Histamine activates HinK to promote the virulence of Pseudomonas aeruginosa

During infections,bacteria stimulate host cells to produce and release histamine,which is a key mediator of vital cellular processes in animals.However,the mech...     

Bioleaching of copper oxide ore by Pseudomonas aeruginosa

Bioleaching is an environmentally friendly method for extraction of metal from ores. In this study, bioleaching of copper oxide ore by Pseudomonas aeruginosa was investigated. Pseudomonas aeruginosa is a heterotrophic bactermm that can produce various organic acids in an appropriate culture medium, and these acids can operate as leaching agents. The parameters, such as particle size, glucose percentage in the culture medium, bioleaching time, and solid/liquid ratio were optimized. Optimum bioleaching conditions were found as follows： particle size of 150-177 μm, glucose percentage of 6%, bioleaching time of 8 d, and solid/liquid ratio of 1：80. Under these conditions, 53% of copper was extracted.     

铜绿假单胞菌随机扩增DNA多态性基因分型研究

利用微量液体稀释法进行药敏检测和RAPD技术进行基因分型,调查了铜绿假单胞菌在临床各科中的流行情况,以期建立稳定的临床检测系统,在控制院内感染的流行病研究中发挥更大的作用.结果表明耐药谱分6型,Ⅰ型占44.5%,Ⅱ型占18.5%,Ⅲ型占7.4%,Ⅳ型占7.4%,Ⅴ型占11.1%,Ⅵ型(不定型)占11.1%;RAPD分9型,A型占51.9%,B型占7.4%,C型占7.4%,D型占7.4%,E型占7.4%,F型占3.7%,G型占3.7%,H型占7.4%,I型占3.7%.说明基因型A型、耐药谱Ⅰ型的铜绿假单胞菌是此次ICU医院感染暴发流行的菌株,其他型别为非流行相关菌株.比较结果还说明RAPD基因分型的灵敏性、特异性及可靠性优于耐药谱分型,在医院感染流行病学调查中具有较大的应用价值.     

一株绿脓假单胞菌对碱性孔雀绿脱色的初步研究

从福建石狮某废水处理厂的曝气池活性污泥中分离筛选到一株对碱性孔雀绿具有较强脱色能力的细菌,经鉴定为绿脓假单胞菌属(Pseudomonasaeruginosa).脱色反应条件初步研究表明,该菌株最适脱色温度为30℃,最适脱色pH值为6.0,有氧条件下的脱色效果较缺氧条件下好.在最佳脱色条件下该菌对碱性孔雀绿处理28h后,脱色率可达到98%.     

Complete genome sequence of Pseudomonas aeruginosa PAO1, an opportunistic pathogen

Pseudomonas aeruginosa is a ubiquitous environmental bacterium that is one of the top three causes of opportunistic human infections. A major factor in its prominence as a pathogen is its intrinsic resistance to antibiotics and disinfectants. Here we report the complete sequence of P. aeruginosa strain PAO1. At 6.3 million base pairs, this is the largest bacterial genome sequenced, and the sequence provides insights into the basis of the versatility and intrinsic drug resistance of P. aeruginosa. Consistent with its larger genome size and environmental adaptability, P. aeruginosa contains the highest proportion of regulatory genes observed for a bacterial genome and a large number of genes involved in the catabolism, transport and efflux of organic compounds as well as four potential chemotaxis systems. We propose that the size and complexity of the P. aeruginosa genome reflect an evolutionary adaptation permitting it to thrive in diverse environments and resist the effects of a variety of antimicrobial substances.     

铜绿假单胞菌耐药机理

铜绿假单胞菌是耐药性十分突出的一类院内感染条件致病革兰氏阴性细菌．本文从生物被膜、细胞密度依赖式毒力因子、外排系统、基因盒一整合子系统及铜绿假单胞菌噬菌体几方面对其耐药性机理进行了概述，并提出了未来对微生物耐药性研究和应用的一些策略。     

铜绿假单胞菌外膜亚蛋白质组图谱的建立

铜绿假单胞菌是人类重要的病原菌,容易造成免疫缺陷患者如烧伤、艾滋病、癌症或囊性纤维化感染,对该菌外膜蛋白的研究有助于了解该菌的致病机制,为进一步疫苗研制奠定基础.采用月桂酰基氨酸钠的方法提取了铜绿假单胞菌的外膜蛋白,首次建立了外膜亚蛋白质组学表达图谱,鉴定了23个外膜蛋白,占所鉴定蛋白的82.1%.然后对其中的一个外膜蛋白基因PA3988进行了克隆及原核表达与纯化,经免疫小鼠获得抗血清后对外膜蛋白进行双向Western blotting分析,验证了质谱的结果.这些研究结果对铜绿假单胞菌外膜蛋白的深入研究具有积极作用.     

铜绿假单胞菌对萘菲的降解研究

文章以萘、菲为惟一碳源,研究了铜绿假单胞菌对萘、菲的降解特性试验.结果表明,铜绿假单胞菌能以萘、菲为惟一碳源,对萘、菲具有较好的降解能力.21天菲与萘的最高降解率分别可达95.1%和92.3%.此菌株对菲、萘的脱氢酶活性有一定的影响,0~10天其脱氢酶活性迅速增强,10天达到最高值,随后逐渐下降.从微生物数量可知,不同浓度的萘、菲对微生物的生长也有较大的影响.浓度过低时,菌体生长缓慢;浓度过高,铜绿假单胞菌本身产生的副作用会抑制微生物的生长.     

铜绿假单胞菌PAO1降解菲、萘的特性及产物分析

目的在前期发现实验室保存的铜绿假单胞菌PAO1具有较强的菲、萘降解能力基础上,对该菌株的菲、萘降解特性及代谢产物进行研究和分析。方法在MM基础培养基中通过改变各种因素来确定PAO1降解的最适条件,应用TLC和HPLC等方法确定了PAO1降解菲、萘过程中存在的重要代谢产物。结果 PAO1对菲、萘的最适降解温度为37℃,最适降解pH值为7.0,对菲、萘的降解属于好氧途径,添加表面活性剂或通过添加低抑制浓度抗生素而增加生物表面活性剂鼠李糖脂的产生都可增加菲、萘的降解,后者效果更好。初步推测PAO1的菲降解存在水杨酸途径和邻苯二甲酸途径;萘降解过程存在水杨酸途径,不存在龙胆酸途径。结论对后续降解途径的进一步清晰以及在此基础上降解酶的确定和工程菌株的构建奠定了基础。     

紫外诱变选育优势铜绿假单胞菌菌株

采用紫外照射的方法对铜绿假单胞菌菌株进行诱变,从中筛选出一株优势正突变菌菌株B2,并对其形态,生长条件及产鼠李糖脂能力进行了研究。研究发现,相对于亲本B0,菌株B2产鼠李糖脂产量大幅度增高,从0.82 g/L增加到2.71 g/L。菌株形态为杆状菌。最佳生长条件为:温度为30℃,甘油30 g/L,酵母膏2 g/L,微量元素5 m L/L。研究结果表明从重金属含量高的制革污泥中筛选得到的铜绿假单胞菌经紫外诱变后可显著提高产鼠李糖脂产量,并进一步确定诱变后的菌株产鼠李糖脂的最佳发酵条件,为鼠李糖脂的量产提供理论基础。     

MALDI-TOF MS对草莓中铜绿假单胞菌和黏质沙雷氏菌的检测

为了评价基质辅助激光解析电离飞行时间质谱法(MALDI-TOF MS)在草莓微生物风险监测的应用价值,确定草莓的危害识别微生物及其特征,采用选择性培养方法对50份草莓样品中铜绿假单胞菌和黏质沙雷氏菌进行分离,MALDI-TOF MS对分离微生物进行鉴定,应用SARAMIS Premium软件对这2种食物感梁性病原微生物的蛋白质图谱进行分析和加权修正。结果表明,铜绿假单胞菌在草莓中的检出率为18%,黏质沙雷氏菌检出率为20%,实验获得草莓中分离铜绿假单胞菌完全拟合特征峰12组,标识峰聚类分析结果表明,分离铜绿假单胞菌差异较大;获得草莓分离黏质沙雷氏菌完全拟合特征峰有8组,标识峰加权聚类分析结果可认定分离的2株黏质沙雷氏菌同源。MALDI-TOF MS方法可标识草莓分离微生物的蛋白质特异性特征,且对微生物的溯源及特异性分析有一定优势,表明其在农产品复杂微生物环境中具有应用潜力。     

