黄绵马酸BB对革兰阳性致病菌的抗菌活性和生物被膜清除作用研究

目的探究黄绵马酸BB对3种革兰阳性致病菌的抗菌活性及生物被膜的清除作用。方法采用微量稀释法测定黄绵马酸BB对耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)、粪肠球菌(Enterococcus faecalis,EFA)及屎肠球菌(Enterococcus faecium,EFM) 15株临床分离株的最小抑菌浓度(minimum inhibitory concentration,MIC)和最小杀菌浓度(minimum bactericidal concentration,MBC);考察黄绵马酸BB对MRSA2、EFA13和EFM15生长周期的影响;采用CCK-8法、扫描电子显微镜(SEM)考察黄绵马酸BB对MRSA2、EFA13和EFM15生物被膜的清除作用。结果黄绵马酸BB对MRSA的MIC为11.49～63.50μg/mL、MBC为22.98～160.00μg/mL,对EFA的MIC为7.07～160.00μg/mL、MBC为28.28～160.00μg/mL,对EFM的MIC为16.82μg/mL、MBC为56.57μg/mL,其中黄绵马酸BB对MRSA1、2和EFA14、15的MIC均小于莫匹罗星;黄绵马酸BB对MRSA2、EFA13和EFM15的生长具有抑制作用,能延迟受试菌进入对数生长期;MIC黄绵马酸BB对MRSA2、EFA13和EFM15生物被膜的清除率分别达到85.15%、76.48%、82.31%,均优于莫匹罗星、万古霉素、达托霉素;黄绵马酸BB对MRSA2生物被膜聚集及成熟阶段的清除效果优于达托霉素,对EFA13生物被膜聚集及成熟阶段的清除效果优于莫匹罗星、万古霉素、达托霉素,对EFM15生物被膜成熟阶段的清除效果优于莫匹罗星、万古霉素、达托霉素。结论黄绵马酸BB具有良好的体外抑菌活性以及对生物被膜的清除作用。     

复方白玉散对金黄色葡萄球菌生物被膜的体外抑制作用研究

目的:研究复方白玉散对金黄色葡萄球菌生物膜形成的体外抑制作用。方法:采用微量肉汤二倍稀释法测定复方白玉散作用于标准菌株ATCC29213和临床分离33株金黄色葡萄球菌的最小抑菌浓度(MIC)、最小杀菌浓度(MBC),用结晶紫染色法检测复方白玉散对生物膜最小抑膜浓度(s MIC)。结果:复方白玉散对标准菌株ATCC29213和强成膜株SA17的MIC分别为25mg/m L和50mg/m L,MBC分别为50mg/m L和100mg/m L。标准菌株ATCC29213为生物膜阳性菌株,并且33株临床分离S.aureus中,有25株为生物膜阳性菌株,生物膜的形成率为75.6%。复方白玉散对标准菌株ATCC29213的s MIC50为1.6mg/m L,s MIC80为6.3mg/m L,对强成膜株SA17的s MIC50为3.2mg/m L,s MIC80为6.3mg/m L。结论:复方白玉散能抑制金黄色葡萄球菌生物膜的生成,并且具有一定的抑菌和杀菌作用。     

忍冬叶与忍冬花体外抗菌作用研究

目的：观察忍冬叶与忍冬花对5株致病菌的抗菌效果。方法：琼脂平板稀释法。测定忍冬叶与花的最低抑菌浓度(MIC)；试管稀释法，测定忍冬叶与花的最低杀菌浓度(MBC)。结果：忍冬叶对金葡菌ATCC25923、金葡菌临床分离株、葡萄球菌临床分离株、大肠埃希菌ATCC25922的MIC为0．0625～0.25g／ml；忍冬花对上述细菌的MIC为0．015～0．03g／ml；忍冬叶与花对金葡菌ATCC25923、葡萄球菌临床分离株和大肠埃希菌ATCC25922的MBC相同。结论：忍冬叶与忍冬花对4株致病菌均有不同程度抗菌作用，对白色念珠菌无明显抗菌作用。     

苦玄参体外抗菌作用的实验研究

目的:研究苦玄参根、茎、叶体外抗菌作用。方法:采用连续稀释法对苦玄参根、茎、叶的水煎液和醇提液进行MIC、MBC的实验研究。结果:苦玄参根、茎、叶的水煎液和醇提液在体外对金黄色葡萄球菌(ATCC209)、金黄色葡萄球菌耐药株、表皮葡萄球菌(ATCC26029)、乙型溶血性链球菌(ATCC32210)等均有一定的抗菌作用;醇提液的体外抗菌作用优于水提液。结论:苦玄参根、茎、叶的醇提液具有明显的抗菌作用。     

忍冬叶与忍冬花体外抗菌作用研究

目的:观察忍冬叶与忍冬花对5株致病菌的抗菌效果.方法:琼脂平板稀释法,测定忍冬叶与花的最低抑菌浓度(MIC);试管稀释法,测定忍冬叶与花的最低杀菌浓度(MBC).结果:忍冬叶对金葡菌ATCC25923、金葡菌临床分离株、葡萄球菌临床分离株、大肠埃希菌ATCC25922的MIC为0.0625～0.25g/ml;忍冬花对上述细菌的MIC为0.015～0.03g/ml;忍冬叶与花对金葡菌ATCC25923、葡萄球菌临床分离株和大肠埃希菌ATCC25922的MBC相同.结论:忍冬叶与忍冬花对4株致病菌均有不同程度抗菌作用,对白色念珠菌无明显抗菌作用.     

五倍子乙醇提取物对金葡菌的体外抗菌研究

目的观察五倍子乙醇提取物对金黄色葡萄球菌(MRSA和MSSA)的体外抗菌活性.方法采用中药抑菌实验方法对五倍子乙醇提取物进行了112株金黄色葡萄球菌的最低抑菌浓度测定.结果五倍子乙醇提取物对84株耐甲氧西林的金黄色葡萄球菌(methicillin-resistant staphylococcus aureus,MRSA)和28株甲氧西林敏感的金黄色葡萄球菌(methicillin-sensitive staphylococcus aureus,MSSA)的MIC50、MIC90分别为0.315、0.315和0.63、0.315 mg/mL.结论五倍子乙醇提取物对金黄色葡萄球菌(84株MRSA和28株MSSA)具有较强的抑菌活性.     

复方清热颗粒剂对MRSA PBP2a表达影响的实验研究

目的 探寻复方清热颗粒剂联用西药对耐甲氧西林金黄色葡萄球菌(MRSA)细胞膜青霉素结合蛋白2a(PBP2a)表达的影响.方法 建立急性耐药菌腹腔感染模型,复方清热颗粒灌胃给药,留取含药血清,测定各组药物对MRSA的最低抑菌浓度(MIC).挑取各组亚抑菌浓度琼脂培养皿中单个菌落,增菌,提取细菌膜蛋白行聚丙烯酰胺凝胶电泳,紫外凝胶成像仪分析目的蛋白的相对含量.结果 复方清热颗粒或含药血清联用万古霉素MICG下降,PBP2a相对含量下降.复方清热颗粒或含药血清分别联合万古霉素或头孢呋辛各组PBP2a的相对含量与其MIC无明显相关.结论 复方清热颗粒或含药血清分别联用万古霉素能降低PBP2a的表达,PBP2a参与影响万古霉素对MRSA的MIC,但尚有其它重要耐药机制的参与.PBP2a含量多少与MRSA对β-内酰胺类抗生素的耐药性强弱无关.     

常见抗菌中草药对耐甲氧西林金黄色葡萄球菌的抑菌作用

目的 探讨金银花、黄连、黄芩等10种常见中草药对耐甲氧西林金黄色葡萄球菌(MRSA)的抑菌作用.方法 从临床标本中分离MRSA,采用水提法制备抗菌中草药无菌药液,通过打孔法测定中草药提取液对MRSA的抑菌圈大小,通过两倍稀释法测定中草药提取液对MRSA的最小抑菌浓度(MIC)和最小杀菌浓度(MBC).结果 10种常见中草药对耐MRSA均有不同程度的抑制作用,以黄连的抑菌效果最好,其次依次为金银花、大黄、黄芩、马齿苋、紫草、苦参、射干、黄柏、艾叶.结论 抗菌中草药对MRSA临床株具有一定的抗菌作用,有望成为抗MRSA的候选药物.     

