藏药二十五味鬼臼丸对金黄色葡萄球菌的抑菌作用及机制研究

目的 研究藏药二十五味鬼臼丸对金黄色葡萄球菌的抑菌作用,初步探讨相关抑菌机制。方法 采用琼脂平板打孔法,测定二十五味鬼臼丸（50、100、200mg·mL^-1）对金黄色葡萄球菌的抑菌圈大小。通过微量肉汤稀释法,测定最小抑菌浓度（MIC）。调整肉汤培养基中的二十五味鬼臼丸浓度为0.5MIC、1.0MIC和2.0MIC,分别加入1.0×10⁸CFU·mL^-1菌悬液,以不含药液而含菌量相同的培养基作为对照组,在37℃、120r·min^-1恒温培养箱中振荡培养,每小时取样,用紫外可见分光光度计在600nm处测定吸光度（A₆₀₀）值,绘制细菌的生长曲线;每2小时取样,离心取上清液,试剂盒法测定碱性磷酸酶（AKP）活性;每小时取样,离心取上清液,用紫外可见分光光度计在260nm处测定A₂₆₀值,以A₂₆₀值表示DNA/RNA大分子相对量;每小时取样,离心取上清液,加入考马斯亮蓝G250溶液,于595nm处测定A₅₉₅值,检测胞外可溶性蛋白含量;培养8h后,离心留沉淀,进行SDS-PAGE电泳,检测菌体蛋白含量。结果 二十五味鬼臼丸50、100、200mg·mL^-1对金黄色葡萄球菌的抑菌圈直径分别为（12.33±0.75）、（16.33±0.41）、（19.17±0.68）mm;对金黄色葡萄球菌的MIC为100mg·mL^-1;与对照组相比,二十五味鬼臼丸组的金黄色葡萄球菌生长显著减缓（P＜0.05）,胞外的AKP活性显著升高（P＜0.05）,胞外DNA/RNA大分子相对量显著升高（P＜0.01）,胞外可溶性蛋白含量显著升高（P＜0.01）,菌体总蛋白表达量明显减少。结论 二十五味鬼臼丸对金黄色葡萄球菌具有抑菌作用,其抗菌作用可能与致细菌细胞壁、细胞膜结构破损,且对菌体蛋白具有一定抑制作用有关。     

地榆鞣质提取物的抗菌活性及对金黄色葡萄球菌的抑菌机制研究

摘 要 目的： 研究地榆鞣质提取物的体外抗菌活性及其对金黄色葡萄球菌的抑菌机制。方法: 采用牛津杯法和试管二倍稀释法测定地榆鞣质提取物的抗菌活性,并以金黄色葡萄球菌为供试菌,测定胞外碱性磷酸酶（AKP）、钾离子（K⁺）、可溶性蛋白含量,及菌体胞内和胞外总三磷酸腺苷酶（T-ATPase）含量;通过聚丙烯酰胺凝胶电泳（SDS-PAGE）观察蛋白谱带变化和通过透射电镜（TEM）观察菌体超微结构,从而阐述地榆鞣质的抗菌机制。结果: 地榆鞣质能够有效抑制革兰阳性菌,而对革兰阴性菌无明显的抑制作用。地榆鞣质作用金黄色葡萄球菌后,菌悬液中AKP、K⁺、可溶性蛋白、DNA和RNA等大分子物质的含量比对照组显著增大;胞内和胞外ATP酶浓度发生显著变化;SDS PAGE蛋白图谱结果表明,经地榆鞣质处理的菌体无明显的蛋白条带形成;透射电镜观察发现,菌体细胞完整性被破坏。结论:地榆鞣质在体外具有显著的抗菌活性,能够改变金黄色葡萄球菌细胞膜的通透性,并破坏细胞的完整性。     

