不同pH值纳米羟基磷灰石复合根充糊剂的体外抑菌性

背景：目前临床应用的根管充填糊剂抗菌作用有限,存在组织刺激性强、成形困难、根管封闭性较差及易降解等缺点。 目的：比较不同pH值纳米羟基磷灰石复合根充糊剂对感染根管常见菌的体外抑菌作用。 方法：建立体外根管粪肠球菌、白色念球菌感染模型,评价pH 8纳米羟基磷灰石糊剂、pH 9纳米羟基磷灰石糊剂、pH 10纳米羟基磷灰石糊剂在离体牙根管内的抗菌作用,并以氧化锌丁香油做对照。 结果与结论：所有根充糊剂均具有抑菌作用。各pH值纳米羟基磷灰石糊剂对粪肠球菌抑制作用实验组优于氧化锌丁香油组(P < 0.05),不同pH值纳米羟基磷灰石组组间比较差异无显著性意义(P > 0.05)。而对白色念珠菌抑制作用各pH值纳米羟基磷灰石组不及氧化锌丁香油组(P < 0.05),各pH值纳米羟基磷灰石组组间比较,pH10纳米羟基磷灰石组>pH 9纳米羟基磷灰石组>pH 8纳米羟基磷灰石组(P < 0.05)。结果表明,感染根管模型中,纳米羟基磷灰石根充糊剂对粪肠球菌的抑制作用好于氧化锌丁香油(P < 0.05),而对白色念珠菌的抑制作用不及氧化锌丁香油(P < 0.05)。pH=10纳米羟基磷灰石复合根充糊剂的抑菌作用最佳。     

三种新型糊剂类根管充填材料在根管治疗中的应用

目的:总结近年3种新型糊剂类根管充填材料(Cortisomol、Vitapex、AH-Plus)在根管治疗中的应用现状。方法:由作者应用计算机检索维普数据库中与3种糊剂类根管充填材料(Cortisomol、Vitapex、AH-Plus)在根管治疗中应用相关的文章,检索时限2006-01/2010-08。检索关键词:Cortisomol;Vitapex;AH-Plus;根管治疗;根管充填;并发症。纳入标准:①糊剂类根管充填材料在根管治疗中应用的文章。②实验结果叙述与材料有关的并发症问题。排除标准:重复研究或较陈旧文献。根据纳入排除标准共保留相关文献19篇。结果:Cortisomol、Vitapex、AH-Plus较以往常用的氧化锌丁香油糊剂有着较为突出的优势,术后的失败率均明显低于ZOE氧化锌丁香油糊剂,三者之间又各有其特点,Cortisomol对于根尖封闭的作用最为突出,而Vitapex在乳牙根管治疗中的作用无可替代,AH-Plus作为三者中最新型的糊剂类根充材料,相关的研究较少,其特点尚待进一步研究确认。结论:Cortisomol、Vitapex、AH-Plus3种材料的根管治疗成功率均较高,值得在临床推广使用。同时,3者又有其不同的特点和用途,在治疗中应加以选择性的应用。     

三种根充糊剂根尖封闭能力的比较研究

目的 利用葡萄糖定量法检测根管微渗漏模型,评价三种根充糊剂的根尖封闭性能.方法 收集新鲜拔除的人前牙65颗,随机分为A、B、C 三个实验组(每组20颗牙齿)和D组作为对照组(5颗牙齿),A、B、C组分别采用AH-Plus糊剂、新型纳米羟基磷灰石根管充填糊剂(n-HA)、氧化锌丁香油(ZOE)糊剂加牙胶尖侧压充填根管.D组为阴性对照组,用粘蜡充填根管.牙根外表面、根管口及根尖孔处涂二层指甲油.于第7 d、14 d、21 d、28 d用葡萄糖氧化酶法检测从冠方向根方漏出的葡萄糖量.结果 采用重复测量方差分析,发现第7d、14d、21d、28d A、C组,B、C组及C、D组微渗漏值有显著性差异(P<0.01),A、B组微渗漏值无显著性差异(P>0.05).但各组第7 d与第28d微渗漏值比较有显著性差异(P<0.05).结论 AH-Plus糊剂、新型纳米羟基磷灰石根管充填糊剂(n-HA)的根尖封闭性优于氧化锌丁香油ZOE糊剂.而前两种糊剂的根尖封闭性能相当.     