黄芩苷体外对耐甲氧西林金黄色葡萄球菌活性影响的研究

目的研究从中药黄芩干燥根中提取分离药效成分黄芩苷体外对耐甲氧西林金黄色葡萄球菌活性的影响。方法以琼脂扩散法、液体稀释微孔板法检测黄芩苷对MRSA的抑菌环大小、最低抑菌浓度(MIC)和最低杀菌浓度(MBC);以96孔酶标板结晶紫法检测黄芩苷对MRSA的最小生物膜清除浓度(MBEC)。结果与DMSO比较,黄芩苷与氯霉素(阳性对照药物)对MRSA的抑菌环半径显著增加(P0.01),与氯霉素比较,黄芩苷对MRSA的抑菌环半径显著缩小(P0.05);黄芩苷对MRSA的MIC为0.5mg/ml;MBC为1mg/ml;黄芩苷对MRSA的MBEC为0.5mg/ml。结论黄芩苷对MRSA有一定的抗菌、抑菌作用,其效应机制可能与其抑制细菌生物膜的形成有关。     

美洲大蠊脱脂膏及其活性炭脱色物体外抗菌活性研究

目的:探讨美洲大蠊脱脂膏及其活性炭脱色物的体外抗菌作用.对比了美洲大蠊脱脂膏及其活性炭脱色物的抗菌谱和抗菌强弱.方法:美洲大蠊脱脂膏用活性炭脱色后进行冷冻干燥得到固体脱色物,然后用脱脂膏和脱色物对金黄色葡萄球菌(Staphylococcus aureas)、白色葡萄球菌(Staphylococcus albus)、大肠杆菌(Escherichia coli)、痢疾志贺菌(Shigella dysenteriae)、甲型副伤寒沙门菌(S.paratyphi A)、乙型副伤寒沙门菌(Salmonella paratyphi B)、绿脓杆菌(Pseudomonas aeruginosa)、枯草杆菌(Bacillus subtilis)、变形杆菌(Proteus vulgaris),白色念珠菌(Candida albicans),金黄色葡萄球菌ATCC25923( Staphylococcus aureus),大肠杆菌ATCC25922(Escherichia coli)进行体外抗菌活性研究,测定最小抑菌浓度(MIC).结果:在实验的各菌株中,脱脂膏仅对白色葡萄球菌具有一定抗菌作用,MIC 31.25 g·L-1,对其他11株细菌均无抗菌活性.脱色物对金黄色葡萄球菌25923、白色念珠菌无抗菌活性,对其他10株细菌均有抗菌活性,MIC 15.63 ～250 g·L-1,其中对白色葡萄球菌和绿脓杆菌抗菌效果较好,MIC分别为15.63,62.5 g·L-1.结论:美洲大蠊中含有抗菌活性成分,脱色物与脱脂膏相比,抗菌效果优于脱脂膏.     

黄绵马酸BB联合红霉素抑制表皮葡萄球菌及其生物被膜的形成研究

目的 探讨黄绵马酸BB与红霉素联用对表皮葡萄球菌(Staphylococcus epidermidis,SE)抑菌活性和生物被膜形成的作用,为黄绵马酸BB开发成为一种新型的生物被膜抑制剂提供理论基础。方法 采用微量稀释法分别测定黄绵马酸BB与红霉素联用对11株SE的最低抑菌浓度(minimum inhibitory concentration,MIC),并采用微量棋盘稀释法测定联合用药的部分抑菌浓度指数(fractional inhibitory concentration index,FICI)与最低抑膜浓度(minimum biofilm inhibitory concentration,MBIC);采用时间-杀菌曲线法,评价联合用药对SE的动态杀菌作用;通过二甲氧唑黄[2.3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[carbonyl(phenylamino)]-2H-tetrazolium hydroxide,XTT]比色法、半定量黏附实验和扫描电子显微镜(scanning electron microscope,SEM)观察,评价联合用药...     

大黄等5味中药及单体成分对临床多重耐药菌的抑制作用

目的:研究大黄、丁香、蒲公英、姜黄、金银花5味中药及大黄素、芦荟大黄素、丁香酚、咖啡酸、绿原酸和姜黄素对临床多重耐药菌的抑制作用。方法:用微量稀释法测定各药物的最小抑菌浓度(MIC)。记录细菌连续24 h的吸光度A595,绘制生长曲线,用聚丙烯酰胺凝胶电泳(SDS-PAGE)分析细菌可溶性蛋白质。结果:大黄的抑菌效果显著,MIC在6.25~12.50g·L-1;丁香的抑菌谱最广,对所有实验菌株均有抑菌作用,MIC在3.13~25.00 g·L-1,蒲公英、金银花和姜黄在本实验中未见抑菌活性;6种单体药物在实验中对铜绿假单胞菌均没有抑菌效果;大黄素、芦荟大黄素和丁香酚对金黄色葡萄球菌的抑菌效果优于其他临床耐药菌株;大黄素的抑菌效果显著,MIC在1.95~15.63 mg·L-1;芦荟大黄素的抑菌效果稍弱,MIC在2.34~75.00 mg·L-1;丁香酚是唯一对鲍曼不动杆菌有抑菌活性的单体化合物,MIC在5.32~10.64 mg·L-1;姜黄素、咖啡酸、绿原酸在实验中未显示抑菌活性。大黄素作用下,金黄色葡萄球菌的生长及可溶性蛋白表达发生明显改变。结论:大黄和丁香以及大黄素和芦荟大黄素、丁香酚对金黄色葡萄球菌等多种临床多重耐药菌具有显著的抑制效果。大黄素、芦荟大黄素和丁香酚分别是大黄和丁香发挥抑菌作用的主要成分,其具体作用机制有待于深入研究。     

白及不同提取部位抗耐甲氧西林金黄色葡萄球菌的体内外活性

目的:研究白及对“超级细菌”——耐甲氧西林金黄色葡萄球菌(MRSA)的抑菌作用及活性部位.方法:规范提取白及乙酸乙酯部位、正丁醇部位、萃取后水部位、醇提后水煎液部位等4个部位,采用琼脂平板二倍稀释法测定以上4个部位对金黄色葡萄球菌(MSSA)及MRSA共6株病原菌的MIC;用白及乙酸乙酯部位以两种给药方式对小鼠进行预防给药,测定白及对MRSA感染SPF小鼠的保护力.结果:乙酸乙酯部位和正丁醇部位对受试病原菌均具明显抑菌活性,4个部位中尤以乙酸乙醇部位的抑菌活性最强,其MIC为0.065 ～0.26 g·L-1;且白及乙酸乙酯部位对MRSA感染小鼠有很强的保护作用,其中尤以ip0.5 g·kg-1的保护达到100％.结论:白及对MSSA和MRSA有明显的抑菌作用,乙酸乙酯部位是其主要的活性部位.     

Antibacterial Effects of Ellagitannins from Acalypha wilkesiana var. macafeana hort.: Surface Morphology Analysis with Environmental Scanning Electron Microcopy and Synergy with Antibiotics

The present study served to gain further insight into the bactericidal effects of ellagitannins from Acalypha wilkesiana var. macafeana hort. against pathogenic bacteria. Ellagitannins from the aerial parts of A. wilkesiana var. macafeana hort. (EAW) inhibited the growth of Bacillus cereus (ATCC 11778), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 11632) and Methicillin‐resistant Staphylococcus aureus (MRSA) clinical strain with inhibition zones equal to 11.01 ± 1.53 mm, 16.63 ± 0.11 mm, 11.40 ± 1.10 mm and 8.22 ± 0.19 mm, respectively. The minimal inhibition concentration and the minimal bactericidal concentration of ellagitannins from A. wilkesiana var. macafeana hort. (EAW) against MRSA were 750 µg/mL and 3000 µg/mL, respectively. We then examined the synergistic effect of EAW with three antibiotics, i.e. ampicillin, streptomycin and tetracycline, via the checkerboard assay and time‐kill assay and observed that EAW is synergistic with ampicillin against S. aureus (ATCC 11632). Environmental electron scanning microscopy analysis showed cell lysis against S. aureus (ATCC 11632) upon treatment with the ellagitannin fraction. The ellagitannin fraction from A. wilkesiana var. macafeana hort. is bactericidal against gram‐positive bacteria tested and works synergistically with ampicillin against S. aureus. Morphology analysis of the cell suggests that the bactericidal property of the ellagitannin fraction mechanism involves lysis of the cell wall. In summary, our studies demonstrate that A. wilkesiana var. macafeana hort. produces bactericidal ellagitannins of clinical and/or cosmetological value. Copyright © 2012 John Wiley & Sons, Ltd.     

In Vitro Antibacterial Activity and Synergistic Antibiotic Effects of Phlorotannins Isolated from Eisenia bicyclis Against Methicillin‐Resistant Staphylococcus aureus

Six phlorotannins, isolated from Eisenia bicyclis, were evaluated for antibacterial activity against methicillin‐resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MIC) of the compounds were in the range 32 to 64 µg/mL. Phlorofucofuroeckol‐A (PFF) exhibited the highest anti‐MRSA activity, with an MIC of 32 µg/mL. An investigation of the interaction between these compounds and the β‐lactam antibiotics ampicillin, penicillin, and oxacillin revealed synergistic action against MRSA in combination with compound PFF. To our knowledge, this is the first report on the anti‐MRSA activity of phlorotannins from E. bicyclis. The results obtained in this study suggest that the compounds derived from E. bicyclis can be a good source of natural antibacterial agents against MRSA. Copyright © 2012 John Wiley & Sons, Ltd.     