2013～2016年单中心血液科细菌感染病原菌分布特点

目的 探讨2013～2016年血液科住院患者细菌感染的病原菌分布特点。方法 回顾性分析2013年1月至2016年12月安徽省肿瘤医院血液科普通病区和层流病房287例患者的临床资料，采用SPSS 17.0统计软件对所有送检标本来源、病原菌种类分布、不同病房病原菌和不同取样部位常见感染菌株差异进行统计分析。结果 共培养出菌株333株，最常见的来源为血液、痰、中段尿，病原菌分布以革兰阴性菌为主（249株，74.77%），其中前3位分别为大肠埃希菌（118株，47.39%）、肺炎克雷伯菌（60株，24.09%）、铜绿假单胞菌（22株，8.84%）；革兰阳性球菌84株，其中前3位分别为凝固酶阴性葡萄球菌（36株，42.86%）、金黄色葡萄球菌（17株，20.24%）、屎肠球菌（14株，16.67%）。来源于血的菌株以大肠埃希菌（90株，44.12%）最常见；来源于痰的菌株以肺炎克雷伯菌（24株，32.00%）最常见；来源于中段尿培养的菌株以大肠埃希菌（21株，70.00%）最常见。层流病房革兰阴性杆菌感染率较普通病房高，差异有统计学意义（P<0.05）。层流病房菌株来源于血液的比例高于普通病区，差异有统计学意义（P<0.05）。结论 血液科患者细菌感染以革兰阴性菌为主，不同感染部位、不同病房细菌分布存在差异，关注病原菌分布特点有助于指导临床经验性用药。     

耐甲氧西林金黄色葡萄球菌血流感染危险因素的系统评价

目的 系统评价耐甲氧西林金黄色葡萄球菌（MRSA）血流感染危险因素，为各级医疗机构预防MRSA血流感染提供依据。方法 计算机检索中国学术期刊全文数据库（CNKI）、万方数据库（Wanfang Data）、维普中文期刊全文数据库（VIP）、中国生物医学文献数据库（CBM）、PubMed、Embase等数据库，检索时限为建库至2023年6月6日，收集国内外MRSA血流感染危险因素的病例对照研究，采用RevMan 5.3软件进行Meta分析。结果 共纳入16篇病例对照研究，涉及感染危险因素49个。结果显示年龄（年龄≥65、60岁），医院感染，合并脑梗死、慢性肝胆疾病、消化性溃疡、感染性休克、肺部感染，中心静脉置管、留置导尿管、气管插管，入住ICU，感染前使用碳青霉烯类、糖肽类、第3代头孢菌素类，感染来源于呼吸道、皮肤软组织、腹腔、导管、感染来源大于2个部位，住院时间，MRSA血流感染组与甲氧西林敏感金黄色葡萄球菌（MSSA）血流感染组相比，差异有统计学意义（P<0.05）。结论 MRSA血流感染危险因素多，临床诊疗活动中应重视患者基础疾病，规范化进行侵入性操作，重视病区环境的消杀和医务人员手卫生，合理使用抗菌药物，动态评估患者生命体征，根据危险因素制定感控策略，从而降低MRSA血流感染发生率。     

