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Enhanced Antibacterial Activity of Bifunctional Fe_(3)O_(4)-Ag Core-Shell Nanostructures

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Nano Research 2009年第12期2卷 955-965页

作者： Bhupendra Chudasama Anjana K.Vala Nidhi Andhariya R.V.Upadhyay R.V.Mehta Department of Applied Physics S.V.National Institute of TechnologySurat 395007India Department of Physics Bhavnagar UniversityBhavnagar 364022India P.D.Patel Institute of Applied Sciences Charotar University of Science and TechnologyEducation campusChanga 388421India

We describe a simple one-pot thermal decomposition method for the production of a stable colloidal suspension of narrowly dispersed superparamagnetic Fe_(3)O_(4)-Ag core-shell *** biocompatible nanostructures are highly toxic to *** activity studies were carried out on both Gram negative(Escherichia coli and Proteus vulgaris)and Gram positive(Bacillus megaterium and Staphylococcus aureus)bacterial *** have been made to understand the underlying molecular mechanism of such antibacterial *** effect of the core-shell nanostructures on Gram negative strains was found to be better than that observed for silver *** minimum inhibitory concentration(MIC)values of these nanostructures were found to be considerably lower than those of commercially available *** attribute this enhanced antibacterial effect of the nanostructures to their stability as a colloid in the medium,which modulates the phosphotyrosine profile of the bacterial proteins and arrests bacterial *** also demonstrate that these core-shell nanostructures can be removed from the medium by means of an external magnetic field which provides a mechanism to prevent uncontrolled waste disposal of these potentially hazardous nanostructures.

关键词： Core-shell nanostructure antimicrobial activity minimum inhibitory concentration phase transfer

Screening test for anti-Helicobacter pylori activity of traditional Chinese herbal medicines

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World Journal of Gastroenterology 2010年第44期16卷 5629-5634页

作者： Feng Ma Ye Chen Jing Li He-Ping Qing Ji-De Wang YaLi Zhang Yang Bai Bei-Guo Long Department of Gastroenterology Nanfang Hospital Southern Medical University Guangzhou 510515 Guangdong Province Department of Microbiology School of Basic Medic al Science sSouthern Medical Unive rsityGuangzhou 510515Guangdong ProvinceChina

AIM:To evaluate the anti-Helicobacter pylori (***) activity of 50 traditional Chinese herbal medicines in order to provide the primary evidence for their use in clinical ***:A susceptibility test of water extract from 50 selected traditional Chinese herbal medicines for in vitro *** Sydney strain 1 was performed with broth dilution *** activity of the selected Chinese herbal medicines was evaluated according to their minimum inhibitory concentration (MIC).RESULTS:The water extract from Rhizoma Coptidis,Radix Scutellariae and Radix isatidis could significantly inhibit the *** activity with their MIC less than 7.8 mg/mL,suggesting that traditional Chinese herbal medicines have anti-inflammatory and antibacterial effects and can thus be used in treatment of *** ***:Rhizoma Coptidis,Radix Scutellariae and Radix isatidis are the potential sources for the synthesis of new drugs against ***.

关键词： Chinese herbal medicines Helicobacter pylori minimum inhibitory concentration Gastric Oral

Antimicrobial Agents from Selected Medicinal Plants in Libya

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Chinese Journal of Integrative Medicine 2016年第3期22卷 177-184页

作者： Hasan MH Muhaisen Miftah Mailoud Ab-Mous Fadel A Ddeeb Aboclaid All Rtemi Omer M Taba Mehtab Parveen Faculty of Science and Arts Sharora University of Najran Saudi Arabia Faculty of Science University of Al-Jabal AI- Gharbi EI-Zintan- Libya Department of Chemistry Aligarh Muslim University Aligarh 202002 India