Vitapex糊剂用于一次性根充术后急症反应的临床观察

目的 比较Vitapex糊剂和氧化锌丁香油糊剂加牙胶尖两种根管充填材料一次性根充后急性反应情况.方法 临床上随机选择247例需要进行根管治疗随机分成实验组与对照组,实验组患牙采用Vitapex糊剂加牙胶尖冷侧压法根充,对照组患牙用氧化锌丁香油糊剂根充,观察术后一周内急性反应的发生情况,用x?检验分析比较.结果 经统计学检验两种术后急性疼痛反应情况,实验组Vitapex糊剂组明显低于对照组氧化锌丁香油糊剂组,两组根充后急性反应比较差异均有统计学意义(P<0.05).结论 Vitapex糊剂加牙胶尖对患牙做一次性根管充填,其术后急性疼痛反应明显减少.     

纳米含氟羟基磷灰石牙种植体的生物相容性

背景：有关纳米含氟羟基磷灰石牙种植体材料生物相容性的报道较少。 目的：检测纳米含氟羟基磷灰石牙种植体材料的体外生物相容性。 方法：采用溶胶凝胶技术分别制备羟基磷灰石与纳米含氟羟基磷灰石。①溶血性实验：在0.2 mL稀释兔抗凝血中分别加入0.01,0.15,0.2 g/L纳米含氟羟基磷灰石溶液、生理盐水及蒸馏水各10 mL,检测各组上清液吸光度值。②体外细胞毒性实验：分别以100%,50%纳米含氟羟基磷灰石浸提液、100%羟基磷灰石浸提液、苯酚溶液及RPMI1640培养液培养传至第2代的L929细胞,MTT法检测培养2,4,7 d的吸光度值。 结果与结论：体外溶血性实验显示,各浓度梯度纳米含氟羟基磷灰石的溶血率均在5%以内,符合医用材料的溶血要求。体外细胞毒性实验显示,随着培养时间的增加,100%,50%纳米含氟羟基磷灰石浸提液组细胞贴壁覆盖率增加,细胞密度增高,细胞为长梭形或多角形,细胞增殖及形态与RPMI1640培养液组、羟基磷灰石组无明显差别,细胞毒性为0级。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

纳米羟基磷灰石/聚羟基丁酸酯骨组织工程支架的制备及性能表征

背景：高分子聚合物聚羟基丁酸酯具有优良的生物相容性、生物降解性及压电性,但也存在脆性大、亲水性较差等不足。 目的：制备不同组成比例的电纺纳米羟基磷灰石/聚羟基丁酸酯纤维支架材料,分析其结构及性能。 方法：通过气流-高压静电纺丝技术制备纳米羟基磷灰石质量百分比分别为0、10%、20%、30%的电纺纳米羟基磷灰石/聚羟基丁酸酯纤维支架,检测支架材料的微观结构、基团组成、晶相分布、热学性能及表面润湿性。 结果与结论：扫描电镜观察显示,随着纳米羟基磷灰石含量的增大,越来越多的纳米羟基磷灰石颗粒分布于复合纤维表面且分布趋于均匀,到含量达到30%时,纳米羟基磷灰石已基本布满纤维表面,纤维表面的粗糙度也随之增加;差示扫描量热法及X射线衍射结果表明,纳米羟基磷灰石的加入可以降低复合纤维中聚羟基丁酸酯的结晶度及结晶规整程度,且纳米羟基磷灰石含量越大效果越明显;随着纳米羟基磷灰石含量的增大,复合支架表面的接触角逐渐降低,亲水性有所提高。表明将纳米羟基磷灰石与聚羟基丁酸酯复合进行电纺可以有效提高材料的表面润湿性及结晶度,改善材料的亲水性及脆性,且纳米羟基磷灰石含量越高作用越明显。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

低温快速成型亲水改性复合人工骨支架的性能测定

背景：低温快速成型技术具有支架成型可控性、保持材料生物学活性和易于实现支架材料的三维多孔立体结构等优势,被迅速用于骨组织工程支架的制备。 目的：采用低温快速成型制备聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石复合支架,并检测其性能。 方法：采用低温快速成型设备分别制备聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石与聚乳酸-乙醇酸/纳米羟基磷灰石复合支架,通过电镜观察支架超微结构,以介质(乙醇)浸泡法测定支架孔隙率,采用电子试验机检测支架力学性能;将两种支架材料分别与大鼠成骨细胞共培养,培养12 h采用沉淀法检测细胞黏附率,培养1,3,5,7,9,12 d采用CCK-8法检测细胞增殖。 结果与结论：两组支架孔径均在理想范围内并具有较高孔隙率,但聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石支架的孔径波动范围大,孔径均值较聚乳酸-乙醇酸/纳米羟基磷灰石支架小且部分有闭塞现象。聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石支架的细胞黏附率及表面细胞增殖活性高于聚乳酸-乙醇酸/纳米羟基磷灰石支架(P < 0.05),力学性能低于聚乳酸-乙醇酸/纳米羟基磷灰石支架(P < 0.05)。表明聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石复合支架具有良好的细胞相容性。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

纳米银羟基磷灰石涂层正畸陶瓷托槽的抗菌与力学性能

背景：临床口腔正畸过程中,陶瓷托槽存在抗菌性能和力学性能不足的情况,容易导致各种不良事件的出现,影响正畸效果。 目的：观察纳米银羟基磷灰石涂层陶瓷托槽的抗菌与力学性能。 方法：制备纳米银羟基磷灰石涂层陶瓷托槽,采用扫描电镜观察涂层表面,并进行涂层表面定量抗菌实验。将50颗离体人上颌前磨牙随机分为2组,实验组(n=25)粘接纳米银羟基磷灰石涂层陶瓷托槽,对照组(n=25)粘接普通陶瓷托槽,检测两组抗剪切强度。 结果与结论：纳米银羟基磷灰石涂层整体结构有序,均匀致密,羟基磷灰石具有多孔状结构,孔径属于微纳米级别,其中均匀分布大量纳米银颗粒。定量抗菌实验显示,纳米银羟基磷灰石涂层陶瓷托槽对大肠杆菌、白色葡萄球菌有较强的抑制作用,抗菌率均在95%以上。实验组抗剪切强度低于对照组(P < 0.05)。表明纳米银羟基磷灰石涂层陶瓷托槽具有良好的抗菌和力学性能,满足临床正畸过程中力学变化的需求。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程      

纳米羟基磷灰石对人脐带静脉血管内皮细胞的毒性评价

背景：有研究应用脉冲激光沉积合成技术在人工心脏机械瓣膜上沉积胶原制备了新型纳米羟基磷灰石薄膜涂层。 目的：观察此种新型纳米羟基磷灰石薄膜对人脐带静脉血管内皮细胞的毒性。 方法：分别采用纳米羟基磷灰石薄膜常温浸提液、纳米羟基磷灰石薄膜高温浸提液、高密度聚乙烯及苯酚溶液培养人脐静脉血管内皮细胞,72 h内倒置相差显微镜下观察细胞生长状况;培养7 d时采用CCK-8法检测细胞增殖与毒性分级。 结果与结论：培养24 h,纳米羟基磷灰石薄膜常温浸提液组、纳米羟基磷灰石薄膜高温浸提液组和高密度聚乙烯组细胞生长良好,呈梭形,折光性强,3组细胞形态、数量无明显差异;苯酚溶液组细胞多为悬浮、圆形、固缩的死细胞;48 h时,除了苯酚溶液组外,其余3组细胞数量明显增加,细胞生长密集,至72 h时细胞生长旺盛,间隙显著减小。培养7 d内,纳米羟基磷灰石薄膜常温浸提液组、纳米羟基磷灰石薄膜高温浸提液组和高密度聚乙烯组细胞增殖活性无差异,均高于苯酚溶液组(P < 0.05),纳米羟基磷灰石薄膜毒性级别为0至1级,表明纳米羟基磷灰石人工心脏机械瓣膜有良好的组织细胞相容性,无毒性作用。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