盐酸环丙沙星壳聚糖纳米粒原位凝胶的制备与评价

目的 制备盐酸环丙沙星壳聚糖纳米粒原位凝胶，并评价其抑菌及创面愈合效果。方法 采用复乳法制备盐酸环丙沙星壳聚糖纳米粒，采用2因素2水平全因子析因实验设计考察了壳聚糖相对分子质量（X₁）和壳聚糖质量浓度（X₂）对壳聚糖纳米粒的药物包封率（Y₁）、粒径分布（Y₂）、多分散系数（Y₃）和Zeta电位（Y₄）的影响；并以泊洛沙姆407作为凝胶基质制备盐酸环丙沙星壳聚糖纳米粒原位凝胶。通过抑菌圈实验比较盐酸环丙沙星乳膏和盐酸环丙沙星壳聚糖纳米粒原位凝胶对金黄色葡萄球菌和铜绿假单胞菌的抑菌活性；使用无菌活检穿刺针在大鼠背部造成直径为5 mm的皮肤全切除的圆形人工创面，并使用金黄色葡萄球菌和铜绿假单胞菌的培养基感染24 h，建立大鼠创面模型，将模型大鼠随机分为模型组、盐酸环丙沙星乳膏组和盐酸环丙沙星壳聚糖纳米粒原位凝胶组，模型组大鼠创面未接受任何处理，给药组大鼠每2天给药1次，每次给药量均约为1 mg，观察并记录每组大鼠创面脱痂时间和愈合时间。结果 选择低相对分子质量壳聚糖、壳聚糖质量浓度为2.0 mg·mL^-1制备盐酸环丙沙星壳聚糖纳米粒，其中盐酸环丙沙星质量浓度为50.0 mg·mL^-1，其包封率为（85.3±0.9）%，平均粒径为（354.7±15.7）nm，PDI为0.357±0.014，Zeta电位为（22.2±0.5）mV，呈球状分布；盐酸环丙沙星壳聚糖纳米粒原位凝胶和盐酸环丙沙星乳膏对金黄色葡萄球菌的抑菌圈直径分别为（38.4±0.2）、（29.2±0.3）mm，对铜绿假单胞菌抗菌圈直径分别为（41.3±0.6）、（32.1±0.1）mm；大鼠创面给予盐酸环丙沙星壳聚糖纳米粒原位凝胶后，其脱痂时间和愈合时间均较模型组和盐酸环丙沙星乳膏组显著缩短（P<0.05）。结论 成功制备盐酸环丙沙星壳聚糖纳米粒原位凝胶，其可以抑制创面细菌繁殖、加速伤口愈合。     

2018—2020年郑州市第七人民医院血流感染分离菌的分布及耐药性分析

目的 了解血流感染分离菌的分布及耐药特征,为临床防治血流感染提供指导和依据。方法 收集2018年1月—2020年12月郑州市第七人民医院血培养分离的非重复菌株,采用WHONET5.6软件统计菌株的分布及耐药特征。结果 共分离546株菌株,革兰阴性菌302株（55.31%）,革兰阳性菌220株（40.29%）,真菌24株（4.40%）。前6位分离菌依次为凝固酶阴性葡萄球菌（CNS,23.44%）、大肠埃希菌（18.68%）、肺炎克雷伯菌（14.84%）、金黄色葡萄球菌（6.04%）、鲍曼不动杆菌（4.21%）和铜绿假单胞菌（3.85%）。大肠埃希菌对碳青霉烯类最敏感,肺炎克雷菌碳对美罗培南和亚胺培南的耐药率分别为30.86%和35.80%,鲍曼不动杆菌耐药较严重,耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）和耐甲氧西林金黄色葡萄球菌（MRSA）的检出率分别为72.66%、42.42%,未发现利奈唑胺和万古霉素耐药的葡萄球菌。结论 革兰阴性菌是医院血流感染的主要致病菌,细菌耐药情况复杂,临床要根据药敏结果合理选择抗菌药物。     

中氮茚并喹啉酮类衍生物的体外抗菌活性研究

摘 要 目的： 测试中氮茚并喹啉酮类衍生物的体外抗菌活性。方法: 采用肉汤稀释法测试中氮茚并喹啉酮类衍生物对金黄色葡萄球菌金黄色亚种、解硫胺素芽孢杆菌、枯草芽孢杆菌、始旋链霉菌、耐甲氧西林金黄色葡萄球菌（MRSA）的抗菌活性。结果: 中氮茚并喹啉酮类衍生物对金黄色葡萄球菌金黄色亚种、解硫胺素芽孢杆菌、枯草芽孢杆菌、始旋链霉菌有一定的抑制作用,尤其对MRSA具有较强的抑制作用,衍生物2a,2b,8a的MIC值（0.062 5μg·mL^-1）仅为万古霉素（2.0 μg·mL^-1）的1/32。结论: 中氮茚并喹啉酮类衍生物对多个菌种有抑制作用,对耐药菌MRSA抑制作用值得关注,其机制有待进一步研究。     

