STUDY ON ANTIBACTERIAL ACTION OF 4-[P-ACETYLAMINO]BENZENESULFONAMIDOL SELENOMORPHOLINE BY MICROCALORIMETRY

Antibacterial action of 4-[p-acetylamino benzenesulfonamido] selenomorpholine (SeB) was studied by microcalorimetry with an LKB-2277 Bioactivity Moni-tor. It was found that SeB had the capacity to inhibit the metabolic growth of Escherichia coli. But in different sol-vent, the extent of inhibition is different. Removing the effect of solvent, we obtained the half-inhibition conce.ntra-tion(IC50) of SeB from the power-time curves. The value of IC50 of SeB was 1319μg ·mL-1.

Initial Screening of 10 Plant Essential Oils in Vitro Antibacterial Activity Against Blueberry Pathogens

In order to develop natural antistaling agent for blueberries preservation,the antibacterial activities of 10 kinds of plant essential oils were analyzed by oxford-cup test and tube dilution method,and their inhibitory abilities to two kinds of representative Gram bacteria which are Escherichia coli and Staphylococcus aureus,and three kinds of harmful fungi in blueberries,involving Alternaria alternata,Penicillium digitatum and Botrytis cinerea,were tested.The results showed that 7 kinds of essential oils can inhibit the three fungi,among which cinnamon oil,clove oil,anise oil and thyme oil have strong fungi static efficacy.Cinnamon oil and thyme oil can effectively inhibit the Gram-positive bacterium(Staphylococcus aureus);cinnamon oil and masson pine oil are strongly inhibitory to Gram-negative bacterium(E.coli).Cinnamon oil has broad-spectrum ability to inhibit fungi,Gram-negative and positive bacteria,with a minimum inhibitory concentration(MIC)ranging from 0.0391 to 0.1560 L/mL.With strong inhibition effects on fungi,cinnamon oil can be used as a compound base oil and mixed with other essential oils to retain the freshness of blueberries,thus achieving better antibacterial and anti-corrosion effects.

Antibacterial, Anti-Inflammatory and Antioxidant Activities of an ACAZY Herbal Formula Used in Traditional Medicine to Treat Respiratory Infections

ACAZY is a plant formula used in traditional medicine in Burkina Faso to treat respiratory infections. After phytochemical analysis, this study evaluated extracts’ anti-inflammatory, antioxidant and antibacterial properties from the ACAZY recipe. Three extractions, an aqueous macerate (AM), an aqueous decoction (AD) and an hydroethanolic macerate (HEM) of the ACAZY recipe powder were carried out. Phytochemical screening of the extracts was carried out using high-performance thin-layer chromatography (HPTLC) and the determination of phenolic compounds. The anti-inflammatory potential was assessed in vitro using pro-inflammatory enzyme inhibition tests. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Ferric-reducing antioxidant power (FRAP) antioxidant properties were also determined. The antibacterial activity was evaluated on Staphylococcus aureus and Streptococcus pneumoniae strains. Phytochemical analysis revealed the presence of flavonoids, saponins, tannins, anthracenosids, sterols and triterpenes in the extracts. The extracts inhibited pro-inflammatory enzymes by more than 40% at only 100 µg/mL. The extracts also showed potent antibacterial activity with a minimum inhibitory concentration 1 mg/mL on Staphylococcus aureus and 2 mg/mL on Streptococcus pneumoniae. The extracts in the ACAZY formula have shown anti-inflammatory and antioxidant properties in vitro. The AD also showed an antibacterial activity. This justifies its use in traditional medicine to treat acute respiratory infections.

