卡泊芬净对生物膜态白色念珠菌体外抑菌作用的试验研究

目的:检测卡泊芬净对生物膜态白色念珠菌分离株的抑菌作用,探讨临床治疗其相关感染的最适治疗剂量。方法:分别测定卡泊芬净对10株白色念珠菌临床株游离态及生物膜态的半数抑菌浓度(MIC50),并对比观察不同浓度卡泊芬净作用下白色念珠菌的增殖活性。结果:卡泊芬净对游离态白色念珠菌的MIC50为0.125～0.5mg.L-1,对生物膜态白色念珠菌的MIC50为0.25～256mg.L-1,当卡泊芬净浓度高于白色念珠菌MIC50时,全部游离态白色念珠菌的增殖活性几乎完全受到抑制,但有7株生物膜态白色念珠菌的增殖活性再次增强,且大于阳性对照的50%。结论:卡泊芬净对生物膜态白色念珠菌有抑菌作用,但并不呈浓度依赖性,当其用于治疗生物膜态白色念珠菌相关感染时的最适治疗剂量有待临床研究验证。     

卡泊芬净治疗老年COPD患者侵袭性肺部真菌感染36例临床分析

目的 观察老年COPD患者应用卡泊芬净治疗侵袭性真菌感染(IFI)的疗效与安全性.方法 回顾分析本院老年临床医学部呼吸内科诊断为IFI并接受卡泊芬净治疗的COPD患者的临床资料.结果 2009年10月～2010年12月共36例COPD患者接受了卡泊芬净治疗,确诊4例,包括念珠菌菌血症2例(光滑念珠菌1例,热带念珠菌l例),肺IFI 2例,为曲霉菌;临床诊断20例,其中曲霉菌15例,白念珠菌5例;拟诊12例,包括白念珠菌6例,光滑念珠菌2例,近平滑念珠菌2例,曲霉菌2例.卡泊芬净的疗程(16.5±6.5)d,痊愈+显效的总有效率72.2％,进步22.2％,无效5.6％.治疗过程中未发现与卡泊芬净有关的不良反应.结论 卡泊芬净治疗老年COPD患者合并IFI有效且安全.     

卡泊芬净的药理特性与临床应用

卡泊芬净（Caspofungin）是第一个获准用于治疗侵袭性真菌感染的棘白菌素类药物。体外体内试验证实卡泊芬净对于重要机会感染病原菌-念珠菌和曲霉菌均具有良好抗菌活性。卡泊芬净通过抑制1,3-β-葡聚糖的合成使得细胞壁破裂,临床显示卡泊芬净对治疗各种念珠菌病和曲霉菌病的均有良好效果。同时还具有良好的安全性与患者耐受性。但是其药理特性相对较复杂,目前了解也不是非常多。     

卡泊芬净引起严重可逆性血小板减少

卡泊芬净(caspofungin)是第一个批准用于抗真菌的一线药物，也被称作棘白菌素。近来被FDA批准其用于治疗曲霉属真菌和念珠菌病的感染。通过阻断真菌细胞壁的重要组分β—(1，3)—D—葡聚糖的合成来抑制念珠菌属真菌的生长。与两性霉素B相比，卡泊芬净的副作用更轻。但是由于其安全性数据是从总数不足1000例的服用单或多剂量卡泊芬净的患者中统计获得，因此临床医生对其进行持续的用药后监测就极为重要。     

基于生物信息学和分子对接分析卡泊芬净引起转氨酶升高的作用机制

目的 研究卡泊芬净引起转氨酶升高的分子作用机制。方法 借助STITCH数据库、Drug Bank数据库及在线的Swiss Target Prediction搜集卡泊芬净的基因靶点;利用DisGeNET数据库筛选转氨酶升高的基因靶点;用Origin2019软件绘制韦恩图,找到卡泊芬净导致肝功能损伤的潜在基因靶点;通过DAVID数据库的通路分析,确定对接的基因靶点;以酮康唑化学结构为参比,运用Auto Dock vina分别对卡泊芬净、酮康唑对接;使用Chimera对卡泊芬净与基因靶点的对接结果进行分析和展示。结果 14个潜在基因靶点为卡泊芬净导致转氨酶升高的靶点。通路分析后,确定MMP9,STAT3和CASP8为对接的基因靶点。卡泊芬净和酮康唑均与对接基因靶点有较稳定的结合,但酮康唑的结合能小于卡泊芬净。对接结果分析表明：卡泊芬净与MMP9蛋白D链有3条氢键形成,与STAT3蛋白A链有2条氢键形成,与CASP8蛋白无氢键形成。结论 卡泊芬净和酮康唑均可导致转氨酶升高,但卡泊芬净引起转氨酶升高的发生率低于酮康唑;卡泊芬净引起转氨酶升高的作用机制可能是与MMP9、STAT3形成氢键,从而激活...     