374例金黄色葡萄球菌烫伤样皮肤综合征患儿病原菌及其药敏试验结果

摘 要 目的：了解金黄色葡萄球菌烫伤样皮肤综合征患儿的病原菌检出情况及其药敏试验结果,为该疾病的临床治疗提供分析数据。方法: 2010年1月～2015年6月我院收治的金黄色葡萄球菌烫伤样皮肤综合征患儿374例作为研究对象。采集患儿的创面分泌物和血液标本进行细菌培养和药敏试验。结果: 创面分泌物标本中检出223株病原菌;血培养阳性17例,阳性率4.55%。共检出金黄色葡萄球菌187株,其中耐甲氧西林金黄色葡萄球菌（MRSA） 64株,检出率34.22%。甲氧西林敏感金黄色葡萄球菌（MSSA）和MRSA对万古霉素、替加环素、替考拉宁、利奈唑胺的敏感率均为100.00%;MRSA对青霉素、苯唑西林、哌拉西林、头孢哌酮、头孢唑林、头孢呋辛、头孢西丁、阿奇霉素、克林霉素的敏感率均为0。结论:金黄色葡萄球菌烫伤样皮肤综合征的病原学检查尤为重要,应根据药敏试验结果合理使用抗菌药物。     

重组人ⅡA型磷脂酶A2对金黄色葡萄球菌超微结构的影响

摘 要 目的：观察重组人ⅡA型磷脂酶A2（PLA2）对金黄色葡萄球菌超微结构的影响。方法: 用琼脂平板计数法测定重组人ⅡA型PLA₂对金黄色葡萄球菌的杀菌活性,ⅡA型PLA₂与金黄色葡萄球菌共同孵育在RPMI-1640培养液中,37℃水浴,分别孵育30,60,120 min后,应用透射电镜观察细胞超微结构的变化。结果:重组人ⅡA型PLA₂杀灭99%金黄色葡萄球菌的最低浓度（MBC）为80 ng·ml^-1。ⅡA型PLA₂作用30～60 min后,金黄色葡萄球菌的菌体略显肿胀,细胞壁与细胞膜因局部分离而出现空隙,细胞膜、细胞壁在横隔结构处裂开。当ⅡA型PLA₂作用120 min后,可见细菌的细胞壁破坏严重,胞质外流。结论:ⅡA型PLA₂对金黄色葡萄球菌有较强的抗菌作用,并可能通过破坏细菌的细胞壁或细胞膜结构来抑制细菌的生长。     

人葡萄球菌血流感染耐药及预后分析

目的 了解人葡萄球菌血流感染的临床特点及菌株耐药情况。方法 回顾性分析安徽医科大学第一附属医院2008～2015年人葡萄球菌血流感染的 101例患者临床资料、实验室检查结果及菌株耐药情况。结果 95例（94.1%）患者存在基础疾病，79例（78.2%）存在免疫缺陷，49例（48.5%）有长期留置导管。好转74例（73.3%），非好转27例（26.7%）；人葡萄球菌血流感染合并恶性肿瘤、不恰当用药是影响患者预后的危险因素（P<0.05）。人葡萄球菌对红霉素、苯唑西林、四环素及复方新诺明耐药率分别是91.1%、78.2%、58.5%和55.4%，万古霉素、喹努普汀/达福普汀、利奈唑胺耐药率低。结论 不恰当用药、合并恶性肿瘤为影响人葡萄球菌血流感染预后的危险因素，人葡萄球菌耐药率高。     

Anti-staphylococcal activity of ent-kaurane-type diterpenoids from Croton tonkinensis

Ent-kaurane-type diterpenpoids 1–11, isolated from the dried leaves of the endemic Vietnamese medicinal plant Croton tonkinensis Gagnep. (Euphorbiaceae), were evaluated for inhibitory activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. The most active diterpenoids, 2, 3, and 8, exhibited minimum inhibitory concentrations (MICs) of 32, 500, and 125 g/ml, respectively, against MRSA strains.     

