金黄色葡萄球菌对喹诺酮类耐药的主动外排机制的研究

目的对临床分离株中主动外排机制介导耐药的流行情况进行调查,为临床合理用药、耐药性控制及新型敏感抗菌药物的开发提供理论依据。方法将金黄色葡萄球菌(金葡菌)标准株ATCC25923及对喹诺酮类敏感临床株接种于含4×MIC氧氟沙星的MH琼脂平板上(含或不含20mg/L的利血平),观察利血平对诱导耐药出现的抑制作用,并测定诱导耐药株对溴乙啶、氧氟沙星、环丙沙星的MIC(含或不含20mg/L的利血平),观察利血平对诱导耐药株MIC的影响,用利血平抑制试验法测定临床上耐喹诺酮类金葡菌中主动外排机制的流行性。结果利血平可抑制喹诺酮类对金葡菌的诱导耐药率,可降低诱导耐药率的MIC。利血平抑制试验是检测金葡菌中主动外排机制简单直观的方法,临床上耐喹诺酮类金葡菌中约50%存在主动外排机制。结论主动外排是临床上金葡菌对喹诺酮类耐药的一种重要机制,利血平可抑制喹诺酮类对金葡菌的诱导耐药率,并可降低耐药菌的MIC,与喹诺酮类可起协同抗菌作用。     

氟喹诺酮类药物的临床应用

 喹诺酮是近年来迅速发展的一类抗菌药，60年代开始应用的萘啶酸等，由于其抗菌谱仍较窄和细菌耐药性的影响，使其临床应用受到了限制。70年代后开发的氟喹诺酮如依诺沙星、诺氟沙星、甲氟沙星、氧氟沙星和环丙沙星等受到了世界各国医药界的瞩目，已广泛应用于临床，疗效肯定。尤其是一些新品种如司帕沙星、妥舒沙星等各具特点。其余尚有氟罗沙星和地氟沙星都处于扩大临床验证中。     

表皮葡萄球菌细胞间脂多糖黏附素的表达与耐药特征的相关性

目的：探讨表皮葡萄球菌细胞间脂多糖黏附素（polysacchatide intercellular adhesion,PIA）的表达与细菌耐药特征的相关性.方法：收集分离临床标本中的表皮葡萄球菌,通过使用刚果红琼脂平皿检测PIA,考察该菌生物膜的形成能力;按照结果分为PIA阳性组和阴性组,选取八种抗生素,应用K-B琼脂扩散法进行药物敏感试验并计算耐药率,同时探讨两者之间的关系.结果：临床标本中分离到的表皮葡萄球菌对青霉素G有极高的耐药率（100%）,对甲氧西林、红霉素、克林霉素、环丙沙星有较高的耐药率（40.5%～96.8%）.对利福平耐药率较低（2.4%～3.1%）,而对万古霉素和替考拉宁耐药率极低（0%）;除对利福平外,PIAF阳性和阴性菌株对其他四组抗生素的耐药率均有显著性差异（P＜0.05）.结论：生物膜形成能力强的表皮葡萄球菌通常对抗生素的耐药性更高（对利福平除外）,推荐使用利福平作为治疗和预防治疗植入物生物膜感染的联合用药.     

喹诺酮类抗菌药物的不良反应

喹诺酮类抗菌药物是人工化学合成抗菌药,自1962年合成第一个喹诺酮类药物萘啶酸以来,该类药物发展迅速,至今已有许多新品种应用于临床.喹诺酮类抗菌药常用于治疗呼吸系统、泌尿系统、肠道、皮肤软组织、腹腔和骨关节等感染.目前常用的喹诺酮类药物有诺氟沙星、氧氟沙星、环丙沙星、左氧氟沙星、培氟沙星、加替沙星、莫西沙星、洛美沙星等¨].与其他抗生素相比,因其价格低廉,口服吸收良好,血药浓度高,可口服和注射给药并迅速分布到体内各组织,临床应用广泛[2].随着研究深入和应用增多,关于喹诺酮类抗菌药不良反应的报道增多,现报道如下.     