In vitro antibacterial activity of Hibiscus rosa-sinensis flower extract against human pathogens

Objective:To access the in vitro antibacterial activity of Hibiscus rosa-sinensis(H.rosa-sinensis) flower extract against human pathogens.Methods:Antibacterial activity was evaluated by using disc and agar diffusion methods.The protein was run through poly acrylmide gel electrophoresis to view their protein profile.Results:The results showed that the cold extraction illustrates a maximum zone of inhibition against Bacillus suhtillis(B.suhtillis),Escherichia coli(E.coli) viz.,(17.00±2.91),(14.50±1.71)mm.followed by hot extraction against.E.coli.Salmonella sp.as(11.66 ±3.14),(10.60±3.09)mm.In methanol extraction showed a highest zone of inhibition recorded against B.suhtillis,E.coli as(18.86±0.18),(18.00±1.63) mm pursued by ethanol extraction shower) utmost zone of inhibition recorded against Salmonella sp.at(20.40±1.54) mm.The crude protein from flower showed a maximum inhibitory zone observed against Salmonella sp.,E.coli viz.,(16.55±1.16),(14.30±2.86)mm.The flower material can be taken as an alternative source of antibacterial agent against the human pathogens.Conclusions:The extracts of the H.rosasinensis art;proved to have potential antibacterial activity,further studies arc highly need for the drug development.

Evaluation of in-vitro antibacterial activity and anti-inflammatory activity for different extracts of Rauvolfia tetraphylla L.root bark

Objective:To assess the in-vitro antihacterial activity and anti-inflammatory activity of orally administered different extracts(Hydro-alcoholic,methanolic,ethyl acetate and hexane)of Rauvolfia tetraphylla(R.tetraphylla)root bark in Carrageetiaii induced acute inflammation in rats.Methods:In-vitro antibacterial activity was evaluated for extracts against four Gram positive and four Gram negative bacteria by using cylinder plate assay.Hydro-alcoholic extract(70%v/v ethanol)at 200,400 and 800 mg/kg doses and methanolic,ethyl acetate and hexane extracts at doses 100,200 and 400 mg/kg were tested for anti-inflammatory activity in Carrageenan induced rat paw oedema model and paw thickness was measured every one hour up to 6 hrs.Results:All extracts of R.tetraphylla root bark showed good zone of inhibition against tested bacterial strains.In Carrageenan induced inflammation model,hydro-alcoholic and methanolic extract of R.tetraphylla root bark at three different doses produced significant(P<0.00l)reduction when compared to vehicle treated control group and hexane,ethyl acetate extracts.Conclusions:In the present study extracts of R.tetraphylla root bark shows good in-vitro antibacterial activity and in-vivo anti-inflammatory activity in rats.

A NEW APPROACH TO THE CURVE FITTING OF IN VITRO RADIOASSAYS BASED ON THE MASS ACTION LOW

A new curve fitting method with its mathematical models derived from the mass action law is presented which is applicable to several in vitro radioassays including RIA and RBA. Experiments revealed that the robustness of this method is better than the conventional methods like Woolf plot in RBA and 4- parameter logistic plot in RIA. However, the robustness of this method is only relative: in some cases of RIA and RBA, the bias of the results may still be too large to be acceptable. Further improvement is expected to be studied.

血红蛋白源抗菌肽hemocidins研究进展

血红蛋白及其降解片段在人和动物体内有着多种多样的生理功能。血红蛋白降解后产生的具有抗菌活性的片段被称为hemocidins。hemocidins是一类重要的内源性抗菌肽,其来源宿主广泛、抗菌谱广。根据抗菌肽的构效关系,计算机辅助设计的hemocidins类似肽也具有较好的抗菌活性。文章主要对hemocidins及其类似肽的抗菌活性和抗菌机制进行了简要综述,以期为深入研究和开发hemocidins及其类似肽提供一些参考,进而为防治人与动物病原菌感染提供理论依据。

In vitro antioxidant and antimicrobial activity cycloart-23-ene-3β,25-diol(B2) isolated from Pongamia pinnata(L.Pierre)