氨基丁酸联合卡泊芬净的体外抗白色假丝酵母菌协同作用研究

目的探讨氨基丁酸联合卡泊芬净体外抗白色假丝酵母菌的协同作用。方法采用CLSI公布的M27-A方案微量棋盘液基稀释法测定氨基丁酸单用以及联合卡泊芬净对白色假丝酵母菌标准株SC5314的MIC80值和FICI值。采用抗真菌试管敏感性实验,考察给药24h后,卡泊芬净单用以及氨基丁酸联合卡泊芬净对白色假丝酵母菌SC5314生长的影响。采用生长曲线实验,测定氨基丁酸联合卡泊芬净抗白色假丝酵母菌SC5314的生长曲线。结果氨基丁酸单用对白色假丝酵母菌SC5314的MIC80>20μmol·L-1,说明氨基丁酸单用对SC5314没有抑菌作用;但1.25μmol·L-1氨基丁酸与卡泊芬净合用的FICI<0.5,说明氨基丁酸与卡泊芬净合用表现出协同关系。另外,在抗真菌试管敏感性实验中,1.25μmol·L-1的氨基丁酸联合0.012 5μg·mL-1的卡泊芬净与0.012 5μg·mL-1的卡泊芬净单用组相比,可以直观地观察到试管内浑浊程度明显减弱,SC5314的生长受到抑制。在生长曲线实验中,1.25μmol·L-1氨基丁酸联合0.012 5μg·mL-1卡泊芬净的生长曲线显著低于同浓度下两药单用的生长曲线(P<0.05)。结论氨基丁酸本身对白色假丝酵母菌标准株SC5314没有抑菌作用,但氨基丁酸能显著增强卡泊芬净对白色假丝酵母菌SC5314的杀菌作用。     

21世纪上市新抗菌药物临床应用现状(三)

<正>1抗真菌药卡泊芬净卡泊芬净(caspofungin)[1,2],商品名科塞斯(cancidas),已于2001年2月获得美国FDA批准上市。本品为棘白菌素类的第一个品种,这类新型抗真菌药的作用机制为通过非竞争性抑制β-(1,3)-D-葡聚糖苷合成酶,从而破坏真菌细胞壁糖苷的合成。卡泊芬净对真菌生物被膜(biofilm)有较好的抑制作用。     

棘白菌素类抗真菌药物卡泊芬净的临床应用研究

目的对抗真菌药物棘白菌素类卡泊芬净在临床上的应用进行研究和探讨。方法通过研究棘白菌素类卡泊芬净的抗真菌机制、抗菌作用和临床应用,对棘白菌素类抗真菌药物卡泊芬净的作用机制及临床应用进行综合评价。结果棘白菌素类抗真菌药物卡泊芬净,其作用机制为对真菌细胞壁上的β-(1,3)-D-葡聚糖合成进行非竞争性抑制,将真菌细胞壁的正常结构破坏,能有效的对抗真菌活性。结论在治疗真菌引起的疾病时,棘白菌素类卡泊芬净可作为治疗的首选药物,在治疗侵袭性曲霉菌感染的患者在无法耐受其他类药物以及其他类抗菌药物治疗无效时,可选用此药。     

