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1

Antimicrobial activity of spices  

Microsoft Academic Search

Spices have been shown to possess medicinal value, in particular, antimicrobial activity. This study compares the sensitivity of some human pathogenic bacteria and yeasts to various spice extracts and commonly employed chemotherapeutic substances. Of the different spices tested only garlic and clove were found to possess antimicrobial activity. The bactericidal effect of garlic extract was apparent within 1 h of

Daljit S Arora; Jasleen Kaur

1999-01-01

2

Super-SERS-active and highly effective antimicrobial Ag nanodendrites  

NASA Astrophysics Data System (ADS)

We have developed simple and green electrochemistry to synthesize Ag nanostructures with high purity, good crystallinity and smooth surface for applications as super-SERS (surface-enhanced Raman scattering), SERS-active substrates and with highly effective antimicrobial activities. This synthesis takes place in a clean and slow reaction environment without any chemical additives, which ensures an ultrahigh active surface of the as-synthesized Ag nanostructures owing to their purity, good crystallinity and smooth morphology. Using this method, we synthesized nearly perfect Ag nanodendrites (NDs), which exhibit super-SERS sensitivity when they are used to detect the SERS spectra of rhodamine 6G at concentrations as low as 5 × 10-16 M, and have an ultrahigh electromagnetic (EM) enhancement factor of the order of 1013, breaking through the theoretical limit of EM enhancement. Meanwhile, the as-synthesized Ag NDs possess highly effective antimicrobial activities for Escherichia coli, Candida albicans and Staphylococcus aureus, which are over 10 times that of silver nanoparticles. Additionally, the basic physics and chemistry involved in the fabrication of Ag nanostructures are pursued. These investigations show that silver nanostructures with highly active surfaces can make the most of Ag nanostructures functioning as super-SERS-active substrates and multiple antibiotics.

Li, H. B.; Liu, P.; Liang, Y.; Xiao, J.; Yang, G. W.

2012-07-01

3

Essential oils—their antimicrobial activity against Escherichia coli and effect on intestinal cell viability  

Microsoft Academic Search

Essential oils are known to possess antimicrobial activity against a wide spectrum of bacteria. The main objective of this study was to evaluate possible harmful effects of four commonly used essential oils and their major components on intestinal cells. Antimicrobial activity of selected plant extracts against enteroinvasive Escherichia coli was dose dependent. However, doses of essential oils with the ability

Fabian Dušan; Sabol Marián; Domaracká Katarína; Buj?áková Dobroslava

2006-01-01

4

Evaluation of antimicrobial activity and bronchodialator effect of a polyherbal drug-Shrishadi  

PubMed Central

Objective To investigate antimicrobial and bronchodialator effect of hydroalcholic extract of polyherbal drug Shirishadi containing Shirisha (Albezzia lebbeck), Nagarmotha (Cyprus rotandus) & Kantakari (Solanum xanthocarpum). Methods Antimicrobial activity was evaluated by disc diffusion method and MIC, MBC, MFC were calculated by micro dilution method. Hydroalcholic extract of this preparation was investigated for its phytochemical analysis, phenol and flavonoid were determined by spectrophotometric method and in vivo bronchodilator effect was analysed by convulsion time. Results The phytochemical tests revealed presence of alkaloids, anthraquinones, carbohydrates, flavonoids, saponins and tannins. The antimicrobial result showed the MIC of 6.25 mg/mL against Staphylococcus aureus and 12.5 mg/mL for Escherichia coli and 12.5 mg/mL against remaining bacteria tested, with strong antifungal activity. The maximum inhibition zone is found against Pseudomonas aeruginosa with MIC 16 mg/mL. Drug showed significant bronchodilator effect with 27.86% & 36.13% increase in preconvulsion time of guinea pigs pretreated with 100 & 200 mg/kg body weight of extract. Conclusions The study reveals that the extracts possess antibacterial activity and antifungal activity in a dose dependent manner. This antimicrobial property may be due to presence of several saponins, further studies are highly needed for the drug development. PMID:23569869

Kajaria, Divya Kumari; Gangwar, Mayank; Kumar, Dharmendra; Kumar Sharma, Amit; Tilak, Ragini; Nath, Gopal; Tripathi, Yamini Bhusan; Tripathi, JS; Tiwari, SK

2012-01-01

5

Investigating the effect of increasing charge density on the hemolytic activity of synthetic antimicrobial polymers.  

PubMed

The current study is aimed at investigating the effect of fine-tuning the cationic character of synthetic mimics of antimicrobial peptides (SMAMPs) on the hemolytic and antibacterial activities. A series of novel norbornene monomers that carry one, two, or three Boc-protected amine functionalities was prepared. Ring-opening metathesis polymerization (ROMP) of the monomers, followed by deprotection of the amine groups resulted in cationic antimicrobial polynorbornenes that carry one, two, and three charges per monomer repeat unit. Increasing the number of amine groups on the most hydrophobic polymer reduced its hemolytic activity significantly. To understand the membrane activity of these polymers, we conducted dye leakage experiments on lipid vesicles that mimic bacteria and red blood cell membranes, and these results showed a strong correlation with the hemolysis data. PMID:18816096

Al-Badri, Zoha M; Som, Abhigyan; Lyon, Sarah; Nelson, Christopher F; Nüsslein, Klaus; Tew, Gregory N

2008-10-01

6

Antimicrobial Activity of Essential Oils against Streptococcus mutans and their Antiproliferative Effects  

PubMed Central

This study aimed to evaluate the activity of essential oils (EOs) against Streptococcus mutans biofilm by chemically characterizing their fractions responsible for biological and antiproliferative activity. Twenty EO were obtained by hydrodistillation and submitted to the antimicrobial assay (minimum inhibitory (MIC) and bactericidal (MBC) concentrations) against S. mutans UA159. Thin-layer chromatography and gas chromatography/mass spectrometry were used for phytochemical analyses. EOs were selected according to predetermined criteria and fractionated using dry column; the resulting fractions were assessed by MIC and MBC, selected as active fractions, and evaluated against S. mutans biofilm. Biofilms formed were examined using scanning electron microscopy. Selected EOs and their selected active fractions were evaluated for their antiproliferative activity against keratinocytes and seven human tumor cell lines. MIC and MBC values obtained for EO and their active fractions showed strong antimicrobial activity. Chemical analyses mainly showed the presence of terpenes. The selected active fractions inhibited S. mutans biofilm formation (P < 0.05) did not affect glycolytic pH drop and were inactive against keratinocytes, normal cell line. In conclusion, EO showed activity at low concentrations, and their selected active fractions were also effective against biofilm formed by S. mutans and human tumor cell lines. PMID:22685486

Galvao, Livia Camara de Carvalho; Furletti, Vivian Fernandes; Bersan, Salete Meyre Fernandes; da Cunha, Marcos Guilherme; Ruiz, Ana Lucia Tasca Gois; de Carvalho, Joao Ernesto; Sartoratto, Adilson; Rehder, Vera Lucia Garcia; Figueira, Glyn Mara; Teixeira Duarte, Marta Cristina; Ikegaki, Masarahu; de Alencar, Severino Matias; Rosalen, Pedro Luiz

2012-01-01

7

The comparison of the effect of enzyme, peroxide, plasma and chitosan processes on wool fabrics and evaluation for antimicrobial activity  

Microsoft Academic Search

Pretreated (enzymatic and enzymatic+hydrogen peroxide) knitted wool fabrics were treated with atmospheric argon and air plasma\\u000a to improve their adsorption capacity. After plasma treatments chitosan solution was applied to have antimicrobial effect on\\u000a wool fabrics. The treated fabrics were evaluated in terms of washing stability as well as antimicrobial activity. The surface\\u000a morphology was characterised by SEM images and FTIR

Asli Demir; Buket Ar?k; Esen Ozdogan; Necdet Seventekin

2010-01-01

8

Which approach is more effective in the selection of plants with antimicrobial activity?  

PubMed

The development of the present study was based on selections using random, direct ethnopharmacological, and indirect ethnopharmacological approaches, aiming to evaluate which method is the best for bioprospecting new antimicrobial plant drugs. A crude extract of 53 species of herbaceous plants collected in the semiarid region of Northeast Brazil was tested against 11 microorganisms. Well-agar diffusion and minimum inhibitory concentration (MIC) techniques were used. Ten extracts from direct, six from random, and three from indirect ethnopharmacological selections exhibited activities that ranged from weak to very active against the organisms tested. The strain most susceptible to the evaluated extracts was Staphylococcus aureus. The MIC analysis revealed the best result for the direct ethnopharmacological approach, considering that some species yielded extracts classified as active or moderately active (MICs between 250 and 1000?µg/mL). Furthermore, one species from this approach inhibited the growth of the three Candida strains. Thus, it was concluded that the direct ethnopharmacological approach is the most effective when selecting species for bioprospecting new plant drugs with antimicrobial activities. PMID:23878595

Silva, Ana Carolina Oliveira; Santana, Elidiane Fonseca; Saraiva, Antonio Marcos; Coutinho, Felipe Neves; Castro, Ricardo Henrique Acre; Pisciottano, Maria Nelly Caetano; Amorim, Elba Lúcia Cavalcanti; Albuquerque, Ulysses Paulino

2013-01-01

9

Which Approach Is More Effective in the Selection of Plants with Antimicrobial Activity?  

PubMed Central

The development of the present study was based on selections using random, direct ethnopharmacological, and indirect ethnopharmacological approaches, aiming to evaluate which method is the best for bioprospecting new antimicrobial plant drugs. A crude extract of 53 species of herbaceous plants collected in the semiarid region of Northeast Brazil was tested against 11 microorganisms. Well-agar diffusion and minimum inhibitory concentration (MIC) techniques were used. Ten extracts from direct, six from random, and three from indirect ethnopharmacological selections exhibited activities that ranged from weak to very active against the organisms tested. The strain most susceptible to the evaluated extracts was Staphylococcus aureus. The MIC analysis revealed the best result for the direct ethnopharmacological approach, considering that some species yielded extracts classified as active or moderately active (MICs between 250 and 1000?µg/mL). Furthermore, one species from this approach inhibited the growth of the three Candida strains. Thus, it was concluded that the direct ethnopharmacological approach is the most effective when selecting species for bioprospecting new plant drugs with antimicrobial activities. PMID:23878595

Silva, Ana Carolina Oliveira; Santana, Elidiane Fonseca; Saraiva, Antonio Marcos; Coutinho, Felipe Neves; Castro, Ricardo Henrique Acre; Pisciottano, Maria Nelly Caetano; Amorim, Elba Lucia Cavalcanti; Albuquerque, Ulysses Paulino

2013-01-01

10

Antimicrobial activity against periodontopathogenic bacteria, antioxidant and cytotoxic effects of various extracts from endemic Thermopsis turcica  

PubMed Central

Objective To investigate the in vitro antimicrobial potential of Thermopsis turcica Kit Tan, Vural & Küçüködük against periodontopathogenic bacteria, its antioxidant activity and cytotoxic effect on various cancer cell lines. Methods In vitro antimicrobial activities of ethanol, methanol, ethyl acetate (EtAc), n-hexane and water extracts of Thermopsis turcica herb against periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans ATCC 29523 and Porphyromonas gingivalis ATCC 33277 were tested by agar well diffusion, minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Antioxidant properties of the extracts were evaluated by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity and ?-carotene bleaching methods. Amounts of phenolic contents of the extracts were also analysed by using the Folin-Ciocalteu reagent. Additionally, cytotoxic activity of the extracts on androgen-insensitive prostate cancer, androgen-sensitive prostate cancer, chronic myelogenous leukemia and acute promyelocytic leukemia human cancer cell lines were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Human gingival fibroblast cells were used as a control. Results Our data showed that EtAc extract had the highest antimicrobial effect on Aggregatibacter actinomycetemcomitans (MIC: 1.562 mg/mL, MBC: 3.124 mg/mL) and Porphyromonas gingivalis (MIC: 0.781 mg/mL, MBC: 1.562 mg/mL). In antioxidant assays, EtAc extract exhibited also the highest radical scavenging activity [IC50=(30.0±0.3) µg/mL] and the highest inhibition [(74.35±0.30)%] against lineloic acide oxidation. The amount of phenolic content of it was also the highest [(162.5±1.2) µg/mg gallic acid]. In cytotoxic assay, only ethanol [IC50=(80.00±1.21) µg/mL] and EtAc extract [IC50=(70.0±0.9) µg/mL] were toxic on acute promyelocytic leukemia cells at 20-100 µg/mL (P<0.05). However, no toxic effect was observed on human gingival fibroblast cells. Conclusions According to our findings, owing to its antioxidant and cytotoxic potential, EtAc extract might include anticancer agents for acute promyelocytic leukemia. PMID:25183268

Bali, Elif Burcu; Ac?k, Leyla; Akca, Gulcin; Sarper, Meral; Elci, Mualla P?nar; Avcu, Ferit; Vural, Mecit

2014-01-01

11

Study on antimicrobial activity of chitosan with different molecular weights  

Microsoft Academic Search

E. coli and Staphylococcus aureus are used to study the antimicrobial activity of chitosan of different molecular weights (MW). The effect of the concentration and MW of chitosan were investigated, respectively, and the antimicrobial mechanism was discussed. For chitosan with MW below 300 kDa, the antimicrobial effect on S. aureus was strengthened as the MW increased. In contrast, the effect

Lian-Ying Zheng; Jiang-Feng Zhu

2003-01-01

12

Effect of mixed antimicrobial agents and flavors in active packaging films.  

PubMed

Active packaging is an emerging food technology to improve the quality and safety of food products. Many works have been developed to study the antimicrobial activity of essential oils. Essential oils have been traditionally used as flavorings in food, so they have an important odor impact but they have as well antimicrobial properties that could be used to protect the food. Recent developments in antimicrobial active packaging showed the efficiency of essential oils versus bread and bakery products among other applications. However, one of the main problems to face is the odor and taste they could provide to the packaged food. Using some aromas to mask the odor could be a good approach. That is why the main objective of this paper is to develop an antimicrobial packaging material based on the combination of the most active compounds of essential oils (hydrocinnamaldehyde, oregano essential oil, cinnamaldehyde, thymol, and carvacrol) together with some aromas commonly used in the food industry. A study of the concentration required to get the antimicrobial properties, the organoleptic compatibility with typical aroma present in many food systems (vanilla, banana, and strawberry), and the right combination of both systems has been carried out. Antimicrobial tests of both the mentioned aromas, the main components of some essential oils, and the combination of both groups were carried out against bacteria (Enterococcus faecalis, Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Salmonella choleraesuis, Yersinia enterocolitica, Escherichia coli), yeasts (Candida albicans, Debaryomyces hansenii, Zygosaccharomyces rouxii), and molds (Botrytis cinerae, Aspergillus flavus, Penicillium roqueforti, Eurotium repens, Penicillium islandicum, Penicillium commune, Penicillium nalgiovensis). The sensory properties of the combinations were evaluated with a triangular test and classification was by an order test; the odor threshold of the aroma compounds was also studied. The results reveal that none of the aromas had antimicrobial properties. The most antimicrobial compounds are thymol, carvacrol, and cinnamaldehyde, but none of them could be combined with banana aroma, whereas only thymol with strawberry aroma gave the right combined organoleptic profile. All of the antimicrobials under study could be combined with vanilla aroma, providing both antimicrobial property and the odor expected. PMID:19711918

Gutiérrez, Laura; Escudero, Ana; Batlle, Ramón; Nerín, Cristina

2009-09-23

13

Investigating the effects of L-to D-amino acid substitution and deamidation on the activity and membrane interactions of antimicrobial peptide anoplin  

E-print Network

- helical antimicrobial peptide found naturally with broad spectrum activity against both GramInvestigating the effects of L- to D-amino acid substitution and deamidation on the activity and membrane interactions of antimicrobial peptide anoplin Amy Won a , Mourin Khan a , Sorin Gustin a , Akuvi

Hitchcock, Adam P.

14

Effect of Flash-Heat Treatment on Antimicrobial Activity of Breastmilk  

PubMed Central

Abstract Background and Objectives The World Health Organization recommends human immunodeficiency virus (HIV)-positive mothers in resource-poor regions heat-treat expressed breastmilk during periods of increased maternal-to-child transmission risk. Flash-heat, a “low tech” pasteurization method, inactivates HIV, but effects on milk protein bioactivity are unknown. The objectives were to measure flash-heat's effect on antimicrobial properties of lactoferrin, lysozyme, and whole milk and on the digestive resistance of lactoferrin and lysozyme. Methods Flash-heated and unheated breastmilk aliquots from HIV-positive mothers in South Africa were “spiked” with Staphylococcus aureus and Escherichia coli and then cultured for 0, 3, and 6 hours. Lysozyme and lactoferrin activities were determined by lysis of Micrococcus luteus cells and inhibition of enteropathogenic E. coli, respectively, measured spectrophotometrically. Percentages of proteins surviving in vitro digestion, lactoferrin and lysozyme activity, and bacteriostatic activity of whole milk in heated versus unheated samples were compared. Results There was no difference in rate of growth of E. coli or S. aureus in flash-heated versus unheated whole milk (p?=?0.61 and p?=?0.96, respectively). Mean (95% confidence interval) antibacterial activity of lactoferrin was diminished 11.1% (7.8%, 14.3%) and that of lysozyme by up to 56.6% (47.1%, 64.5%) by flash-heat. Digestion of lysozyme was unaffected (p?=?0.12), but 25.4% less lactoferrin survived digestion (p?activity of whole milk against representative bacteria was unaffected. This suggests flash-heated breastmilk likely has a similar profile of resistance to bacterial contamination as that of unheated milk. Clinical significance of the decreased bioactivity should be tested in clinical trials. PMID:21091243

Wiedeman, Jean; Buehring, Gertrude; Peerson, Janet M.; Hayfron, Kweku; K'Aluoch, Okumu; Lonnerdal, Bo; Israel-Ballard, Kiersten; Coutsoudis, Anna; Abrams, Barbara

2011-01-01

15

Antimicrobial activity of Potentilla species.  

PubMed

The antibacterial and antifungal activities of aqueous extracts obtained from aerial parts of Potentilla species: P. anserina, P. argentea, P. erecta, P. fruticosa, P. grandiflora, P. nepalensis var.'Miss Willmott', P. recta, P. rupestris and P. thuringiaca were investigated. The extracts showed the strongest antimicrobial activity against H. pylori (MIC=0.1/0.5 mg/ml). PMID:18664379

Tomczyk, Micha?; Leszczy?ska, Katarzyna; Jakoniuk, Piotr

2008-12-01

16

Antimicrobial activity of Potentilla species  

Microsoft Academic Search

The antibacterial and antifungal activities of aqueous extracts obtained from aerial parts of Potentilla species: P. anserina, P. argentea, P. erecta, P. fruticosa, P. grandiflora, P. nepalensis var.‘MissWillmott’, P. recta, P. rupestris and P. thuringiaca were investigated. The extracts showed the strongest antimicrobial activity against H. pylori (MIC=0.1÷0.5 mg\\/ml).

Micha? Tomczyk; Katarzyna Leszczy?ska; Piotr Jakoniuk

2008-01-01

17

Effect of ?-cyclodextrin and hydroxypropyl ?-cyclodextrin complexation on physicochemical properties and antimicrobial activity of cefdinir  

Microsoft Academic Search

The solid-state properties, dissolution profile and antimicrobial activity of inclusion complexes of cefdinir (CEF) with ?-cyclodextrin (?CD) and hydroxypropyl ?-cyclodextrin (HP?CD) were investigated. The phase solubility profiles of cefdinir with ?CD and HP?CD were classified as AL-type, which indicates the formation of 1:1 stoichiometry inclusion complexes. Stability constants with 1:1 molar ratio obtained from the phase solubility diagrams were 120.38±1.07

Omair Aleem; Bhanudas Kuchekar; Yogesh Pore; Sameer Late

2008-01-01

18

Antimicrobial activities of plumeria acutifolia  

Microsoft Academic Search

Ethanolic extract of Plumeria acutifolia Poir. (Apocynaceae) stembark was tested for antimicrobial activity against Gram-positive bacteria (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus), Gram-negative bacteria (Escherichia coli, Klebsiella Pnumoniae, Psuedomonas aeruginosa, Salmonella typhimurium) and fungi (Aspergillus niger and candida albicans) by disc diffusion method. Minimal inhibitory concentration (MIC) and acute toxicity were also assayed. The ethanol extract showed the strong in

Rasool S. N; Suresh Kumar Chitta; Jayaveera K. N

2008-01-01

19

Antimicrobial Activity of Commercial Nanoparticles  

NASA Astrophysics Data System (ADS)

Engineered nanoparticles are finding increased use in applications ranging from biosensors to prophylactic antimicrobials embedded in socks. The release of heavy metal-containing nanoparticles (NP) into the environment may be harmful to the efficacy of beneficial microbes that function in element cycling, pollutant degradation, and plant growth. Antimicrobial activity of commercial NP of Ag, CuO, and ZnO is demonstrated here against the beneficial soil microbe, Pseudomonas putida KT2440, which was modified to serve as a bioluminescent sentinel organism. "As manufactured" preparations of nano- Ag, -CuO, and -ZnO caused rapid, dose dependent loss of light output in the biosensor. Bulk equivalents of these products showed no inhibitory activity, indicating that particle size was determinant in activity.

Gajjar, Priyanka; Pettee, Brian; Britt, David W.; Huang, Wenjie; Johnson, William P.; Anderson, Anne J.

2009-07-01

20

Antimicrobial activity of ultrasonic cleaners.  

PubMed

This study assessed the antimicrobial activity of two cleaning solutions and tap water after varying periods of use in one ultrasonic cleaner. Testing involved filling the cleaner's tank and a centred glass beaker with the same test solution. An aluminium foil strip test first determined that no significant differences in cavitational activity existed inside the beaker compared with outside. Standardized solutions of Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella choleraesuis were left at room temperature for 10 min. Aliquots were exposed to both cleaning solution and ultrasonic action. Unused test solution was removed from the tank, filter-sterilized, mixed with bacterial suspension and placed into a sterile beaker. Cleaning was allowed for 10 min. The beaker was removed and its contents examined. The tank was allowed to cool for 30 min and the process was repeated four times. The entire experimental set was repeated once. Exposure to test solution alone in all but one case produced reductions in bacterial numbers from initial >/=2 x 10(9) by 19.9-52.6%. Application of both chemical exposure and ultrasonic cleaning produced greater bacterial kill (46.4-99.7% reductions). However, kill became less effective on repeated use of a commercial cleaning solution. Reduction was highest when fresh ultrasonic cleaning solutions were used. In no case did complete sterilization occur. As well as removing adherent material, ultrasonic cleaning may also markedly reduce the number of viable organisms present. PMID:15949617

Muqbil, I; Burke, F J T; Miller, C H; Palenik, C J

2005-07-01

21

Effect of beta-cyclodextrin and hydroxypropyl beta-cyclodextrin complexation on physicochemical properties and antimicrobial activity of cefdinir.  

PubMed

The solid-state properties, dissolution profile and antimicrobial activity of inclusion complexes of cefdinir (CEF) with beta-cyclodextrin (betaCD) and hydroxypropyl beta-cyclodextrin (HPbetaCD) were investigated. The phase solubility profiles of cefdinir with betaCD and HPbetaCD were classified as A(L)-type, which indicates the formation of 1:1 stoichiometry inclusion complexes. Stability constants with 1:1 molar ratio obtained from the phase solubility diagrams were 120.38+/-1.07 and 58.60+/-1.20 M(-1) for betaCD and HPbetaCD, respectively. Binary systems of CEF with betaCD and HPbetaCD prepared by kneading method were characterized by Fourier transformation-infrared spectroscopy (FTIR) and X-ray powder diffractometry (XRD). The aqueous solubility of CEF was enhanced by 101% for betaCD and 23.4% for HPbetaCD, respectively. The dissolution profiles of inclusion complexes were determined and compared with those of CEF alone and their physical mixtures. The dissolution rate of CEF was increased by betaCD and HPbetaCD inclusion complexation moderately. However, the antimicrobial activity of CEF was increased significantly (p<0.001) by betaCD and HPbetaCD inclusion complexation against S. aureus and E. coli. In all these studies, HPbetaCD had superior antimicrobial activity than that of betaCD while betaCD had greater effect on solubility enhancement of CEF. PMID:18367363

Aleem, Omair; Kuchekar, Bhanudas; Pore, Yogesh; Late, Sameer

2008-07-15

22

Antimicrobial Activities of Fidaxomicin  

PubMed Central

Fidaxomicin is bactericidal against Clostridium difficile. The combined results of 8 in vitro studies of 1323 C. difficile isolates showed the minimum inhibitory concentration (MIC) range of fidaxomicin to be ?0.001–1 ?g/mL, with a maximum MIC for inhibition of 90% of organisms (MIC90) of 0.5 ?g/mL. Isolates from 2 phase III clinical trials demonstrated that fidaxomicin MICs of baseline isolates did not predict clinical cure, failure, or recurrence of C. difficile infections. No resistance to fidaxomicin developed during treatment in either study, although a single strain recovered from a cured patient had an elevated MIC of 16 µg/mL at the time of recurrence. For 135 strains, OP-1118, a major metabolite, had an MIC for inhibition of 50% of organisms of 4 ?g/mL and an MIC90 of 8 ?g/mL. Changes in inoculum size (102–105 colony-forming units/spot) or cation concentrations of calcium or magnesium appeared to have no effect on fidaxomicin MICs. Fidaxomicin has little or no activity against gram-negative aerobes and anaerobes or yeast. PMID:22752863

Goldstein, Ellie J. C.; Babakhani, Farah; Citron, Diane M.

2012-01-01

23

?-Boomerang Antimicrobial and Antiendotoxic Peptides: Lipidation and Disulfide Bond Effects on Activity and Structure  

PubMed Central

Drug-resistant Gram-negative bacterial pathogens and endotoxin- or lipopolysaccharide (LPS)-mediated inflammations are among some of the most prominent health issues globally. Antimicrobial peptides (AMPs) are eminent molecules that can kill drug-resistant strains and neutralize LPS toxicity. LPS, the outer layer of the outer membrane of Gram-negative bacteria safeguards cell integrity against hydrophobic compounds, including antibiotics and AMPs. Apart from maintaining structural integrity, LPS, when released into the blood stream, also induces inflammatory pathways leading to septic shock. In previous works, we have reported the de novo design of a set of 12-amino acid long cationic/hydrophobic peptides for LPS binding and activity. These peptides adopt ?-boomerang like conformations in complex with LPS. Structure-activity studies demonstrated some critical features of the ?-boomerang scaffold that may be utilized for the further development of potent analogs. In this work, ?-boomerang lipopeptides were designed and structure-activity correlation studies were carried out. These lipopeptides were homo-dimerized through a disulfide bridge to stabilize conformations and for improved activity. The designed peptides exhibited potent antibacterial activity and efficiently neutralized LPS toxicity under in vitro assays. NMR structure of C4YI13C in aqueous solution demonstrated the conserved folding of the lipopeptide with a boomerang aromatic lock stabilized with disulfide bond at the C-terminus and acylation at the N-terminus. These lipo-peptides displaying bacterial sterilization and low hemolytic activity may be useful for future applications as antimicrobial and antiendotoxin molecules. PMID:24756162

Mohanram, Harini; Bhattacharjya, Surajit

2014-01-01

24

?-Boomerang Antimicrobial and Antiendotoxic Peptides: Lipidation and Disulfide Bond Effects on Activity and Structure.  

PubMed

Drug-resistant Gram-negative bacterial pathogens and endotoxin- or lipopolysaccharide (LPS)-mediated inflammations are among some of the most  prominent health issues globally. Antimicrobial peptides (AMPs) are eminent molecules that can kill drug-resistant strains and neutralize LPS toxicity. LPS, the outer layer of the outer membrane of Gram-negative bacteria safeguards cell integrity against hydrophobic compounds, including antibiotics and AMPs. Apart from maintaining structural integrity, LPS, when released into the blood stream, also induces inflammatory pathways leading to septic shock. In previous works, we have reported the de novo design of a set of 12-amino acid long cationic/hydrophobic peptides for LPS binding and activity. These peptides adopt ?-boomerang like conformations in complex with LPS. Structure-activity studies demonstrated some critical features of the ?-boomerang scaffold that may be utilized for the further development of potent analogs. In this work, ?-boomerang lipopeptides were designed and structure-activity correlation studies were carried out. These lipopeptides were homo-dimerized through a disulfide bridge to stabilize conformations and for improved activity. The designed peptides exhibited potent antibacterial activity and efficiently neutralized LPS toxicity under in vitro assays. NMR structure of C4YI13C in aqueous solution demonstrated the conserved folding of the lipopeptide with a boomerang aromatic lock stabilized with disulfide bond at the C-terminus and acylation at the N-terminus. These lipo-peptides displaying bacterial sterilization and low hemolytic activity may be useful for future applications as antimicrobial and antiendotoxin molecules. PMID:24756162

Mohanram, Harini; Bhattacharjya, Surajit

2014-01-01

25

Effect of water-aging on the antimicrobial activities of an ORMOSIL-containing orthodontic acrylic resin  

PubMed Central

Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol–gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly (methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3 month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4 wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances. PMID:23485857

Gong, Shi-qiang; Epasinghe, D. Jeevanie; Zhou, Bin; Niu, Li-na; Kimmerling, Kirk A.; Rueggeberg, Frederick A.; Yiu, Cynthia K.Y.; Mao, Jing; Pashley, David H.; Tay, Franklin R.

2013-01-01

26

Antimicrobial activity of flavonoids  

Microsoft Academic Search

Flavonoids are ubiquitous in photosynthesising cells and are commonly found in fruit, vegetables, nuts, seeds, stems, flowers, tea, wine, propolis and honey. For centuries, preparations containing these compounds as the principal physiologically active constituents have been used to treat human diseases. Increasingly, this class of natural products is becoming the subject of anti-infective research, and many groups have isolated and

T. P. Tim Cushnie; Andrew J. Lamb

2005-01-01

27

[Propolis' antimicrobial activity: what's new?].  

PubMed

Propolis is a hive product that bees manufacture from balsamic resins actively secreted by plants on leaf buds and barks. Propolis composition is highly variable, depending on the plant species and on the season of collection. However, propolis essentially contains resins, balsams, essential oils, flavonoids, vitamins, minerals and pollen, albeit at different concentrations. Although more than 300 constituents have been identified in propolis samples, biological activity is mainly due to few substances, such as flavonoids, terpens, caffeic, ferulic and cumaric acids and esters. Propolis is characterized by multifactorial activities, but only some of them have been substantiated by clinical and experimental evidence. It is widely acknowledged to exert antimicrobial activity against a wide range of microorganisms (bacteria, fungi and viruses), but also exerts antiinflammatory, anaesthetic, healing, vasoprotective, antioxidant, antitumoral, antiulcer and hepatoprotective activities. The wide spectrum of activities has led in recent years to the development of new technologies to improve propolis properties of the traditional hydroalcoholic extract. This paper reviews the antimicrobial properties of propolis, focusing on respiratory pathogens. These characteristics make propolis a valid option for therapy of upper respiratory tract infections. PMID:17515670

De Vecchi, Elena; Drago, Lorenzo

2007-03-01

28

The effect of standard heat and filtration processing procedures on antimicrobial activity and hydrogen peroxide levels in honey  

PubMed Central

There is increasing interest in the antimicrobial properties of honey. In most honey types, antimicrobial activity is due to the generation of hydrogen peroxide (H2O2), but this can vary greatly among samples. Honey is a complex product and other components may modulate activity, which can be further affected by commercial processing procedures. In this study we examined honey derived from three native Australian floral sources that had previously been associated with H2O2-dependent activity. Antibacterial activity was seen in four red stringybark samples only, and ranged from 12 to 21.1% phenol equivalence against Staphylococcus aureus. Antifungal activity ranged from MIC values of 19–38.3% (w/v) against Candida albicans, and all samples were significantly more active than an osmotically equivalent sugar solution. All honey samples were provided unprocessed and following commercial processing. Processing was usually detrimental to antimicrobial activity, but occasionally the reverse was seen and activity increased. H2O2 levels varied from 0 to 1017 ?M, and although samples with no H2O2 had little or no antimicrobial activity, some samples had relatively high H2O2 levels yet no antimicrobial activity. In samples where H2O2 was detected, the correlation with antibacterial activity was greater in the processed than in the unprocessed samples, suggesting other factors present in the honey influence this activity and are sensitive to heat treatment. Antifungal activity did not correlate with the level of H2O2 in honey samples, and overall it appeared that H2O2 alone was not sufficient to inhibit C. albicans. We conclude that floral source and H2O2 levels are not reliable predictors of the antimicrobial activity of honey, which currently can only be assessed by standardized antimicrobial testing. Heat processing should be reduced where possible, and honey destined for medicinal use should be retested post-processing to ensure that activity levels have not changed. PMID:22866051

Chen, Cuilan; Campbell, Leona T.; Blair, Shona E.; Carter, Dee A.

2012-01-01

29

Antimicrobial Activity of Indigenous Medicinal Plants Against Enterococcus  

E-print Network

Antimicrobial Activity of Indigenous Medicinal Plants Against Enterococcus faecalis By Daniel, temperate zone of Chile. The collected plants were then tested for antimicrobial activity in a laboratory. #12;Antimicrobial Activity of Indigenous Medicinal Plants Against Enterococcus faecalis Introduction

Firestone, Jeremy

30

Novel light-activated antimicrobial coatings are effective against surface-deposited Staphylococcus aureus.  

PubMed

Aerosols constitute a major route of transmission for a wide range of infectious diseases in the hospital setting. The aim of this study was to determine the survival of Staphylococcus aureus on a light-activated antimicrobial coating. S. aureus suspended in phosphate-buffered saline (PBS), saliva, or horse serum was sprayed onto cellulose acetate coatings containing toluidine blue O and rose bengal and the survival of the organism on these surfaces was determined following 6 h of exposure to a 28-W domestic fluorescent lamp (light intensity = 3700 +/- 20 lux). Kills ranging from 78.9% (in horse serum) to 99.8% (in PBS) were obtained when the bacterial density on the coatings was approximately 10(5) colony-forming units/m(2). The results of this study have shown that a coating containing toluidine blue and rose bengal can achieve significant kills of S. aureus when illuminated by a domestic light source. Light-activated coatings could provide a simple, low-cost means of reducing the microbial load in hospitals and other facilities. PMID:18587617

Decraene, Valérie; Pratten, Jonathan; Wilson, Michael

2008-10-01

31

Antimicrobial activity of selected cyclic dipeptides.  

PubMed

Cyclic dipeptides are products of rational drug design, which may exhibit both antimicrobial and antitumor properties. The aim of this study was to investigate both the antimicrobial effects of the cyclic dipeptides cyclo(L-phenylalanyl-L-prolyl), cyclo(L-tyrosyl-L-prolyl), cyclo(L-tryptophanyl-L-prolyl) and cyclo(L-tryptophanyl-L-tryptophanyl) and the effects of these cyclic dipeptides on the gastrointestinal epithelium in vitro. Furthermore, a relevant solvent for the possible pharmaceutical application of the products was sought concurrently. The antimicrobial effect of the cyclic dipeptides was assayed using the Kirby-Bauer disc diffusion assay against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis, Streptococcus pneumoniae, Candida albicans, Aspergillus niger and Penicillium notatum. The effect of the cyclic dipeptides on the gastrointestinal epithelium was assessed by changes in alkaline phosphatase expression of HT-29 cells. Cyclo(Pro-Trp) and cyclo(Phe-Pro) show broad spectrum antibacterial properties and cyclo(Trp-Pro) and cyclo(Trp-Trp) show broad spectrum antifungal properties. The maturation of the gastrointestinal cells was enhanced by cyclo(Phe-Pro), cyclo(Tyr-Pro), cyclo(Trp-Trp) and cyclo(Trp-Pro). The activity of these cyclic dipeptides thus indicates potential application of these compounds as pharmacological agents. PMID:10563376

Graz, M; Hunt, A; Jamie, H; Grant, G; Milne, P

1999-10-01

32

Antimicrobial activity of extracts of Terminalia catappa root.  

PubMed

The effect against bacteria of petroleum ether (60-80 degrees C), chloroform and methanolic extract of dried root of Terminalia catappa Linn. (combrataceae) was employed by cup plate agar diffusion method. The chloroform extract showed prominent antimicrobial activity against S. aureus and E. coli as compared to other tested microorganisms, while petroleum ether extract was devoid of antimicrobial activity. The methanolic: extract exhibited MIC of 0.065 mg/ml against E. coli. and chloroform extract exhibited MIC of 0.4 mg/ml against S. aureus The chloroform has well as methanolic extracts showed good antimicrobial activity against Gram positive and Gram negative microorganisms. PMID:12649950

Pawar, S P; Pal, S C

2002-06-01

33

A Novel Beta-Defensin Antimicrobial Peptide in Atlantic Cod with Stimulatory Effect on Phagocytic Activity  

PubMed Central

A novel defensin antimicrobial peptide gene was identified in Atlantic cod, Gadus morhua. This three exon/two intron defensin gene codes for a peptide precursor consisting of two domains: a signal peptide of 26 amino acids and a mature peptide of 40 residues. The mature cod defensin has six conserved cysteine residues that form 1–5, 2–4 and 3–6 disulphide bridges. This pattern is typical of beta-defensins and this gene was therefore named cod beta-defensin (defb). The tertiary structure of Defb exhibits an ?/? fold with one ? helix and ?1?2?3 sheets. RT-PCR analysis indicated that defb transcripts were present mainly in the swim bladder and peritoneum wall but could also be detected at moderate to low levels in skin, head- and excretory kidneys. In situ hybridisation revealed that defb was specifically expressed by cells located in the swim bladder submucosa and the oocytes. During embryonic development, defb gene transcripts were detectable from the golden eye stage onwards and their expression was restricted to the swim bladder and retina. Defb was differentially expressed in several tissues following antigenic challenge with Vibrio anguillarum, being up-regulated up to 25-fold in head kidney. Recombinant Defb displayed antibacterial activity, with a minimal inhibitory concentration of 0.4–0.8 µM and 25–50 µM against the Gram-(+) bacteria Planococcus citreus and Micrococcus luteus, respectively. In addition, Defb stimulated phagocytic activity of cod head kidney leucocytes in vitro. These findings imply that beta-defensins may play an important role in the innate immune response of Atlantic cod. PMID:23638029

Ruangsri, Jareeporn; Kitani, Yoichiro; Kiron, Viswanath; Lokesh, Jep; Brinchmann, Monica F.; Karlsen, Bard Ove; Fernandes, Jorge M. O.

2013-01-01

34

Kombucha fermentation and its antimicrobial activity.  

PubMed

Kombucha was prepared in a tea broth (0.5% w/v) supplemented with sucrose (10% w/v) by using a commercially available starter culture. The pH decreased steadily from 5 to 2.5 during the fermentation while the weight of the "tea fungus" and the OD of the tea broth increased through 4 days of the fermentation and remained fairly constant thereafter. The counts of acetic acid-producing bacteria and yeasts in the broth increased up to 4 days of fermentation and decreased afterward. The antimicrobial activity of Kombucha was investigated against a number of pathogenic microorganisms. Staphylococcus aureus, Shigella sonnei, Escherichia coli, Aeromonas hydrophila, Yersinia enterolitica, Pseudomonas aeruginosa, Enterobacter cloacae, Staphylococcus epidermis, Campylobacter jejuni, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus, Helicobacterpylori, and Listeria monocytogenes were found to be sensitive to Kombucha. According to the literature on Kombucha, acetic acid is considered to be responsible for the inhibitory effect toward a number of microbes tested, and this is also valid in the present study. However, in this study, Kombucha proved to exert antimicrobial activities against E. coli, Sh. sonnei, Sal. typhimurium, Sal. enteritidis, and Cm. jejuni, even at neutral pH and after thermal denaturation. This finding suggests the presence of antimicrobial compounds other than acetic acid and large proteins in Kombucha. PMID:10888589

Sreeramulu, G; Zhu, Y; Knol, W

2000-06-01

35

Inhibitory effects of 4-chlorosalicylic acid on mushroom tyrosinase and its antimicrobial activities  

Microsoft Academic Search

The inhibitory effects of 4-chlorosalicylic acid on the activity of mushroom tyrosinase have been investigated. The results showed that 4-chlorosalicylic acid could strongly inhibit both monophenolase activity and diphenolase activity. The IC50 values were estimated as 1.89mM and 1.10mM for monophenolase and diphenolase activities, respectively. For the monophenolase activity, 4-chlorosalicylic acid could not only lengthen the lag time, but also

Peng Han; Chao-Qi Chen; Chun-Le Zhang; Kang-Kang Song; Han-Tao Zhou; Qing-Xi Chen

2008-01-01

36

Antimicrobial activity of extractives of Solidago microglossa  

Microsoft Academic Search

The antimicrobial activity of the methanol extract from Solidago microglossa roots, essential oil from its aerial part and some isolated compounds was investigated. The oil exhibited concentration-dependent activity against all the tested bacteria and yeasts.

A. F. Morel; G. O. Dias; C. Porto; E. Simionatto; C. Z. Stuker; I. I. Dalcol

2006-01-01

37

Acute inhibitory impact of antimicrobials on acetoclastic methanogenic activity.  

PubMed

The study evaluated the short-term inhibition impact of three antimicrobials, sulfamethoxazole, erythromycin and tetracycline, on the methanogenic activity of acclimated biomass fed with acetate. Batch reactors were inoculated each with a different antimicrobial concentration in the range of 1-1000 mg/L and they were operated during 6 days. Organic substrate removal was monitored by both soluble COD and acetate measurements, together with daily measurements of biogas and methane generation. While acetate was almost fully removed in all experiments, methane generation exhibited a significant drop with increasing antimicrobial doses. Almost complete methane inhibition was observed for antimicrobial doses above 500 mg/L. Together with adverse impact on process kinetics in the early phases of the experiments, the final acute impact of antimicrobials was on process stoichiometry, preventing complete utilization of acetate removed in metabolic reactions. The observed effect was found compatible with uncompetitive inhibition, which similarly exerts a binding impact on substrate-enzyme complex. PMID:22459958

Cetecioglu, Zeynep; Ince, Bahar; Orhon, Derin; Ince, Orhan

2012-06-01

38

Characterization of antimicrobial peptide activity by electrochemical impedance spectroscopy  

E-print Network

Characterization of antimicrobial peptide activity by electrochemical impedance spectroscopy Accepted 21 June 2008 Available online 1 July 2008 Keywords: Antimicrobial peptides Cationic peptides exposure to antimicrobial peptides (AMPs). We show that two model cationic peptides, very similar

Wimley, William C.

39

Antimicrobial activity of flowers from Anthemis cotula  

Microsoft Academic Search

The flavonoid containing total extract of Anthemis cotula flowers, tested at the concentration of 200 ?g\\/ml, showed interesting antimicrobial activity against both Gram-negative and Gram-positive microorganisms.

M. V Quarenghi; M. L Tereschuk; M. D Baigori; L. R Abdala

2000-01-01

40

Antimicrobial activity of flowers from Anthemis cotula.  

PubMed

The flavonoid containing total extract of Anthemis cotula flowers, tested at the concentration of 200 microg/ml, showed interesting antimicrobial activity against both Gram-negative and Gram-positive microorganisms. PMID:11077183

Quarenghi, M V; Tereschuk, M L; Baigori, M D; Abdala, L R

2000-12-01

41

Effects of Net Charge and the Number of Positively Charged Residues on the Biological Activity of Amphipathic ?-Helical Cationic Antimicrobial Peptides  

PubMed Central

In our previous study, we utilized a 26-residue amphipathic ?-helical antimicrobial peptide L-V13K (Chen et al., Antimicrob Agents Chemother 2007, 51, 1398?1406) as the framework to study the effects of peptide hydrophobicity on the mechanism of its antimicrobial action. In this study, we explored the effects of net charge and the number of positively charged residues on the hydrophilic/polar face of L-V13K on its biological activity (antimicrobial and hemolytic) and biophysical properties (hydrophobicity, amphipathicity, helicity, and peptide self-association). The net charge of V13K analogs at pH 7 varied between ?5 and +10 and the number of positively charged residues varied from 1 to 10. The minimal inhibitory concentrations (MIC) against six strains of Pseudomonas aeruginosa as well as other gram-negative and gram-positive bacteria were determined along with the maximal peptide concentration that produces no hemolysis of human red blood cells (MHC). Our results show that the number of positively charged residues on the polar face and net charge are both important for both antimicrobial activity and hemolytic activity. The most dramatic observation is the sharp transition of hemolytic activity on increasing one positive charge on the polar face of V13K i.e., the change from +8 to +9 resulted in greater than 32-fold increase in hemolytic activity (250 ?g/ml to <7.8 ?g/ml, respectively). PMID:18098173

Jiang, Ziqing; Vasil, Adriana I.; Hale, John D.; Hancock, Robert E. W.; Vasil, Michael L.; Hodges, Robert S.

2009-01-01

42

Antimicrobial activity of borate-buffered solutions.  

PubMed Central

A minimal salts medium adjusted to physiological pH and osmolality was buffered with either 0.3% phosphate or 1.2% borate and evaluated for antimicrobial activity. The borate-buffered medium, either with or without a carbon source, exhibited significant antimicrobial activity against 15 Pseudomonas strains, 12 strains of enteric bacteria, and 7 strains of staphylococci. The borate-buffered system appears suitable for use as a generic vehicle for ophthalmic pharmaceutical agents. PMID:3729341

Houlsby, R D; Ghajar, M; Chavez, G O

1986-01-01

43

Antimicrobial activity and clinical effectiveness of sisomicin: an evaluation of the literature (1995-2011).  

PubMed

The authors sought to evaluate whether sisomicin has a place in the current therapeutic armamentarium. PubMed and Scopus databases were systematically searched. Ten cohort studies and 11 case reports and case series were included evaluating, in total, 383 Gram-positive and 83 Gram-negative isolates. Sisomicin was active in vitro against 41% of Enterococcus spp., 97% of Staphylococcus spp. and was the most active in vitro (74%) aminoglycoside against Stenotrophomonas maltophilia isolates in one study. Regarding clinical effectiveness, sisomicin topical cream was effective in all 290 patients with pyoderma in one study, while the intravenous formulation of sisomicin was effective as prophylaxis for the development of postoperative pneumonia in 91% of lung surgery patients in another. In conclusion, sisomicin may be useful against certain pathogens; however, clinical data are scarce. Further studies are needed and may shed additional light in this area. PMID:23566151

Tansarli, Giannoula S; Rafailidis, Petros I; Papazoglou, Anthia A; Falagas, Matthew E

2013-04-01

44

Evaluation of Persistent Antimicrobial Effects of an Antimicrobial Formulation  

PubMed Central

Context: Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) is becoming more prevalent in healthy athletic populations. Various preventive measures have been proposed, but few researchers have evaluated the protective effects of a prophylactic application of a commercially available product. Objective: To compare the persistent antimicrobial properties of a commercially available antimicrobial product containing 4% chlorhexidine gluconate (Hibiclens) with those of a mild, nonmedicated soap (Dr. Bronner's Magic Soap). Design: Cross-sectional study. Setting: Microbiology laboratory, contract research organization. Patients or Other Participants: Twenty healthy human volunteers. Intervention(s): The test and control products were randomly assigned and applied to both forearms of each participant. Each forearm was washed for 2 minutes with the test or control product, rinsed, and dried. At, 1, 2, and 4 hours after application, each forearm was exposed to MRSA for approximately 30 minutes. Main Outcome Measure(s): Differences in numbers of MRSA recovered from each forearm, test and control, at each postapplication time point were compared. Results: Fewer MRSA (P < .0001) were recovered from the forearms treated with the test product (4% chlorhexidine gluconate) than from the forearms treated with the control product (nonmedicated soap). Conclusions: The 4% chlorhexidine gluconate product demonstrated persistent bactericidal activity versus MRSA for up to 4 hours after application. PMID:22488188

Ferrara, Michael S.; Courson, Ron; Paulson, Daryl S.

2011-01-01

45

Medicinal plants and antimicrobial activity  

Microsoft Academic Search

In the present paper, we analyze the past, present and future of medicinal plants, both as potential antimicrobial crude drugs as well as a source for natural compounds that act as new anti-infection agents. In the past few decades, the search for new anti-infection agents has occupied many research groups in the field of ethnopharmacology. When we reviewed the number

J. L. Ríos; M. C. Recio

2005-01-01

46

Probing Membrane Insertion Activity of Antimicrobial Polymers via Coarse-Grain Molecular Dynamics  

E-print Network

, non- peptidic synthetic antimicrobials show promise as effective alternatives to their natural peptide here is a desire to under- stand the nature of poration caused by synthetic antimicrobial (AMProbing Membrane Insertion Activity of Antimicrobial Polymers via Coarse-Grain Molecular Dynamics

Nielsen, Steven O.

47

Original article Antimicrobial activity of fatty acids  

E-print Network

. For example, while myr- istic acid (14:0) was only slightly active (10 mm inhibition zone), myristoleic acidOriginal article Antimicrobial activity of fatty acids against Bacillus larvae, the causative agent and unsaturated free fatty acids were tested for their antibiotic activ- ity against Bacillus larvae

Paris-Sud XI, Université de

48

Temporin L: antimicrobial, haemolytic and cytotoxic activities, and effects on membrane permeabilization in lipid vesicles.  

PubMed Central

The temporins are a family of small, linear antibiotic peptides with intriguing biological properties. We investigated the antibacterial, haemolytic and cytotoxic activities of temporin L (FVQWFSKFLGRIL-NH2), isolated from the skin of the European red frog Rana temporaria. The peptide displayed the highest activity of temporins studied to date, against both human erythrocytes and bacterial and fungal strains. At variance with other known temporins, which are mainly active against Gram-positive bacteria, temporin L was also active against Gram-negative strains such as Pseudomonas aeruginosa A.T.C.C. 15692 and Escherichia coli D21 at concentrations comparable with those that are microbiocidal to Gram-positive bacteria. In addition, temporin L was cytotoxic to three different human tumour cell lines (Hut-78, K-562 and U-937), causing a necrosis-like cell death, although sensitivity to the peptide varied markedly with the specific cell line tested. A study of the interaction of temporin L with liposomes of different lipid compositions revealed that the peptide causes perturbation of bilayer integrity of both neutral and negatively charged membranes, as revealed by the release of a vesicle-encapsulated fluorescent marker, and that the action of the peptide is modulated to some extent by membrane lipid composition. In particular, the presence of negatively charged lipids in the model bilayer inhibits the lytic power of temporin L. We also show that the release of fluorescent markers caused by temporin L is size-dependent and that the peptide does not have a detergent-like effect on the membrane, suggesting that perturbation of bilayer organization takes place on a local scale, i.e. through the formation of pore-like openings. PMID:12133008

Rinaldi, Andrea C; Mangoni, Maria Luisa; Rufo, Anna; Luzi, Carla; Barra, Donatella; Zhao, Hongxia; Kinnunen, Paavo K J; Bozzi, Argante; Di Giulio, Antonio; Simmaco, Maurizio

2002-01-01

49

Antimicrobial activity of different Finnish monofloral honeys against human pathogenic bacteria  

PubMed Central

The antimicrobial activity and phenolic compounds of five Finnish honey products against important human pathogens Streptococcus pneumoniae, S. pyogenes, Staphylococcus aureus, and methicillin-resistant S. aureus were analyzed. Microbroth dilution method and HPLC-DAD were used in antimicrobial testing and phenolic compound determination, respectively. Significant antimicrobial activity (p?antimicrobial activity of Finnish monofloral honeys against streptococcal and staphylococcal bacteria. To our knowledge this is also the first report on the antimicrobial effect of honey against S. pneumoniae. PMID:23278378

Huttunen, Sanna; Riihinen, Kaisu; Kauhanen, Jussi; Tikkanen-Kaukanen, Carina

2013-01-01

50

Protease Inhibitors from Plants with Antimicrobial Activity  

PubMed Central

Antimicrobial proteins (peptides) are known to play important roles in the innate host defense mechanisms of most living organisms, including plants, insects, amphibians and mammals. They are also known to possess potent antibiotic activity against bacteria, fungi, and even certain viruses. Recently, the rapid emergence of microbial pathogens that are resistant to currently available antibiotics has triggered considerable interest in the isolation and investigation of the mode of action of antimicrobial proteins (peptides). Plants produce a variety of proteins (peptides) that are involved in the defense against pathogens and invading organisms, including ribosome-inactivating proteins, lectins, protease inhibitors and antifungal peptides (proteins). Specially, the protease inhibitors can inhibit aspartic, serine and cysteine proteinases. Increased levels of trypsin and chymotrypsin inhibitors correlated with the plants resistance to the pathogen. Usually, the purification of antimicrobial proteins (peptides) with protease inhibitor activity was accomplished by salt-extraction, ultrafiltration and C18 reverse phase chromatography, successfully. We discuss the relation between antimicrobial and anti-protease activity in this review. Protease inhibitors from plants potently inhibited the growth of a variety of pathogenic bacterial and fungal strains and are therefore excellent candidates for use as the lead compounds for the development of novel antimicrobial agents. PMID:19582234

Kim, Jin-Young; Park, Seong-Cheol; Hwang, Indeok; Cheong, Hyeonsook; Nah, Jae-Woon; Hahm, Kyung-Soo; Park, Yoonkyung

2009-01-01

51

Antimicrobial and healing activity of kefir and kefiran extract.  

PubMed

Kefir and its insoluble polysaccharide, kefiran, were both tested for antimicrobial and cicatrizing activities against several bacterial species and Candida albicans using an agar diffusion method. Comparator antimicrobials were also tested. Cicatrizing experiments were carried out on Wistar rats with induced skin lesions and Staphylococcus aureus inoculation, using a topical application of a 70% kefir gel. Both kefir and kefiran showed some activity against all organisms tested; the highest activity was against Streptococcus pyogenes. Cicatrizing experiments using 70% kefir gel had a protective effect on skin connective tissue and 7 days treatment enhanced wound healing compared with 5 mg/kg of neomycin-clostebol emulsion. PMID:15848295

Rodrigues, Kamila Leite; Caputo, Lucélia Rita Gaudino; Carvalho, Jose Carlos Tavares; Evangelista, João; Schneedorf, Jose Maurício

2005-05-01

52

Use of rosemary, oregano, and a commercial blend of essential oils in broiler chickens: in vitro antimicrobial activities and effects on growth performance.  

PubMed

The present study was conducted to characterize the in vitro antimicrobial activities of 3 essential oils [oregano, rosemary, and a commercial blend of essential oils (BEO)] against pathogenic and nonpathogenic bacteria and to evaluate their effects on broiler chicken performances. The chemical composition of the essential oils was determined using the gas chromatography interfaced with a mass spectroscopy. The disc diffusion method, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) were applied for the determination of antimicrobial activities of essential oils. In vivo study, a total of seven hundred fifty 1-d-old male broiler chickens were assigned to 6 dietary treatment groups: basal diet (control; CON), CON + 44 mg of avilamycin/kg (A), CON + 100 mg of rosemary essential oil/kg (ROS), CON + 100 mg of oregano essential oil/kg (OR), CON + 50 mg of rosemary and 50 mg of oregano essential oils/kg (RO), and CON + 1,000 mg of BEO/kg (essential oil mixture, EOM). The essential oils isolated from rosemary and oregano were characterized by their greater content of 1,8-cineole (49.99%) and carvacrol (69.55%), respectively. The BEO was mainly represented by the aldehyde (cinnamaldehyde) and the monoterpene (1,8-cineole) chemical groups. The results of the disc diffusion method indicated that the rosemary essential oil had antibacterial activity (P ? 0.05) against only 3 pathogenic bacteria, Escherichia coli (8 mm), Salmonella indiana (11 mm), and Listeria innocua (9 mm). The essential oil of oregano had antimicrobial activities (P ? 0.05) on the same bacteria as rosemary but also on Staphylococcus aureus (22 mm) and Bacillus subtilis (12 mm). Oregano essential oil had greater (P ? 0.05) antimicrobial activities against pathogenic bacteria than rosemary essential oil but they had no synergism between them. The BEO showed an increased antimicrobial activity (P ? 0.05) against all studied bacteria (pathogenic and nonpathogenic bacteria) except for Lactobacillus rhamnosus. The supplementation of the basal diet with avilamycin or essential oils improved (P ? 0.05) broiler chicken BW, BW gain, and G:F compared with the CON diet. There were no differences in growth performances among birds fed A, ROS, OR, RO, or EOM diets. In general, essential oils contained in rosemary, oregano, and BEO can substitute for growth promoter antibiotics. Although the 3 essential oils had different antimicrobial activities, they exhibited the same efficiency in broiler chickens. PMID:22064737

Mathlouthi, N; Bouzaienne, T; Oueslati, I; Recoquillay, F; Hamdi, M; Urdaci, M; Bergaoui, R

2012-03-01

53

In vitro evaluation of the antimicrobial activity of a range of probiotics against pathogens: evidence for the effects of organic acids.  

PubMed

The aim of this study was to investigate the antimicrobial properties of fifteen selected strains belonging to the Lactobacillus, Bifidobacterium, Lactococcus, Streptococcus and Bacillus genera against Gram-positive and Gram-negative pathogenic bacteria. In vitro antibacterial activity was initially investigated by an agar spot method. Results from the agar spot test showed that most of the selected strains were able to produce active compounds on solid media with antagonistic properties against Salmonella Typhimurium, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and Clostridium difficile. These results were also confirmed when cell-free culture supernatants (CFCS) from the putative probiotics were used in an agar well diffusion assay. Neutralization of the culture supernatants with alkali reduced the antagonistic effects. These experiments are able to confirm the capacity of potential probiotics to inhibit selected pathogens. One of the main inhibitory mechanisms may result from the production of organic acids from glucose fermentation and consequent lowering of culture pH. This observation was confirmed when the profile of organic acids was analysed demonstrating that lactic and acetic acid were the principal end products of probiotic metabolism. Furthermore, the assessment of the haemolytic activity and the susceptibility of the strains to the most commonly used antimicrobials, considered as basic safety aspects, were also studied. The observed antimicrobial activity was mainly genus-specific, additionally significant differences could be observed among species. PMID:22959627

Tejero-Sariñena, Sandra; Barlow, Janine; Costabile, Adele; Gibson, Glenn R; Rowland, Ian

2012-10-01

54

Poisson Parameters of Antimicrobial Activity: A Quantitative Structure-Activity Approach  

PubMed Central

A contingency of observed antimicrobial activities measured for several compounds vs. a series of bacteria was analyzed. A factor analysis revealed the existence of a certain probability distribution function of the antimicrobial activity. A quantitative structure-activity relationship analysis for the overall antimicrobial ability was conducted using the population statistics associated with identified probability distribution function. The antimicrobial activity proved to follow the Poisson distribution if just one factor varies (such as chemical compound or bacteria). The Poisson parameter estimating antimicrobial effect, giving both mean and variance of the antimicrobial activity, was used to develop structure-activity models describing the effect of compounds on bacteria and fungi species. Two approaches were employed to obtain the models, and for every approach, a model was selected, further investigated and found to be statistically significant. The best predictive model for antimicrobial effect on bacteria and fungi species was identified using graphical representation of observed vs. calculated values as well as several predictive power parameters. PMID:22606039

Sestras, Radu E.; Jantschi, Lorentz; Bolboaca, Sorana D.

2012-01-01

55

Antimicrobial activity of ethylenediaminedisuccinate metal complexes.  

PubMed

It is shown that metal complexes of the biodegradable ligand ethylenediaminedisuccinic acid (edds) present antimicrobial activity towards fungi and bacteria. [Cd(edds)], in particular, is more toxic than free Cd2+ to Aspergillus niger, behaving as a 'Trojan Horse' in the facilitated delivery of the toxic metal into the fungus. PMID:18972505

Costa, Natália J S; Bombardieri, Cíntia R; Kuribayashi, Juliana S; de Camargo, Maristela M; Andrade, Leandro H; Kagohara, Edna; Espósito, Breno P

2008-10-01

56

Innate Antimicrobial Activity of Nasal Secretions  

Microsoft Academic Search

Minimally manipulated nasal secretions, an accessible form of airway surface fluid, were tested against indigenous and added bacteria by using CFU assays. Antimicrobial activity was found to vary between donors and with different target bacteria and was markedly diminished by dilution of the airway secretions. Donor-to- donor differences in electrophoresis patterns of nasal secretions in sodium dodecyl sulfate-polyacrylamide gel electrophoresis

ALEXANDER M. COLE; PUNEET DEWAN; TOMAS GANZ

1999-01-01

57

Antimicrobial activities of constituents of Uvaria chamae.  

PubMed

The antimicrobial activities of a number of cytotoxic C-benzylated flavonoids from Uvaria chamae have been determined. The minimum inhibitory concentration values of these flavonoids and certain of their derivatives against Straphylococcus aureus, Bacillus subtilis, and Mycobacterium smegmatis compare favorably with those of streptomycin sulfate. PMID:651562

Hufford, C D; Lasswell, W L

1978-01-01

58

Mechanisms of antimicrobial activity of calcium hydroxide: a critical review  

Microsoft Academic Search

Siqueira Jr JF, Lopes HP. Mechanisms of antimicrobial activity of calcium hydroxide: a critical review (Review). Interna- tional Endodontic Journal, 32, 361-369, 1999. Literature review The primary function of calcium hydroxide as a routine intracanal medicament is to provide antimicrobial activity. However, the mechanisms of antimicrobial activity of calcium hydroxide are not well known. Physicochemical properties of this substance may

J. F. Siqueira Jr; H. P. Lopes

1999-01-01

59

Antimicrobial effect of various combinations of plant extracts  

Microsoft Academic Search

The combined extracts of corni fructus, cinnamon and Chinese chive were used to evaluate its antimicrobial activity on common foodborne micro-organisms, including bacteria, yeasts and moulds. The combined extract (8:1:1, v\\/v\\/v) showed an entire antimicrobial spectrum and outstanding inhibitory effect. The combined extract was very stable under heat treatment. The inhibitory effect of the combined extract was greater with more

Pao-Chuan Hsieh; Jeng-Leun Mau; Shu-Hui Huang

2001-01-01

60

Antimicrobial and Antioxidant Activities of Pycnocycla spinosa Extracts  

PubMed Central

Background: Pycnocycla spinosa (P. spinosa) a member of the Umbelliferae family is traditionally used for treatment of different ailments. Objectives: This study aimed to evaluate the total phenolic and flavonoid content of P. spinosa extracts (methanol, ethanol and aqueous) and their antioxidant and antimicrobial effects. Materials and Methods: The antimicrobial activity of different extracts of P. spinosa was evaluated using micro broth dilution. Total phenolic and flavonoid contents were measured. Their antioxidant effect was evaluated using DPPH assay and ?-carotene linoleic acid test. Results: P. spinosa ethanol extract with higher-level phenolic and flavonoid contents showed the highest antioxidant and antimicrobial effects, in comparison with the other extracts. Bacillus sp. and Streptococcus sp. showed higher sensitivity to P. spinosa ethanol extract. Conclusions: P. spinosa ethanol extract can be used as a mouthwash for treatment of the oral infections. More clinical and toxicological studies are required for providing its efficacy.

Mahboubi, Mohaddese; Taghizadeh, Mohsen; Kazempour, Nastaran

2014-01-01

61

Antimicrobial Activity of Calcium Hydroxide in Endodontics: A Review  

PubMed Central

The purpose of endodontic therapy is to preserve the patient's natural teeth without compromising the patient's local or systemic health. Calcium hydroxide has been included in several materials and antimicrobial formulations that are used in several treatment modalities in endodontics, such as inter-appointment intracanal medicaments. The purpose of this article was to review the antimicrobial properties of calcium hydroxide in endodontics. Calcium hydroxide has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. Calcium hydroxide has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also a valuable anti-endotoxin agent. However, its effect on microbial biofilms is controversial. PMID:23323217

Shalavi, S; Yazdizadeh, M

2012-01-01

62

Antimicrobial activity of two essential oils.  

PubMed

The aim of the study was to evaluate the antimicrobial activity of essential oils in vitro for possible application to reduce the content of microorganisms in the air of animal houses. The essential oils of Cymbopogon citrarus L. and Malaleuca alternifolia L. were screened against bacteria Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis and yeast Candida albicans. The minimal inhibitory concentration of the active essential oils was tested using broth dilution assay. The essential oils concentrations ranged from 0.1-50.0%. The combined effects of essential oils were tested for Malaleuca alternifolia L. and Cymbopogon citrarus L. concentrations ranged from 0.005-50.0%. The oils showed a wide spectrum of antibacterial activity. Concentrations of 0.1-0.5% of Cymbopogon citrarus L. and Malaleuca alternifolia L. reduced total microorganisms count of Proteus mirabilis and Candida albicans. High antibacterial activity was also revealed for Cymbopogon citrarus L. with bactericidal concentrations of 0.8% for Escherichia coli, 5.0% for Enterococcus faecium, 5.0% for Pseudomonas aeruginosa and 8.0% for Staphylococcus aureus. Bactericidal concentrations of Malaleuca alternifolia L. were 5.0% for Pseudomonas aeruginosa and Enterococcus faecium, and 8.0% for Staphylococcus aureus. The essential oils of Cymbopogon citrarus and Malaleuca alternifolia may be a promising alternative of air disinfection in animal houses. PMID:21739934

Mickien?, R?ta; Bakutis, Bronius; Baliukonien?, Violeta

2011-06-01

63

Effectiveness of antimicrobial food packaging materials  

Microsoft Academic Search

Antimicrobial additives have been used successfully for many years as direct food additives. The literature provides evidence that some of these additives may be effective as indirect food additives incorporated into food packaging materials. Antimicrobial food packaging is directed toward the reduction of surface contamination of processed, prepared foods such as sliced meats and Frankfurter sausages (hot dogs). The use

K. Cooksey

2005-01-01

64

In vitro antimicrobial activity of Achyranthes coynei Sant.  

PubMed Central

Objective To validate the traditional use of Achyranthes coynei (A. coynei) Sant. as an antimicrobial in treatment of various infectious diseases. Methods Leaf extracts of A. coynei obtained through successive solvent extraction using petroleum ether, dichrloromethane, chloroform and methanol were used to screen the antimicrobial activity on five Gram positive, five Gram negative bacteria and two fungi. Minimum inhibitory concentration (MIC) was determined by two fold tube-dilution method. Results Methanolic leaf extract was more effective than other three extracts on the tested bacteria. Methanolic extract was efficient on Staphylococcus epidermis, Bacillus subtilis, Staphylococcus aureus and Pseudomonas aeruginosa with MIC values (0.62±0.00) mg/mL. The fungal organisms were less susceptible against extracts tested. Conclusions These results support the traditional use of leaf extracts of A. coynei as they have antimicrobial potential. Further studies are needed for establishing safety, toxicity and pharmacological activity with phytochemical investigation.

Ankad, Gireesh; Upadhya, Vinayak; Pai, Sandeep R.; Hegde, Harsha V.; Roy, Subarna

2013-01-01

65

Antistaphylococcal activity of oritavancin and its synergistic effect in combination with other antimicrobial agents.  

PubMed

Oritavancin exhibited in vitro activity against 169 strains of vancomycin-susceptible, methicillin-resistant Staphylococcus aureus (MRSA) with MICs ranging from 0.03 to 1 ?g/ml and against vancomycin-intermediate MRSA (VISA; n = 29), heterogeneous vancomycin-intermediate MRSA (hVISA; n = 5), and vancomycin-resistant MRSA (n = 5) strains, with MICs ranging from 0.12 to 4 ?g/ml. For 10 MRSA isolates comprising 5 VISA and 5 hVISA strains, synergy between oritavancin and gentamicin, linezolid, or rifampin was observed against most of the strains tested using a time-kill method. PMID:25022588

Lin, Gengrong; Pankuch, Glenn; Appelbaum, Peter C; Kosowska-Shick, Klaudia

2014-10-01

66

Molybdenum doped titanium dioxide photocatalytic coatings for use as hygienic surfaces: the effect of soiling on antimicrobial activity.  

PubMed

Titanium dioxide (TiO2) surfaces doped with molybdenum (Mo) were investigated to determine if their photocatalytic ability could enhance process hygiene in the brewery industry. Doping TiO2 with Mo showed a 5-log reduction in bacterial counts within 4 to 24?h and a 1-log reduction in yeast numbers within 72?h. The presence of a dilute brewery soil on the surface did not interfere with antimicrobial activity. The TiO2-Mo surface was also active in the dark, showing a 5-log reduction in bacteria within 4 to 24?h and a 1-log reduction in yeast numbers within 72?h, suggesting it could have a novel dual function, being antimicrobial and photocatalytic. The study suggests the TiO2-Mo coating could act as a secondary barrier in helping prevent the build-up of microbial contamination on surfaces within the brewery industry, in particular in between cleaning/disinfection regimes during long production runs. PMID:25184432

Fisher, L; Ostovapour, S; Kelly, P; Whitehead, K A; Cooke, K; Storgårds, E; Verran, J

2014-09-01

67

Antimicrobial and Immunomodulatory Activities of PR-39 Derived Peptides  

PubMed Central

The porcine cathelicidin PR-39 is a host defence peptide that plays a pivotal role in the innate immune defence of the pig against infections. Besides direct antimicrobial activity, it is involved in immunomodulation, wound healing and several other biological processes. In this study, the antimicrobial- and immunomodulatory activity of PR-39, and N- and C-terminal derivatives of PR-39 were tested. PR-39 exhibited an unexpected broad antimicrobial spectrum including several Gram positive strains such as Bacillus globigii and Enterococcus faecalis. Of organisms tested, only Staphylococcus aureus was insensitive to PR-39. Truncation of PR-39 down to 15 (N-terminal) amino acids did not lead to major loss of activity, while peptides corresponding to the C-terminal part of PR-39 were hampered in their antimicrobial activity. However, shorter peptides were all much more sensitive to inhibition by salt. Active peptides induced ATP leakage and loss of membrane potential in Bacillus globigii and Escherichia coli, indicating a lytic mechanism of action for these peptides. Finally, only the mature peptide was able to induce IL-8 production in porcine macrophages, but some shorter peptides also had an effect on TNF-? production showing differential regulation of cytokine induction by PR-39 derived peptides. None of the active peptides showed high cytotoxicity highlighting the potential of these peptides for use as an alternative to antibiotics. PMID:24755622

Veldhuizen, Edwin J. A.; Schneider, Viktoria A. F.; Agustiandari, Herfita; van Dijk, Albert; Tjeerdsma-van Bokhoven, Johanna L. M.; Bikker, Floris J.; Haagsman, Henk P.

2014-01-01

68

The antimicrobial activities of the cinnamaldehyde adducts with amino acids.  

PubMed

Cinnamaldehyde is a well-established natural antimicrobial compound. It is probable for cinnamaldehyde to react with amino acid forming Schiff base adduct in real food system. In this paper, 9 such kind of adducts were prepared by the direct reaction of amino acids with cinnamaldehyde at room temperature. Their antimicrobial activities against Bacillus subtilis, Escherichia coli and Saccharomyces cerevisiae were evaluated with benzoic acid as a reference. The adducts showed a dose-dependent activities against the three microbial strains. Both cinnamaldehyde and their adducts were more active against B. subtilis than on E. coli, and their antimicrobial activities were higher at lower pH. Both cinnamaldehyde and its adducts were more active than benzoic acid at the same conditions. The adduct compound A was non-toxic by primary oral acute toxicity study in mice. However, in situ effect of the adduct compound A against E. coli was a little lower than cinnamaldehyde in fish meat. This paper for the first time showed that the cinnamaldehyde adducts with amino acids had similar strong antimicrobial activities as cinnamaldehyde, which may provide alternatives to cinnamaldehyde in food to avoid the strong unacceptable odor of cinnamaldehyde. PMID:21856030

Wei, Qing-Yi; Xiong, Jia-Jun; Jiang, Hong; Zhang, Chao; Wen Ye

2011-11-01

69

Antimicrobial Persistence and Residual Effect in Healthcare Personnel Handwashes  

Microsoft Academic Search

BACKGROUND: Alcohol-based hand sanitizers can reduce nosocomial infections by >30.0%. The Food and Drug Administration (FDA) via the Tentative Final Monograph assesses efficacy immediately post wash. Antimicrobial persistence and residual effect are not evaluated. Recently a novel water-optional, alcohol-based formulation preserved with zinc pyrithione has been developed that provides antimicrobial persistence and residual activity, while surpassing the FDA criteria as

D. Paulson

2004-01-01

70

Antimicrobial silver: An unprecedented anion effect  

PubMed Central

Silver is an indispensable metal but its use has to be minimised for sustainable growth. Much of the silver lost during use is unrecoverable; an example being its use as an antimicrobial agent, a property known since ages. While developing methods to create an affordable drinking water purifier especially for the developing world, we discovered that 50 parts per billion (ppb) of Ag+ released continuously from silver nanoparticles confined in nanoscale cages is enough to cause antimicrobial activity in conditions of normal water. Here we show that the antibacterial and antiviral activities of Ag+ can be enhanced ~1,000 fold, selectively, in presence of carbonate ions whose concentration was maintained below the drinking water norms. The protective layers of the organisms were affected during the carbonate-assisted antimicrobial activity. It is estimated that ~1,300 tons of silver can be saved annually using this new way to enhance its antimicrobial activity.

Swathy, J. R.; Sankar, M. Udhaya; Chaudhary, Amrita; Aigal, Sahaja; Anshup; Pradeep, T.

2014-01-01

71

Effect of efflux pump inhibitors on antimicrobial resistance and in vivo colonization of Campylobacter jejuni  

E-print Network

and proven to potentiate the activity of antimicrobial agents against Gram-negative bacteria. We demonstratedEffect of efflux pump inhibitors on antimicrobial resistance and in vivo colonization spectrum of antimicrobial agents and is also essential for Campylobacter colonization by mediation of bile

Grissino-Mayer, Henri D.

72

Antioxidant, antimicrobial and antiproliferative activities of five lichen species.  

PubMed

The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells. PMID:21954369

Mitrovi?, Tatjana; Stamenkovi?, Slaviša; Cvetkovi?, Vladimir; Toši?, Svetlana; Stankovi?, Milan; Radojevi?, Ivana; Stefanovi?, Olgica; Comi?, Ljiljana; Da?i?, Dragana; Cur?i?, Milena; Markovi?, Snežana

2011-01-01

73

Antioxidant, Antimicrobial and Antiproliferative Activities of Five Lichen Species  

PubMed Central

The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells. PMID:21954369

Mitrovic, Tatjana; Stamenkovic, Slavisa; Cvetkovic, Vladimir; Tosic, Svetlana; Stankovic, Milan; Radojevic, Ivana; Stefanovic, Olgica; Comic, Ljiljana; ?acic, Dragana; Curcic, Milena; Markovic, Snezana

2011-01-01

74

Mechanism of a prototypical synthetic membrane-active antimicrobial: Efficient hole-punching  

E-print Network

Mechanism of a prototypical synthetic membrane- active antimicrobial: Efficient hole-punching via against the membrane-active phenylene ethynylene antimicrobials, whereas the opposite is true when a prototypical class of synthetic antimicrobial compounds that mimic antimicrobial peptides pro- duced

Tew, Gregory N.

75

[Effectiveness of antimicrobial prophylaxis in prevention of surgical site infections].  

PubMed

Preventing surgical site infection (SSI) is important in providing safe and high-quality surgical care. Antimicrobial prophylaxis is given to prevent SSI. Many reports revealed that antimicrobial prophylaxis is effective to reduce SSI rates, when its initial dose is given at proper timing and additional dose is properly given in longer operations. Initial dose of antimicrobial prophylaxis is recommended to be administered within one hour before starting operation. Additional dose is recommended to be administered each two to three hours in longer operations. Antimicrobial prophylaxis should be given according to pharmacokinetics/pharmacodynamics (PK/PD). Beta-lactam drugs are recommended to be administered three or four times a day to obtain longer time above MIC and effective antimicrobial activity. In United States, Surgical Care Improvement Project (SCIP) is ongoing to reduce complications after surgery. Proper usage of antimicrobial prophylaxis is strongly recommended to reduce SSI in this project. Surgical team hopes to reduce SSI by proper administration of antimicrobial prophylaxis with the cooperatiing of anesthesiologists and operating room staffs. PMID:20486570

Harihara, Yasushi; Konishi, Toshiro

2010-05-01

76

Antimicrobial activity of Castanopsis acuminatissima  

Microsoft Academic Search

The methanol extracts of Castanopsis acuminatissima leaves, stem and root barks were partitioned (petrol, dichloromethane, ethyl acetate). Though all of the crude methanolic extracts and obtained fractions from them, showed a broad spectrum of antibacterial activity, in most cases the activity was decreased on fractionation. None was active against tested moulds.

M. R. Khan; M. Kihara; A. D. Omoloso

2001-01-01

77

Antimicrobial activity of Castanopsis acuminatissima.  

PubMed

The methanol extracts of Castanopsis acuminatissima leaves, stem and root barks were partitioned (petrol, dichloromethane, ethyl acetate). Though all of the crude methanolic extracts and obtained fractions from them, showed a broad spectrum of antibacterial activity, in most cases the activity was decreased on fractionation. None was active against tested moulds. PMID:11223229

Khan, M R; Kihara, M; Omoloso, A D

2001-02-01

78

Impedance measurements to study the antimicrobial activity of essential oils from Lamiaceae and Compositae  

Microsoft Academic Search

A wide range of essential oils from sage, mint, hyssop, camomile and oregano were tested for their inhibitory effects against nine strains of Gram-negative bacteria and six strains of Gram-positive bacteria. Three principles were used in describing the antimicrobial effects of the essential oils: the overall antimicrobial activity determined by use of an impedometric method, the bactericidal effect determined as

Marilena Marino; Carla Bersani; Giuseppe Comi

2001-01-01

79

Antimicrobial activity of topical skin pharmaceuticals - an in vitro study.  

PubMed

The aim of this study was to investigate the antimicrobial activity of currently available topical skin pharmaceuticals against Candida albicans, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pyogenes. The agar dilution assay was used to determine the minimal inhibitory concentration for cream formulations and their active substances. Corticosteroid formulations with the antiseptics clioquinol or halquinol were active against all microbes. The hydrogen peroxide formulation was primarily active against staphylococci. Clotrimazole, miconazole and econazole showed an effect against staphylococci in addition to their effect on C. albicans. In contrast, terbinafine had no antibacterial effect. Fusidic acid was active against staphylococci, with slightly weaker activity against S. pyogenes and no activity against C. albicans or E. coli. In summary, some topical skin pharmaceuticals have broad antimicrobial activity in vitro, clioquinol and halquinol being the most diverse. In limited superficial skin infection topical treatment can be an alternative to systemic antibiotics and should be considered. With the global threat of multi-resistant bacteria there is a need for new, topical, non-resistance-promoting, antimicrobial preparations for the treatment of skin infections. PMID:20526539

Alsterholm, Mikael; Karami, Nahid; Faergemann, Jan

2010-05-01

80

Antimicrobial Activities of Selected Cyathus Species  

Microsoft Academic Search

Twelve selected Cyathus species were tested for their abilities to produce antimicrobial metabolites. Most of them were found to produce secondary\\u000a exo-metabolites that could induce morphological abnormalities of rice pathogenic fungi Pyricularia oryzae. Some extracts from the cultivated liquid obviously inhibited human pathogenic fungi Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans. Activities against six human pathogenic bacteria were also obtained

Ya-Jun Liu; Ke-Qin Zhang

2004-01-01

81

Macin Family of Antimicrobial Proteins Combines Antimicrobial and Nerve Repair Activities*  

PubMed Central

The tertiary structures of theromacin and neuromacin confirmed the macin protein family as a self-contained family of antimicrobial proteins within the superfamily of scorpion toxin-like proteins. The macins, which also comprise hydramacin-1, are antimicrobially active against Gram-positive and Gram-negative bacteria. Despite high sequence identity, the three proteins showed distinct differences with respect to their biological activity. Neuromacin exhibited a significantly stronger capacity to permeabilize the cytoplasmic membrane of Bacillus megaterium than theromacin and hydramacin-1. Accordingly, it is the only macin that displays pore-forming activity and that was potently active against Staphylococcus aureus. Moreover, neuromacin and hydramacin-1 led to an aggregation of bacterial cells that was not observed with theromacin. Analysis of the molecular surface properties of macins allowed confirmation of the barnacle model as the mechanistic model for the aggregation effect. Besides being antimicrobially active, neuromacin and theromacin, in contrast to hydramacin-1, were able to enhance the repair of leech nerves ex vivo. Notably, all three macins enhanced the viability of murine neuroblastoma cells, extending their functional characteristics. As neuromacin appears to be both a functional and structural chimera of hydramacin-1 and theromacin, the putative structural correlate responsible for the nerve repair capacity in leech was located to a cluster of six amino acid residues using the sequence similarity of surface-exposed regions. PMID:22396551

Jung, Sascha; Sönnichsen, Frank D.; Hung, Chien-Wen; Tholey, Andreas; Boidin-Wichlacz, Céline; Haeusgen, Wiebke; Gelhaus, Christoph; Desel, Christine; Podschun, Rainer; Waetzig, Vicki; Tasiemski, Aurélie; Leippe, Matthias; Grötzinger, Joachim

2012-01-01

82

Antioxidant, antimicrobial and neutrophil-modulating activities of herb extracts.  

PubMed

The present study provides a comprehensive data on the antioxidant, antimicrobial and neutrophil-modulating activities of extracts from six medicinal plants--blackberry (Rubus fruticosus) leaves, chokeberry (Aronia melanocarpa) leaves, hawthorn (Crataegus monogyna) leaves, lady's mantle (Alchemilla glabra) aerial parts, meadowsweet (Filipendula ulmaria) aerial parts and raspberry (Rubus idaeus) leaves. In order to analyze the antioxidant activity of the herbs, several methods (ORAC, TRAP, HORAC and inhibition of lipid peroxidation) were used. Blackberry leaves and meadowsweet extracts revealed the highest antioxidant activities via all methods. All extracts studied blocked almost completely the opsonized zymosan particle-activated ROS production by neutrophils from human whole blood. On the other hand, the effect of extracts on phorbol myristate acetate-activated ROS production was much milder and even nonsignificant in the case of chokeberry leaves. This latter result suggests that extracts (apart from their antioxidative activity) interfere with the signaling cascade of phagocyte activation upstream of the protein kinase C activation. The antimicrobial activity of the investigated extracts against 11 human pathogens was investigated using three different methods. Meadowsweet and blackberry leaves extracts had the highest antimicrobial effect and the lowest minimal inhibiting concentrations (MICs) against the microorganisms tested. PMID:24945135

Denev, Petko; Kratchanova, Maria; Ciz, Milan; Lojek, Antonin; Vasicek, Ondrej; Blazheva, Denitsa; Nedelcheva, Plamena; Vojtek, Libor; Hyrsl, Pavel

2014-01-01

83

Antimicrobial activity of enterocins from Enterococcus faecalis SL5 against Propionibacterium acnes , the causative agent in acne vulgaris, and its therapeutic effect  

Microsoft Academic Search

A lactic acid bacterial strain was isolated from human fecal specimen and identified as Enterococcus faecalis SL-5. The isolated strain showed antimicrobial activity against Gram-positive pathogens assayed, especially the highest activity\\u000a against Propionibacterium acnes. The antimicrobial substance was purified and verified as a bacteriocin (named ESL5) of E. faecalis SL-5 by activity-staining using P. acnes as an indicator. N-terminal sequence

Bong Seon Kang; Jae-Gu Seo; Gwa-Su Lee; Jung-Hwa Kim; Sei Yeon Kim; Ye Won Han; Hoon Kang; Hyung Ok Kim; Ji Hwan Rhee; Myung-Jun Chung; Young Min Park

2009-01-01

84

Antimicrobial stewardship activities: a survey of Queensland hospitals.  

PubMed

Objective In 2011, the Australian Commission on Safety and Quality in Health Care (ACSQHC) recommended that all hospitals in Australia must have an Antimicrobial Stewardship (AMS) program by 2013. Nevertheless, little is known about current AMS activities. This study aimed to determine the AMS activities currently undertaken, and to identify gaps, barriers to implementation and opportunities for improvement in Queensland hospitals. Methods The AMS activities of 26 facilities from 15 hospital and health services in Queensland were surveyed during June 2012 to address strategies for effective AMS: implementing clinical guidelines, formulary restriction, reviewing antimicrobial prescribing, auditing antimicrobial use and selective reporting of susceptibility results. Results The response rate was 62%. Nineteen percent had an AMS team (a dedicated multidisciplinary team consisting of a medically trained staff member and a pharmacist). All facilities had access to an electronic version of Therapeutic Guidelines: Antibiotic, with a further 50% developing local guidelines for antimicrobials. One-third of facilities had additional restrictions. Eighty-eight percent had advice for restricted antimicrobials from in-house infectious disease physicians or clinical microbiologists. Antimicrobials were monitored with feedback given to prescribers at point of care by 76% of facilities. Deficiencies reported as barriers to establishing AMS programs included: pharmacy resources, financial support by hospital management, and training and education in antimicrobial use. Conclusions Several areas for improvement were identified: reviewing antimicrobial prescribing with feedback to the prescriber, auditing, and training and education in antimicrobial use. There also appears to be a lack of resources to support AMS programs in some facilities. What is known about the topic? The ACSQHC has recommended that all hospitals implement an AMS program by 2013 as a requirement of Standard 3 (Preventing and Controlling Healthcare-Associated Infections) of the National Safety and Quality Health Service Standards. The intent of AMS is to ensure appropriate prescribing of antimicrobials as part of the broader systems within a health service organisation to prevent and manage healthcare-associated infections, and improve patient safety and quality of care. This criterion also aligns closely with Standard 4: Medication Safety. Despite this recommendation, little is known about what AMS activities are undertaken in these facilities and what additional resources would be required in order to meet these national standards. What does the paper add? This is the first survey that has been conducted of public hospital and health services in Queensland, a large decentralised state in Australia. This paper describes what AMS activities are currently being undertaken, identifies practice gaps, barriers to implementation and opportunities for improvement in Queensland hospitals. What are the implications for practitioners? Several areas for improvement such as reviewing antimicrobial prescribing with feedback to the prescriber, auditing, and training and education in antimicrobial use have been identified. In addition, there appears to be a lack of resources to support AMS programs in some facilities. PMID:25376911

Avent, Minyon L; Hall, Lisa; Davis, Louise; Allen, Michelle; Roberts, Jason A; Unwin, Sean; McIntosh, Kylie A; Thursky, Karin; Buising, Kirsty; Paterson, David L

2014-11-01

85

Antimicrobial activity of aroma chemicals and essential oils  

Microsoft Academic Search

Determination of the minimum inhibitory concen-trations (MIC) of 212 common soap fragrance raw materials demonstrated that\\u000a the paper disc-petri plate technique does not reflect the relative anti-microbial activity of these materials. Commonly used\\u000a soap bacteriostats were shown to be 100 to 1000 times more effective than the most active fragrance materials. Of 521 fragrance\\u000a materials initially screened by the petri

J. A. Morris; A. Khettry; E. W. Seitz

1979-01-01

86

Chemical Composition, Antioxidant and Antimicrobial Activities of Thymus capitata Essential Oil with Its Preservative Effect against Listeria monocytogenes Inoculated in Minced Beef Meat.  

PubMed

The chemical composition, antioxidant and antimicrobial activities, and the preservative effect of Thymus capitata essential oil against Listeria monocytogenes inoculated in minced beef meat were evaluated. The essential oil extracted was chemically analyzed by gas chromatography-mass spectrometry. Nineteen components were identified, of which carvacrol represented (88.89%) of the oil. The antioxidant activity was assessed in vitro by using both the DPPH and the ABTS assays. The findings showed that the essential oil exhibited high antioxidant activity, which was comparable to the reference standards (BHT and ascorbic acid) with IC50 values of 44.16 and 0.463 ? g/mL determined by the free-radical scavenging DPPH and ABTS assays, respectively. Furthermore, the essential oil was evaluated for its antimicrobial activity using disc agar diffusion and microdilution methods. The results demonstrated that the zone of inhibition varied from moderate to strong (15-80?mm) and the minimum inhibition concentration values ranged from 0.32 to 20?mg/mL. In addition, essential oil evaluated in vivo against Listeria monocytogenes showed clear and strong inhibitory effect. The application of 0.25 or 1% (v/w) essential oil of T. capitata to minced beef significantly reduced the L. monocytogenes population when compared to those of control samples (P-value??<0.01). PMID:24719640

El Abed, Nariman; Kaabi, Belhassen; Smaali, Mohamed Issam; Chabbouh, Meriem; Habibi, Kamel; Mejri, Mondher; Marzouki, Mohamed Nejib; Ben Hadj Ahmed, Sami

2014-01-01

87

Antimicrobial activity of the metals and metal oxide nanoparticles.  

PubMed

The ever increasing resistance of pathogens towards antibiotics has caused serious health problems in the recent years. It has been shown that by combining modern technologies such as nanotechnology and material science with intrinsic antimicrobial activity of the metals, novel applications for these substances could be identified. According to the reports, metal and metal oxide nanoparticles represent a group of materials which were investigated in respect to their antimicrobial effects. In the present review, we focused on the recent research works concerning antimicrobial activity of metal and metal oxide nanoparticles together with their mechanism of action. Reviewed literature indicated that the particle size was the essential parameter which determined the antimicrobial effectiveness of the metal nanoparticles. Combination therapy with the metal nanoparticles might be one of the possible strategies to overcome the current bacterial resistance to the antibacterial agents. However, further studies should be performed to minimize the toxicity of metal and metal oxide nanoparticles to apply as proper alternatives for antibiotics and disinfectants especially in biomedical applications. PMID:25280707

Dizaj, Solmaz Maleki; Lotfipour, Farzaneh; Barzegar-Jalali, Mohammad; Zarrintan, Mohammad Hossein; Adibkia, Khosro

2014-11-01

88

Antimicrobial activity and biofilm formation inhibition of green tea polyphenols on human teeth  

Microsoft Academic Search

The antimicrobial effects and biofilm formation inhibition of tea polyphenols (TPP) extracted from Korean green tea (Camellia sinensis L) were evaluated against 12 oral microorganisms. Effective antimicrobial activity against all microorganisms tested, including\\u000a Lactobacillus spp. (Lactobacillus acidophilus and Lactobacillus plantarum), Streptococcus spp. (Streptococcus mutans, Streptococcus sanguis, Streptococcus sobrinus, Streptococcus mitis, and Streptococcus salivarius), Staphylococcus aureus, Neisseria meningitidis, Escherichia coli, Enterobacter

Yun-Seok Cho; Jay Jooyoung Oh; Kye-Heon Oh

2010-01-01

89

Molecular Design, Structures, and Activity of Antimicrobial Peptide-Mimetic Polymers  

PubMed Central

There is an urgent need for new antibiotics which are effective against drug-resistant bacteria without contributing to resistance development. We have designed and developed antimicrobial copolymers with cationic amphiphilic structures based on the mimicry of naturally occurring antimicrobial peptides. These copolymers exhibit potent antimicrobial activity against a broad spectrum of bacteria including methicillin-resistant Staphylococcus aureus with no adverse hemolytic activity. Notably, these polymers also did not result in any measurable resistance development in E. coli. The peptide-mimetic design principle offers significant flexibility and diversity in the creation of new antimicrobial materials and their potential biomedical applications. PMID:23832766

Takahashi, Haruko; Palermo, Edmund F.; Yasuhara, Kazuma; Caputo, Gregory A.

2014-01-01

90

Repurposing the Antihistamine Terfenadine for Antimicrobial Activity against Staphylococcus aureus.  

PubMed

Staphylococcus aureus is a rapidly growing health threat in the U.S., with resistance to several commonly prescribed treatments. A high-throughput screen identified the antihistamine terfenadine to possess, previously unreported, antimicrobial activity against S. aureus and other Gram-positive bacteria. In an effort to repurpose this drug, structure-activity relationship studies yielded 84 terfenadine-based analogues with several modifications providing increased activity versus S. aureus and other bacterial pathogens, including Mycobacterium tuberculosis. Mechanism of action studies revealed these compounds to exert their antibacterial effects, at least in part, through inhibition of the bacterial type II topoisomerases. This scaffold suffers from hERG liabilities which were not remedied through this round of optimization; however, given the overall improvement in activity of the set, terfenadine-based analogues provide a novel structural class of antimicrobial compounds with potential for further characterization as part of the continuing process to meet the current need for new antibiotics. PMID:25238555

Perlmutter, Jessamyn I; Forbes, Lauren T; Krysan, Damian J; Ebsworth-Mojica, Katherine; Colquhoun, Jennifer M; Wang, Jenna L; Dunman, Paul M; Flaherty, Daniel P

2014-10-23

91

The Effect of Anti-Inflammatory and Antimicrobial Herbal Remedy PADMA 28 on Immunological Angiogenesis and Granulocytes Activity in Mice  

PubMed Central

PADMA 28 is a herbal multicompound remedy that originates from traditional Tibetan medicine and possesses anti-inflammatory, antioxidant, antimicrobial, angioprotecting, and wound healing properties. The aim of the present study was to evaluate the influence of this remedy on immunological angiogenesis and granulocytes metabolic activity in Balb/c mice. Mice were fed daily, for seven days, with 5.8?mg of PADMA (calculated from recommended human daily dose) or 0.085?mg (dose in the range of active doses of other herbal extracts studied by us previously). Results. Highly significant increase of newly formed blood vessels number in ex vivo cutaneous lymphocyte-induced angiogenesis test (LIA) after grafting of Balb/c splenocytes from both dosage groups to F1 hybrids (Balb/c × C3H); increase of blood lymphocytes and granulocytes number only in mice fed with lower dose of remedy; and significant suppression of metabolic activity (chemiluminescence test) of blood granulocytes in mice fed with higher dose of PADMA. Conclusion. PADMA 28 behaves as a good stimulator of physiological angiogenesis, but for this purpose it should be used in substantially lower doses than recommended by producers for avoiding the deterioration of granulocyte function. PMID:23864768

Radomska-Lesniewska, Dorota M.; Skopinski, Piotr; Zdanowski, Robert; Lewicki, Slawomir; Kocik, Janusz; Skopinska-Rozewska, Ewa; Stankiewicz, Wanda

2013-01-01

92

Antimicrobial activity and durability of a novel antimicrobial-impregnated bladder catheter  

Microsoft Academic Search

The main objective of this study was to examine the antimicrobial activity and durability of a novel indwelling bladder catheter impregnated with minocycline and rifampin. Thirty antimicrobial-impregnated bladder catheters were inserted transurethrally in spinal cord-injured patients and removed, in six groups of five catheters each, at 3, 7, 10, 14, 17 or 21 days. Removed catheters had detectable zones of

R. O Darouiche; O. Z Hampel; T. B Boone; I. I Raad

1997-01-01

93

Antimicrobial activity of Sesbania grandiflora flower polyphenol extracts on some pathogenic bacteria and growth stimulatory effect on the probiotic organism Lactobacillus acidophilus.  

PubMed

Polyphenolic extracts (PE) of edible flower of Sesbania grandiflora were tested to evaluate its antimicrobial effect against some common pathogenic bacteria and growth promoting property against probiotic organism Lactobacillus acidophilus. The antimicrobial activity of S. grandiflora flower PE against selected pathogens was evaluated using both in vitro and in situ methods. In vitro studies suggested that PE has inhibitory effect against Staphylococcus aureus, Shigella flexneri 2a, Salmonella Typhi, Escherichia coli and Vibrio cholerae. The gram-positive organism S. aureus was the most sensitive organism to PE and minimum inhibitory concentration (MIC) was found to be 0.013 mg/mL where as the MIC of PE against V. cholerae was the highest (0.25 mg/mL). On the other hand PE showed growth promoting effect on the common probiotic bacterium L. acidophilus. The major finding was that S. grandiflora PE induced a significant biomass increase of L. acidophilus grown in liquid culture media. PE showed reduction of S. aureus growth in food (fish) during storage at 10°C. High performance liquid chromatography analysis showed that rutin, a major flavonoid of the PE diminished in the culture medium MRS broth with the growth of L. acidophilus. PMID:22583547

China, Ratna; Mukherjee, Sayani; Sen, Sauradip; Bose, Sreedipa; Datta, Sanjukta; Koley, Hemanta; Ghosh, Santinath; Dhar, Pubali

2012-09-01

94

Chitosan: antimicrobial activity, interactions with food components and applicability as a coating on fruit and vegetables  

Microsoft Academic Search

Chitosan has recently gained more interest due to its applications in food and pharmaceutics. Among others, the antimicrobial activity of chitosan has been pointed out as one of its most interesting properties of chitosan.The aim of this study was threefold: (1) the quantification of the antimicrobial effect of chitosan with a deacetylation degree of 94% and a molecular weight of

F Devlieghere; A Vermeulen; J Debevere

2004-01-01

95

In vitro antimicrobial activity of Nigella sativa oil agains t multi-drug resistant bacteria  

Microsoft Academic Search

Abstract: An alarming increase in bacterial strains resistant to existing antimicrobial agents demands,a renewed effort to seek agents effective against pathogenic bacteria resistant to current antimicrobials. Nigella sativa L. essential oil was studied for antibacterial activity against various clinical isolates of bacteria resistant to a number of antibiotics, in varying concentrations by Disc Agar diffusion technique using impregnated filter paper

Mohd Tariq Salman; Rahat Ali Khan; Indu Shukla

96

Synthesis and antimicrobial activity of novel quinazolone derivatives.  

PubMed

Three novel series of 4-oxoquinazoline derivatives were prepared and evaluated as potential antimicrobial agents. Evaluation of the antimicrobial activity of a variety of 4-substituted-1-thiosemicarbazides, 3,4-disubstituted thiazolines, and 3-substituted-5-thiazolidones reveals that the majority possess significant in vitro activity against Gram-positive organisms. Some derivatives also exhibited antifungal activity. PMID:6381690

Habib, N S; Khalil, M A

1984-07-01

97

Antimicrobial Activities of Some Tetrahydronaphthalene-Benzimidazole Derivatives  

Microsoft Academic Search

Novel retinoid derivatives containing a benzimidazole moiety were synthesized and tested for their antimicrobial activity. Their antimicrobial activities against methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Candida krusei and Candida albicans were evaluated. While some of the compounds exhibited moderate activity against MRSA, S. aureus, E. faecalis, C. krusei and C. albicans, none of the

Zeynep Ates-Alagoz; Sulhiye Yildiz; Erdem Buyukbingol

2007-01-01

98

Antimicrobial activity of endophytic fungi isolated from Swietenia macrophylla leaves.  

PubMed

The endophytic fungi isolated from leaves of Swietenia macrophylla of different ages were examined for antimicrobial activity. The agar plug diffusion assay was used for primary screening, followed by the disc diffusion method. A total of 461 filamentous endophytic fungi were isolated and cultured to examine their antimicrobial properties. In the primary screen, 315 isolates (68.3%) exhibited activity against at least one of the test pathogenic microorganisms. The percentage of isolates exhibiting antimicrobial activity increased with leaf age. Endophytic fungal assemblages, as well as those isolates exhibiting antimicrobial properties appeared to increase with leaf age. The main antimicrobial compounds were produced extracellularly by the endophytic fungi. The results suggest that healthy leaves at older stages of growth can be a potential source for the isolation of endophytic fungi with antimicrobial properties. PMID:24689302

Ibrahim, Darah; Lee, Chong Chai; Sheh-Hong, Lim

2014-02-01

99

Impact of interspecific interactions on antimicrobial activity among soil bacteria  

PubMed Central

Certain bacterial species produce antimicrobial compounds only in the presence of a competing species. However, little is known on the frequency of interaction-mediated induction of antibiotic compound production in natural communities of soil bacteria. Here we developed a high-throughput method to screen for the production of antimicrobial activity by monocultures and pair-wise combinations of 146 phylogenetically different bacteria isolated from similar soil habitats. Growth responses of two human pathogenic model organisms, Escherichia coli WA321 and Staphylococcus aureus 533R4, were used to monitor antimicrobial activity. From all isolates, 33% showed antimicrobial activity only in monoculture and 42% showed activity only when tested in interactions. More bacterial isolates were active against S. aureus than against E. coli. The frequency of interaction-mediated induction of antimicrobial activity was 6% (154 interactions out of 2798) indicating that only a limited set of species combinations showed such activity. The screening revealed also interaction-mediated suppression of antimicrobial activity for 22% of all combinations tested. Whereas all patterns of antimicrobial activity (non-induced production, induced production and suppression) were seen for various bacterial classes, interaction-mediated induction of antimicrobial activity was more frequent for combinations of Flavobacteria and alpha- Proteobacteria. The results of our study give a first indication on the frequency of interference competitive interactions in natural soil bacterial communities which may forms a basis for selection of bacterial groups that are promising for the discovery of novel, cryptic antibiotics. PMID:25389421

Tyc, Olaf; van den Berg, Marlies; Gerards, Saskia; van Veen, Johannes A.; Raaijmakers, Jos M.; de Boer, Wietse; Garbeva, Paolina

2014-01-01

100

Antimicrobial activities of some Euphorbia species.  

PubMed

In this study, the antimicrobial activities of methanolic extracts and latex of some Euphorbia species used for medical purposes in Turkey were investigated. The extracts of Euphorbia aleppica L., Euphorbia szovitsii Fisch.&Mey. var. harputensis Aznav. ex M. S. Khan, Euphorbia falcata L. sub. falcata var. falcata, Euphorbia denticulata Lam., Euphorbia macroclada Boiss., Euphorbia cheiradenia Boiss.&Hohen, Euphorbia virgata Waldst.&Kit., Euphorbia petiolata Banks&Sol. were prepared with methanol. The antimicrobial activities of these extracts were examined on test microorganisms as follows: Staphylococcus aureus COWAN 1, Bacillus megaterium DSM 32, Proteus vulgaris FMC 1, Klebsiella pneumonia FMC 5, Escherichia coli ATCC 25922, Pseudomonas aeruginosa DSM 50071, Candida albicans FMC 17, Candida glabrata ATCC 66032, Epidermophyton sp. and Trichophyton sp. by the disc diffusion methods and well agar method. The MIC values of extracts were determined according to the broth microdulitions method. Results indicated that extracts of Euphorbia species inhibited the growth of tested microorganisms in the different ratio. Also, the MIC values of extracts were determined as 31,2-1000 µg. PMID:24311840

Kirbag, Sevda; Erecevit, P?nar; Zengin, Fikriye; Guvenc, Ay?e Nilay

2013-01-01

101

In vitro antimicrobial activity against 10 North American and European Lawsonia intracellularis isolates  

E-print Network

In vitro antimicrobial activity against 10 North American and European Lawsonia intracellularis to evaluate the antimicrobial activities of most intracellular organisms since these bacteria only propagate themselves inside the host cell. Therefore, most in vitro studies of antimicrobial activities against

Singer, Randall

102

Antimicrobial activity of flavonoids from leaves of Tagetes minuta  

Microsoft Academic Search

The total extract and fractions with different solvents, obtained from leaves of Tagetes minuta, showed several degrees of antimicrobial activity against Gram positive and Gram negative microorganisms. The same fractions were inactive against Lactobacillus, Zymomonas and Saccharomices species. The major component of the extract: quercetagetin-7-arabinosyl-galactoside, showed significant antimicrobial activity on pathogen microorganisms tested. Correlation results were carried out using chloramphenicol

Mar??a L Tereschuk; Marta V. Q Riera; Guillermo R Castro; Lidia R Abdala

1997-01-01

103

Antimicrobial activity of Caesalpinia pulcherrima, Euphorbia hirta and Asystasia gangeticum  

Microsoft Academic Search

The ethanolic extracts of the dry fruits of Caesalpinia pulcherrima, aerial parts of Euphorbia hirta and flowers of Asystasia gangeticum were tested for antimicrobial activity. The three plants exhibited a broad spectrum of antimicrobial activity, particularly against Escherichia coli (enteropathogen), Proteus vulgaris, Pseudomonas aeruginosa and Staphylococcus aureus.

M. Sudhakar; Ch. V. Rao; P. M. Rao; D. B. Raju; Y. Venkateswarlu

2006-01-01

104

Antimicrobial activity of Caesalpinia pulcherrima, Euphorbia hirta and Asystasia gangeticum.  

PubMed

The ethanolic extracts of the dry fruits of Caesalpinia pulcherrima, aerial parts of Euphorbia hirta and flowers of Asystasia gangeticum were tested for antimicrobial activity. The three plants exhibited a broad spectrum of antimicrobial activity, particularly against Escherichia coli (enteropathogen), Proteus vulgaris, Pseudomonas aeruginosa and Staphylococcus aureus. PMID:16730921

Sudhakar, M; Rao, Ch V; Rao, P M; Raju, D B; Venkateswarlu, Y

2006-07-01

105

The antimicrobial activity of liposomal lauric acids against Propionibacterium acnes  

E-print Network

The antimicrobial activity of liposomal lauric acids against Propionibacterium acnes Darren Yang a Liposome a b s t r a c t This study evaluated the antimicrobial activity of lauric acid (LA) and its liposomal derivatives against Propionibacterium acnes (P. acnes), the bacterium that promotes inflammatory

Zhang, Liangfang

106

Antimicrobial activity of selected herbal extracts.  

PubMed

METHANOLIC EXTRACT OF OLEORESINS OF ARAUCARIA BIDWILLI HOOK: and aerial parts of Cytisus scoparius Linn. Were screened for antimicrobial activity against two bacterial strains-Bacillus subtilis (Gram Positive) and Escherichia coli (Gem negative), and two fungal strains - Candida albicans and crytococcus neoformans by two-fold serial dilution technique. The results showed that all the microorganisms used were sensitive to the extracts. The minimum inhibitory concentrations (MIC) for A. bidwilli were found to be 31.25 ?g/ml for Bacillus subtilis and 500 ?g/ml for all other organisms used in the study. In case of C. Scoparius, the MIC values were 250 ?g/ml for B. Subtilis and 500 ?g/ml for allthe other strains used. However, in comparison the ampicillin (MIC: 62.5 ?g/ml), and Amphotericin-B (MIC: 125 ?g/ml ), the activities of both the extracts were less except A. bidwilli against B.Subtilis. PMID:22557052

Gowthamarajan, K; Kulkarni, T Giriraj; Mahadevan, N; Santhi, K; Suresh, B

2002-01-01

107

Antimicrobial activity of toothpastes containing natural extracts, chlorhexidine or triclosan.  

PubMed

The objective of this in vitro study was to evaluate the antimicrobial effect of toothpastes containing natural extracts, chlorhexidine or triclosan. The effectiveness of toothpastes containing natural extracts (Parodontax(r)), 0.12% chlorhexidine (Cariax(r)), 0.3% triclosan (Sanogil(r)) or fluoride (Sorriso(r), control) was evaluated against yeasts, Gram-positive and Gram-negative bacteria using the disk diffusion method. Water was used as a control. Disks impregnated with the toothpastes were placed in Petri dishes containing culture media inoculated with 23 indicative microorganisms by the pour plate method. After incubation, the inhibition growth halos were measured and statistical analyses (?=0.05) were performed. The results indicated that all formulations, except for conventional toothpaste (Sorriso(r)), showed antimicrobial activity against Gram-positive bacteria and yeasts. The toothpaste containing natural extracts (Parodontax(r)) was the only product able to inhibit the growth of Pseudomonas aeruginosa. The toothpastes containing chlorhexidine, triclosan or natural extracts presented antimicrobial activity against Gram-positive bacteria and yeasts. PMID:25252251

Rossi, Andiara De; Ferreira, Danielly Cunha Araújo; Silva, Raquel Assed Bezerra da; Queiroz, Alexandra Mussolino de; Silva, Léa Assed Bezerra da; Nelson-Filho, Paulo

2014-07-01

108

NANOCOMPOSITES OF POLYMERS WITH LAYERED INORGANIC NANOFILLERS: ANTIMICROBIAL ACTIVITY, THERMO-MECHANICAL PROPERTIES, MORPHOLOGY, AND DISPERSION.  

E-print Network

??In the first part of the thesis, polyethylene/layered silicate nanocomposites that exhibit an antimicrobial activity were synthesized and studied. Their antimicrobial activity was designed to… (more)

Songtipya, Ponusa

2010-01-01

109

Effects of Cultivation Techniques and Processing on Antimicrobial and Antioxidant Activities of Hericium erinaceus (Bull.:Fr.) Pers. Extracts  

Microsoft Academic Search

Summary Hericium erinaceus, a temperate mushroom, is currently cultivated in Malaysia. As culti- vation and processing conditions may affect the medicinal properties, antimicrobial and an- tioxidant properties of locally grown H. erinaceus have been investigated. The fruitbodies that were fresh, oven-dried or freeze-dried were extracted with methanol. Their properties were compared to those exhibited by mycelium extract of the same

Kah Hui Wong; Vikineswary Sabaratnam; Noorlidah Abdullah; Umah Rani Kuppusamy; Murali Naidu

2009-01-01

110

Wound healing activity of the human antimicrobial peptide LL37.  

PubMed

Antimicrobial peptides (AMPs) are part of the innate immune system and are generally defined as cationic, amphipathic peptides, with less than 50 amino acids, including multiple arginine and lysine residues. The human cathelicidin antimicrobial peptide LL37 can be found at different concentrations in many different cells, tissues and body fluids and has a broad spectrum of antimicrobial and immunomodulatory activities. The healing of wound is a complex process that involves different steps: hemostasis, inflammation, remodeling/granulation tissue formation and re-epithelialization. Inflammation and angiogenesis are two fundamental physiological conditions implicated in this process. We have recently developed a new method for the expression and purification of recombinant LL37. In this work, we show that the recombinant peptide P-LL37 with a N-terminus proline preserves its immunophysiological properties in vitro and in vivo. P-LL37 neutralized the activation of macrophages by lipopolysaccharide (LPS). Besides, the peptide induced proliferation, migration and tubule-like structures formation by endothelial cells. Wound healing experiments were performed in dexamethasone-treated mice to study the effect of LL37 on angiogenesis and wound regeneration. The topical application of synthetic and recombinant LL37 increased vascularization and re-epithelialization. Taken together, these results clearly demonstrate that LL37 may have a key role in wound regeneration through vascularization. PMID:21693141

Ramos, Reinaldo; Silva, João Pedro; Rodrigues, Ana Cristina; Costa, Raquel; Guardão, Luísa; Schmitt, Fernando; Soares, Raquel; Vilanova, Manuel; Domingues, Lucília; Gama, Miguel

2011-07-01

111

Effect of postharvest UV-C treatment on the bacterial diversity of Ataulfo mangoes by PCR-DGGE, survival of E. coli and antimicrobial activity.  

PubMed

Since Mexico is the second largest exporter of mangoes, its safety assurance is essential. Research in microbial ecology and knowledge of complex interactions among microbes must be better understood to achieve maximal control of pathogens. Therefore, we investigated the effect of UV-C treatments on bacterial diversity of the Ataulfo mangoes surface using PCR-DGGE analysis of variable region V3 of 16S rRNA genes, and the survival of E. coli, by plate counting. The UV-C irradiation reduced the microbial load on the surface of mangoes immediately after treatment and the structure of bacterial communities was modified during storage. We identified the key members of the bacterial communities on the surface of fruits, predominating Enterobacter genus. Genera as Lactococcus and Pantoea were only detected on the surface of non-treated (control) mangoes. This could indicate that these genera were affected by the UV-C treatment. On the other hand, the treatment did not have a significant effect on survival of E. coli. However, genera that have been recognized as antagonists against foodborne pathogens were identified in the bands patterns. Also, phenolic compounds were determined by HPLC and antimicrobial activity was assayed according to the agar diffusion method. The main phenolic compounds were chlorogenic, gallic, and caffeic acids. Mango peel methanol extracts (UV-C treated and control mangoes) showed antimicrobial activity against strains previously isolated from mango, detecting significant differences (P < 0.05) among treated and control mangoes after 4 and 12 days of storage. Ps. fluorescens and Ps. stutszeri were the most sensitive. PMID:23761788

Fernández-Suárez, Rocío; Ramírez-Villatoro, Guadalupe; Díaz-Ruiz, Gloria; Eslava, Carlos; Calderón, Montserrat; Navarro-Ocaña, Arturo; Trejo-Márquez, Andrea; Wacher, Carmen

2013-01-01

112

Effect of postharvest UV-C treatment on the bacterial diversity of Ataulfo mangoes by PCR-DGGE, survival of E. coli and antimicrobial activity  

PubMed Central

Since Mexico is the second largest exporter of mangoes, its safety assurance is essential. Research in microbial ecology and knowledge of complex interactions among microbes must be better understood to achieve maximal control of pathogens. Therefore, we investigated the effect of UV-C treatments on bacterial diversity of the Ataulfo mangoes surface using PCR-DGGE analysis of variable region V3 of 16S rRNA genes, and the survival of E. coli, by plate counting. The UV-C irradiation reduced the microbial load on the surface of mangoes immediately after treatment and the structure of bacterial communities was modified during storage. We identified the key members of the bacterial communities on the surface of fruits, predominating Enterobacter genus. Genera as Lactococcus and Pantoea were only detected on the surface of non-treated (control) mangoes. This could indicate that these genera were affected by the UV-C treatment. On the other hand, the treatment did not have a significant effect on survival of E. coli. However, genera that have been recognized as antagonists against foodborne pathogens were identified in the bands patterns. Also, phenolic compounds were determined by HPLC and antimicrobial activity was assayed according to the agar diffusion method. The main phenolic compounds were chlorogenic, gallic, and caffeic acids. Mango peel methanol extracts (UV-C treated and control mangoes) showed antimicrobial activity against strains previously isolated from mango, detecting significant differences (P < 0.05) among treated and control mangoes after 4 and 12 days of storage. Ps. fluorescens and Ps. stutszeri were the most sensitive. PMID:23761788

Fernandez-Suarez, Rocio; Ramirez-Villatoro, Guadalupe; Diaz-Ruiz, Gloria; Eslava, Carlos; Calderon, Montserrat; Navarro-Ocana, Arturo; Trejo-Marquez, Andrea; Wacher, Carmen

2013-01-01

113

Antimicrobial and healing activity of kefir and kefiran extract  

Microsoft Academic Search

Kefir and its insoluble polysaccharide, kefiran, were both tested for antimicrobial and cicatrizing activities against several bacterial species and Candida albicans using an agar diffusion method. Comparator antimicrobials were also tested. Cicatrizing experiments were carried out on Wistar rats with induced skin lesions and Staphylococcus aureus inoculation, using a topical application of a 70% kefir gel. Both kefir and kefiran

Kamila Leite Rodrigues; Lucélia Rita Gaudino Caputo; Jose Carlos Tavares Carvalho; João Evangelista; Jose Maurício Schneedorf

2005-01-01

114

The antimicrobial activity, toxicity and antimicrobial mechanism of a new type of tris(alkylphenyl)sulfonium.  

PubMed

The antimicrobial activity, toxicity and antimicrobial mechanism of a new type of tris(4-alkylphenyl)sulfonium which has sterically bulky alkyl substituents (bTAPS), were estimated and compared with those of other sulfoniums which we reported previously. Concerning tris {4-(iso-propyl)phenyl}sulfonium (bTAPS-iso3) and tris{4-(tert-butyl)phenyl}sulfonium (bTAPS-tert4), the antimicrobial activity of these compounds tended to be lower than both tri(n-alkyl)sulfoniums (TASs) and tris{4-(n-alkylphenyl)}sulfoniums (TAPSs) at similar ClogP values. However, the activities of tris{4-(cyclohexyl)phenyl}sulfonium (bTAPS-cyclo6) were clearly higher than those of TAS and were almost similar to those of TAPS at similar ClogP values. The mutagenicities of tested bTAPSs were judged to be all negative. Both the acute oral toxicity strength and the acute skin irritation/corrosion toxicity strength tended to follow the order of TAPSs > bTAPSs > TASs. However, only the acute skin irritation/corrosion toxicity strength of bTAPS-cyclo6 was almost as low as that of TAS which has a similar ClogP value to bTAPS-cyclo6. Because bTAPS-cyclo6 has both high antimicrobial activity and low toxicity, this compound might become to be an alternative antimicrobial compound to relatively hazardous antimicrobials which have been widely used in many fields. PMID:22451429

Hirayama, Michiasa

2012-03-01

115

Antimicrobial and cytotoxic effects of Mexican medicinal plants.  

PubMed

The antimicrobial effects of the Mexican medicinal plants Guazuma ulmifolia, Justicia spicigera, Opuntia joconostle, O. leucotricha, Parkinsonia aculeata, Phoradendron longifolium, P. serotinum, Psittacanthus calyculatus, Tecoma stans and Teucrium cubense were tested against several human multi-drug resistant pathogens, including three Gram (+) and five Gram (-) bacterial species and three fungal species using the disk-diffusion assay. The cytotoxicity of plant extracts on human cancer cell lines and human normal non-cancerous cells was also evaluated using the MTT assay. Phoradendron longifolium, Teucrium cubense, Opuntia joconostle, Tecoma stans and Guazuma ulmifolia showed potent antimicrobial effects against at least one multidrug-resistant microorganism (inhibition zone > 15 mm). Only Justicia spicigera and Phoradendron serotinum extracts exerted active cytotoxic effects on human breast cancer cells (IC50 < or = 30 microg/mL). The results showed that Guazuma ulmifolia produced potent antimicrobial effects against Candida albicans and Acinetobacter lwoffii, whereas Justicia spicigera and Phoradendron serotinum exerted the highest toxic effects on MCF-7 and HeLa, respectively, which are human cancer cell lines. These three plant species may be important sources of antimicrobial and cytotoxic agents. PMID:22312741

Jacobo-Salcedo, Maria del Rosario; Alonso-Castro, Angel Josabad; Salazar-Olivo, Luis A; Carranza-Alvarez, Candy; González-Espíndola, Luis Angel; Domínguez, Fabiola; Maciel-Torres, Sandra Patricia; García-Lujan, Concepción; González-Martínez, Marisela del Rocio; Gómez-Sánchez, Maricela; Estrada-Castillón, Eduardo; Zapata-Bustos, Rocio; Medellin-Milán, Pedro; García-Carrancá, Alejandro

2011-12-01

116

Enhanced antimicrobial activity of engineered human lysozyme  

PubMed Central

Lysozymes contain a disproportionately large fraction of cationic residues, and are thereby attracted towards the negatively charged surface of bacterial targets. Importantly, this conserved biophysical property may inhibit lysozyme antibacterial function during acute and chronic infections. A mouse model of acute pulmonary Pseudomonas aeruginosa infection demonstrated that anionic biopolymers accumulate to high concentrations in the infected lung, and the presence of these species correlates with decreased endogenous lysozyme activity. To develop antibacterial enzymes designed specifically to be used as antimicrobial agents in the infected airway, the electrostatic potential of human lysozyme (hLYS) was remodeled by protein engineering. A novel, high throughput screen was implemented to functionally interrogate combinatorial libraries of charge engineered hLYS proteins, and variants with improved bactericidal activity were isolated and characterized in detail. These studies illustrate a general mechanism by which polyanions inhibit lysozyme function, and they are the first direct demonstration that decreasing hLYS's net cationic character improves its antibacterial activity in the presence of disease-associated biopolymers. In addition to avoiding electrostatic sequestration, at least one charge engineered variant also kills bacteria more rapidly in the absence of inhibitory biopolymers; this observation supports a novel hypothesis that tuning the cellular affinity of peptidoglycan hydrolases may be a general strategy for improving kinetics of bacterial killing. PMID:20604527

Scanlon, Thomas C.; Teneback, Charlotte C.; Gill, Avinash; Bement, Jenna L.; Weiner, Joshua A.; Lamppa, John W.; Leclair, Laurie W.; Griswold, Karl E.

2010-01-01

117

Studies on Anticancer Activities of Antimicrobial Peptides  

PubMed Central

In spite of great advances in cancer therapy, there is considerable current interest in developing anticancer agents with a new mode of action because of the development of resistance by cancer cells towards current anticancer drugs. A growing number of studies have shown that some of the cationic antimicrobial peptides (AMPs), which are toxic to bacteria but not to normal mammalian cells, exhibit a broad spectrum of cytotoxic activity against cancer cells. Such studies have considerably enhanced the significance of AMPs, both synthetic and from natural sources, which have been of importance both for an increased understanding of the immune system and for their potential as clinical antibiotics. The electrostatic attraction between the negatively charged components of bacterial and cancer cells and the positively charged AMPs is believed to play a major role in the strong binding and selective disruption of bacterial and cancer cell membranes, respectively. However, it is unclear why some host defense peptides are able to kill cancer cells when others do not. In addition, it is not clear whether the molecular mechanism(s) underlying the antibacterial and anticancer activities of AMPs are the same or different. In this article, we review various studies on different AMPs that exhibit cytotoxic activity against cancer cells. The suitability of cancer cell-targeting AMPs as cancer therapeutics is also discussed. PMID:18078805

Hoskin, David W.; Ramamoorthy, Ayyalusamy

2008-01-01

118

Antimicrobial Effect of Some Essential Oils  

Microsoft Academic Search

Commercially available oils of lavender (Lavandula angustifolia Mill.), lemon-balm (Melissa officinalis L.), juniper berry (Juniperus communis L.), lemon verbena (Lippia citriodora Kunth), rosemary (Rosmarinus officinalis L.) and cypress (Cupressus sempervirens L.) were evaluated for their antimicrobial activity. Analyses of the oils by GC-FID and GC\\/MS revealed that the major constituents of these oils were linalool (23.1%) and linalyl acetate (23.1%)

Flora V. Romeo; Serena De Luca; Amalia Piscopo; Marco Poiana

2008-01-01

119

Synthesis and antimicrobial activity of 3-alkoxyjatrorrhizine derivatives.  

PubMed

The compounds 3-ethoxy- ( 2), 3-butoxy- ( 3), 3-hexyloxy- ( 4), 3-octyloxy- ( 5), 3-decyloxy- ( 6) and 3-dodecyloxyjatrorrhizine chlorides ( 7) were synthesized and tested for their antimicrobial activity in vitro to evaluate structure-activity relationships. Substitution of the H with alkyl groups at C-3-OH led to significant changes in the antimicrobial activity. The antimicrobial activity of the substituted derivatives was 32 - 1000 times higher than that of jatorrhizine ( 1), which increased as the aliphatic chain was elongated and then decreased slightly when the alkyl chain exceeded eight carbon atoms. 3-Octyloxyjatrorrhizine ( 5) displayed the highest antimicrobial activity of all compounds. The LD (50) values of compounds 1 - 7 were more than 6000 mg/kg body weight, showing a low toxicity. The toxicities of compounds 2 - 7 were slightly lower than that of ( 1). PMID:18300191

Wang, Li-jun; Ye, Xiao-li; Li, Xue-gang; Sun, Qing-lei; Yu, Gang; Cao, Xiao-gang; Liang, Yan-ting; Zhang, Hua-san; Zhou, Jia-zhou

2008-02-01

120

INSECT-SYMBIONT INTERACTIONS Actinomycetes with Antimicrobial Activity Isolated from Paper Wasp  

E-print Network

antibiotic, natural products, actinobacteria, Polistes dominula Antimicrobial producing bacteria have beenINSECT-SYMBIONT INTERACTIONS Actinomycetes with Antimicrobial Activity Isolated from Paper Wasp ABSTRACT ActinomycetesÃ?a group of antimicrobial producing bacteriaÃ?have been successfully cultured

Starks, Philip

121

Antimicrobial activity of 10-isobutyryloxy-8,9-epoxythymol isobutyrate  

Microsoft Academic Search

10-Isobutyryloxy-8,9-epoxythymol isobutyrate was found to be a major constituent of Inula helenium and Inula royleana root cultures. The compound showed moderate antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Escherischia coli, Pseudomonas aeruginosa and Candida albicans.

Anna Stojakowska; Bogdan K?dzia; Wanda Kisiel

2005-01-01

122

Size-Dependent Antimicrobial Effects of Novel Palladium Nanoparticles  

PubMed Central

Investigating the interactions between nanoscale materials and microorganisms is crucial to provide a comprehensive, proactive understanding of nanomaterial toxicity and explore the potential for novel applications. It is well known that nanomaterial behavior is governed by the size and composition of the particles, though the effects of small differences in size toward biological cells have not been well investigated. Palladium nanoparticles (Pd NPs) have gained significant interest as catalysts for important carbon-carbon and carbon-heteroatom reactions and are increasingly used in the chemical industry, however, few other applications of Pd NPs have been investigated. In the present study, we examined the antimicrobial capacity of Pd NPs, which provides both an indication of their usefulness as target antimicrobial compounds, as well as their potency as potential environmental pollutants. We synthesized Pd NPs of three different well-constrained sizes, 2.0±0.1 nm, 2.5±0.2 nm and 3.1±0.2 nm. We examined the inhibitory effects of the Pd NPs and Pd2+ ions toward gram negative Escherichia coli (E. coli) and gram positive Staphylococcus aureus (S. aureus) bacterial cultures throughout a 24 hour period. Inhibitory growth effects of six concentrations of Pd NPs and Pd2+ ions (2.5×10?4, 10?5, 10?6, 10?7, 10?8, and 10?9 M) were examined. Our results indicate that Pd NPs are generally much more inhibitory toward S. aureus than toward E. coli, though all sizes are toxic at ?10?5 M to both organisms. We observed a significant difference in size-dependence of antimicrobial activity, which differed based on the microorganism tested. Our work shows that Pd NPs are highly antimicrobial, and that fine-scale (<1 nm) differences in size can alter antimicrobial activity. PMID:24465824

Adams, Clara P.; Walker, Katherine A.; Obare, Sherine O.; Docherty, Kathryn M.

2014-01-01

123

Composition and antimicrobial activity of Prangos platychlaena and P. uechtritzii  

Microsoft Academic Search

The chemical compositions and antimicrobial activities of the essential oils from two Turkish endemic species, Prangos platychlaena and P. uechtritzii, were investigated. Hydrodistillation was used to isolate the essential oils, and the chemical analyses were performed by\\u000a GC and GC-MS. The antimicrobial activity was tested by the microdilution technique against Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa,

A. Uzel; T. Dirmenci; A. Celik; T. Arabaci

2006-01-01

124

Antimicrobial activity of Myagropsis myagroides and interaction with food composition  

Microsoft Academic Search

Ethanol extract of Myagropsis myagroides (MMEE) has substantial antimicrobial activity against Gram-positive bacteria and some of the yeasts. The minimum inhibitory\\u000a concentration (MIC) of MMEE ranged from 0.0625 to 0.125 mg\\/mL for Bacillus subtilis, Listeria monocytogenes, and Clostridium perfringens. Chloroform fraction obtained through liquid-liquid extraction possessed the strongest antimicrobial activity, and was separated\\u000a by silica gel column chromatography. Among 22

So-Young Lee; Eu-Jin Song; Koth-Bong-Woo-Ri Kim; Seong-Il Lim; Yong-Ki Hong; Dong-Hyun Ahn

2011-01-01

125

Polymer-Ag Nanocomposites with Enhanced Antimicrobial Activity against Bacterial Infection.  

PubMed

Herein, a nontoxic nanocomposite is synthesized by reduction of silver nitrate in the presence of a cationic polymer displaying strong antimicrobial activity against bacterial infection. These nanocomposites with a large concentration of positive charge promote their adsorption to bacterial membranes through electrostatic interaction. Moreover, the synthesized nanocomposites with polyvalent and synergistic antimicrobial effects can effectively kill both Gram-positive and Gram-negative bacteria without the emergence of bacterial resistance. Morphological changes obtained by transmission electron microscope observation show that these nanocomposites can cause leakage and chaos of intracellular contents. Analysis of the antimicrobial mechanism confirms that the lethal action of nanocomposites against the bacteria started with disruption of the bacterial membrane, subsequent cellular internalization of the nanoparticles, and inhibition of intracellular enzymatic activity. This novel antimicrobial material with good cytocompatibility promotes healing of infected wounds in diabetic rats, and has a promising future in the treatment of other infectious diseases. PMID:25170799

Mei, Lin; Lu, Zhentan; Zhang, Xinge; Li, Chaoxing; Jia, Yanxia

2014-09-24

126

Synergistic effects of antimicrobial peptides and antibiotics against Clostridium difficile.  

PubMed

Accelerating rates of health care-associated infections caused by Clostridium difficile, with increasing recurrence and rising antibiotic resistance rates, have become a serious problem in recent years. This study was conducted to explore whether a combination of antibiotics with human antimicrobial peptides may lead to an increase in antibacterial activity. The in vitro activities of the antimicrobial peptides HBD1 to HBD3, HNP1, HD5, and LL-37 and the antibiotics tigecycline, moxifloxacin, piperacillin-tazobactam, and meropenem alone or in combination against 10 toxinogenic and 10 nontoxinogenic C. difficile strains were investigated. Bacterial viability was determined by flow cytometry and toxin production by enzyme-linked immunosorbent assay (ELISA). When combined at subinhibitory concentrations, antimicrobial peptides and antibiotics generally led to an additive killing effect against toxinogenic and nontoxinogenic C. difficile strains. However, LL-37 and HBD3 acted in synergism with all the antibiotics that were tested. Electron microscopy revealed membrane perturbation in bacterial cell walls by HBD3. In 3 out of 10 toxinogenic strains, HBD3, LL-37, piperacillin-tazobactam, and meropenem administration led to an increased toxin release which was not neutralized by the addition of HNP1. Antimicrobial peptides increase the bacterial killing of antibiotics against C. difficile regardless of the antibiotics' mode of action. Membrane perturbation in or pore formation on the bacterial cell wall may enhance the uptake of antibiotics and increase their antibacterial effect. Therefore, a combination of antibiotics with antimicrobial peptides may represent a promising novel approach to the treatment of C. difficile infections. PMID:25022581

Nuding, Sabine; Frasch, Tina; Schaller, Martin; Stange, Eduard F; Zabel, Lutz T

2014-10-01

127

Antimicrobial activity of the cyanobacteria Anabaena wisconsinense and Oscillatoria curviceps against pathogens of fish in aquaculture  

Microsoft Academic Search

Cultures of the blue green algae (cyanobacteria)Anabaena wisconsinense andOscillatoria curviceps were isolated from fish farms and their antimicrobial effects were studied. Solvent extracts of exponential phase algae were\\u000a screened for antimicrobial activity against different species of Gram positive (Lactobacillus sp. andBacillus firmus) and Gram negative (Aeromonas hydrophila, Pseudomonas fluorescens andPseudomonas anguilliseptica) bacteria and the fungi (Aspergillus niger andSaprolegnia parasitica) which

Mostafa M. El-Sheekh; Aida M. Dawah; Azza M. ABD El-Rahman; Hamed M. El-Adel; Reham A. ABD El-Hay

2008-01-01

128

Phytochemical profiles, antioxidant and antimicrobial activities of three Potentilla species  

PubMed Central

Background Extracts from Potentilla species have been applied in traditional medicine and exhibit antioxidant, hypoglycemic, anti-inflammatory, antitumor and anti-ulcerogenic properties, but little has been known about the diversity of phytochemistry and pharmacology on this genus. This study investigated and compared the phytochemical profiles, antioxidant and antimicrobial activities of leaf extracts from three Potentilla species (Potentilla fruticosa, Potentilla glabra and Potentilla parvifolia) in order to discover new resources for lead structures and pharmaceutical products. Methods Chemical composition and content of six phenolic compounds were evaluated and determined by RP-HPLC; Total phenolic and total flavonoid content were determined using Folin-Ciocalteau colourimetric method and sodium borohydride/chloranil-based method (SBC); Antioxidant activities were determined using DPPH, ABTS and FRAP assays; Antimicrobial properties were investigated by agar dilution and mycelial growth rate method. Results The results showed hyperoside was the predominant phenolic compound in three Potentilla species by RP-HPLC assay, with the content of 8.86 (P. fruticosa), 2.56 (P. glabra) and 2.68 mg/g (P. parvifolia), respectively. The highest content of total identified phenolic compounds (hyperoside, (+)-catechin, caffeic acid, ferulic acid, rutin and ellagic acid) was observed in P. parvifolia (14.17 mg/g), follow by P. fruticosa (10.01 mg/g) and P. glabra (7.01 mg/g). P. fruticosa possessed the highest content of total phenolic (84.93 ± 0.50 mmol gallic acid equivalent/100 g) and total flavonoid (84.14 ± 0.03 mmol quercetin equivalent/100 g), which were in good correlation with its significant DPPHIC50 (16.87 ?g/mL), ABTS (2763.48 ?mol Trolox equivalent/g) and FRAP (1398.70 ?mol Trolox equivalent/g) capacities. Furthermore, the effective methodology to distinguish the different species of Potentilla was also established by chromatographic fingerprint analysis for the first time. The results of antimicrobial activities showed P. fruticosa exhibited the strongest inhibition aganist Gram-positive bacteria, Pseudomonas aeruginosa and Candida albicans with MIC values of 0.78–6.25 mg/mL. P. parvifolia possessed antibacterial and antifungal activities against all the microorganisms tested, with EC50 and MIC values of 20.52–47.02 mg/mL and 0.78–50 mg/mL, respectively. Conclusions These results indicated that leaf extracts from three Potentilla species could become useful supplement for pharmaceutical products as a new antioxidant and antimicrobial agents. PMID:24252124

2013-01-01

129

Fungi treated with small chemicals exhibit increased antimicrobial activity against facultative bacterial and yeast pathogens.  

PubMed

For decades, fungi have been the main source for the discovery of novel antimicrobial drugs. Recent sequencing efforts revealed a still high number of so far unknown "cryptic" secondary metabolites. The production of these metabolites is presumably epigenetically silenced under standard laboratory conditions. In this study, we investigated the effect of six small mass chemicals, of which some are known to act as epigenetic modulators, on the production of antimicrobial compounds in 54 spore forming fungi. The antimicrobial effect of fungal samples was tested against clinically facultative pathogens and multiresistant clinical isolates. In total, 30 samples of treated fungi belonging to six different genera reduced significantly growth of different test organisms compared to the untreated fungal sample (growth log reduction 0.3-4.3). For instance, the pellet of Penicillium restrictum grown in the presence of butyrate revealed significant higher antimicrobial activity against Staphylococcus (S.) aureus and multiresistant S. aureus strains and displayed no cytotoxicity against human cells, thus making it an ideal candidate for antimicrobial compound discovery. Our study shows that every presumable fungus, even well described fungi, has the potential to produce novel antimicrobial compounds and that our approach is capable of rapidly filling the pipeline for yet undiscovered antimicrobial substances. PMID:25121102

Zutz, Christoph; Bandian, Dragana; Neumayer, Bernhard; Speringer, Franz; Gorfer, Markus; Wagner, Martin; Strauss, Joseph; Rychli, Kathrin

2014-01-01

130

Antioxidant and Antimicrobial activity of Pedicularis sibthorpii Boiss. And Pedicularis wilhelmsiana Fisch ex.  

PubMed Central

Purpose: This research paper presents antioxidant and antimicrobial activities of Pedicularis sibthorpii and Pedicularis wilhelmsiana which grow in Azerbaijan/Iran with claimed a lot of therapeutic effects. Methods: DPPH assay and agar well diffusion method were carried out to determine antioxidant and antimicrobial activities respectively. Results: Methanolic extract showed better antioxidant activity compared to other crude extracts (n-hexane and dichloromethane). Methanolic extracts of both Pedicularis sibthorpii and Pedicularis wilhelmsiana were found to have antibacterial activity especially against gram positive strains of S. ureus, S.epidermidis. No antifungal activity was observed in the tested extracts. Conclusion: Existence of some phenolic compounds in methanolic extracts, such as phenylethanoids and flavonoids (found in other species of Pedicularis), which cause both antioxidant and antibacterial activities, is probable. Antimicrobial and antioxidant activity of the methanolic extracts supports further studies related to phytochemical investigation and bioassay of different fractions to isolate pure compounds of plants. PMID:24312775

khodaie, Laleh; Delazar, Abbas; Lotfipour, Farzaneh; Nazemiyeh, Hossein

2012-01-01

131

Evidence for antimicrobial activity associated with common house spider silk  

PubMed Central

Background Spider silk is one of the most versatile materials in nature with great strength and flexibility. Native and synthetically produced silk has been used in a wide range of applications including the construction of artificial tendons and as substrates for human cell growth. In the literature there are anecdotal reports that suggest that native spider silk may also have antimicrobial properties. Findings In this study we compared the growth of a Gram positive and a Gram negative bacterium in the presence and absence of silk produced by the common house spider Tegenaria domestica. We demonstrate that native web silk of Tegenaria domestica can inhibit the growth of the Gram positive bacterium, Bacillus subtilis. No significant inhibition of growth was detected against the Gram negative bacterium, Escherichia coli. The antimicrobial effect against B. subtilis appears to be short lived thus the active agent potentially acts in a bacteriostatic rather than bactericidal manner. Treatment of the silk with Proteinase K appears to reduce the ability to inhibit bacterial growth. This is consistent with the active agent including a protein element that is denatured or cleaved by treatment. Tegenaria silk does not appear to inhibit the growth of mammalian cells in vitro thus there is the potential for therapeutic applications. PMID:22731829

2012-01-01

132

Bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity  

Microsoft Academic Search

BACKGROUND AND AIMSThe gastrointestinal microflora exerts a barrier effect against enteropathogens. The aim of this study was to examine if bifidobacteria, a major species of the human colonic microflora, participates in the barrier effect by developing antimicrobial activity against enterovirulent bacteria.METHODSAntibacterial activity was examined in vitro against a wide range of Gram negative and Gram positive pathogens. Inhibition ofSalmonella typhimurium

V Liévin; I Peiffer; S Hudault; F Rochat; D Brassart; J-R Neeser; A L Servin

2000-01-01

133

Antimicrobial activity of some macrophytes from Lake Manzalah (Egypt).  

PubMed

The antimicrobial activities of aqueous and organic solvents (chloroform, ethanol and methanol) extracts of four plants Ceratophyllum demersum L., Eichhornia crassipes, Potamogeton crispus and Potamogeton pectinatus were tested in vitro against seventeen different microorganisms including Gram-positive and Gram-negative bacteria and fungi. Nine of these identified organisms were obtained from different sources, Bacillus subtilis 1020, Bacillus cereus 1080, Staphylococcus aureus, Erwinia carotovora NCPPB 312, Candida albicans, Candida tropicalis, Aspergillus niger, Fusarium oxysporum and Penicillium italicum. The other eight organisms were isolated from Manzalah lake water and identified using API 20E strip system (BioMereux). One hundred pathogenic bacterial isolates representing eight genera were identified to species level. These organisms are Escherichia coli (20%), Pseudomonas aeruginosa (16%), Klebsiella pneumoniae (14%), Salmonella colerasuis (13%), Shigella sp. (11%), Serratia liquefaciens (10%), Proteus vulgaris (9%) and Brenneria nigrifluens (7%). The extracts of all tested plants demonstrated antimicrobial activity against the used organisms. The efficiency of the extracts varied with, solvent used in the extraction as well as plant species and the part of plant used. The aqueous extract appeared to be the highly effective extract against all tested organisms especially Fusarium oxysporum causing inhibition zone 48 +/- 0.01 mm, Pseudomonas aeruginosa 59 +/- 0.02 mm and Salmonella cholerasuis 55 +/- 0.01 mm when using P. crispus, P. pectinatus and C. demersum, respectively. Ethanol extracts of C. demersum, P. crispus and E. crassipes root showed antimicrobial activities against all tested organisms except Aspergillus niger. At the same time the extract of P. pectinatus had no effect also on Fusarium oxysporum and the extract of E. crassipes leaves have no effect on Penicillium italicum. On using chloroform extracts Escherichia coli, Aspergillus niger and Penicillium italicum showed resistance. Comparing the effect of different plants extracts C. demersum appeared to be the most effective followed by P. pectinatus. Furthermore, the extracts of E. crassipes leaves being more effective than that, of its roots. Elemental analysis were also takes place in water and plant samples and the results revealed the presence of Mn and Pb in higher concentration in P. pectinatus (Mn 603 +/- 4.243 ppm and Pb 44 +/- 2.828 ppm), at the same time the highest values of Fe 1680 +/- 2.2 ppm, Zn 31.5 +/- 2.1 ppm and Cu 26.5 +/- 2.1 ppm were recorded for C. demersum. Comparing the two parts of E. crassipes (leaves and roots), the roots have the highest values of all studied metals. PMID:19205264

Fareed, M F; Haroon, A M; Rabeh, S A

2008-11-01

134

Influence of montmorillonite on antimicrobial activity of tetracycline and ciprofloxacin  

NASA Astrophysics Data System (ADS)

Antibiotics are used not only to fight infections and inhibit bacterial growth, but also as growth promotants in farm livestock. Farm runoff and other farm-linked waste have led to increased antibiotic levels present in the environment, the impact of which is not completely understood. Soil, more specifically clays, that the antibiotic contacts may alter its effectiveness against bacteria. In this study a swelling clay mineral montmorillonite was preloaded with antibiotics tetracycline and ciprofloxacin at varying concentrations and bioassays were conducted to examine whether the antibiotics still inhibited bacterial growth in the presence of montmorillonite. Escherichia coli was incubated with montmorillonite or antibiotic-adsorbed montmorillonite, and then the number of viable bacteria per mL was determined. The antimicrobial activity of tetracycline was affected in the presence of montmorillonite, as the growth of non-resistant bacteria was still found even when extremely high TC doses were used. Conversely, in the presence of montmorillonite, ciprofloxacin did inhibit E. coli bacterial growth at high concentrations. These results suggest that the effectiveness of antimicrobial agents in clayey soils depends on the amount of antibiotic substance present, and on the interactions between the antibiotic and the clays in the soil, as well.

Lv, Guocheng; Pearce, Cody W.; Gleason, Andrea; Liao, Libing; MacWilliams, Maria P.; Li, Zhaohui

2013-11-01

135

Copper(II) complexes with cyanoguanidine and o-phenanthroline: Theoretical studies, in vitro antimicrobial activity and alkaline phosphatase inhibitory effect  

NASA Astrophysics Data System (ADS)

Calculations based on density functional methods are carried out for two Cu(II) complexes with cyanoguanidine (cnge) and o-phenanthroline (o-phen): [Cu(o-phen)2(cnge)](NO3)2?2H2O (1) and [Cu(o-phen)(cnge)(H2O)(NO3)2] (2). The calculated geometrical parameters are in agreement with the experimental values. The results of Atoms in Molecules (AIM) topological analysis of the electron density indicate that the Cu-N(phen) bonds in complex (1) have lower electron density, suggesting that those bonds are stronger in complex (2). Moreover, the ionic character of the Cu-N bond in the complex (1) is slightly stronger than that in the complex (2) and this situation would explain the fact that only complex (2) was stable in water solution. For this reason, the antimicrobial and enzymatic assays were performed using complex (2). It is well known that the increased use of antibiotics has resulted in the development of resistant bacterial and fungal strains. In this context, the study of novel antimicrobial agents has an enormous importance and metal complexes represent an interesting alternative for the treatment of infectious diseases. The aim of this work is to prove the modification of some biological properties like antimicrobial activity or alkaline phosphatase inhibitory activity upon copper complexation.

Martínez Medina, Juan J.; Islas, María S.; López Tévez, Libertad L.; Ferrer, Evelina G.; Okulik, Nora B.; Williams, Patricia A. M.

2014-01-01

136

Structure-activity relationship of benzophenanthridine alkaloids from Zanthoxylum rhoifolium having antimicrobial activity.  

PubMed

Zanthoxylum rhoifolium (Rutaceae) is a plant alkaloid that grows in South America and has been used in Brazilian traditional medicine for the treatment of different health problems. The present study was designed to evaluate the antimicrobial activity of the steam bark crude methanol extract, fractions, and pure alkaloids of Z. rhoifolium. Its stem bark extracts exhibited a broad spectrum of antimicrobial activity, ranging from 12.5 to 100 µg/mL using bioautography method, and from 125 to 500 µg/mL in the microdilution bioassay. From the dichloromethane basic fraction, three furoquinoline alkaloids (1-3), and nine benzophenanthridine alkaloids (4-12) were isolated and the antimicrobial activity of the benzophenanthridine alkaloids is discussed in terms of structure-activity relationships. The alkaloid with the widest spectrum of activity was chelerythrine (10), followed by avicine (12) and dihydrochelerythrine (4). The minimal inhibitory concentrations of chelerythrine, of 1.50 µg/mL for all bacteria tested, and between 3.12 and 6.25 µg/mL for the yeast tested, show this compound to be a more powerful antimicrobial agent when compared with the other active alkaloids isolated from Z. rhoifolium. To verify the potential importance of the methylenedioxy group (ring A) of these alkaloids, chelerythrine was selected to represent the remainder of the benzophenanthridine alkaloids isolated in this work and was subjected to a demethylation reaction giving derivative 14. Compared to chelerythrine, the derivative (14) was less active against the tested bacteria and fungi. Kinetic measurements of the bacteriolytic activities of chelerythrine against the bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) were determined by optical density based on real time assay, suggesting that its mechanism of action is not bacteriolytic. The present study did not detect hemolytic effects of chelerythrine on erythrocytes and found a protective effect considering the decrease in TBARS and AOPP (advanced oxidized protein products) levels when compared to the control group. PMID:24824737

Tavares, Luciana de C; Zanon, Graciane; Weber, Andréia D; Neto, Alexandre T; Mostardeiro, Clarice P; Da Cruz, Ivana B M; Oliveira, Raul M; Ilha, Vinicius; Dalcol, Ionara I; Morel, Ademir F

2014-01-01

137

Structure-Activity Relationship of Benzophenanthridine Alkaloids from Zanthoxylum rhoifolium Having Antimicrobial Activity  

PubMed Central

Zanthoxylum rhoifolium (Rutaceae) is a plant alkaloid that grows in South America and has been used in Brazilian traditional medicine for the treatment of different health problems. The present study was designed to evaluate the antimicrobial activity of the steam bark crude methanol extract, fractions, and pure alkaloids of Z. rhoifolium. Its stem bark extracts exhibited a broad spectrum of antimicrobial activity, ranging from 12.5 to 100 µg/mL using bioautography method, and from 125 to 500 µg/mL in the microdilution bioassay. From the dichloromethane basic fraction, three furoquinoline alkaloids (1–3), and nine benzophenanthridine alkaloids (4–12) were isolated and the antimicrobial activity of the benzophenanthridine alkaloids is discussed in terms of structure-activity relationships. The alkaloid with the widest spectrum of activity was chelerythrine (10), followed by avicine (12) and dihydrochelerythrine (4). The minimal inhibitory concentrations of chelerythrine, of 1.50 µg/mL for all bacteria tested, and between 3.12 and 6.25 µg/mL for the yeast tested, show this compound to be a more powerful antimicrobial agent when compared with the other active alkaloids isolated from Z. rhoifolium. To verify the potential importance of the methylenedioxy group (ring A) of these alkaloids, chelerythrine was selected to represent the remainder of the benzophenanthridine alkaloids isolated in this work and was subjected to a demethylation reaction giving derivative 14. Compared to chelerythrine, the derivative (14) was less active against the tested bacteria and fungi. Kinetic measurements of the bacteriolytic activities of chelerythrine against the bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) were determined by optical density based on real time assay, suggesting that its mechanism of action is not bacteriolytic. The present study did not detect hemolytic effects of chelerythrine on erythrocytes and found a protective effect considering the decrease in TBARS and AOPP (advanced oxidized protein products) levels when compared to the control group. PMID:24824737

Tavares, Luciana de C.; Zanon, Graciane; Weber, Andreia D.; Neto, Alexandre T.; Mostardeiro, Clarice P.; Da Cruz, Ivana B. M.; Oliveira, Raul M.; Ilha, Vinicius; Dalcol, Ionara I.; Morel, Ademir F.

2014-01-01

138

Mode of Action of Lactoperoxidase as Related to Its Antimicrobial Activity: A Review  

PubMed Central

Lactoperoxidase is a member of the family of the mammalian heme peroxidases which have a broad spectrum of activity. Their best known effect is their antimicrobial activity that arouses much interest in in vivo and in vitro applications. In this context, the proper use of lactoperoxidase needs a good understanding of its mode of action, of the factors that favor or limit its activity, and of the features and properties of the active molecules. The first part of this review describes briefly the classification of mammalian peroxidases and their role in the human immune system and in host cell damage. The second part summarizes present knowledge on the mode of action of lactoperoxidase, with special focus on the characteristics to be taken into account for in vitro or in vivo antimicrobial use. The last part looks upon the characteristics of the active molecule produced by lactoperoxidase in the presence of thiocyanate and/or iodide with implication(s) on its antimicrobial activity.

Bafort, F.; Parisi, O.; Perraudin, J.-P.; Jijakli, M. H.

2014-01-01

139

Antioxidant and antimicrobial activity of some lichen species  

Microsoft Academic Search

The aim of the research is to explore the overall in vitro antioxidant activity, total phenol content, reduction power and\\u000a antimicrobial activity of the methanol extracts of the lichens Cetraria pinastri, Cladonia digitata, Cladonia fimbriata, Fulgensia fulgens, Ochrolechia parella and Parmelia crinita. The methanol extract of the Cetraria pinastri showed a strong antioxidant activity, whereas the extracts of the species

B. Rankovi?; D. Rankovic; D. Maric

2010-01-01

140

Polyhexamethylene biguanide functionalized cationic silver nanoparticles for enhanced antimicrobial activity  

NASA Astrophysics Data System (ADS)

Polyhexamethylene biguanide (PHMB), a broad spectrum disinfectant against many pathogens, was used as a stabilizing ligand for the synthesis of fairly uniform silver nanoparticles. The particles formed were characterized using UV-visible spectroscopy, FTIR, dynamic light scattering, electrophoretic mobility, and TEM to measure their morphology and surface chemistry. PHMB-functionalized silver nanoparticles were then evaluated for their antimicrobial activity against a gram-negative bacterial strain, Escherichia coli. These silver nanoparticles were found to have about 100 times higher bacteriostatic and bactericidal activities, compared to the previous reports, due to the combined antibacterial effect of silver nanoparticles and PHMB. In addition to other applications, PHMB-functionalized silver nanoparticles would be extremely useful in textile industry due to the strong interaction of PHMB with cellulose fabrics.

Ashraf, Sumaira; Akhtar, Nasrin; Ghauri, Muhammad Afzal; Rajoka, Muhammad Ibrahim; Khalid, Zafar M.; Hussain, Irshad

2012-05-01

141

Antimicrobial activities of southern Nepalese medicinal plants.  

PubMed

In an ethnopharmacological screening of selected medicinal plants used in Nepal, methanol extracts from 20 plant species were assayed for activity against eleven strains of bacteria and four strains of fungi. Duplicate assays were conducted with and without exposure to ultraviolet (UV)-A radiation to test for light-activated or light-enhanced activity. Fifteen of the extracts showed activity against bacteria and fourteen showed activity against fungi. Five extracts were active only when exposed to UV-A light, and the antibiotic or antifungal effect of five extracts was enhanced upon exposure to light. Two of the most active extracts were from plants used to treat diarrhoea and dysentery. Bark from both Terminalia alata (Combretaceae) and Mallotus phillppensis (Euphorbiaceae) was active against Gram-positive and Gram-negative bacteria. PMID:8866730

Taylor, R S; Edel, F; Manandhar, N P; Towers, G H

1996-02-01

142

Development and evaluation of antimicrobial activated carbon fiber filters using Sophora flavescens nanoparticles.  

PubMed

Activated carbon fiber (ACF) filters have a wide range of applications, including air purification, dehumidification, and water purification, due to their large specific surface area, high adsorption capacity and rate, and specific surface reactivity. However, when airborne microorganisms such as bacteria and fungi adhere to the carbon substrate, ACF filters can become a source of microbial contamination, and their filter efficacy declines. Antimicrobial treatments are a promising means of preventing ACF bio-contamination. In this study, we demonstrate the use of Sophora flavescens in antimicrobial nanoparticles coated onto ACF filters. The particles were prepared using an aerosol process consisting of nebulization-thermal drying and particle deposition. The extract from S. flavescens is an effective, natural antimicrobial agent that exhibits antibacterial activity against various pathogens. The efficiency of Staphylococcus epidermidis inactivation increased with the concentration of S. flavescens nanoparticles in the ACF filter coating. The gas adsorption efficiency of the coated antimicrobial ACF filters was also evaluated using toluene. The toluene-removal capacity of the ACF filters remained unchanged while the antimicrobial activity was over 90% for some nanoparticle concentrations. Our results provide a scientific basis for controlling both bioaerosol and gaseous pollutants using antimicrobial ACF filters coated with S. flavescens nanoparticles. PMID:24951887

Sim, Kyoung Mi; Kim, Kyung Hwan; Hwang, Gi Byoung; Seo, SungChul; Bae, Gwi-Nam; Jung, Jae Hee

2014-09-15

143

Fractionation of Mastic Gum in Relation to Antimicrobial Activity  

PubMed Central

Mastic gum is a viscous light-green liquid obtained from the bark of Pistacia lentiscus var. chia. which belongs to the Anacardiaceae family. The gum has been fractionated to investigate the antimicrobial activity of the whole gum and its fractions against various strains of Helicobacter pylori. The polymeric gum fraction was separated from the essential oil and the resin (trunk exudates without essential oil) to assess and compare the anti-H. pylori activity of the polymer fraction against lower molecular weight fractions, the gum itself and masticated gum. The polymer fraction was also oxidized and assessed for antimicrobial activity.

Sharifi, Mohammad Sharif; Hazell, Stuart Loyd

2009-01-01

144

Effects of Antimicrobial Peptides on Methanogenic Archaea  

PubMed Central

As members of the indigenous human microbiota found on several mucosal tissues, Methanobrevibacter smithii and Methanosphaera stadtmanae are exposed to the effects of antimicrobial peptides (AMPs) secreted by these epithelia. Although antimicrobial and molecular effects of AMPs on bacteria are well described, data for archaea are not available yet. Besides, it is not clear whether AMPs affect them as the archaeal cell envelope differs profoundly in terms of chemical composition and structure from that of bacteria. The effects of different synthetic AMPs on growth of M. smithii, M. stadtmanae, and Methanosarcina mazei were tested using a microtiter plate assay adapted to their anaerobic growth requirements. All three tested methanoarchaea were highly sensitive against derivatives of human cathelicidin, of porcine lysin, and a synthetic antilipopolysaccharide peptide (Lpep); however, sensitivities differed markedly among the methanoarchaeal strains. The potent AMP concentrations affecting growth were below 10 ?M, whereas growth of Escherichia coli WBB01 was not affected at peptide concentrations up to 10 ?M under the same anaerobic growth conditions. Atomic force microscopy and transmission electron microscopy revealed that the structural integrity of the methanoarchaeal cells is destroyed within 4 h after incubation with AMPs. The disruption of the cell envelope of M. smithii, M. stadtmanae, and M. mazei within a few minutes of exposure was verified by using LIVE/DEAD staining. Our results strongly suggest that the release of AMPs by eukaryotic epithelial cells is a potent defense mechanism targeting not only bacteria, but also methanoarchaea. PMID:22585226

Bang, C.; Schilhabel, A.; Weidenbach, K.; Kopp, A.; Goldmann, T.; Gutsmann, T.

2012-01-01

145

Screening of some indigenous Qatari medicinal plants for antimicrobial activity.  

PubMed

Aqueous, ethanol and butanol crude extracts of the aerial parts of ten plants exhibited variable degrees of antimicrobial activity against four bacterial and two fungal species. Aqueous extracts had low antimicrobial activity against E.coli, P.aeruginosa, B. cerreus, S.aureus, C.albicans and A.flavus. Avicennia marina (AM) aqueous extract exhibited a moderate antifungal activity. Ethanol and butanol crude extracts exhibited an improved antimicrobial activity. However, butanol exhibited a superior antimicrobial activity compared with aqueous and ethanol crudes. Compared with the standard antibiotics tested the butanol extract had the highest activity. Butanol extracts at 2000 microg/disc of AM, Lotus halophilus (LA), Pulicaria gnaphaloides (PG) and Capparis spinosa (CS) had a very good antibacterial activity against both gram-positive and -negative bacteria as well as moderate to good antifungal activity against C. albicans and A. flavus. Medicago laciniata (ML), Limonium axillare (LA) and (PG) butanol crude extract compared with standard chloramphenicol, tetracycline and nalidixic acid exhibited a superior antifungal activity. PMID:12458480

Mahasneh, Adel M

2002-12-01

146

Antimicrobial, antibiofilm and cytotoxic activities of Hakea sericea Schrader extracts  

PubMed Central

Background: Hakea sericea Schrader is an invasive shrub in Portuguese forests. Objective: The goal of this work was to evaluate the antimicrobial activity of H. sericea extracts against several strains of microorganisms, including the ability to inhibit the formation of biofilms. Additionally the cytotoxic properties of these extracts, against human cells, were assessed. Materials and Methods: The antimicrobial activity of the methanolic extracts of H. sericea was assessed by disk diffusion assay and Minimum Inhibitory Concentration (MIC) value determination. The antibiofilm activity was determined by quantification of total biofilm biomass with crystal violet. Cytotoxicity was evaluated by hemolysis assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. Results: For Gram-positive bacteria, MIC values of H. sericea methanolic extracts ranged between 0.040 and 0.625 mg/mL, whereas the fruits extract yielded the lowest MIC for several strains of microorganisms, namely, S. aureus, B. cereus, L. monocytogenes and clinical methicillin-resistant S. aureus (MRSA). Stems and fruits extract at 2.5 mg/mL effectively eradicated the biofilm of S. aureus ATCC 25923, SA 01/10 and MRSA 12/10. Regarding leaves extract, hemolysis was not observed, and in the case of stems and fruits, hemolysis was verified only for higher concentrations, suggesting its low toxicity. Fruits extract presented no toxic effect to normal human dermal fibroblasts (NHDF) cells however for concentrations of 0.017 and 0.008 mg/mL this extract was able to decrease human breast adenocarcinoma cells (MCF-7) viability in about 60%, as MTT test results had confirmed. This is a clearly demonstrator of the cytotoxicity of this extract against MCF-7 cells. PMID:24914310

Luis, Angelo; Breitenfeld, Luiza; Ferreira, Susana; Duarte, Ana Paula; Domingues, Fernanda

2014-01-01

147

A screening for antimicrobial activities of Caribbean herbal remedies  

PubMed Central

Background The TRAMIL program aims to understand, validate and expand health practices based on the use of medicinal plants in the Caribbean, which is a “biodiversity hotspot” due to high species endemism, intense development pressure and habitat loss. The antibacterial activity was examined for thirteen plant species from several genera that were identified as a result of TRAMIL ethnopharmacological surveys or were reported in ethnobotanical accounts from Puerto Rico. The aim of this study was to validate the traditional use of these plant species for the treatment of bacterial infections, such as conjunctivitis, fever, otitis media and furuncles. Methods An agar disc diffusion assay was used to examine five bacterial strains that are associated with the reported infections, including Staphylococcus saprophyticus (ATCC 15305), S. aureus (ATCC 6341), Escherichia coli (ATCC 4157), Haemophilus influenzae (ATCC 8142), Pseudomonas aeruginosa (ATCC 7700) and Proteus vulgaris (ATCC 6896), as well as the fungus Candida albicans (ATCC 752). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined for each of the extracts that showed inhibitory activity. Results The decoctions of Pityrogramma calomelanos, Tapeinochilus ananassae, and Syzygium jambos, as well as the juice of Gossypium barbadense, showed?>?20% growth inhibition against several bacteria relative to the positive control, which was the antibiotic Streptomycin. Extracts with the best antimicrobial activities were S. jambos that showed MIC?=?31 ?g/mL and MBC?=?1.0 mg/mL against P. vulgaris and T. ananassae that showed MIC?=?15 ?g/mL against S. aureus. Conclusion This report confirms the traditional use of P. calomelanos for the treatment of kidney infections that are associated with stones, as well as the antimicrobial and bactericidal effects of T. ananassae against P. vulgaris and S. saprophyticus and the effects of S. jambos against S. aureus and S. saprophyticus. PMID:23731467

2013-01-01

148

Synthetic histatin analogues with broad-spectrum antimicrobial activity.  

PubMed Central

Histatins are salivary histidine-rich cationic peptides, ranging from 7 to 38 amino acid residues in length, that exert a potent killing effect in vitro on Candida albicans. Starting from the C-terminal fungicidal domain of histatin 5 (residues 11-24, called dh-5) a number of substitution analogues were chemically synthesized to study the effect of amphipathicity of the peptide in helix conformation on candidacidal activity. Single substitutions in dh-5 at several positions did not have any effect on fungicidal activity. However, multi-site substituted analogues (dhvar1 and dhvar2) exhibited a 6-fold increased activity over dh-5. In addition, dhvar1 and dhvar2 inhibited the growth of the second most common yeast found in clinical isolates, Torulopsis glabrata, of oral- and non-oral pathogens such as Prevotella intermedia and Streptococcus mutans, and of a methicillin-resistant Staphylococcus aureus. In their broad-spectrum activity, dhvar1 and dhvar2 were comparable to magainins (PGLa and magainin 2), antimicrobial peptides of amphibian origin. Both the fungicidal and the haemolytic activities of dhvar1, dhvar2 and magainins increased at decreasing ionic strength. PMID:9337848

Helmerhorst, E J; Van't Hof, W; Veerman, E C; Simoons-Smit, I; Nieuw Amerongen, A V

1997-01-01

149

Synthesis and antimicrobial activity of silver-doped hydroxyapatite nanoparticles.  

PubMed

The synthesis of nanosized particles of Ag-doped hydroxyapatite with antibacterial properties is of great interest for the development of new biomedical applications. The aim of this study was the evaluation of Ca(10-x)Ag(x)(PO4)6(OH)2 nanoparticles (Ag:HAp-NPs) for their antibacterial and antifungal activity. Resistance to antimicrobial agents by pathogenic bacteria has emerged in the recent years and became a major health problem. Here, we report a method for synthesizing Ag doped nanocrystalline hydroxyapatite. A silver-doped nanocrystalline hydroxyapatite was synthesized at 100°C in deionised water. Also, in this paper Ag:HAp-NPs are evaluated for their antimicrobial activity against gram-positive and gram-negative bacteria and fungal strains. The specific antimicrobial activity revealed by the qualitative assay is demonstrating that our compounds are interacting differently with the microbial targets, probably due to the differences in the microbial wall structures. PMID:23509801

Ciobanu, Carmen Steluta; Iconaru, Simona Liliana; Chifiriuc, Mariana Carmen; Costescu, Adrian; Le Coustumer, Philippe; Predoi, Daniela

2013-01-01

150

Chemical composition and antimicrobial activity of Polish herbhoneys.  

PubMed

The present study focuses on samples of Polish herbhoneys (HHs), their chemical composition and antimicrobial activity. A gas chromatography-mass spectrometry (GC-MS) method was used to analyse eight samples of herbal honeys and three samples of nectar honeys. Their antimicrobial activities were tested on selected Gram-positive (Bacillus cereus, Staphylococcus aureus, Staphylococcus schleiferi) and Gram-negative (Escherichia coli) bacteria, as well as on pathogenic fungi Candida albicans. Ether extracts of HHs showed significant differences in composition but the principal groups found in the extracts were phenolics and aliphatic hydroxy acids typical of royal jelly and unsaturated dicarboxylic acids. In spite of the differences in chemical composition, antimicrobial activity of the extracts of HHs against all the tested microorganisms except E. coli was observed. PMID:25308646

Isidorov, V A; Bagan, R; Bakier, S; Swiecicka, I

2015-03-15

151

Screening of some Cuban medicinal plants for antimicrobial activity  

Microsoft Academic Search

The antimicrobial activities of 23 extracts of 12 Cuban plant species reported in traditional medicine were tested. The agar diffusion method was used to assess the activity against four bacteria and one yeast: Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The results, evaluated as the diameter of the inhibition zone of microbial growth, showed that nine

M. J. Martínez; J. Betancourt; N. Alonso-González; A. Jauregui

1996-01-01

152

Antimicrobial activity of some Clerodendrum species from Egypt.  

PubMed

Chloroformic and methanolic extracts of four Clerodendrum species cultivated in Egypt were screened for antimicrobial activities. Chloroformic extracts of the flowers of Clerodendrum chinense and Clerodendrum splendens were active against Plasmodium falciparum (IC50?active against Trypanosoma cruzi (IC50?=?1.21 and 1.12?µg?mL(-1), respectively) with marginal cytotoxicity. Chloroformic extracts of the leaves of C. chinense and C. splendens showed promising activities against T. cruzi (IC50?=?3.39 and 1.98?µg?mL(-1), respectively) without cytotoxic effect on a human cell line. None of the selected plants showed significant activity against Gram-negative or Gram-positive bacteria or Candida albicans. Verbascoside, a phenyl propanoid glycoside isolated from the leaves of C. chinense, showed marginal activity against T. cruzi. Rengyolone, a cyclohexyl ethanoid isolated from the leaves of C. chinense, showed a broad but not specific activity against the tested organisms. PMID:22594542

Abouzid, Sameh F; Wahba, Haytham M; Elshamy, Ali; Cos, Paul; Maes, Louis; Apers, Sandra; Pieters, Luc; Shahat, Abdelaaty A

2013-01-01

153

Antimicrobial Browning-Inhibitory Effect of Flavor Compounds in Seaweeds  

Microsoft Academic Search

Since ancient times, the antimicrobial properties of seaweeds have been recognized. However, antimicrobial activities of volatile compounds in seaweeds have not been explored so far. Here, essential oils from seaweeds including green, brown and red algae such as Laminaria japonica, Kjellmaniella crassifolia, Gracilaria verrucosa and Ulva pertusa were prepared by using SDE (simultaneous distillation and extraction) apparatus. Volatile compounds in

Tadahiko Kajiwara; Kenji Matsui; Yoshihiko Akakabe; Takushi Murakawa; Chikako Arai

2006-01-01

154

ANTIMICROBIAL EFFECTS ON STARCH-BASED FILMS INCORPORATED WITH LYSOZYMES  

Microsoft Academic Search

An antimicrobial (AM) Active Packaging can be made by incorporating and immobilizing suitable AM agents into food packages and applying a bio switch concept. A starch-based film was prepared and incorporated with antimicrobial agents, i.e. lysozyme and EDTA as chelating agent. This film was then inoculated with the bacteria Escherichia coli and Bacillus subtilis to carry out the microbial contamination

Nozieana Khairuddin; Ida Idayu Muhamad

155

Effect of floral sources on the antioxidant, antimicrobial, and anti-inflammatory activities of honeys in Taiwan.  

PubMed

We evaluated the antioxidant, antibacterial, and anti-inflammatory activities of honey made from different floral sources, including the medicinal herb Bidens pilosa, fruit trees, Dimocarpus longan, Litchi chinensis, and Citrus maxima, the Taiwanese endemic plant Aglaia formosana, and a multifloral forest. The total phenolic and flavonoid contents of the honey made from B. pilosa were significantly higher than those of the other honeys. The honey from B. pilosa also had significantly greater scavenging activities for 1,1-diphenyl-2-picrylhydrazyl (DPPH·) and hydroxyl radical, and substantially more reducing power. In addition, the honey from B. pilosa showed greater antibacterial activity against gram-positive and gram-negative bacteria. However, B. pilosa honey showed little inhibitory activity against IL-8 secretion, whereas the other honeys did. These findings suggest that the levels of antioxidant and antibacterial activities are attributable to the total phenolic and flavonoid contents of honeys, while the IL-8 inhibition is attributable to components other than phenols. PMID:23561193

Liu, Je-Ruei; Ye, Yi-Ling; Lin, Ting-Yu; Wang, Yun-Wen; Peng, Chi-Chung

2013-08-15

156

Synthesis and anti-microbial activity of hydroxylammonium ionic liquids.  

PubMed

Eight hydroxylammonium-based room temperature ionic liquids (ILs) have been synthesized by acid-base neutralization of ethanolamines with organic acids. The ILs were characterized by infrared and nuclear magnetic resonance spectroscopies and elemental analysis. Their anti-microbial activities were determined using the well-diffusion method. All eight ILs were toxic to Staphylococcus aureus, while 2-hydroxyethylammonium lactate and 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium acetate showed high anti-microbial activity against a wide range of human pathogens. PMID:21421256

Ismail Hossain, M; El-Harbawi, Mohanad; Noaman, Yousr Abdulhadi; Bustam, Mohd Azmi B; Alitheen, Noorjahan Banu Mohamed; Affandi, Nor Azrin; Hefter, Glenn; Yin, Chun-Yang

2011-06-01

157

Chemical composition, antimicrobial and antioxidant activities of essential oils from organically cultivated fennel cultivars.  

PubMed

Essential oils of the fruits of three organically grown cultivars of Egyptian fennel (Foeniculum vulgare var. azoricum, Foeniculum vulgare var. dulce and Foeniculum vulgare var. vulgare) were examined for their chemical constituents, antimicrobial and antioxidant activities. Gas chromatography/mass spectrometry analysis of the essential oils revealed the presence of 18 major monoterpenoids in all three cultivars but their percentage in each oil were greatly different. trans-Anethole, estragole, fenchone and limonene were highly abundant in all of the examined oils. Antioxidant activities of the essential oils were evaluated using the DPPH radical scavenging, lipid peroxidation and metal chelating assays. Essential oils from the azoricum and dulce cultivars were more effective antioxidants than that from the vulgare cultivar. Antimicrobial activities of each oil were measured against two species of fungi, two species of Gram negative and two species of Gram positive bacteria. All three cultivars showed similar antimicrobial activity. PMID:21285921

Shahat, Abdelaaty A; Ibrahim, Abeer Y; Hendawy, Saber F; Omer, Elsayed A; Hammouda, Faiza M; Abdel-Rahman, Fawzia H; Saleh, Mahmoud A

2011-01-01

158

Comparison of antimicrobial activities of naphthoquinones from Impatiens balsamina.  

PubMed

Lawsone (1), lawsone methyl ether (2), and methylene-3,3'-bilawsone (3) are the main naphthoquinones in the leaf extracts of Impatiens balsamina L. (Balsaminaceae). Antimicrobial activities of these three naphthoquinones against dermatophyte fungi, yeast, aerobic bacteria and facultative anaerobic and anaerobic bacteria were evaluated by determination of minimal inhibitory concentrations (MICs) and minimal bactericidal or fungicidal concentrations (MBCs or MFCs) using a modified agar dilution method. Compound 2 showed the highest antimicrobial activity. It showed antifungal activity against dermatophyte fungi and Candida albicans with the MICs and MFCs in the ranges of 3.9-23.4 and 7.8-23.4?µg?mL(-1), respectively, and also had some antibacterial activity against aerobic, facultative anaerobic and anaerobic bacteria with MICs in the range of 23.4-93.8, 31.2-62.5 and 125?µg?mL(-1), respectively. Compound 1 showed only moderate antimicrobial activity against dermatophytes (MICs and MFCs in the ranges of 62.5-250 and 125-250?µg?mL(-1), respectively), but had low potency against aerobic bacteria, and was not active against C. albicans and facultative anaerobic bacteria. In contrast, 3 showed significant antimicrobial activity only against Staphylococus epidermidis and Bacillus subtilis (MIC and MBC of 46.9 and 93.8?µg?mL(-1), respectively). PMID:21895457

Sakunphueak, Athip; Panichayupakaranant, Pharkphoom

2012-01-01

159

Antimicrobial activity of 20 plants used in folkloric medicine in the Palestinian area  

Microsoft Academic Search

Ethanolic and aqueous extracts of 20 Palestinian plant species used in folk medicine were investigated for their antimicrobial activities against five bacterial species (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa) and one yeast (Candida albicans). The plants showed 90% of antimicrobial activity, with significant difference in activity between the different plants. The most antimicrobially active plants were

M. S Ali-Shtayeh; Reem M.-R Yaghmour; Y. R Faidi; Khalid Salem; M. A Al-Nuri

1998-01-01

160

Antimicrobial activity of the Anseriform outer eggshell and cuticle.  

PubMed

The avian eggshell is a complex, multifunctional biomineral composed of a calcium carbonate mineral phase and an organic phase of lipids and proteins. The outermost layer of the eggshell, the eggshell cuticle, is an organic layer of variable thickness composed of polysaccharides, hydroxyapatite crystals, lipids and glycoprotein. In addition to regulating gas exchanges, the eggshell cuticle may contain antimicrobial elements. In this study, we investigated the antimicrobial activity of eggshell cuticle and outer eggshell protein extracts from four Anseriform species: wood duck (Aix sponsa), hooded merganser (Lophodytes cucullatus), Canada goose (Branta canadensis) and mute swan (Cygnus olor). Cuticle and outer eggshell protein was extracted by urea or HCl treatment of eggs. C-type lysozyme, ovotransferrin and an ovocalyxin-32-like protein were detected in all extracts. Cuticle and outer eggshell protein extracts inhibited the growth of Staphylococcus aureus, Escherichia coli D31, Pseudomonas aeruginosa and Bacillus subtilis. The presence of active antimicrobial proteins within the avian cuticle and outer eggshell suggests a role in antimicrobial defense. Protein extracts from the cavity nesting hooded merganser were especially potent. The unique environmental pressures exerted on cavity-nesting species may have led to the evolution of potent antimicrobial defenses. PMID:18289902

Wellman-Labadie, Olivier; Picman, Jaroslav; Hincke, Maxwell T

2008-04-01

161

Antimicrobial activity of sub- and supercritical CO2 extracts of the green alga Dunaliella salina.  

PubMed

The objective of this research was to evaluate the antimicrobial activity of carbon dioxide extracts of the unicellular biflagellated green alga Dunaliella salina against Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus niger. The effects of different extraction pressures ranging from 185 to 442 bar and extraction temperatures ranging from 9.8 to 45.2 degrees C on the extracts' composition and consequently on their antimicrobial activities were investigated. The extracts were analyzed by gas chromatography-mass spectrometry in order to identify the compounds responsible for the antimicrobial activity detected. Fourteen different volatile compounds and several fatty acids were identified. The highest antimicrobial activity was obtained using 314 bar and 9.8 degrees C. Under these conditions, the presence of an indolic derivative that had never been reported in D. salina was detected in the extract, together with polyunsaturated fatty acids and compounds related to carotene metabolism, such as beta-ionone and neophytadiene, with known antimicrobial activity. PMID:18939768

Mendiola, Jose A; Santoyo, Susana; Cifuentes, Alejandro; Reglero, Guillermo; Ibáñez, Elena; Señoráns, F Javier

2008-10-01

162

Antimicrobial and antibiofilm activity of designed and synthesized antimicrobial peptide, KABT-AMP.  

PubMed

Lysine-rich peptide, designated as KABT-AMP, was designed and synthesized to supersede the irrational use of chemical antibiotics as standard therapy. KABT-AMP is a 22-amino acid helical cationic peptide (+10) and amphipathic in nature. The antimicrobial kinetics of the peptide was ascertained in the representative strains of gram-positive, gram-negative, and fungal strains, viz., Staphylococcus aureus MTCC 2940, Escherichia coli MTCC 2939, and Candida albicans MTCC 227, respectively. KABT-AMP was synthesized by solid-phase synthesis and purified using reverse-phase high-performance liquid chromatography which resulted in >95 % purity, and matrix-assisted laser desorption/ionization time of flight revealed the mass of the peptide to be 2.8 kDa. KABT-AMP showed significant broad-spectrum antimicrobial activity against the bacterial and fungal strains analyzed in the present study with survivability of 30.8, 30.6, and 31.7 % in E. coli, S. aureus, and C. albicans, respectively, at 6 h. KABT-AMP also demonstrated antibiofilm activity against the tested biofilm forming clinical isolate, Candida tropicalis. The putative membranolytic activity of the peptide was substantiated by electron microscopic analysis. Results reveal that KABT-AMP will exhibit noteworthy antimicrobial activity against multidrug-resistant bacteria and fungus at micromolar concentrations with minimal cytotoxicity and thus could be conceived for biomedical application. PMID:23649308

Thankappan, Bency; Jeyarajan, Sivakumar; Hiroaki, Sakaue; Anbarasu, Kumarasamy; Natarajaseenivasan, Kalimuthusamy; Fujii, Noriko

2013-07-01

163

Antioxidant and antimicrobial activities of Solidago virgaurea extracts  

Microsoft Academic Search

Solidago virgaurea is an herbaceous perennial plant of the family Asteraceae. It has been traditionally used to terat urinary tract, nephrolithiasis and prostate. Our objective was to determine the antioxidant activities, reducing powers, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scaenging activities and antimicrobial activities of metanol and hot water extracts of S. virgaurea from Bursa region in Turkey. The highest antioxidant activity was found

Hülya Demir; Leyla Açik; E. Burcu Bali; L. Yasemin Koç; Gönül Kaynak

164

Antimicrobial activity of plant compounds against Salmonella Typhimurium DT104 in ground pork and the influence of heat and storage on the antimicrobial activity.  

PubMed

Salmonella enterica is a predominant foodborne pathogen that causes diarrheal illness worldwide. A potential method of inhibiting pathogenic bacterial growth in meat is through the introduction of plant-derived antimicrobials. The objectives of this study were to investigate the influence of heat (70°C for 5 min) and subsequent cold storage (4°C up to 7 days) on the effectiveness of oregano and cinnamon essential oils and powdered olive and apple extracts against Salmonella enterica serovar Typhimurium DT104 in ground pork and to evaluate the activity of the most effective antimicrobials (cinnamon oil and olive extract) at higher concentrations in heated ground pork. The surviving Salmonella populations in two groups (heated and unheated) of antimicrobial-treated pork were compared. Higher concentrations of the most effective compounds were then tested (cinnamon oil at 0.5 to 1.0% and olive extract at 3, 4, and 5%) against Salmonella Typhimurium in heated ground pork. Samples were stored at 4°C and taken on days 0, 3, 5, and 7 for enumeration of survivors. The heating process did not affect the activity of antimicrobials. Significant 1.3- and 3-log reductions were observed with 1.0% cinnamon oil and 5% olive extract, respectively, on day 7. The minimum concentration required to achieve . 1-log reduction in Salmonella population was 0.8% cinnamon oil or 4% olive extract. The results demonstrate the effectiveness of these antimicrobials against multidrug-resistant Salmonella Typhimurium in ground pork and their stability during heating and cold storage. The most active formulations have the potential to enhance the microbial safety of ground pork. PMID:23834804

Chen, Cynthia H; Ravishankar, Sadhana; Marchello, John; Friedman, Mendel

2013-07-01

165

Antimicrobial effect of nylon fiber immersed with nano-silver  

NASA Astrophysics Data System (ADS)

The development of new products based on the immobilization of nanoparticles on fibers has recently received a growing interest from both the academic and industrial sectors. A wide range of nanoparticles and nano-structures can be immobilized on fibers, which brings new properties to the final product. In the present work, silver nanoparticle was immobilized on nylon fibers by immersed deposition method as an antimicrobial agent. Silver colloid was produced by chemical reduction of silver salt (silver nitrate) solution, in the presence of sodium citrate. Synthesis of silver colloid was carried out by using chemical reduction method at temperature of 95 and 100°C. The mixture was heated until color changed into pale yellow. UV-Vis spectrometry indicated formation of silver nanoparticles. UV-Vis analysis was reported that the absorption spectrum of silver nanoparticles showed a maximum between 420 and 450 nm. Characterization of silver nanoparticles was conducted using Fourier Transformed Infra Red (FTIR) spectroscopy, UV-Vis spectroscopy, particle size analyzer (PSA), and scanning electron microscope (SEM). It was found that silver nanoparticles forms aggregates on the surface of fiber, during deposition process. The size of aggregates varied from 19.9 +/- 4.8 nm to 49.5 +/- 12.5 nm. To evaluate the antimicrobial effects against microorganisms, we used representative microorganisms S. aureus. Silver nanoparticles showed antimicrobial activity reducing bacterial growth.

Haryono, Agus; Harmami, Sri Budi; Sondari, Dewi

2010-05-01

166

Phytochemical screening and in vitro antimicrobial activity of Thymus lanceolatus Desf. from Algeria  

PubMed Central

Objective To investigate the antimicrobial activity of an endemic Thyme, Thymus lanceolatus (T. lanceolatus), against a large number of pathogens. Methods Four solvent extracts were evaluated for antimicrobial activity using disc diffusion method and MIC determination on twenty-one strains. Results T. lanceolatus extracts showed a broad-spectrum antimicrobial activity, especially ethanol extract with inhibition zone diameters ranging from 14 to 32 mm, and MIC values from 0.052 to 0.500 mg/mL. Chloroform extract was more active against Gram-positive bacteria, since it has an inhibitory potency on Staphylococcus aureus and Enterococcus faecalis at only 31 µg/mL. While, hexane and water extracts were less effective since they were inactive against several strains. Conclusions The findings of this study indicate that T. lanceolatus has a strong antimicrobial potential, which justifies its use in folk medicine for treatment of infectious diseases. Since this species is poorly investigated, further refined studies on it pure secondary metabolites are needed and very important, in the perspective to identify new antimicrobial molecules from this endemic plant.

Benbelaïd, Fethi; Khadir, Abdelmounaïm; Abdoune, Mohamed Amine; Bendahou, Mourad

2013-01-01

167

The effect of pH and chloride concentration on the stability and antimicrobial activity of chlorine-based sanitizers.  

PubMed

Chlorinated water and electrolyzed oxidizing (EO) water solutions were made to compare the free chlorine stability and microbicidal efficacy of chlorine-containing solutions with different properties. Reduction of Escherichia coli O157:H7 was greatest in fresh samples (approximately 9.0 log CFU/mL reduction). Chlorine loss in "aged" samples (samples left in open bottles) was greatest (approximately 40 mg/L free chlorine loss in 24 h) in low pH (approximately 2.5) and high chloride (Cl(-) ) concentrations (greater than 150 mg/L). Reduction of E. coli O157:H7 was also negatively impacted (<1.0 log CFU/mL reduction) in aged samples with a low pH and high Cl(-) . Higher pH values (approximately 6.0) did not appear to have a significant effect on free chlorine loss or numbers of surviving microbial cells when fresh and aged samples were compared. This study found chloride levels in the chlorinated and EO water solutions had a reduced effect on both free chlorine stability and its microbicidal efficacy in the low pH solutions. Greater concentrations of chloride in pH 2.5 samples resulted in decreased free chlorine stability and lower microbicidal efficacy. PMID:24621341

Waters, Brian W; Hung, Yen-Con

2014-04-01

168

Effects of antimicrobial peptide L-K6, a temporin-1CEb analog on oral pathogen growth, Streptococcus mutans biofilm formation, and anti-inflammatory activity.  

PubMed

Dental caries and periodontitis are common bacterial mouth infections. As a potentially attractive substitute for conventional antibiotics, antimicrobial peptides have been widely tested and used for controlling bacterial infections. In this study, we tested the efficacy of the peptides from the skin secretions of Rana chensinensis for killing several major cariogenic and periodontic pathogens as well as Candida albicans. L-K6, a temporin-1CEb analog, exhibited high antimicrobial activity against the tested oral pathogens and was able to inhibit Streptococcus mutans biofilm formation and reduce 1-day-old S. mutans biofilms with a minimum biofilm inhibitory concentration and reducing concentration of 3.13 and 6.25 ?M, respectively. The results of confocal laser scanning microscopy demonstrated that the peptide significantly reduced cell viability within oral biofilms. Furthermore, as little as 5 ?M L-K6 significantly inhibited lipopolysaccharide (LPS)- and interleukin-1?-induced productions of interleukin-8 and tumor necrosis factor-? from THP-1 monocytic cells. This anti-inflammatory activity is associated with the binding of L-K6 to LPS and neutralizing LPS-induced proinflammatory responses in THP-1 cells, as well as dissociating LPS aggregates. Our results suggest that L-K6 may have potential clinical applications in treating dental caries by killing S. mutans within dental plaque and acting as anti-inflammatory agents in infected tissues. PMID:25056289

Shang, Dejing; Liang, Hao; Wei, Shi; Yan, Xin; Yang, Qingzu; Sun, Yue

2014-10-01

169

Inducible ASABF-Type Antimicrobial Peptide from the Sponge Suberites domuncula: Microbicidal and Hemolytic Activity in Vitro and Toxic Effect on Molluscs in Vivo†  

PubMed Central

Since sponges, as typical filter-feeders, are exposed to a high load of attacking prokaryotic and eukaryotic organisms, they are armed with a wide arsenal of antimicrobial/cytostatic low-molecular-weight, non-proteinaceous bioactive compounds. Here we present the first sponge agent belonging to the group of ASABF-type antimicrobial peptides. The ASABF gene was identified and cloned from the demosponge Suberites domuncula. The mature peptide, with a length of 64 aa residues has a predicted pI of 9.24, and comprises the characteristic CS? ? structural motif. Consequently, the S. domuncula ASABF shares high similarity with the nematode ASABFs; it is distantly related to the defensins. The recombinant peptide was found to display besides microbicidal activity, anti-fungal activity. In addition, the peptide lyses human erythrocytes. The expression of ASABF is upregulated after exposure to the apoptosis-inducing agent 2,2?-dipyridyl. During the process of apoptosis of surface tissue of S. domuncula, grazing gastropods (Bittium sp.) are attracted by quinolinic acid which is synthesized through the kynurenine pathway by the enzyme 3-hydroxyanthranilate 3,4-dioxygenase (HAD). Finally, the gastropods are repelled from the sponge tissue by the ASABF. It is shown that the effector peptide ASABF is sequentially expressed after the induction of the HAD gene and a caspase, as a central enzyme executing apoptosis. PMID:22073005

Wiens, Matthias; Schroder, Heinz C.; Korzhev, Michael; Wang, Xiao-Hong; Batel, Renato; Muller, Werner E. G.

2011-01-01

170

Antimicrobial Activity of Synthetic Magainin Peptides and Several Analogues  

Microsoft Academic Search

We have previously reported the isolation of two broad-spectrum antimicrobial peptides (``magainins'') from the skin of the African clawed frog Xenopus laevis. These natural peptides are active against many species of bacteria and fungi and also induce osmotic lysis of protozoa. In this report we demonstrate that synthetic magainin peptides appear to be indistinguishable from the natural products with respect

Michael Zasloff; Brian Martin; Hao-Chia Chen

1988-01-01

171

Antimicrobial activity of six constituents of essential oil from Salvia.  

PubMed

The antimicrobial activity of three Salvia species, i.e. S. santolinifolia, S. hydrangea and S. mirzayanii, essential oils were investigated. The essential oils were obtained from the aerial parts of plants and analyzed by GC-MS. The main constituents of aforementioned species were alpha-pinene (72.4%), beta-pinene (6.6%) and limonene (5.3%); beta-caryophyllene (25.1%), 1,8-cineol (15.2%) and caryophyllene oxide (11.5%); alpha-terpinenyl acetate (22.6%), 1,8-cineol (21.2%) and linalool (8.9%), respectively. Bioassays exhibited that the property of the oil of S. myrzayanii was superior to others. The antimicrobial activity of essential oil from Salvia species may well be due to the presence of synergy between six tested compounds (linalool, 1,8-cineol, alpha-pinene, beta-pinene, beta-caryophyllene and limonene) and other constituents of the oils with various degrees of antimicrobial activity. Among these, linalool and 1,8-cineol had the highest antimicrobial activity. PMID:16729570

Sonboli, Ali; Babakhani, Babak; Mehrabian, Ahmad Reza

2006-01-01

172

A multicenter evaluation of linezolid antimicrobial activity in North America  

Microsoft Academic Search

Overall, 141 centers in North America enrolled in this international surveillance study designed to evaluate the in vitro antimicrobial activity and spectrum of linezolid, a new oxazolidinone. Each participant tested the susceptibility of clinical isolates of staphylococcal species (n = 85) against 12 drugs, and enterococcal species (n = 40) against 6 drugs using reference broth microdilution trays; and of

Charles H. Ballow; Ronald N. Jones; Douglas J. Biedenbach

2002-01-01

173

Methodologies for the analysis of antimicrobial effects of immobilized photocatalytic materials.  

PubMed

Photocatalytic coatings are considered sustainable materials as they only need sunlight for their activation and regeneration. Some photocatalytic disinfecting coatings are already commercialized, but many more are still in the developmental stage. Efficient and reliable analytical methodologies for testing the antimicrobial effects of photocatalytic coatings should therefore be used and further developed (1) to avoid inactive or unstable final products, (2) to allow fast, reproducible, and inexpensive antimicrobial activity measurements, and (3) to reflect real environmental conditions and challenges for these materials. Aiming to improve the existing methodologies of antimicrobial testing, this mini review summarizes and discusses the testing parameters and procedures in this expanding research field, including research on antimicrobial activity of photocatalytic coatings for different applications, i.e., self-cleaning/disinfecting coatings (films) and photocatalytic coatings for water and air treatment/disinfection. PMID:24384751

Žvab, Urška; Lavren?i? Štangar, Urška; Bergant Maruši?, Martina

2014-03-01

174

Divalent Metal Ion Triggered Activity of a Synthetic Antimicrobial in Cardiolipin Membranes  

E-print Network

Divalent Metal Ion Triggered Activity of a Synthetic Antimicrobial in Cardiolipin Membranes that although antimicrobial activity is largely ablated in PE-knockout strains of E. coli,4 residual antimicrobial activity still remains. Moreover, the previous results specifically implicated PE lipid, although

Tew, Gregory N.

175

1,2,3-Triazole-derived naphthalimides as a novel type of potential antimicrobial agents: synthesis, antimicrobial activity, interaction with calf thymus DNA and human serum albumin.  

PubMed

A series of 1,2,3-triazole-derived naphthalimides as a novel type of potential antimicrobial agents were synthesized and characterized by IR, NMR and HRMS spectra. All the new compounds were screened for their antimicrobial activity against four Gram-positive bacteria, four Gram-negative bacteria and three fungi. Bioactive assay manifested that 3,4-dichlorobenzyl compound 9e and its corresponding hydrochloride 11e showed better anti-Escherichia coli activity than Norfloxacin and Chloromycin. Preliminary research revealed that compound 9e could effectively intercalate into calf thymus DNA to form compound 9e-DNA complex which might block DNA replication and thus exert antimicrobial activities. Human serum albumin could effectively store and carry compound 9e by electrostatic interaction. PMID:24295786

Lv, Jing-Song; Peng, Xin-Mei; Kishore, Baathulaa; Zhou, Cheng-He

2014-01-01

176

Antimicrobial activity of kaurane diterpenes against oral pathogens.  

PubMed

Two kaurane diterpenes, ent-kaur-16(17)-en-19-oic acid (KA) and 15-beta-isovaleryloxy-ent-kaur-16(17)-en-19-oic acid (KA-Ival), isolated from Aspilia foliacea, and the methyl ester derivative of KA (KA-Me) were evaluated against oral pathogens. KA was the most active compound, with MIC values of 10 microg mL(-1) against the following microorganisms: Streptococcus sobrinus, Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, and Lactobacillus casei. However, KA did not show significant activity against Streptococcus salivarius and Enterococcus faecalis, with MIC values equal to 100 and 200 microg mL(-1), respectively. Our results show that KA has potential to be used as a prototype for the discovery of new effective anti-infection agents against microorganisms responsible for caries and periodontal diseases. Moreover, these results allow to conclude that minor structural differences among these diterpenes significantly influence their antimicrobial activity, bringing new perspectives to studies on the structure-activity relationship of this type of metabolites with respect to caries and periodontal diseases. PMID:18669015

Ambrosio, Sergio R; Furtado, Niege A J C; de Oliveira, Dionéia C R; da Costa, Fernando B; Martins, Carlos H G; de Carvalho, Tatiane C; Porto, Thiago S; Veneziani, Rodrigo C S

2008-01-01

177

ANTIMICROBIAL ACTIVITY OF SOME BIGINELLI COMPOUNDS  

Microsoft Academic Search

3,4-Dihydropyrimidin-2(1H)-ones(thiones) and their derivatives have attracted great interest due to their promising biological effects, including antibacterial, antiviral, antitumor, antiinflammatory, antihypertensive, calcium channel blocker, ?-1a-antagonist and neuropeptide Y (NPY) antagonist activities (1). In our previous study, we have reported the preparation of some 5-acetyl-3,4-dihydro-6-methyl-4- (substituted phenyl)-2(1H)-pyrimidinone derivatives by using the Biginelli three-component cyclocondensation reaction of substituted benzaldehyde, acetylacetone and thiourea (2).

Ekrem KILIÇ; Meral ÖZALP; Selma SARAÇ

178

Chemical composition and antimicrobial activity of essential oil of Heracleum rigens.  

PubMed

The essential oil was extracted from the seeds of Heracleum rigens by hydrodistillation and a total of twenty compounds accounting for 98.5% of the total oil composition were identified. Physicochemical properties and chemical composition of the oil was determined by a combination GC/FID and GC/MS analysis. The major compounds identified were bornyl acetate (51.2%), alpha-pinene (22.6%), limonene (9.62%), octyl acetate (3.94%), rho-cymene (2.85%) and gamma-terpinene (1.93%). The antimicrobial activity of the oil was screened by the disc diffusion method against nine pathogenic bacterial strains. Maximum antimicrobial activity was noted against Klebsiella pneumonia and Bacillus subtillis. This investigation corroborates the traditional claim of H. rigens as an effective antimicrobial agent. PMID:22908589

Jagannath, Nataraj; Ramakrishnaiah, Hanumanthaiah; Krishna, Venkatarangaiah; Gowda, Prameela Javarayi

2012-07-01

179

Antimicrobial activity of Amazon Astrocaryum aculeatum extracts and its association to oxidative metabolism.  

PubMed

Several compounds present in fruits as polyphenols are able to kill or inhibit the growth of microorganisms. These proprieties are relevant mainly in tropical areas, as Amazonian region where infectious are highly prevalent. Therefore, this study investigated the antimicrobial activity of tucumã Amazonian fruit against 37 microorganisms. The potential role of oxidative metabolism imbalance was also studied as causal mechanism of antimicrobial activity. The results showed antibacterial effect of pulp and peel tucumã hydro-alcoholic extracts on three Gram-positive bacteria (Enterococcus faecalis, Bacillus cereus, Listeria monocytogenes) and antifungal effect against Candida albicans. The antimicrobial contribution of main chemical compounds (quercetin, rutin, ?-carotene and gallic, caffeic and chlorogenic acids) found in tucumã extracts was also investigated showing an inhibitory effect depending of the organism mainly by quercetin in bacteria and rutin in C. albicans. Analysis of kinetic of DNA releasing in extracellular medium by fluorescence using DNA Pico Green assay(®) and reactive oxygen species production (ROS) showed potential oxidative imbalance contribution on tucumã inhibitory effect. In B. cereus and C. albicans this effect was clear since after 24h the ROS levels were higher when compared to negative control group. In conclusion, tucumã extracts present antimicrobial activity to four microorganisms that have large problems of drug resistance, and the possible mechanism of action of this Amazon fruit is related to REDOX imbalance. PMID:23870852

Jobim, Micheli Lamberti; Santos, Roberto Christ Vianna; dos Santos Alves, Camilla Filippi; Oliveira, Raul Moreira; Mostardeiro, Clarice Pinheiro; Sagrillo, Michele Rorato; de Souza Filho, Olmiro Cezimbra; Garcia, Luiz Filipe Machado; Manica-Cattani, Maria Fernanda; Ribeiro, Euler Esteves; da Cruz, Ivana Beatrice Mânica

2014-04-01

180

Antimicrobial and antiproliferative activity of Athamanta sicula L. (Apiaceae)  

PubMed Central

Background: Athamanta sicula L., a member of Apiaceae, is an annual perennial herb and it is known in Sicilian popular medicine with the name of “spaccapietre” (rock splitters), because fresh roots infusions are indicated as diuretic and used in the treatment of diseases of the urinary tract, and to dissolve kidney stones. Materials and Methods: Acetone extracts of leaves, flowers, and stems of A. sicula L. were investigated in vitro for antibacterial and cytotoxic activities. Antimicrobial activity was carried out against bacterial and fungal strains and antiproliferative activity against a group of human cancer cell lines (K-562, NCI-H460, and MCF-7). Results: All acetone extracts, apiol and myristicin, resulted inactive as antimicrobial agents at the maximum tested concentration of 200 ?g/mL, but they induced significant antiproliferative activity on the tested cancer cell lines. Conclusions: Our study show that both apiol and myristicin could be tested as novel treatment in cancer chemotherapy. PMID:21472076

Stefano, Vita Di; Pitonzo, Rosa; Schillaci, Domenico

2011-01-01

181

Radical scavenging, antioxidant and antimicrobial activities of halophytic species Laetitia Meot-Durosa*  

E-print Network

Radical scavenging, antioxidant and antimicrobial activities of halophytic species Laetitia Meot maritimum, Cakile maritima, Crithmum maritimum, antimicrobial, antioxidant, phenol content Abbreviations; BCC: Brittany Culture Collection; GAE: Gallic Acid Equivalents; TAC: Total Antioxidant Capacity. hal

Paris-Sud XI, Université de

182

Influence of Lipid Composition on Membrane Activity of Antimicrobial Phenylene Ethynylene Oligomers  

E-print Network

Influence of Lipid Composition on Membrane Activity of Antimicrobial Phenylene Ethynylene Oligomers of antimicrobial activity and are nontoxic to mammalian cells.1 Animals defend themselves against invading the membranes of bacterial cells over that of host cells. As a result, their antimicrobial properties have been

Tew, Gregory N.

183

Antimicrobial effectiveness of silver nanoparticles co-stabilized by the bioactive copolymer pluronic F68  

PubMed Central

Background Silver nanoparticles (AgNps) have attracted much interest in biomedical engineering, since they have excellent antimicrobial properties. Therefore, AgNps have often been considered for incorporation into medical products for skin pathologies to reduce the risk of contamination. This study aims at evaluating the antimicrobial effectiveness of AgNps stabilized by pluronic™ F68 associated with other polymers such as polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP). Methods AgNps antimicrobial activity was evaluated using the minimum inhibitory concentration (MIC) method. The action spectrum was evaluated for different polymers associated with pluronic™ F68 against the gram negative bacteria P. aeuroginosa and E. coli and the gram positive bacteria S. Aureus. Results AgNps stabilized with PVP or PVA and co-stabilized with pluronic™ F68 are effective against E. coli and P. aeruginosa microorganisms, with MIC values as low as 0.78% of the concentration of the original AgNps dispersion. The antimicrobial action against S. aureus is poor, with MIC values not lower than 25%. Conclusions AgNps stabilized by different polymeric systems have shown improved antimicrobial activity against gram-negative microorganisms in comparison to unstabilized AgNps. Co-stabilization with the bioactive copolymer pluronic™ F68 has further enhanced the antimicrobial effectiveness against both microorganisms. A poor effectiveness has been found against the gram-positive S. aureus microorganism. Future assays are being delineated targeting possible therapeutic applications. PMID:23193983

2012-01-01

184

Many chemokines including CCL20\\/MIP3  display antimicrobial activity  

Microsoft Academic Search

Previous studies have demonstrated that -defensins exhibit chemotactic activity by sharing the chemokine receptor CCR6 with the CC chemokine ligand CCL20\\/macrophage-inflamma- tory protein-3 (MIP-3). Structural analysis of CCL20\\/MIP-3 revealed that most of the positively charged residues are concentrated at one area of its topological surface, a characteristic considered to be important for the antimicrobial activity of defensins. Here, we report

De Yang; