周口地区2种常见野生中草药的单方抑菌效果

通过水煎剂法提取野黄菊花和猫眼草的有效成分,采用滤纸片扩散法检测它们对大肠杆菌、金黄色葡萄球菌的抑菌效果.结果表明:野黄菊花和猫眼草对两种菌均有明显的抑制功效,猫眼草对大肠杆菌和金黄色葡萄球菌的最佳抑菌浓度是1.0 g/mL.野黄菊花对大肠杆菌的最佳抑菌浓度是1.0 g/mL,对金黄色葡萄球菌的最佳抑菌浓度是0.25 g/mL.     

2-（1-（（2-胺基苯基）亚胺基）乙基）-5-甲氧基苯酚及其配合物的合成和抑菌活性研究

采用液相合成出2-（1-（（2-胺基苯基）亚胺基）乙基）-5-甲氧基苯酚,通过IR,H1-NMR表征其结构,进一步合成其5种金属配合物（M=Cu^2＋,Mn^2＋,Ni^2＋,Zn^2＋,CO^2＋）,大肠杆菌的生物活性实验表明：配体与锰形成的配合物对大肠杆菌的抑菌活性比配体强．     

人类睾丸凋亡相关基因蛋白(TSARG2)在大肠杆菌中的表达和纯化

目的获得重组TsARG2基因蛋白,为进一步研究其功能和制备特异抗体奠定基础.方法根据已报道的TsARG2基因序列,采用RT-PCR的方法获得TsARG2基因.将所得的PCR产物插入原核表达载体pQE30中,得重组质粒(pQE/TSARG2)并转化大肠杆菌(E.coli)M15,通过IPTG诱导表达出带有六个组氨酸的融合蛋白,采用镍固定金属亲和层析法纯化.结果序列分析表明TSARG2基因成熟肽编码区含有918bp,编码305个氨基酸;与GenBank(AY040204)中已报道的TSARG2分离物的核苷酸序列有100%同源性.经IPTG诱导表达,SDS-PAGE电泳分析显示,表达的融合蛋白占菌体蛋白总量的66%,分子质量约为35kDa.经Ni2 -NTAagarose纯化获得SDS-PAGE电泳下单一条带.结论在大肠杆菌中获得了TsARG2基因蛋白的高效表达,为研究其生物学功能和制备单克隆抗体奠定了基础.     

尿路感染病原菌分布及大肠埃希菌的耐药性分析

目的：了解保山某院尿路感染病原菌的分布情况及大肠埃希菌的耐药情况,为临床合理使用抗生素提供依据。方法：用VITET-2Compact60全自动微生物分析仪鉴定细菌,K—B纸片扩散法做体外药敏试验,统计、分析细菌的检出率和药敏结果。结果：尿路感染病原菌占第一位的是大肠埃希菌（74．2％）,其次为肺炎克雷伯菌（10％）,次之为表皮葡萄球菌（4.3％）;病原菌在临床各科室分布情况为泌尿科45．7％、康复科20％、ICU14.3％;52株大肠埃希菌对13种抗生素的耐药率居前三位的分别为：氨苄西林98％、复方新诺明76．9％、庆大霉素65．4％,52株大肠埃希菌对厄他培南、亚胺培南均敏感;52株大肠埃希菌中产ESBLsIg／29株占55．8％,非产ESBLs的23株占44．2％。结论：医院尿路感染病原菌以大肠埃希菌为主,科室分布以泌尿科为首,尿路感染大肠埃希菌的耐药情况较严重,医院应加强其耐药性监测,医生应依据体外药敏试验结果合理选择抗生素。     

稀土水杨酸8-羟基喹啉三元配合物对大肠杆菌抑制作用的研究

为探究稀土水杨酸8-羟基喹啉三元配合物RE(sal)2hq(RE=Pr、Gd)对大肠杆菌的抑菌效果.实验采用杯碟法和二倍稀释法,通过测量抑菌圈直径探讨了两种配合物及其配体的抑菌能力.结果表明:配体8-羟基喹啉、配合物RE(sal)2hq(RE=Pr、Gd)都具有很好的抑菌效果,而配体水杨酸及稀土(RE=Pr、Gd)离子抑菌效果都不明显.配合物Pr(sal)2hq、Gd(sal)2hq和配体8-羟基喹啉的最小抑菌浓度MIC值分别为:0.5 mmo/lL、1 mmo/lL和1 mmo/lL.最小杀菌浓度MBC值分别为:4mmo/lL、5mmo/lL和14mmo/lL.初步推测稀土水杨酸8-羟基喹啉三元配合物可以作为药物运用于有害大肠杆菌的防治中.     