Objective： To test the in vitro antimicrobial efficacy of water and methanol extracts of 23 plant species that are commonly used in Libyan folk medicine. Methods： The antimicrobial activity was determined using the well-diffusion method. Four test microorganisms were used namely, Escherichia coil, Salmonella species, Staphylococcus aureus and Bacillus subtilis. The minimum inhibitory concentration （MIC） was determined for the high biologically active crude plant extracts. Results： Among 23 medicinal plants used in the study, only 5 methanolic extracts [Rosmarinus offcinalis L., Carduus marianium L., Lantana camara L., Rhus tripartite （ueria） Grande, and Thymus capitatus （L.） Hoffm （link）] showed the highest antimicrobial activity against Staphylococcus aureus, Bacillus subtilis and Salmonella species, while 22 methanolic and aqueous extracts showed moderate to weak antimicrobial activity on all tested organisms. However 19 of the extracts showed no activity at all against Gram -ve and Gram ＋ve microorganisms. MIC was found to be 1.25 mg/mL （Thymus capitatus）, 3 mg/mL （Rhus tripartite）, 4 mg/mL （Carduus marianium）, 5 mg/mL （Rosamarinus officinalis） and 5 mg/mL （Lantana camara）, respectively. Condusions： The present results revealed that, crude methanolic extracts of the investigated Libyan folk medicinal plants exhibited mild to high in vitro antibactedal activities against Gram-positive and Gram-negative microorganisms.

关键词： medicinal plant extracts antimicrobial activity minimum inhibitory concentration Ubyan folk medicine

Synthesis, Antibacterial Activities and Theoretical Studies of Benzopyranocoumarin Derivatives

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Chinese Journal of Structural Chemistry 2015年第10期34卷 1606-1611页

作者：鲁光英方军 Boch Pharma.Technology (Shanghai) Co.Ltd

Three benzopyranocoumarins（OBH, OMH and ODH） were synthesized and characterized via IR, ^1H NMR and HRMS. The HB energy in OBH, OMH and ODH was performed with the density functional theory（DFT） [B3LYP/6-31G＊] method. The in vitro antibacterial activity of OBH, OMH and ODH against drug-sensitive S. aureus（S. aureus ATCC 29213） strain, MRSA strain（MRSA XJ 75302）, drug-sensitive S. epidermidis strain（S. epidermidis ATCC 14990） and methicillin-resistant S. epidermidis strain（MRSE XJ 75284） was evaluated by observing the minimum inhibitory concentration. The results showed that among the three compounds, ODH exhibited the most potent antibacterial activity.

关键词： benzopyranocoumarin density functional theory Staphylococcus aureus minimum inhibitory concentration

Characteristics of Baicalin Synergy with Penicillin or Notopterygium Ethanol Extracts Against Staphylococcus aureus

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Tsinghua Science and Technology 2006年第4期11卷 459-461页

作者：孟甄郑进燮游雪甫邢东明王伟杜力军 Laboratory of Pharmaceutical Sciences Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100050 China

Baicalin facilitates the effectiveness of both penicillin and Notopterygium ethanol extracts （NEE） on Staphylococcus aureus. Two Staphylococcus aureus strains, ATCC29213 and 03-21 （a clinical isolate）, were tested. When combined with 128 μ***^-1 of baicalin, the minimum inhibitory concentration （MIC） of penicillin was reduced from 0.25 μ***^-1 to 0.06 μ***^-1, while that of NEE was reduced from 32 μg·mL^-1 to 8μg·mL^-1 against ATCC29213. Against the 03-21 strain, the MIC of penicillin was reduced from 4 μ***^-1 to 1 μ***^-1, while that of NEE was reduced from 32 μ***^-1 to 4 μg·mL^-1. Viable number counting results show that combination of baicalin and penicillin acts on the killing mechanism, while the baicalin and NEE acts on the inhibition. These results show that baicalin acts as a synergistic ally with both penicillin and NEE but has different modes of action.

关键词： baicalin synergy minimum inhibitory concentration Staphylococcus aureus

Antibacterial activities of some selected plant extracts of local herbal medicines in Lahore-Pakistan

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Journal of Chinese Pharmaceutical Sciences 2012年第3期21卷 278-282页

作者： Fouzia Noreen Naqi Hussain Muhammad Zaheer Salma Rahman Applied Chemistry Research Center PCSIR Laboratories ComplexFerozepur RoadLahore 54600Pakistan

The antibacterial activity of methanol and acetone extracts of five plant extracts being utilized for the cure of different ailments in Pakistan was *** extracts of Curcuma zedoaria,Ipomea turpethum,Sphaeranthus indicus,Terminalia chebula and Tricholepis glaberrima were tested against seven different bacterial strains by well diffusion method and microdilution *** pattern of zone of inhibition varied with the plant extracts,the solvent used for extraction and organisms *** extracts(20 mg/mL) were used to evaluate antibacterial *** zone of inhibition exhibited by methanol extracts varied between 11 mm and 32 mm while those of acetone extracts varied between 9 mm and 25 mm *** minimum inhibitory concentration(MIC) exhibited by methanol extracts ranged between(18.4-51.1) mg/*** methanolic extracts showed more activity than the acetone extracts against tested organisms except for *** plants were also analyzed for their elemental composition using atomic absorption spectrophotometer to explore natural sources of essential elements that can be utilized for medicinal purposes.

关键词： minimum inhibitory concentration minimum bactericidal concentration Elemental composition Atomic absorption spectrophotometer

Nanoencapsulation of Thymol and Eugenol with Chitosan Nanoparticles and the Effect against <i>Ralstonia solanacearum</i>

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Advances in Microbiology 2021年第12期11卷 723-739页

作者： George Oluoch Viviene Matiru Edward George Mamati Moses Nyongesa Department of Molecular Biology & Biotechnology Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI) Nairobi Kenya Department of Botany Jomo Kenyatta University of Agriculture and Technology (JKUAT) Nairobi Kenya Department of Horticulture and Food Security Jomo Kenyatta University of Agriculture and Technology (JKUAT) Nairobi Kenya National Potato Research Centre Kenya Agricultural and Livestock Research Organization (KALRO) Limuru Kenya

Essential oils (EOs) are natural bioactive compounds with antibacterial activity against a variety of microorganisms including phytopathogens. The use of EOs and their components as viable therapeutic antibacterials is however greatly compromised by their volatile nature, hydrophobicity and instability when exposed to environmental and physiological factors. Encapsulation of these compounds in an appropriate carrier system can alleviate these challenges. This study therefore aimed at developing, characterizing and evaluating the efficacy of antibacterial potential of thymol and eugenol loaded chitosan nanoparticles (TCNPs and ECNPs) against Ralstonia solanacearum, the bacterial wilt-causing pathogen in potatoes. Synthesis of TCNP and ECNP was achieved via ionic gelation method and the prepared nanoparticles characterized by their particle size distributions, encapsulation efficiency, loading capacity (LC) and in-vitro release characteristics. Antibacterial activities of the nanoparticles were investigated using agar dilution and colony counting methods and their minimum inhibitory concentration (MIC) determined by 96-well broth micro-dilution method. Scanning electron microscope images of TCNPs and ECNPs showed that the nanoparticles were spherical in shape and were well separated with an average particle size of 590 nm and 555 nm respectively. The average size of chitosan nanoparticles alone was however 375 nm. The encapsulation efficiency was 72.9% for TCNP (with 48.3% LC) and 71.7% for ECNP (with 49.5% LC). The release of thymol and eugenol from the microcapsules was found to be pH dependent with the highest release at pH 1.5. The growth inhibition of R. solanacearum was 92% and 94% for TCNP and ECNPs respectively. The MIC of thymol and eugenol before encapsulation was 175 μg/ml and 275 μg/ml respectively, but this reduced significantly to 22.5 μg/ml and 45 μg/ml after encapsulation. Thus, encapsulation of thymol and eugenol in chitosan nanop

关键词： Essential Oil Loading Capacity Encapsulation Efficiency minimum inhibitory concentration Bactericide

Antimicrobial activity of crude and semi-purified fractions of Warburgia ugandensis against some pathogens

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Journal of Coastal Life Medicine 2013年第3期 233-240页

作者： Yibeltal Merawie Samuel Sahile Feleke Moges Azamal Husen Department of Biology Faculty of Natural and Computational SciencesUniversity of GondarP.O.Box#196GondarEthiopia Department of Microbiology University of GondarP.O.Box#196GondarEthiopia

Objective:To investigate in vitro antimicrobial activities of leaves and heartwood crude and semi-purified fractions of Warburgia ugandensis(Canellaceae)(***)on some ***:were *** bacteria[Klebsiella pneumoniae(***),Escherichia coli(***),Pseudomonas aeruginosa Crude and semi-purified fractions of the leaves and heartwood of ***(***),Shigella boydii(***),Staphylococcus aureus(***)and Streptococcus pneumonia]and one fungus(Candida albicans)were tested by agar well diffusion and broth dilution method to determine minimum inhibitory concentration(MIC).Results:*** and *** were found to be the most susceptible bacterial isolated in agar well diffusion and broth dilution method of both the crude and petroleum ether extracts,while *** was the most resistant bacterium isolated under the same condition except in chloroform *** had shown MIC value of 10 mg/mL in the leaves and heartwood in both the crude and petroleum ether *** and *** had shown the MIC value of 1.0 mg/mL in the crude extract for the both leaves and heartwood;Whereas the petroleum ether semi-purified fraction had shown 0.5 mg/mL in the *** the crude extract,*** and *** exhibits similar MIC value of 1.75 mg/*** semi purified petroleum ether extract,*** had MIC value of 1.0 mg/mL;Whereas *** had shown no change in crude *** albicans revealed equal MIC value of 1.0 mg/mL for the both crude and semi-purified fractions of the leaves and ***:The crude and semi-purified fractions of *** have considerable effect on ***-purified petroleum ether fraction has better antimicrobial activity in both agar well diffusion and broth dilution *** study further shows the potential of *** for further study in order to be use as a modern drug.

关键词： Antimicrobial activity Leaves and heartwood Agar well diffusion Broth dilution method minimum inhibitory concentration Warburgia ugandensis

Identity and Safety of a Novel <i>Aurantiochytrium sp.</i>for Terrestrial Heterotrophic Docosahexaenoic Acid Production

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Advances in Bioscience and Biotechnology 2020年第12期11卷 489-509页

作者： Andrew Norman William Bell Colm Anthony Moran Regulatory Affairs Department Alltech Ireland Dunboyne Ireland Regulatory Affairs Department Alltech SARL Vire France

The objective of the studies in this paper was to expand on the published toxicological assessment of Aurantiochytrium limacinum (AURA) with further strain characterization and to investigate the potential for the biomass or extracted oil to have antimicrobial properties or undesirable substances. AURA is being investigated as a novel source of the omega-3 long-chain polyunsaturated fatty acid docosahexaenoic acid (DHA) for enriching foods of animal origin by means of feed supplementation. In the first studies, we provided the 18S rRNA identification of the novel marine isolated thraustochytrid, established the nutritional composition of AURA biomass for application as a food or feed ingredient including proximate analysis and fatty acid profiling, and confirmed the DHA production potential of the strain. We determined through minimum inhibitory concentration (MIC) analysis that the unextracted AURA biomass was safe, showing no antimicrobial influence and no evidence of any deleterious effects of this product or its extracts at concentrations up to 1% w/w on the reference human intestinal bacteria tested. This would indicate that AURA should not stimulate selective pressure on the commensal microbiota and is therefore unlikely to aid development of antimicrobial resistance and the concomitant harm to humans and animals. Further analysis revealed that the AURA biomass produced through industrial heterotrophic fermentation was free from undesirables;toxic marine microalgal metabolites, heavy metals, pesticides, microbial contaminants, and mycotoxins. Including heterotrophically-grown AURA in food or feed, up to 1% w/w, is a safe and environmentally beneficial strategy for DH

关键词： Thraustochytrid Docosahexaenoic Acid Fatty Acids Aurantiochytrium limacinum minimum inhibitory concentration Antimicrobial Resistance