Objective:To evaluate the in-vitro antioxidant and antimicrobial activity of cvcloart-23- ene-3β,25-diol(called as B2) isolated from stem bark of Pongamia pinnata.Methods:In vitro antioxidant activity of B2 was determined by methods for determination of Dl’PH radical scavenging,reducing power,superoxide anion radical scavenging,hydroxyl radical scavenging, hydrogen peroxide scavenging,metal chelating and nitric oxide radical scavenging at the doses of 20.40.60.80 and 100μg/mL,respectively.3 -tocopherol with same concentration was used as a standard antioxidant.In vitro antimicrobial activity of B2 was determined by cup plate method in different concentration range of 10-100μg/mL.Results:The results indicated that dose dependent%reduction against DPPH radical,reducing power,superoxide anion radical scavenging,hydroxyl radical scavenging,metal chelating,hydrogen peroxide scavenging and nitric oxide radical scavenging by B2 andβ-tocopherol.Conclusions:It is concluded that cycloart 23-ene-3β,25 diol(B2) showed dose dependent antioxidant activity.B2 showed more DPPH radical scavenging,reducing power,superoxide scavenging,hydroxyl radical scavenging, metal chelating scavenging,hydrogen peroxide radical scavenging and nitric oxide radical scavenging activity thanβ-tocopherol and in case of antimicrobial activity B2 exhibited broad-spectrum activ ity against bacteria and strong activity against yeast type of fungi.

In vitro prebiotic effects of seaweed polysaccharides

Although prebiotic activities of alginate and agar oligosaccharides isolated from seaweeds have been reported, it remains unknown whether seaweed polysaccharides have prebiotic activity. In this study, we isolated polysaccharides from four species of seaweeds, such as Grateloupia fi licina(GFP), Eucheuma spinosum(ESP), Ulva pertusa(UPP), and A scophyllum nodosum(ANP), and characterized their structures and prebiotic ef fects in vitro. The results showed that these polysaccharides were dif ferent in total sugar and sulfate contents as well as monosaccharide composition. GFP and ESP significantly promoted bifi dobacterium proliferation and 0.1% ESP and 0.4% GFP resulted in the highest proliferation rates of beneficial bacteria, whereas UPP and ANP inhibited the growth of beneficial bacteria at all tested concentrations(0.1%–0.5%). The different behaviors of the four seaweed-originated polysaccharides might be refl ected by differences in monosaccharide composition and structure. Therefore, polysaccharides isolated from GFP and ESP could be utilized as prebiotics. However, more studies must be carried out in vivo.

Molecular Epidemiology of Oxacillin-resistant Staphylococcus aureus and in vitro Activity of Glycopeptides against Staphylococcus species

The purpose of this subject was to investigate molecular epidemiology of oxacillin-resistant Staphylococcus aureus (MRSA) isolated from hospitalized patients, and to survey the in vitro activity of teicoplanin, vancomycin and other 9 antibiotics against Staphylococcus species . MRSA were detected by oxacillin-NaCl-containing screen agar. The homology of nosocomial MRSA from ICU and RCU was determined by pulse-field gel electrophoresis. Agar diffusion, E test and agar dilution were used to compare the in vitro activity of teicoplanin and vancomycin against Staphylococcus spp from 2001 to 2003 at Peking Union Medical College Hospital. WHONET-5.3 software was used to analyze the antimicrobial susceptibility data. From 2001 to 2003, the prevalences of MRSA were 56.5%, 65.3%, 64.7%, respectively. PFGE found most of MRSA from ICU and RCU were closely related. All of S.aureus and S.epidimidis isolates were susceptible to teicoplanin and vancomycin from 2001 to 2003. However, 1 isolate of S.haemolyticus was resistant and 9 isolates intermediate to teicoplanin. The minimal inhibitory concentration of teicoplanin did not correlate well with zone diameter, when inoculum increased by 100 folds, the zone diameters of teicoplanin decreased more greatly than those of vancomycin. In 2002, severe outbreaks caused by MRSA strains had been found in ICU and RCU wards. Teicoplanin and vancomycin had good activity against clinical isolates of Staphylococci spp . Teicoplanin was less active than vancomycin against S.haemolyticus . Most of S.haemolyticus isolates were intermediate to teicoplanin. Antimicrobial susceptibility testing of teicoplanin was influenced by the diffusion speed in the agar and inoculum size.