卡泊芬净联合伏立康唑、伊曲康唑或两性霉素B对尖端赛多孢子菌体外抑菌活性

目的 观察卡泊芬净(棘白霉素类抗真菌药)联合伏立康唑、伊曲康唑(三唑素)或两性霉素B(多烯类).作用于15株尖端赛多孢子菌的体外抑菌活性.方法 参照美国国家临床和实验室标准研究所(CLSI)的M38-A方案,药物间相互作用用分数抑菌浓度(FIC值)表示.结果 体外单独用药时,伏立康唑的MIC值的几何均数(GM)显著低于其他药物.在15株受试菌中,卡泊芬净与伊曲康唑联合时,全部菌株显示为协同作用;卡泊芬净与两性霉素B联合时,有27%的菌株显示为协同作用;卡泊芬净与伏立康唑联合时,均表现为无关作用.结论 卡泊芬净可增强伊曲康唑的体外抗真菌活性,卡泊芬净与伊曲康唑联合用药有望作为临床上治疗尖端赛多孢子菌感染的一种有效方法.     

氨基丁酸联合卡泊芬净抗白色假丝酵母菌生物被膜协同作用研究

目的探讨氨基丁酸联合卡泊芬净抗白色假丝酵母菌生物被膜的协同作用。方法利用白色假丝酵母菌标准菌株SC5314,采用生物被膜形成实验,分为空白对照组、氨基丁酸单用组、卡泊芬净单用组、氨基丁酸联合卡泊芬净组,对比各组生物被膜形成情况。采用XTT还原法测定氨基丁酸、卡泊芬净单用以及氨基丁酸联合卡泊芬净对成熟生物被膜细胞代谢活性的抑制作用。采用YNB培养基菌丝形成实验,考察氨基丁酸与卡泊芬净合用是否具有协同抑制菌丝形成的作用。结果卡泊芬净0.1μg·mL-1联合氨基丁酸0.1μmol·L-1对白色假丝酵母菌SC5314生物被膜的形成具有显著的抑制作用。此外,XTT还原法测定氨基丁酸6.25μmol·L-1联合卡泊芬净0.1μg·mL-1时降低被膜细胞代谢活性的效率能够达到约15%。采用YNB培养基形成菌丝,氨基丁酸6.25μmol·L-1联合卡泊芬净0.1μg·mL-1对白色假丝酵母菌SC5314菌丝形成能力有显著的抑制作用。结论氨基丁酸联合卡泊芬净表现出显著的体外协同抗白色假丝酵母菌标准菌株SC5314生物被膜作用。     

ε-聚赖氨酸对白念珠菌抑菌活性及机制研究

目的 研究ε-多聚赖氨酸(ε-poly-L-lysine, ε-PL)对白念珠菌(Candida albicans)的抑菌活性及抑菌机制。方法 以白念珠菌的标准菌株ATCC64548(氟康唑敏感株)、ATCC64550(氟康唑耐药株)以及临床收集的50株菌为实验菌株,按照CLISI- M27文件中的微量稀释法测定ε-多聚赖氨酸的MIC、MFC和SMIC50值;绘制48h内的浮游菌株时间-生长曲线和生物膜抑制-时间曲线;连续观测并记录4h内的芽管形成率和芽管长度;测定药物处理前后白念珠菌的丙二醛和活性氧(ROS)含量。结果 ε-PL对白念珠的最低抑菌浓度(MIC)为512μg/mL,最低杀菌浓度(MFC)为1024μg/mL,SMIC50为512μg/mL,ε-PL对白念珠菌浮游菌及生物膜的抑菌作用随着浓度的升高作用愈明显。抑菌-时间曲线结果表明ε-PL对白念珠菌的浮游菌和生物膜在12h左右即产生明显抑制作用。芽管实验的结果表明高浓度的ε-PL对白念珠菌的芽管形成率及芽管长度具有明显抑制作用。ε-PL作用于白念珠菌后MDA和ROS含量呈现上升趋势,并且与药物浓度大小成正相关。结论 ε-PL对白念珠菌浮游菌株及生物膜均有良好的抑制作用,高浓度ε-PL对白念珠菌主要毒力菌丝有明显抑制作用,ε-PL作用导致白念珠菌内产生大量的活性氧(ROS)以及产生一定程度的脂质氧化,提示ε-PL可能通过氧化作用发挥抑菌效果。     

Possible role of azole and echinocandin lock solutions in the control of Candida biofilms associated with silicone