连翘对金黄色葡萄球菌及表皮葡萄球菌的体外抗菌活性研究

[目的]观察连翘对金黄色葡萄球菌及表皮葡萄球菌的体外抗菌活性。[方法]用新的中药抑菌实验方法进行连翘对84株金葡菌和140株表皮葡萄球菌的体外抗菌活性的测定。[结果]连翘对金葡菌和表皮葡萄球菌能抑制50%菌株的最低细菌浓度(MIC50)均为0.122g/L,而能抑制90%菌株的最低抑菌浓度(MIC90)分别为0.98和0.244g/L。[结论]连翘对金黄色葡萄球菌和表皮葡萄球菌均有较好的体外抗菌效果。     

氟喹诺酮类抗菌剂卡德沙星的合成研究

 目的研究氟喹诺酮类抗菌剂卡德沙星的合成工艺。方法以3-二氟甲氧基-2,4,5-三氟笨甲酸为起始原料,经酰氯化、缩合、脱羧、醚化、环丙胺置换、环合、螯合、上甲基哌嗪、水解得本品。结果卡德沙星经红外、核磁、质谱确证。结论本法原料易得,操作简单,总收率高,而且整个过程不需柱色谱纯化,是理想的工业化生产路线。     

氟喹诺酮类药物的临床应用和不良反应

目的：加强临床医生、护士、药师对氟喹诺酮类药物应用及不良反应的认识,提高临床合理用药水平。方法：对氟喹诺酮类药物的临床应用和报道较多的不良反应做一概述。结果：氟喹诺酮类药物具有广谱、高效、安全的特点,在临床上应用广泛,但随之而来的不良反应报道越来越多。临床应用时应严格遵照卫生部有关文件规定执行,以减少不良反应的发生。     

黄连提取物对耐药金黄色葡萄球菌的耐药抑制机理初探

目的:探讨黄连提取物对耐药金黄色葡萄球菌的耐药抑制机理。方法:采用荧光分光光度法、SDS-PAGE电泳法和半自动生化仪器分别测定了黄连提取物作用前后耐药性金黄色葡萄球菌体内的药物蓄积量、细菌蛋白电泳图谱及细菌胞外某些酶活性。结果:黄连提取物处理后菌体内诺氟沙星蓄积浓度显著高于空白对照组(P<0.01);耐药金黄色葡萄球菌在35～38 kDa分子量范围内的某些蛋白质恢复表达;黄连提取物对细菌胞外酶活性无影响(P>0.05)。结论:黄连提取物对耐药金葡菌的耐药抑制作用是多种化学成分、多靶位共同作用的结果,但确切的分子水平机理还有待进一步的深入研究。     

鱼腥草素钠对表皮葡萄球菌生物被膜作用的研究

 目的 通过中药有效成分鱼腥草素钠对表皮葡萄球菌生物被膜抑制作用的研究,为表皮葡萄球菌生物被膜引起的相关感染提供新的治疗途径。方法 利用XTT减低法评价鱼腥草素钠对表皮葡萄球菌初始黏附及生物被膜内细菌代谢的影响,镜下观察该药对表皮葡萄球菌生物被膜的形态学影响。结果 鱼腥草素钠对表皮葡萄球菌生物被膜菌的SMIC₅₀和SMIC₈₀分别为62.5和1 000 mg·L-1;1 000 mg·L-1质量浓度的鱼腥草素钠对表皮葡萄球菌早期黏附有抑制作用;500 mg·L-1质量浓度的鱼腥草素钠对表皮葡萄球菌生物被膜的形态有显著影响。结论 鱼腥草素钠对表皮葡萄球菌生物被膜的形成与黏附均有抑制作用。     

Antimicrobial effect of sodium houttuyfonate on Staphylococcus epidermidis and Candida albicans biofilms

Objective

To study antimicrobial effect of Sodium houttuyfonate (SH) on Staphylococcus epidermidis (SE) and Candida albicans (CA).

Methods

The prepared strain broths (OD₆₀₀=0.05) containing SE and CA were firstly used to test the minimal inhibitory concentrations (MICs) of SH, azithromycin (AZM) and fluconazole (FLU) by micro-dilution method. Then the biofilms of SE and CA were matured in 96-well plates, and co-cultured with SH, AZM and FLU for 1, 2 and 3 days to assess the antibiofilm efficacies of the agents with different concentrations by crystal violet staining method. At last, the treated biofilms of SE and CA by 2×MIC agents were observed by scanning electronic microscope.