In Vitro Anti-Bacterial and Anti-Fungal Activities of Extracts from Different Parts of 7 Zingiberaceae Plants

This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family.The inhibitory rate,minimum inhibitory concentration(MIC),and minimum bactericidal concentration(MBC)of leaf and stem,and root and rhizome extracts from Alpinia katsumadai Hayata,Alpinia oxyphylla Miq×Alpinia henryi K.Schumann,Alpinia oblongifolia Hayata,Alpinia nigra(Gaertn.)Burtt,Amomum villosum Lour,Alpinia zerumbet(Pers.)Burtt.et Smith and Alpinia oxyphylla Miq were determined using the fungus cake method and double dilution method.The seven Zingiberaceae plants exhibited characteristic antibacterial activities against pathogenic bacteria and fungi.At a 1.5 mg mL^(−1),A.zerumbet root and rhizome extracts exhibited strong inhibitory activity against S.aureus and E.coli,with 83.23%and 79.62%,respectively.In addition,A.zerumbet leaf and stem extracts had an inhibitory rate of 90.85%against P.aeruginosa.At the same concentration,the leaf and stem,root and rhizome extracts of A.katsumadai had the best anti-bacterial effect against F.oxysporum,with inhibition rates of 84.46%and 84.73%,respectively.Moreover,A.katsumadai and A.zerumbet leaf and stem extracts had the most significant antibacterial effect against S.aureus,with a MIC of 0.063 mg mL^(−1).Thus,both A.katsumadai and A.zerumbet extracts had significant antibacterial activity.In addition,by comparing the inhibitory effect of extracts from different parts,it was found that the inhibitory rate and average inhibitory rate of extracts from leaf and stem were higher than those from root and rhizome.The chemical constituents of A.katsumadai and A.zerumbet,determined by the high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),revealed that citric acid(CA),alpinetin,and pinocembrin(PNCB)were the functional constituents yielding the antibacterial activity.Overall,A.katsumadai and A.zerumbet have the potential to be developed as new plant fungicides and bactericides.

Study on Antibacterial Effect of Single Chinese Herbs on Staphylococcus aureus

[Objectives] This study was conducted to determine in-vitro antibacterial effect of 58 Chinese herbs on Staphylococcus aureus,and screen single Chinese herbs with better in-vitro antibacterial effect for formulation of prescription. [Methods]Effective components in Chinese herbs were extracted with water,and inhibition zone diameters and minimal inhibitory concentrations of the 58 Chinese herbs against S. aureus were determined by agar plate punching method and micro two-fold method,respectively. [Results] Twenty two kinds of Chinese herbs including Terminalia chebula Retz.,Anemarrhena asphodeloides Bunge.,Prunella vulgaris L,Rheum palmatum L. and Mosla chinensis Maxim. had better antibacterial effect,among which T. chebula Retz.,A. asphodeloides Bunge.,P. vulgaris L,R. palmatum L. and C. sappan Linn showed the best antibacterial effect,with average inhibition zone over 20 mm and MIC lower than 15. 6 mg/ml.[Conclusions]Traditional Chinese herbs have certain antibacterial effect,and this study will provide important theoretical reference for clinical medication and development of prescription.