Synthesis and antibacterial activities of novel pleuromutilin derivatives bearing an aminothiophenol moiety

We synthesized a series of novel thioether pleuromutilin derivatives incorporating 2‐aminothiophenol moieties into the C14 side chain via acylation reactions under mild conditions. We evaluated the in‐vitro antibacterial activities of the derivatives against methicillin‐resistant Staphylococcus aureus (MRSA, ATCC 43300), Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922). The majority of the synthesized derivatives possessed moderate antibacterial activities. Compound 8 was found to be the most active antibacterial derivative against MRSA. We conducted docking experiments to understand the possible mode of interactions between compounds 8 , 9b , 11a and 50S ribosomal subunit. The docking results proved that there is a reasonable correlation between the binding free energy and the antibacterial activity. Compound 8 was evaluated for its in‐vivo antibacterial activity and showed higher efficacy than tiamulin against MRSA in mouse infection model.     

Polygosumic acid,a new cadinane sesquiterpene from <Emphasis Type="Italic">Polygonum viscosum</Emphasis>, inhibits the growth of drug-resistant <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> (MRSA) in vitro

Three new sesquiterpenes, 6-hydroxy-7-(1-methylethyl)-3,3a,6,7,8,8a-hexahydroazulene-1,4-dicarboxylic acid methyl ester (1, named viscozulenic acid methyl ester), 7-(1-methylethyl)-3,3a,6,7,8,8a-hexahydroazulene-1,4-dicarboxylic acid 1-methyl ester (2, named viscoazucinic acid) and 3-oxo-1-epi-sclerosporin (3, named polygosumic acid), have been isolated from the chloroform extract of the aerial parts of Polygonum viscosum by reversed-phase preparative high performance liquid chromatography (HPLC). The structures of these compounds were established conclusively by ultraviolet (UV), mass spectrometry (MS) and a series of 1D and 2D nuclear magnetic resonance (NMR) analyses. The anti-bacterial properties of 1–3 against 12 pathogenic bacterial strains have also been assessed by the rapid and robust microtitre-plate-based serial dilution method incorporating resazurin as an indicator of cell growth. Polygosumic acid was the most active among the sesquiterpenes and inhibited the growth of penicillin-resistant Escherichia coli (minimum inhibitory concentration, MIC=0.05 mg/ml) and methicillin-resistant Staphylococcus aureus (MRSA) (MIC=0.10 mg/ml).     

Eugenol alters the integrity of cell membrane and acts against the nosocomial pathogen Proteus mirabilis

Eugenol, a member of the phenylpropanoids class of chemical compounds, is a clear to pale yellow oily liquid extracted from certain essential oils especially from clove oil, nutmeg, cinnamon, and bay leaf. The antibacterial activity of eugenol and its mechanism of bactericidal action against Proteus mirabilis were evaluated. Treatment with eugenol at their minimum inhibitory concentration [0.125 % (v/v)] and minimum bactericidal concentration [0.25 % (v/v)] reduced the viability and resulted in complete inhibition of P. mirabilis. A strong bactericidal effect on P. mirabilis was also evident, as eugenol inactivated the bacterial population within 30 min exposure. Chemo-attractant property and the observance of highest antibacterial activity at alkaline pH suggest that eugenol can work more effectively when given in vivo. Eugenol inhibits the virulence factors produced by P. mirabilis as observed by swimming motility, swarming behavior and urease activity. It interacts with cellular membrane of P. mirabilis and makes it highly permeable, forming nonspecific pores on plasma membrane, which in turn directs the release of 260 nm absorbing materials and uptake of more crystal violet from the medium into the cells. SDS–polyacrylamide gel, scanning electron microscopy and Fourier transform infrared analysis further proves the disruptive action of eugenol on the plasma membrane of P. mirabilis. The findings reveal that eugenol shows an excellent bactericidal activity against P. mirabilis by altering the integrity of cell membrane.     

Anti-Staphylococcal Biofilm Effects of Human Cathelicidin Peptides

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Recent advances in Clp protease modulation to address virulence,resistance and persistence of MRSA infection

The Clp protease is an AAA⁺ protease that executes abnormally folded or malfunctioning proteins, and has an important role in producing virulence factors, forming biofilms or persisters and developing methicillin-resistant Staphylococcus aureus (MRSA). Recent studies showed that Clp protease controls virulence via agr signaling and degrades antitoxins of the toxin–antitoxin system to modulate the formation of persisters and biofilms. In this review, we focus on recent developments concerning the virulence and persistence regulatory pathways and resistance-related mechanism of Clp protease in S. aureus, with an overview of the Clp modulators developed to treat MRSA infection.     

Chemical Composition,In Vitro Antimicrobial and Antioxidant Activities of the Essential Oils of Ocimum Gratissimum,O. Sanctum and their Major Constituents

The essential oils of the flowering aerial parts of two Ocimum species viz., Ocimum gratissimum and O. sanctum were analyzed by gas chromatography and gas chromatography/mass spectroscopy. The principal constituent of O. gratissimum and O. sanctum was eugenol (75.1%) and methyl eugenol (92.4%), comprising 99.3 and 98.9% of the total oils, respectively. In vitro antimicrobial activity of the essential oils of O. gratissimum, O. sanctum and their major compounds eugenol and methyl eugenol were screened by using tube dilution methods. O. gratissimum oil was found highly active against S. marcescens while O. sanctum oil showed significant activity against A. niger and S. faecalis. Methyl eugenol exhibited significant activity against P. aeruginosa while eugenol was effective only against S. aureus. Antioxidant activity of oils, eugenol, and methyl eugenol was determined by 2,2-diphenyl-1-picrylhydrazyl and 2,2’- azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) assays. Essential oil of O. gratissimum showed comparative antioxidant activity with IC₅₀ values 23.66±0.55 and 23.91±0.49 μg/ml in 2,2-diphenyl-1-picrylhydrazyl and 2,2’- azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) models, respectively. Eugenol showed slightly weaker antioxidant activity compared to oil of O. gratissimum, while O. sanctum oil demonstrated very feeble antioxidant activity and methyl eugenol did not show any activity. Eugenol and methyl eugenol would be elite source from O. gratissimum and O. sanctum, respectively, of this region could be consider as a source of natural food antioxidant, preservatives, and as an antiseptic.     

Identification of the Molecular Determinants of the Antibacterial Activity of LmutTX,a Lys49 Phospholipase A2 Homologue Isolated from Lachesis muta muta Snake Venom (Linnaeus, 1766)

Snake venom phospholipases A₂ (PLA₂s) are responsible for numerous pathophysiological effects in snakebites; however, their biochemical properties favour antimicrobial actions against different pathogens, thus constituting a true source of potential microbicidal agents. This study describes the isolation of a Lys49 PLA₂ homologue from Lachesis muta muta venom using two chromatographic steps: size exclusion and reverse phase. The protein showed a molecular mass of 13,889 Da and was devoid of phospholipase activity on an artificial substrate. The primary structure made it possible to identify an unpublished protein from L. m. muta venom, named LmutTX, that presented high identity with other Lys49 PLA₂s from bothropic venoms. Synthetic peptides designed from LmutTX were evaluated for their cytotoxic and antimicrobial activities. LmutTX was cytotoxic against C2C12 myotubes at concentrations of at least 200 μg/mL, whereas the peptides showed a low cytolytic effect. LmutTX showed antibacterial activity against Gram‐positive and Gram‐negative bacteria; however, S. aureusATCC 29213 and MRSA strains were more sensitive to the toxin's action. Synthetic peptides were tested on S. aureus, MRSA and P. aeruginosaATCC 27853 strains, showing promising results. This study describes for the first time the isolation of a Lys49 PLA₂ from Lachesis snake venom and shows that peptides from specific regions of the sequence may constitute new sources of molecules with biotechnological potential.