Expression and purification of bioactive high-purity human midkine in Escherichia coli

Midkine is a heparin-binding growth factor,which plays important roles in the regulation of cell growth and differentiation.The non-tagged recombinant human midkine (rhMK) is therefore required to facilitate its functional studies of this important growth factor.In the present work,rhMK was expressed in Escherichia coli (E.coli) BL21 (DE3).The expression of midkine was efficiently induced by isopropyl-β-D-thiogalactopyranoside (IPTG).After sonication,midkine was recovered in an insoluble form,and was dissolved in guaoidine hydrochloride buffer.Renaturation of the denatured protein was carried out in the defined protein refolding buffer,and the refolded protein was purified using S-Sepharose ion-exchange chromatography.The final preparation of the rhMK was greater than 98% pure as measured by sodium dodecylsulfate-polyacrylamid gel electrophoresis (SDS-PAGE) and reverse phase high performance liquid chromatography (RP-HPLC).The purified rhMK enhanced the proliferation of NIH3T3 cells.     

污水处理系统中肠出血性大肠杆菌O157噬菌体的分离及其生物学特性

采用双层平板法从污水处理厂曝气池中分离出一株肠出血性大肠杆菌O157强裂解性噬菌体,命名为PO157-Z。通过透射电镜、基因组酶切以及最佳感染复数、裂解曲线和酸碱耐受性等生物学特性测定分析发现:噬菌体PO157-Z头部呈正六面体的立体对称结构,直径约70 nm,尾部较短,长和宽均约10 nm.EcoR I酶切表明,其核酸类型为dsDNA.该噬菌体的最佳感染复数为0.01,其对酸碱耐受性较好,且耐受范围较宽.此外,对宿主菌的裂解曲线进一步表明,其对大肠杆菌O157具有高效快速的裂解作用.因此, PO157-Z作为一株肠出血性大肠杆菌O157强裂解性噬菌体,属dsDNA短尾科噬菌体,其对宿主菌的高效裂解性以及强酸碱耐受性等特点,为污水处理系统中大肠杆菌O157的生物防控,提供了新思路和技术支持.     

Sensing Escherichia coli O157：H7 via frequency shift through a self-assembled monolayer based QCM immunosensor

By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157H7 detection was developed in this work. As a suitable surfactant, 16-mercaptohexadecanoic acid (MHDA) was introduced onto the Au surface of QCM, and then self-assembled with N-hydroxysuccinimide (NHS) raster as a reactive intermediate to provide an active interface for the specific antibody immobilization. The binding of target bacteria with the immobilized antibodies decreased the sensor's resonant frequency, and the frequency shift was correlated to the bacterial concentration. The stepwise assembly of the immunosensor was characterized by means of the electrochemical techniques. Using the immersion-dry-immersion procedure, this QCM biosensor could detect 2.0×102 colony forming units (CFU)/ml E. coli O157H7. In order to reduce the fabrication time, a polyelectrolyte layer-by-layer self-assembly (LBL-SA) method was adopted for fast construction. Finally, the reproducibility of this biosensor was discussed.     

基于自组装及纳米磁球放大的大肠杆菌O157：H7的压电免疫检测

应用压电免疫传感器快速检测了大肠杆菌O157:H7(E．coli O157:H7)．将巯基乙酸(MACA)自组装在AT切向的压电金电极上,以N-羟基琥珀酰亚胺(NHS)为反应介质,形成酰氨键固定大肠杆菌抗体．并通过α-甲基丙烯酸(MAA)把抗体修饰在纳米磁球上,采用夹心法将抗原夹在两个抗体间,压电石英晶体交流阻抗(PQCI)和循环伏安法对修饰过程进行了表征,抗原浓度与形成夹心复合物前后的PQCI振动频移相关,其免疫传感器能在3h内检测2×103-8×108CFU／mL范围内的目标细茵,105CFU／mL情况下重复性实验的RSD在7％以下。     

大肠杆菌生产基因重组草鱼生长激素的分离纯化

草鱼生长激素cDNA在大肠杆菌细胞中表达后，重组草鱼生长激素在胞内形成不溶性的包含体．这种包含体在洗涤、变性、复性和C12反相层析等步骤后，产物再经快速蛋白液相色谱，重组草鱼生长激素在SDS-聚丙烯酰凝胶电泳中显示均一性，纯度可达90％放射免疫分析表明：重组草鱼生长激素具有草鱼生长激素的免疫活住．分离纯化产率约为1L细菌培养液1～2m重组草鱼生长激素．