原薯蓣皂苷体外抗产NDM-1耐碳青霉烯Raoultella ornithinolytica B1645-1B的机制研究

目的:研究原薯蓣皂苷(protodioscin,PD)对产碳青霉烯酶NDM-1解鸟氨酸乌拉尔菌(carbapenem-re⁃sistant Raoultella ornithinolytica)B1645-1B的体外抑菌作用及逆转耐药性机制研究。方法:采用微量肉汤稀释法测定PD对B1645-1B的最低抑菌浓度(minimum inhibitory concentration,MIC)。应用棋盘法测定中药单体PD联合亚胺培南(Imipenem,IMP)对B1645-1B的MIC,计算抑菌浓度指数(fractional inhibitory concentration,FIC)。采用实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)检测PD作用菌株B1645-1B后NDM-1 mRNA合成。利用MOE(Molecular Operating Environment)软件预测PD与NDM-1蛋白分子对接。通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)检测PD作用纯化后菌株B1645-1B的NDM-1蛋白表达。结果:PD对B1645-1B的MIC为10000μg/mL。PD联合IMP对B1645-1B的FIC为0.75,出现协同作用。PD作用后菌株B1645-1B的NDM-1 mRNA合成抑制和酶活性降低。结论:PD可能是一种很有前途的新型有效的协同抗菌剂及NDM-1酶抑制剂。

TEMOCILLIN体外抗菌活性的研究

本文报告Temocillin对490株致病菌体外抗菌活性的研究,并与其它6种β-内酰胺类抗生素和庆大霉素进行了比较。结果显示,本品对大多数肠道杆菌有较好抗菌活性,MIC_(50)为1～4μg/ml。MIC_(90)均为≤16μg/ml。本品对沙雷氏菌中度敏感,其MIC_(90)为3μg/ml;对绿脓杆菌和不动杆菌耐药。革蓝氏阳性球菌对本品不敏感。同其它几种抗生素比较,本品对大多数肠道杆菌的抗菌活性较头孢噻肟略差,与Moxalactam接近,较哌拉西林、头孢唑啉、头孢西丁、头孢呋肟和庆大霉素为强。本研究为该药的临床应用提供参考。

国产Augmentin体外抗菌作用的研究

本文主要研究了国产Augmentin对547株临床分离产酶致病菌的体外抗菌作用及克拉维酸的抑酶作用。研究结果表明:国产Augmentin的体外抗菌效果与进口Augmentin相似。对大肠杆菌、克雷伯氏肺炎杆菌、沙门氏菌的MIC_(50)、MIC_(90)比羟氨苄青霉素强8～30倍以上;对阴沟肠杆菌MIC_(50)、MIC_(90)强2倍以上;对痢疾杆菌的MIC_(90)强8倍以上;对金葡球菌MIC_(60)强4倍。抑酶实验表明:克拉维酸不仅对质粒介导的广谱酶有效,对染色体介导的超广谱酶亦有较强的作用。

Levofloxacin体外抗菌活性研究

利用试管双倍稀释法及纸片法测定ｌｅｖｏｆｌｏｘａｃｉｎ（ＬＶＬＸ）体外抗菌活性，并与其它１０种药物比较。结果表明ＬＶＬＸ对革兰氏阴性菌具有良好抗菌作用，尤以对痢疾杆菌、伤寒杆菌、变形杆菌、肺炎杆菌、产气杆菌、大肠杆菌作用更为突出，ＭＩＣ５０≤０．０３～０．２８μｇ／ｍｌ，ＭＩＣ９０≤０．０３～１２８μｇ／ｍｌ，抑菌率６０％～１００％；其活性为氧氟沙星的１～４倍，比诺氟沙星、头孢呋辛强，与环丙沙星、庆大霉素及头孢噻肟相当。ＬＶＬＸ抗葡萄球菌活性为所测喹诺酮中最强，与头孢唑林相当，对肺炎球菌、溶血性及草绿色链球菌作用与头孢菌素相当。ＬＶＬＸ有较强抗铜绿假单胞菌活性，ＭＩＣ５０与ＭＩＣ９０分别为０．５与６４μｇ／ｍｌ，与阿米卡星及头孢哌酮相当。ＬＶＬＸ为一广谱高效抗菌药物。