Results

The MICs of SE and CA were 256 and 1024 µg/mL, respectively. After the 1st, 2nd and 3rd day of medications, the suppressions of biofilm were about 60% (P<0.01), 76% (P=0.000) and 75% (P=0.000) by 2×MIC SH, the suppressions of biofilm were about 90% (P=0.000), 88% (P=0.000) and 90% (P=0.000) by 2×MIC SH, which could be testified by scanning electron microscope results. However, the inhibitions of biofilm attachment had no significant difference for SE by SH and azithromycin and CA by SH and fluconazole.

Conclusion

SH had widely anti-pathogenic effect on pathogenic biofilm formation of either bacteria or fungus, had more influence on enclosed cells of SE and CA than the traditional antibiotics, revealing its target might be the extracellular polymeric substances, and was more active to inhibit the growth of CA than SE.     

76株耐甲氧西林葡萄球菌药敏结果分析

目的 分析耐甲氧西林葡萄球菌药敏结果,以提高MRSA和MRS的检出率。 方法 分析我院2009年1月-2010年2月分离的76株耐甲氧西林葡萄球菌药敏结果。 结果药敏试验结果显示,耐甲氧西林葡萄球菌对万古霉素敏感率最高,达100.00%。治愈67例,治愈率为88.16%（67/76）; 治愈出院者平均住院时间为15.02±7.3天。 结论 耐甲氧西林葡萄球菌对万古霉素敏感率最高。     

Effect of Corilagin on Membrane Permeability of Escherichia coli,Staphylococcus aureus and Candida albicans

Corilagin is a member of polyphenolic tannins. Its antimicrobial activity and action mechanism against Escherichia coli, Staphylococcus aureus and Candida albicans were investigated through membrane permeability. Crystal violet staining determination, outer membrane (OM) and inner membrane (IM) permeability, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) and atomic force microscopy (AFM) were used as methods for our investigation. The minimum inhibitory concentrations were 62.5, 31.25 and 62.5 µg/mL for E. coli, S. aureus and C. albicans, respectively. Crystal violet results and SDS‐PAGE of supernatant proteins showed that corilagin dose‐dependently affected membrane permeability of E. coli and C. albicans but not of S. aureus. OM and IM permeability assays revealed comparable results for E. coli. By using AFM, we demonstrated extensive cell surface alterations of corilagin‐treated E. coli and C. albicans. SDS‐PAGE of precipitated proteins revealed possible targets of corilagin, i.e. Fib, Sae R, Sar S in S. aureus and Tye 7p in C. albicans. In conclusion, corilagin inhibited the growth of E. coli and C. albicans by disrupting their membrane permeability and that of S. aureus by acting on Fib, Sae R and Sar S but not on membrane integrity. Copyright © 2012 John Wiley & Sons, Ltd.     

Antimicrobial effect of sodium houttuyfonate on Staphylococcus epidermidis and Candida albicans biofilms

OBJECTIVE： To study antimicrobial effect of Sodi- um houttuyfonate （SH） on Staphylococcus epider- midis （SE） and Candida albicans （CA）. METHODS： The prepared strain broths （OD600=0.05） containing SE and CA were firstly used to test the minimal inhibitory concentrations （MICs） of SH, azithromycin （AZM） and fluconazole （FLU） by mi- cro-dilution method. Then the biofilms of SE and CA were matured in 96-well plates, and co-cultured with SH, AZM and FLU for 1, 2 and 3 days to assess the antibiofilm efficacies of the agents with differ- ent concentrations by crystal violet staining meth- od. At last, the treated biofilms of SE and CA by 2× MIC agents were observed by scanning electronic microscope. RESULTS： The MlCs of SE and CA were 256 and 1024 μg/mL, respectively. After the 1st, 2nd and3rd day of medications, the suppressions of biofilm were about 60% （P〈0.01）, 76% （P=0.000） and 75% （P=0.000） by 2×MIC SH, the suppressions of biofilm were about 90% （P=0.000）, 88% （P=0.000） and 90% （P=0.000） by 2×MIC SH, which could be testified by scanning electron microscope results. However, the inhibitions of biofilm attachment had no significant difference for SE by SH and azithromycin and CA by SH and fluconazole. CONCLUSION： SH had widely anti-pathogenic ef- fect on pathogenic biofilm formation of either bac- teria or fungus, had more influence on enclosed cells of SE and CA than the traditional antibiotics, revealing its target might be the extracellular poly- meric substances, and was more active to inhibit the growth of CA than SE.     