Until now, management of candidiasis related to implanted devices has remained problematic. The aim of this study was to investigate antifungal lock strategies against Candida albicans and Candida glabrata biofilms in vitro. Three antifungal agents were used against eight C. albicans and six C. glabrata clinical strains isolated from infected catheters. Caspofungin and micafungin, both echinocandins, as well as the azole posaconazole were tested. An in vitro model of Candida biofilm on 100% silicone catheters was used. Efficacy of the antifungal lock was tested against biofilms aged 12h and 5 days following exposure to caspofungin (5mg/L and 25mg/L), micafungin (5mg/L and 15 mg/L) and posaconazole (10mg/L) for 12h. Persistence of antibiofilm activity was investigated 1-3 days following drug elimination. Antifungal lock was considered effective in the event of a significant decrease (P<0.001) in the metabolic activity of the biofilm yeast. The results showed that micafungin had significant inhibitory effectiveness against young and mature C. albicans and C. glabrata biofilms. Moreover, this activity appeared to persist for up to 3 days. Caspofungin displayed similar activity against all C. albicans biofilms, but the activity was less persistent for C. glabrata biofilms. Posaconazole was less effective against C. albicans biofilms, but its activity was sustained. Echinocandin lock therapy could significantly enhance the management of candidiasis in patients with indwelling catheters by combating biofilms and enabling device maintenance in situ.     

莫西沙星对耐药葡萄球菌生物膜药效学研究

目的：研究莫西沙星对4株临床耐药葡萄球菌生物膜的体外药效学。方法：采用微量肉汤稀释法测定莫西沙星的最低抑菌浓度（Minimal inhibitory concentration,MIC）、最低抑制生物被膜浓度（Minimal biofilm inhibitory concentration,MBIC）和最低摧毁生物被膜浓度（minimal biofilm eradication concentration,MBEC）;测定莫西沙星对细菌生物膜形成量以及存活菌的影响;采用微量稀释棋盘法测定莫西沙星与局部用药瑞他帕林的联合抗生物膜效果。结果：莫西沙星在16~256mg/L的范围内可完全摧毁细菌生物膜;2 × MIC显著降低生物被膜的形成量;100 × MIC可显著降低生物被膜存活菌数;与瑞他帕林的联合抗生物膜分数（fractional biofilm inhibitory concentration,FBIC）均小于1.0。结论：莫西沙星对4株临床耐药葡萄球菌生物被膜具有抑制和摧毁作用,而且与局部用药瑞他帕林具有协同作用。     

单宁酸联合氟康唑抑制金黄色葡萄球菌与白念珠菌混合生物膜的作用及机制研究

摘要：目的 分析单宁酸联合氟康唑降低金黄色葡萄球菌与白念珠菌混合生物膜的作用及其机制。方法 收集2019年临床 分离的3株耐甲氧西林金黄色葡萄球菌(MRSA),分别命名为SA1,SA2和SA3;利用分光光度法检测单宁酸单独或联合氟康唑对 金黄色葡萄球菌与白念珠菌DAY185混合菌群生长能力的影响,进一步采用结晶紫染色法测定对混合生物膜形成能力的影响; 扫描电子显微镜观察单宁酸联合氟康唑对混合生物膜结构影响;实时荧光定量PCR(qRT-PCR)检测白念珠菌DAY185生物膜形成 相关基因(ALS1、ALS3和RBT1)和SA1生物膜形成相关基因(icaA、sarA和cidA)的表达量变化。结果 单宁酸可以降低金黄色葡萄 球菌与白念珠菌混合菌群的生长能力和混合生物膜形成能力,当联合氟康唑时抑制作用更加明显;扫描电子显微镜显示单宁酸 联合氟康唑可以明显减少金黄色葡萄球菌在白念珠菌菌丝上的黏附;qRT-PCR结果表明：单宁酸联合氟康唑主要可以降低混合 生物膜中白念珠菌ALS3基因(P＜0.05)和金黄色葡萄球菌icaA和sarA基因(P＜0.05)的表达量。结论 单宁酸联合氟康唑可以降低 金黄色葡萄球菌与白念珠菌混合生物膜的形成,其机制主要通过降低白念珠菌菌丝形成相关基因ALS3和金黄色葡萄球菌黏附相 关基因icaA和sarA的表达水平。     

Induction of MRSA Biofilm by Low-Dose β-Lactam Antibiotics: Specificity,Prevalence and Dose-Response Effects

