌引起的疾病的有效药物是庆大霉素、丁胺卡那毒素和托普霉素。但随着抗生素的使用,耐药菌也不断出现。为此必须进一步寻找新的更有效的抗生素和免疫制剂。本文报道了探索绿脓杆菌的血清型及对抗生素耐药性关系,寻找抗绿脓杆菌的更有效的药物筛选“模型”和免疫制剂的“抗原”等研究情况。     

绿脓杆菌外毒素A的研究进展

<正>绿脓杆菌广泛存在于土壤、水及各种动物体内,是一种常见条件致病菌。绿脓杆菌导致的感染占革兰氏阴性感染的10%,常继发于肿瘤,大面积烧伤、面积创伤及免疫抑制剂使用者。感染类型多种多样,有急、慢性局部感染,也有全身性感染。因为感染绿脓杆菌的患者往往免疫功能低下、临床有效的抗生素种类少,又缺乏有效的疫苗等因素给临床治疗带来了很大困难。     

抗大肠杆菌免疫核糖核酸活性的研究——白细胞粘附抑制试验测定 iRNA 的细胞免疫活性

抗菌免疫核糖核酸(iRNA)已被应用于抗感染的临床治疗,对烧伤病人及其它感染病人中的条件致病菌,如大肠杆菌、绿脓杆菌等的防治方面取得了较好的治疗效果。为评定抗菌 iRNA 的免疫活性及探讨其抗感染作用机理,我们应用了白     

应用人型单克隆抗体治疗感染疾病

<正> 接受免疫仰制剂治疗癌症、重度烧伤等免疫功能低下的患者,常招致严重的绿脓杆菌(P、aeruginosa)感染。此外,可对现有抗生素很快产生抗药性,用化学疗法很难治疗。 Millican等(1958年)首次报道抗绿脓杆菌免疫血清抗体疗法有实用价值。以后,许多作者对抗绿脓杆菌各种成分的抗体进行了深入研究,结果发现脂多糖(LPS,存在于菌体外膜)抗体,可借助吞噬细胞的免疫吞噬作用而感染。用鼠型单克隆抗体(McAp)试验也有同样的结果,并发现抗外膜蛋白McAp的防御感染作用比抗LPSMcAp效果差。 最近,制备抗绿脓杆菌脂多糖的人型McAp已获成功,产生人型McAp的细胞是采用Epstein-Barr病毒(EBV)转化法或杂交细胞瘤法。作者对健康人未梢血淋巴细胞的病毒转化细胞产生的抗绿脓杆菌人型     

健康人和感染患者抗绿脓杆菌内毒素蛋白(EP)抗体水平的测定分析

用微量间接血凝法检测了健康人和绿脓杆菌感染患者血清抗EP抗体.健康人共检测154人.基础抗体水平绝大部分在1:8以下(占85.05%)EP—HA GMT为1:7.3.无性别差异(x~2=3.04、P>0.05).绿脓杆菌感染患者检测38例,免疫前GMT高于健康人1.43倍,免疫后较免疫前GMT提高4倍.绿脓杆菌EP是绿脓杆菌共同抗原,检查人抗EP抗体水平对诊断、防治绿脓杆菌感染具有重要临床意义.     

应用免疫核糖核酸治疗条件致病性细菌的感染

一近年来临床由于广泛使用抗菌素、抗癌药物、免疫抑制剂以及肾皮质激索等,经常出现所谓“条件致病菌”的感染。在外界分布甚广的绿脓杆菌、大肠杆菌等肠道杆菌不仅是最常见的条件致病菌,而且是自然抗药性发生率高的细菌。由这类菌引起的感染(如烧伤感染等),多在机体抵抗力     

唐山地震截瘫病人中尿路感染调查分析

目前,大肠杆菌和绿脓杆菌仍然是引起医院内机体衰弱病人尿路感染的主要病原菌。地震截瘫病人长期卧床,多有不同程度排尿障碍和尿潴留,局部免疫功能低下,因而容易发生尿路上行感染。为了防治尿路感染,促进病人康复,本文对109例唐山地震截瘫住院病人尿路大肠杆菌、绿脓杆菌感染状况及其菌株药物敏感性作了调查研究,以供临床参考。结果表明,大肠杆菌和绿脓杆菌感染率为49.54%(54/109)。其中,单纯大肠杆菌感染率为27.52%(30/109),单纯绿脓杆菌感染率为20.18%(22/109),两菌混合感染率为1.83%(2/109)。     

铜绿假单胞菌外毒素A的调控基因

铜绿假单胞菌(绿脓杆菌)外毒素A(PEA)为该菌最主要的致病物质,由toxA基因编码.本文综述PEA的调控基因,包括正调控基因regA、regB、lasR、ptxR、vfr和负调控基因fur、ptxS.regA是影响toxA转录的最主要基因.除lasR外,其余其因均在转录水平上通过regA调控PEA的产量.     

The in vitro effects of EDTA-tris, EDTA-tris-lysozyme, and antimicrobial agents on equine genital isolants of Pseudomonas aeruginosa

Five isolants of Pseudomonas aeruginosa collected from clinical cases of equine genital infection and one standard strain of P. aeruginosa were exposed to various concentrations of ethylene-diaminetetraacetic acid (EDTA) and tris (hydroxymethyl) aminomethane (tris buffer pH 8) and EDTA-tris lysozyme. Colony forming units of the isolants and minimal inhibitory concentrations for 11 antimicrobial agents were determined with each isolant before and after exposure to the EDTA solutions. Decreased cellular viability was found with all six isolants after exposure to the EDTA-tris solutions. Reversal of antimicrobial resistance was variable and unpredictable. These effects were not enhanced by the addition of lysozyme. The results suggest that EDTA-tris could be a useful adjunct in treating equine genital infections caused by Pseudomonas aeruginosa .     

Results of using polyvalent Pseudomonas aeruginosa vaccine in children with burns by various medical centers

Polyvalent Pseudomonas aeruginosa vaccine, prepared at the Institute of Hematology from 10 hospital strains isolated from burn wounds, was administered to 32 children with extensive and deep burns. The vaccine was well tolerated. The vaccine produced a high degree of the immunity against Pseudomonas aeruginosa infection. Agglutinin serum titre increased significantly. Vaccination either prevented or inhibited the infection of burn wounds with Pseudomonas aeruginosa in all immunized children. The symptoms of Pseudomonas aeruginosa infection usually disappeared following one or two vaccinations. Bacteriemia caused by P. aeruginosa was not observed in 31 out of 32 children. In the remaining child transient bacteriemia was noted. No septicemia caused by P. aeruginosa was seen. Due to the high efficiency of the polyvalent P. aeruginosa vaccine all burned children with burns exceeding 10% of the total body surface should by vaccinated to prevent the life-threatening infections with Pseudomonas aeruginosa.     

铜绿假单胞菌群体感应系统研究进展

群体感应系统是一种细胞密度依赖的基因表达系统,其广泛存在于细菌性病原体中,是细菌细胞通讯方式的一种。群体感应系统可利用细菌释放的信号分子不断监控周围细菌的密度。当细菌密度达到阈值时,群体感应系统网络将启动,参与调控生物被膜、细菌毒力等特定基因的表达,从而使临床抗感染治疗失败。而通过抑制群体感应系统,可一定程度上治疗铜绿假单胞菌引起的感染。本文通过查阅近年国内外相关文献,对铜绿假单胞菌群体感应系统研究进展进行总结,为临床铜绿假单胞菌治疗提供新的方向,即群体感应系统抑制剂有可能成为治疗铜绿假单胞菌感染的新策略。     

Inhibition of adhesion to buccal epithelial cells of Pseudomonas aeruginosa by dextran

Adhesion of Pseudomonas aeruginosa strains to buccal epithelial cells appears to be a necessary precondition for colonization and infection of respiratory tract. There are many strategies to prevent host organisms for Pseudomonas aeruginosa. The purpose of these studies was to evaluate the potential for preventing adhesion of Pseudomonas aeruginosa to epithelial cells with dextran. Dextran (5,000 MW) inhibited adhesion of Pseudomonas aeruginosa to buccal cells, at 20 mM was most inhibitory. The inhibitory effect appeared to be nonspecific because other neutral polysaccharides (glycogen and mannan) were also inhibitory. Dextran is an inexpansive and nontoxic agent and may be useful to prevent colonization and infection of respiratory tract with Pseudomonas aeruginosa.     

环丙沙星耐药的铜绿假单胞菌药敏情况分析

目的了解对环丙沙星耐药的铜绿假单胞菌的药敏情况。方法细菌的鉴定及药敏试验,均采用法国生物梅里埃公司的VITEK2微生物鉴定与药敏系统,选择经VITEK2测定耐环丙沙星的铜绿假单胞菌(耐药株)68株及对环丙沙星敏感的铜绿假单胞菌(敏感株)67株,统计分析两者对亚胺培南、阿米卡星、庆大霉素、头孢他啶、哌拉西林和哌拉西林他唑巴坦等几种临床上常用抗生素的药敏情况。结果耐药株对以上6种抗生素的敏感率分别为亚胺培南706%,阿米卡星206%,庆大霉素191%,头孢他啶279%,哌拉西林632%,哌拉西林他唑巴坦721%。而敏感株对6种抗生素的敏感率则分别为925%、328%、687%、657%、881%与896%,明显高于耐药株,经χ2检验,除阿米卡星005相似文献   