425例金黄色葡萄球菌耐药性分析

目的:分析我院临床分离的金黄色葡萄球菌标本来源分布及耐药特点。方法:收集2012年1月-2013年7月我院临床分离的不重复金黄色葡萄球菌标本来源、患者临床特点、科室分布及抗生素耐药情况。结果:临床共分离到425株不重复金黄色葡萄球菌,其中创口分泌物44株,穿刺液23株,血液19株,以上3类标本来源临床分布首位科室分别是手显微外科、甲乳外科、重症医学科。临床特点分析显示创口分泌物来源和血液来源患者有慢性疾病(高血压病、糖尿病、慢性肾病)者分别占38.6%和73.7%。临床分布前3位分别是儿科、新生儿科及神经外科。所分离菌株中耐甲氧西林的金黄色葡萄球菌(MRSA)占28.0%,产β-内酰胺酶菌株占77.1%,抗生素敏感性分析中显示青霉素耐药率最高(99.8%),暂未发现耐万古霉素、替考拉宁及利奈唑胺的金黄色葡萄球菌。结论:我院金葡菌感染是临床呼吸道、创口及血流感染分离的重要病原菌,尤其有基础疾病人群易感,目前该类细菌β-内酰胺耐药严重,对万古霉素、替考拉宁及利奈唑胺仍具有较好的敏感性。     

五倍子对224株耐甲氧西林葡萄球菌(MRSA和MRSE)的抑菌效果观察

目的：用新的中药抑菌实验方法进行五倍子对224株耐甲氧西林葡萄球菌的抗菌效果观察。方法：用琼脂稀释方法进行最小抑菌浓度（MIC）的测定。结果：五倍子对MRSA、MRSE、MSSA和MSSE的MIC50均为0．051mg/ml,其MIC90分别为0．102、0．203、0．102、0．102mg/ml。结论：五倍子对MRSA（84株）、MSSA（28株）、MRSE（84株）和MSSE（28株）的抑菌效果均很好。     

Total alkaloids of Sophora alopecuroides- and matrine-induced reactive oxygen species impair biofilm formation of Staphylococcus epidermidis and increase bacterial susceptibility to ciprofloxacin

ObjectiveTo investigate the mechanism by which total alkaloids of Sophora alopecuroides (TASA) and matrine (MT) impair biofilm to increase the susceptibility of Staphylococcus epidermidis (S. epidermidis) to ciprofloxacin.MethodsThe minimum biofilm inhibitory concentration (mBIC) was determined using a 2-fold dilution method. Structure of biofilm of S. epidermidis was examined by Confocal Laser Scanning Microscope (CLSM). The cellular reactive oxygen species (ROS) was determined using a DCFH-DA assay. The key factors related to the regulation of ROS were accessed using respective kits.ResultsTASA and MT were more beneficial to impair biofilm of S. epidermidis than ciprofloxacin (CIP) (P < 0.05). TASA and MT were not easily developed resistance to biofilm-producing S. epidermidis. The mBIC of CIP decreased by 2–6-fold following the treatment of sub-biofilm inhibitory concentration (sub-BIC) TASA and MT, whereas the mBIC of CIP increased by 2-fold following a treatment of sub-BIC CIP from the first to sixth generations. TASA and MT can improve the production of ROS in biofilm-producing S. epidermidis. The ROS content was decreased 23%−33% following the treatment of sub-mBIC CIP, whereas ROS content increased 7%−24% following treatment with TASA + CIP and MT + CIP combination from the first to sixth generations. Nitric oxide (NO) as a ROS, which was consistent with the previously confirmed relationship between ROS and drug resistance. Related regulatory factors-superoxide dismutase (SOD) and glutathione peroxidase (GSH) could synergistically maintain the redox balance in vivo.ConclusionTASA and MT enhanced reactive oxygen species to restore the susceptibility of S. epidermidis to ciprofloxacin.