杜仲胶作为根管充填材料的可行性

背景：杜仲胶具有较好的热塑性、流动性、黏结性及抗菌性,目前尚无将其用于根管充填材料的研究。 目的：比较不同含量气相纳米二氧化硅对以杜仲胶为基质复合材料力学性能的影响,以及充填根管后的效果观察。 方法：在硫酸钡(20%)及纳米羟基磷灰石(10%)质量分数恒定的情况下,分别加入不同质量分数的杜仲胶与气相纳米二氧化硅(40%与15%,45%与20%,50%与25%,55%与30%),制备4组根管填充复合材料,以纯杜仲胶作为空白对照,检测5组材料的硬度、拉伸强度及断裂伸长率。采用ObturaⅡ技术将4组复合材料与杜仲胶、古塔胶颗粒充填到新鲜拔出的前磨牙根管中,X射线片及扫描电镜观察根管充填效果。 结果与结论：随着气相纳米二氧化硅含量的增加,杜仲胶复合材料的硬度呈上升趋势,拉伸强度呈先增大后减小的趋势,断裂伸长率呈降低趋势。杜仲胶组对X射线透射,无法显示充填材料的影像,4组复合材料均具有一定的X射线阻射性,显示复合材料均充填至根管中且充填均匀,充填物内无气泡,与根管内壁接触良好,充填效果满意;扫描电镜显示,杜仲胶组材料表面指状突起最多最长,随着气相纳米二氧化硅含量的增加,4组复合材料表面的指状突起长度呈降低趋势。表明杜仲胶复合材料在热流动状态下可注入根管内达到较好的封闭效果。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

口腔纳米载银无机抗菌材料的抗菌性能

背景：纳米载银无机抗菌剂具有抗菌谱广、抗菌能力强等特点,是目前口腔无机抗菌材料研究的热点之一。 目的：研究纳米载银无机抗菌材料的抗菌性能及抗菌机制,为基础实验研究和临床应用提供参考信息。 方法：研究多种口腔纳米载银无机抗菌材料对常见病原菌如变形链球菌、白色念珠菌以及粘性放线菌等的抗菌性能,其中包括最低杀菌浓度以及抗菌率等,同时进行对比分析。并且研究纳米载银无机抗菌材料的抗菌机制,明确其优点与不足。 结果与结论：口腔纳米载银无机抗菌材料具有较广的抗菌谱,对变形链球菌、乳酸杆菌、粘性放线菌、白色念珠菌、牙龈卟啉单胞菌、金黄色葡萄球菌以及大肠埃希菌等均具有较强的抗菌性能,最低杀菌浓度较低,而抗菌率较高。但是同一纳米载银无机抗菌材料对不同的病原菌,其最低杀菌浓度不同,抗菌率也不同,而不同的纳米载银无机抗菌材料对同一病原菌的最低杀菌浓度也不相同,抗菌率也不同。     

Antimicrobial activity and tightness of a DCPD-CaO-based hydraulic calcium phosphate cement for root canal filling

Calcium hydroxide is currently used in dentistry for endodontic treatments where its main advantage is its antibacterial and anti-inflammatory activity. However, it also has some drawbacks such as pulp necrosis, slight solubility, slow and insufficient hardening, and retraction on drying. In consequence, it is used only as temporary material for root canal disinfection. By mixing calcium hydrogen phosphate dihydrate (CaHPO4 . 2H2O, also called dicalcium phosphate dihydrate, DCPD) and calcium oxide with a sodium phosphate buffer as liquid phase, we obtained a CPC with better mechanical properties than calcium hydroxide pastes. The setting reaction produced either hydroxyapatite (HA) or a mixture of HA and calcium hydroxide depending on the relative masses of DCPD and CaO in the cement powder. The presence of calcium hydroxide a priori confers antimicrobial properties to this cement which were investigated in agar plates (diffusion method) against Streptococcus mutans, Lactobacillus acidophilus, Candida albicans, Enterococcus faecalis, Staphylococcus hominis (clinical isolates), and a preparation of polymicrobial flora isolated from dental plaque. The cement samples tested were prepared at molar calcium-to-phosphate ratios (Ca/P) of 1.67 to 2.75. A pure calcium hydroxide paste was used as reference material. Clear and reproducible bacterial growth inhibition was observed for cement samples with Ca/P > or = 2 against all the microorganisms tested. With Ca/P = 2.5, this cement alkalinizes dentinal tubules and provides a fluid-tight sealing that well compares with sealing obtained using a zinc oxide-eugenol cement without gutta-percha point. DCPD-CaO-based cement is therefore a potential root canal filler.     

Antimicrobial activity of cytotoxic drugs may influence isolation of bacteria and fungi from blood cultures.

The potential antimicrobial activity of cyclophosphamide, vincristine, and adriamycin against Gram positive and negative bacteria and Candida albicans was examined. The time taken for different microbial inocula to turn a simulated blood culture positive in the presence of different concentrations of these drugs was measured. Doxorubicin retarded the growth of Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus sanguis in a concentration dependent manner. Cyclophosphamide and vincristine showed minimal antimicrobial activity. Escherichia coli and Pseudomonas aeruginosa were unaffected by any of the drugs. An inoculum dependent effect was seen with some combinations of microbial inocula and cytotoxic drug concentrations.     

An N-halamine-based rechargeable antimicrobial and biofilm controlling polyurethane

An N-halamine precursor, 5,5-dimethylhydantoin (DMH), was covalently linked to the surface of polyurethane (PU) with 1,6-hexamethylene diisocyanate (HDI) as the coupling agent. The reaction pathways were investigated using propyl isocyanate (PI) as a model compound. The results suggested that the imide and amide groups of DMH have very similar reactivities toward the isocyanate groups on PU surfaces activated with HDI. After bleach treatment the covalently bound DMH moieties were transformed into N-halamines. The new N-halamine-based PU provided potent antimicrobial effects against Staphylococcus aureus (Gram-positive bacterium), Escherichia coli (Gram-negative bacterium), methicillin-resistant Staphylococcus aureus (MRSA, drug-resistant Gram-positive bacterium), vancomycin-resistant Enterococcus faecium (VRE, drug-resistant Gram-positive bacterium), and Candida albicans (fungus), and successfully prevented bacterial and fungal biofilm formation. The antimicrobial and biofilm controlling effects were stable for longer than 6 months under normal storage in open air. Furthermore, if the functions were lost due to prolonged use they could be recharged by another chlorination treatment. The recharging could be repeated as needed to achieve long-term protection against microbial contamination and biofilm formation.     

Effects of pH and salinity on the antimicrobial properties of clavanins.

Clavanins are histidine-rich, amidated alpha-helical antimicrobial peptides that were originally isolated from the leukocytes (hemocytes) of a tunicate, Styela clava. The activities of clavanin A amide and clavanin A acid against Escherichia coli, Listeria monocytogenes, and Candida albicans were substantially greater at pH 5.5 than at pH 7.4. In contrast, clavanin AK, a synthetic variant of clavanin A acid containing 4 histidine-->lysine substitutions exerted substantial activity at both pH 7.4 and pH 5.5. Each of these three clavanins permeabilized the outer and inner membranes of E. coli very effectively at pH 5.5, but only clavanin AK did so at pH 7.4. Unlike magainin 1 and cecropin P1, alpha-helical antimicrobial peptides from frog skin and porcine intestine, respectively, clavanins were broadly effective against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus, as well as gram-negative organisms. Because clavanins exert substantial antimicrobial activity in 0.1 to 0.3 M NaCl, they provide templates for designing broad-spectrum peptide antibiotics intended to function in extracellular environments containing normal or elevated NaCl concentrations. The pH-dependent properties of histidine-rich antimicrobial peptides may allow the design of agents that would function selectively in acidic compartments, such as the gastric lumen, or within phagolysosomes.     

Surface antimicrobial activity and biocompatibility of incorporated polyethylenimine nanoparticles

The antimicrobial effect and biocompatibility of insoluble cross-linked quaternary ammonium polyethylenimine (PEI) nanoparticles incorporated at 1 or 2%w/w in a resin composite were assayed. The antimicrobial effect against Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli was tested using the direct contact test (DCT), agar diffusion test (ADT) and scanning electron microscopy (SEM). Biocompatibility was tested by assessing macrophage viability, and TNFalpha secretion. Samples incorporating 2%w/w nanoparticles inhibited the growth of all bacterial strains tested. Reducing the amount of the added nanoparticles to 1%w/w resulted in complete inhibition of S. aureus and E. faecalis, and decreased growth of S. epidermidis, P. aeruginosa and E. coli (p<0.0001). The DCT results were confirmed by SEM. However, ADT showed no inhibition halo in all test bacteria, indicating the antimicrobial nanoparticles are not diffusing into the agar milieu. Biocompatibility tests revealed macrophage viability, and TNFalpha secretion was not altered by the presence of the nanoparticles in the resin. Incorporation of PEI nanoparticles in a resin composite had a long lasing antimicrobial effect against a wide range of bacteria with no measured effect on biocompatibility.     