Quercus infectoria: a candidate for the control of methicillin-resistant Staphylococcus aureus infections

Acetone, ethyl acetate, 95% ethanol and aqueous extracts of Quercus infectoria (Q. infectoria) demonstrated significant antibacterial activities against all strains of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA). Inhibition zones were in the range 11.75-16.82 mm. Both MRSA and MSSA strains exhibited minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values at 0.13 and 0.13-1.00 mg/mL, respectively. At 2 MIC, the growth of two representative MRSA strains was continually inhibited for at least 20 h. Surviving MRSA cells were not detected within 12-14 h after treatment with the extract at 4 MIC concentration. Staphylococcus aureus ATCC 25923 demonstrated similar results.     

Two New Xanthones from Hypericum sampsonii and biological activity of the isolated compounds

Phytochemical investigation of the CH₂Cl₂ extract of the aerial part of Hypericum sampsonii yielded two new prenylated xanthones, hypericumxanthone A and B, together with three known xanthones. Their structures were elucidated by analysis of physical and spectral (UV, IR, mass and NMR) data and comparison of spectroscopic data with those reported previously. All these compounds were evaluated for in vitro antibacterial activity against methicillin‐resistant Staphylococcus aureus (MRSA). Two new compounds were also tested for their cytotoxicity against human breast (MCF‐7), hepatoma (HepG2), colon (HT‐29) and lung (A549) tumour cell lines. Two new compounds showed moderate antibacterial activities at minimum inhibitory concentrations (MIC) of 16 and 32 µg/mL, respectively, whereas the positive standard antibacterial drug, vancomycin, showed an MIC of 8 µg/mL. The other compounds were inactive against MRSA. In addition, hypericumxanthone B showed weak inhibitory activities against four human tumour cell lines. Copyright © 2010 John Wiley & Sons, Ltd.     

金莲花总黄酮抗菌作用的实验研究

目的:观察金莲花总黄酮(FTLR)体内外的抗菌活性。方法:体外抗菌实验,采用营养肉汤对金黄色葡萄球菌等14个菌株进行试管连续稀释法和营养琼脂扩散法测定FTLR的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。体内实验采用金黄色葡萄球菌26002-6标准株感染昆明种小鼠作为模型,模型小鼠被随机分为FTLR 440,220,110 mg.kg-1剂量组,金莲花片2 400 mg.kg-1对照组(金莲花片2 400 mg.kg-1与FTLR 440 mg.kg-1的生药剂量相等)及模型对照组,以感染后24,48 h小鼠的死亡率为指标,观察对金黄色葡萄球菌的体内抗菌活性。结果:在体外抑菌实验中,FTLR对13个细菌标准菌株和10个临床株均有抑制作用,其MIC和MBC均低于双黄连口服液;在体内抑菌实验中,FTLR各剂量组金黄色葡萄球菌感染小鼠48 h死亡率均明显低于模型对照组,440 mg.kg-1组死亡率低于金莲花片2 400 mg.kg-1组。结论:对多种细菌有明显的抑制作用。相等生药量的总黄酮对金黄色葡萄球菌感染小鼠的保护作用强于金莲花片。     

Ursolic, oleanolic and betulinic acids: antibacterial spectra and selectivity indexes

ETHNOPHARMACOLOGICAL RELEVANCE: Ursolic acid (UA), oleanolic acid (OA) and betulinic acid (BA), three hydroxyl pentacyclic triterpenoic acids (HPTAs) naturally found in a large variety of vegetarian foods, medicinal herbs and plants have been investigated for antibacterial activity. AIM OF THE STUDY: To determine the antibacterial activity of UA, OA and BA, as well as the toxic impact on eukaryotic cells. MATERIALS AND METHODS: Minimum inhibitory concentrations were determined against five reference strains (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 & ATCC 29213, Enterococcus faecalis ATCC 29212 and Pseudomonas aeruginosa ATCC 27853), as well as five antibiotic-resistant clinical isolates. Toxicity was evaluated against MRC-5 and HaCaT cell lines. RESULTS: No antibacterial activity was observed for BA; while OA and more particularly UA, did show a moderate to good antibacterial activity, but limited to Gram-positive bacteria. Nevertheless, OA and UA were devoid of antibacterial activities against clinical isolates. Moreover, viability and cytotoxic assays demonstrated that the three compounds induced a significant cytotoxicity. CONCLUSIONS: Despite of a relative similar chemical structure; UA, OA and BA harboured different antibacterial activities, with more significant ones for UA. However, considering both viability and toxicity values, these compounds seem to have a significant impact on eukaryotic cell viability.