584株铜绿假单胞菌的耐药性分析与研究

目的监测本单位的病原菌对抗菌药物的敏惑性与耐药性,从而提高抗生素的治疗效果,针对性地选用抗菌药物,控制医院铜绿低单胞菌感染的发生率。方法采用vitek-2的ID-GNB鉴定卡和AST-GN药敏卡,用K-B法手工药敏鉴定检测,用铜绿假单胞菌ATCC27853、大肠埃希菌ATCC25922进行质量控制。结果丁胺卡那霉素、哌拉西林/他唑巴坦抗菌作用最强;美洛培南、哌拉西林、妥布霉素、头孢吡肟、亚胺培南、庆大霉素次之;头孢曲松、头孢唑肟、头孢噻肟、头孢他啶、四环素、复方新诺明等的抗菌作用最弱。结论单一抗生素对铜绿假单胞菌的治疗不理想,易出现耐药株,主张联合用药。     

Bis-methionine axial ligation of haem in bacterioferritin from Pseudomonas aeruginosa

The iron-containing bacterioferritins contain the protoporphyrin IX haem group. It has been established that Escherichia coli cytochrome b1, cytochrome b557 and bacterioferritin are identical. The optical spectra at room temperature of the haem group show it to be predominantly low-spin in both the ferrous and ferric states. The nature of the axial ligands binding the haem group to the polypeptide has, however, remained unknown. Low-spin, bis-coordinate haem centres in proteins typically have a role in rapid electron transfer as redox changes at the metal ion lead to little structural rearrangement. There are only four amino acids with side-chains that have ligand field strengths sufficient to generate the low-spin state of haem, namely, histidine, lysine, methionine and cysteine. Hence there are, potentially, ten different pairs of these four ligands which could be discovered in electron transfer haemoproteins. To date only three have been established with certainty. They are bis-histidine, as in mammalian cytochrome b5, methionine-histidine, typified by cytochrome c and lysine-histidine, recently recognized by spectroscopic methods in cytochrome f. Here we report the electron paramagnetic resonance and near infrared magnetic circular dichroism spectra of the oxidized state of Ps. aeruginosa bacterioferritin which enable the axial ligands to be identified as the thioether side chains of two methionine residues, a ligation scheme not previously reported for haem in any protein.     

铜绿假单胞菌对Cu2+的吸附条件及动力学初步研究

从温州东方集团电镀厂废水池淤泥中分离到一株抗Cu2 细菌 ,经鉴定为铜绿单胞菌 (Pseudomonsaerug inosa)。并进一步研究了该菌对Cu2 吸附行为与影响吸附的主要因素 ,其中包括吸附剂与Cu2 接触反应时间、Cu2 浓度、原初pH。结果表明 :该吸附剂对Cu2 有较强的吸附能力 ,最大吸附量为 1 4.45mg/g,pH对此菌的吸附效果有很大影响 ,最佳pH为 4.0 ,Cu2 浓度在 1 0～ 80mg/L范围内 ,吸附量为 1 0 .2 1～ 1 4.45mg/g ,吸附反应在lh基本达到平衡。吸附过程符合Freundlich和Langmuir吸附等温方程 :Cu2 和H 对吸附剂上的化学基团有明显的吸附竞争。     

铜绿假单胞菌鞭毛运动相关基因的研究

建立优化的转化条件,将M u转座复合物电转化到临床分离的一株铜绿假单胞菌(P seud om onasaerug inosa)PA 68中,最高转化效率达3.66×104CFU/μg DNA.通过表型筛选,得到三株鞭毛运动能力缺陷的突变子,Sourn thern杂交证实转座子为单点插入.经基因克隆、核苷酸测序研究,证明转座子分别插入到uvrD、phzF 1、zw f三个基因中,这是首次在国际上将M u转座重组技术应用到鞭毛运动相关基因的研究中.由于人工M u转座技术具有随机单点插入的优点,克服了传统转座子能在染色体上迁移的缺点,为进一步研究P.aerug inosa的鞭毛运动机理及致病性奠定基础.     

LS-1型测听亭的开发

介绍LS-1测听亭的设计，主要包括隔音墙、门、窗、底座、通风、采光、电磁屏蔽等方面的设计。