1999-2006年北京朝阳医院革兰阳性球菌耐药性分析

目的 探讨北京朝阳医院1999-2006年临床分离的革兰阳性球菌的耐药变迁,以指导临床合理使用抗菌药物.方法 采用MIC法进行抗菌药物敏感性试验,以WHONET5.3软件分析数据.结果 6192株临床分离的革兰阳性球菌中,前4位病原菌依次为凝同酶阴性葡萄球菌、金黄葡萄球菌、粪肠球菌、屎肠球菌.耐甲氧西林金黄葡萄球菌(MRSA)、耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)平均检出率分别为88.4%、86.9%,金黄葡萄球菌对青霉素、氨苄西林耐药率最高,8年间始终保持在90.0%以上.未发现对万古霉素耐药或中介的金黄葡萄球菌或凝固酶阴性葡萄球菌.2003年首次分离耐万古霉素肠球菌(VRE),至2006年共发现30株VRE,其中13株为耐万古霉索粪肠球菌,均为VanB基因型;17株为耐万古霉素屎肠球菌,均为VanA基因型,耐万古霉素屎肠球菌分离率呈上升趋势.对于粪肠球菌活性最高的是万古霉素、氨苄西林、青霉素,敏感率分别为98.7%、95.7%、85.6%.但是青霉素敏感性略有下降,从94.3%降至84.6%.克林霉素的耐药率8年中始终维持在99.0%以上.屎肠球菌对红霉素、克林霉素的耐药率均达95.0%以上,对青霉素、氨苄西林、环丙沙星的耐药率均大于90.0%.屎肠球菌最为敏感的药物是万古霉素,对四环素敏感性出现上升的趋势,从27.8%升到82.6%.结论 万古霉素对临床常见的革兰阳性菌保持很高的活性,发现30株耐万古霉素的肠球菌.     

气相法纳米二氧化硅季胺盐衍生物的合成和性能

考察实验室制备的一种气相法纳米二氧化硅季胺盐衍生物的合成及抗菌性能。通过红外光谱、激光粒度Zeta电位仪对气相法纳米二氧化硅季铵盐衍生物进行表征和测定．用悬菌定量实验（Suspension quantitative test）研究其抗菌性能，结果显示：（1）气相法纳米二氧化硅的零点位在pH=4．8，气相法纳米二氧化硅季铵盐衍生物的零电位在pH=10．5～10．8之间．季铵盐的引入使其零电位发生了较大的位移；（2）悬菌定量实验对大肠杆菌（8099）。金黄色葡萄球菌（ATCC6538）以及白色念珠菌（ACTT10231）的15min抑菌率分别为99．99％，99．99％和94．12％，显示气相法纳米二氧化硅季胺盐衍生物对细菌有较强的抑菌效果。     

Evaluation of a novel automated chemiluminescent assay system for antimicrobial susceptibility testing

The newly developed Rapid Lumi Eiken/IS60 (RL/IS60) system automatically determines MICs by detecting chemiluminescence produced in the reaction of a chemiluminescent probe and oxygen metabolites from living microorganisms. The present study evaluated this system for accuracy in antimicrobial susceptibility testing. Chemiluminescence intensities after 4 h of cultivation of clinically important strains were plotted against various concentrations of antimicrobial agents, which resulted in curves reflecting the levels of susceptibility. Sixty-percent inhibitory concentrations based on the susceptibility curves agreed with MICs determined by the reference microdilution method. When the MICs of antimicrobial agents for four quality control (QC) strains (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa) were determined by the RL/IS60 system, most (91.1%) of them were within the QC limits proposed by the National Committee for Clinical Laboratory Standards. The system was further assessed for a total of 162 clinical isolates, including E. coli, Citrobacter freundii, Enterobacter cloacae, Klebsiella pneumoniae, Serratia marcescens, Proteus mirabilis, Morganella morganii, P. aeruginosa, Haemophilus influenzae, S. aureus, coagulase-negative staphylococci, Enterococcus faecalis, Enterococcus faecium, and Streptococcus pneumoniae. Overall, there was 90.6% agreement between the RL/IS60 system and the reference microdilution method. Our results suggest that the RL/IS60 system provides rapid and reliable MICs of a variety of antimicrobial agents for clinical isolates as well as QC strains.