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of hospital- and community-associated infections. The formation of adherent clusters of cells known as biofilms is an important virulence factor in MRSA pathogenesis. Previous studies showed that subminimal inhibitory (sub-MIC) concentrations of methicillin induce biofilm formation in the community-associated MRSA strain LAC. In this study we measured the ability sub-MIC concentrations of eight other β-lactam antibiotics and six non-β-lactam antibiotics to induce LAC biofilm. All eight β-lactam antibiotics, but none of the non-β-lactam antibiotics, induced LAC biofilm. The dose-response effects of the eight β-lactam antibiotics on LAC biofilm varied from biphasic and bimodal to near-linear. We also found that sub-MIC methicillin induced biofilm in 33 out of 39 additional MRSA clinical isolates, which also exhibited biphasic, bimodal and linear dose-response curves. The amount of biofilm formation induced by sub-MIC methicillin was inversely proportional to the susceptibility of each strain to methicillin. Our results demonstrate that induction of biofilm by sub-MIC antibiotics is a common phenotype among MRSA clinical strains and is specific for β-lactam antibiotics. These findings may have relevance to the use of β-lactam antibiotics in clinical and agricultural settings.     

Antifungal activity and potential mechanism of action of caspofungin in combination with ribavirin against Candida albicans

The number of invasive fungal infections has increased dramatically, resulting in high morbidity and mortality among immunocompromised patients. With increasing use of caspofungin (CAS), resistant strains have emerged frequently and led to limitations in the treatment of patients with severe invasive Candida albicans infections. Combination therapy is an important method to deal with this issue. As such, this study investigated the activity of CAS in combination with ribavirin (RBV) against C. albicans. The results of this in-vitro study showed that the minimum inhibitory concentrations (MICs) of CAS and RBV when they were used as monotherapy were 0.5–1 μg/mL and 2–8 μg/mL, respectively, while the MIC of CAS decreased from 0.5–1 μg/mL to 0.0625–0.25 μg/mL when used in combination with RBV, with a fractional inhibitory concentration index (FICI) ≤0.5. In addition, the RBV + CAS combination group displayed synergistic effects against C. albicans biofilm over 4 h; the sessile MIC (sMIC) of CAS decreased from 0.5–1 µg/mL to 0.0625–0.25µg/mL and the sMIC of RBV decreased from 4–16 µg/mL to 1–2 µg/mL, with FICI <0.5. The survival of C. albicans-infected Galleria mellonella was prolonged, the fungal burden was decreased, and the area of tissue damage was reduced after combination therapy. Further study showed that the mechanisms of action of the synergistic effect were related to the inhibition of biofilm formation, the inhibition of hyphal growth, and the activation of metacaspases, but were not related to the accumulation of reactive oxygen species. It is hoped that these findings will contribute to the understanding of drug resistance in C. albicans, and provide new insights for the application of RBV.     

In vitro analysis of flufenamic acid activity against Candida albicans biofilms

In a recent high-throughput screen against specific Candida albicans drug targets, several compounds that exhibited non-specific antifungal activity were identified, including the non-steroidal anti-inflammatory drug flufenamic acid (FFA). This study sought to determine the effect of different doses of FFA, alone or in combination with fixed concentrations of the standard antifungal agents amphotericin B (AmB), caspofungin (CAS) or fluconazole (FLU), for the prevention and treatment of C. albicans biofilms. Biofilms were formed in a 96-well microplate followed by evaluation of antifungal activity using the XTT assay. FFA concentrations of ≥512 mg/L demonstrated >80% prevention of biofilm formation. FFA concentrations of 1024 mg/L demonstrated >85% reduction of mature biofilms. When FFA (≥8 mg/L) was used in combination with FLU (32 mg/L), antifungal activity increased to 99% for the prevention of biofilm formation. Similarly, when a FFA concentration of ≥8 mg/L was used in combination with either AmB (0.25 mg/L) or CAS (0.125 mg/L), antifungal activity also increased up to 99% for the prevention of biofilm formation. The inhibitory effect of FFA on C. albicans biofilms has not been reported previously, therefore these findings suggest that FFA in combination with traditional antifungals might be useful for the treatment and prevention of C. albicans biofilms.