铜绿假单胞菌菌苗对尿路感染的免疫功能调节

铜绿假单胞菌菌苗是一种新型的细菌性免疫调节剂。用其治疗反复发作性尿路感染 ,其中体液免疫检测结果实验组治疗后的广谱抗体效价比治疗前的广谱抗体效价提高 8～ 6 4倍 ,细胞免疫的检测中T细胞亚群中各项指标治疗前后均有显著性差异 (P <0 .0 1)。提示 ,该菌苗是通过调整患者自身的体液免疫和细胞免疫功能 ,从而达到治疗效果     

铜绿假单胞菌的院内感染分布及耐药性的调查

目的了解铜绿假单胞菌（PA）在医院内感染的分布特点及其耐药性,指导临床合理用药,降低医院感染率。方法回顾分析2005年1月至2008年11月我院临床分离的铜绿假单胞菌152株,按WHO推荐的NC-CLS标准方法（K—B法）进行药敏试验,分析菌株的临床分布特征及体外药敏结果。结果铜绿假单胞菌在临床上主要以呼吸道感染为主。在17种临床常用抗生素中,多表现为多重耐药。美洛培南、亚胺培南及左旋氧氟沙星抗PA效果最好,耐药率分别只有14．47％、14．47和5．26％。结论多重耐药铜绿假单胞菌在临床广泛存在,应当根据临床体外药敏结果合理选择抗菌药物进行治疗,以取得良好临床效果并减少耐药菌产生;同时规范院内感染控制措施,减少耐药菌株的播散。     

TLRs 2 and 4 are not involved in hypersusceptibility to acute Pseudomonas aeruginosa lung infections

TLRs are implicated in defense against microorganisms. Animal models have demonstrated that the susceptibility to a number of Gram-negative pathogens is linked to TLR4, and thus LPS of many Gram-negative bacteria have been implicated as virulence factors. To assess the role of this pathogen-associated molecular pattern as it is exposed on intact Pseudomonas aeruginosa, the susceptibility of mice lacking TLR4 or both TLR2 and TLR4 was examined in a model of acute Pseudomonas pneumonia. These mutant mice were not hypersusceptible to the Pseudomonas challenge and mounted an effective innate response that cleared the organism despite low levels of TNF-alpha and KC in the airways. Bacterial and neutrophil counts in the lung were similar in control and TLR-deficient mice at 6 and 24 h after infection. MyD88(-/-) mice were, however, hypersusceptible, with 100% of mice dying within 48 h with a lower dose of P. aeruginosa. Of note there were normal levels of IL-6 and G-CSF in the airways of TLR mutant mice that were absent from the MyD88(-/-) mice. Thus, the susceptibility of mice to P. aeruginosa acute lung infection does not go through TLR2 or TLR4, implying that Pseudomonas LPS is not the most important virulence factor in acute pneumonia caused by this organism. Furthermore, G-CSF treatment of infected MyD88(-/-) mice results in improved clearance and survival. Thus, the resistance to infection in TLR2/TLR4(-/-) mice may be linked to G-CSF and possibly IL-6 production.     

Purified Pseudomonas aeruginosa PA-I lectin induces gut growth when orally ingested by rats

Abstract The effects of PA-I lectin isolated from the human pathogen Pseudomonas aeruginosa upon cellular metabolism in vivo have been studied using the rat gut as a model system. Orally ingested PA-I lectin stimulated metabolic activity and induced polyamine accumulation and growth in the small intestine, caecum and colon. The nature and extent of the changes induced by PA-I lectin were similar to those caused by dietary kidney bean lectin and were likely to lead to impaired epithelial cell function and integrity. This finding contributes to our understanding of the possible roles of these lectins in Pseudomonas aeruginosa infection.     

Superbugs in the coming new decade; multidrug resistance and prospects for treatment of Staphylococcus aureus, Enterococcus spp. and Pseudomonas aeruginosa in 2010

New resistance problems have emerged recently among hospital and community-acquired pathogens such as in Staphylococcus aureus, Enterococcus faecium and Pseudomonas aeruginosa. Hospital-acquired and now community-acquired methicillin-resistant S. aureus are emerging worldwide whereas vancomycin-resistant S. aureus remain extremely rare. Hospital-acquired outbreaks of vancomycin-resistant enterococci and multidrug resistant Pseudomonas aeruginosa infections are increasingly reported worldwide. Whereas novel molecules are being developed for treating Gram-positive infections, difficult to non possible-to-treat pandrug-resistant P. aeruginosa infections may become a therapeutic challenge soon.