抗菌肽buforin Ⅱ衍生物抑制细菌核酸合成的机制研究

目的探究抗菌肽buforin Ⅱ的衍生物buforin Ⅱ-A(BF2-A)和buforin Ⅱ-B(BF2-B)对细菌的胞内抑菌作用机制。方法体外用原子力显微镜观察抗菌肽与基因组DNA的结合情况,荧光光谱分析肽与基因组DNA的结合方式。体内用透射电镜观察抗菌肽作用后金黄色葡萄球菌细胞膜超微结构的变化,流式细胞仪分析肽对金黄色葡萄球菌细胞周期的影响。最后通过凝胶阻滞实验推测肽与金黄色葡萄球菌DNA合成相关基因的结合引起了细胞周期的改变。结果肽与基因组DNA发生了结合,与溴化乙锭(EB)竞争性嵌入基因组DNA;BF2-A/BF2-B与金黄色葡萄球菌作用后几乎在不破坏细胞膜的情况下渗透进入胞内,与DNA合成相关基因发生了结合,特异性阻滞细胞周期中的DNA合成阶段;肽与DNA合成相关基因发生了结合。另外,所有的实验结果显示了BF2-B穿透细胞、与DNA结合的能力及对细胞周期的影响强于BF2-A。结论 BF2-A/BF2-B与DNA穿过金黄色葡萄球菌细胞膜后在细胞内通过与DNA结合,特异性的将细胞阻滞在了细胞周期的DNA合成期而发挥了抑菌作用,而且BF2-B的上述作用强于BF2-A。

Clarithromycin的体外抗菌作用研究

评价国产ｃｌａｒｉｔｈｒｏｍｙｃｉｎ（ＣＲＭ）对临床分离到的４６４株致病菌的体外抗菌作用，并与红霉素（ＥＭ）、麦迪霉素（ＭＤＭ）、麦白霉素（ＭＬＭ）、柱晶白霉素（吉他霉素，ＬＵＭ）进行比较。结果表明ＣＲＭ对ＥＭ敏感的金葡球菌、表葡球菌、肺炎链球菌和化脓链球菌的抗菌作用优于ＥＭ，明显优于其它３种同类对照药，ＭＩＣ（９０）为０．０６２～２ｍｇ／Ｌ；对部分ＥＭ耐药的表葡球茵，化脓链球菌和粪链球菌也有一定的抗菌作用；对流感嗜血杆菌和对ＥＭ敏感的粪链球菌的抗菌作用同ＥＭ，优于其它３种同类对照药，ＭＩＣ_（９０）为０．５～２ｍｇ／Ｌ；对部分厌氧菌也有一定的抗菌作用，细菌接种量对ＣＲＭ的抗菌作用有一定的影响，但仍在敏感范围之中；ｐＨ值的变化影响ＣＲＭ抗菌作用，其抗菌作用在碱性条件下较强，尤以ｐＨ８．５时为显著；少量的人血清不影响ＣＲＭ的抗菌作用，但浓度加至７５％，ＣＲＭ的抗菌作用减弱。

鸭抗菌肽Cathelicidin的衍生物设计及抑菌机制研究

鸭抗菌肽Cathelicidin分子[Cath(1-20)]富含疏水性氨基酸及正电荷,通过人工方法设计合成Cath(1-20)的截短肽衍生物,筛选新型安全Cath(1-20)衍生肽,探讨其作用机制。结果表明,与母肽Cath(1-20)相似,三种衍生肽Cath(5-20)、Cath(4-20)、Cath(3-20)均具有明显广谱抑菌活性,MIC值在1~8μmol·L^(-1)范围内,但仅Cath(5-20)溶血及细胞毒性明显降低,治疗指数达19.5,显著高于Cath(1-20)、Cath(4-20)及Cath(3-20)。Cath(1-20)及其衍生肽可破坏E.coli UB1005的内膜完整性,产生去极化作用,并存在时间和剂量依赖效应;透射电镜结果显示Cath(1-20)及Cath(5-20)可破坏细菌细胞膜。研究证实氨基端的色氨酸对鸭抗菌肽Cath(1-20)溶血及细胞毒性起关键作用,其作用靶点主要为细菌细胞膜。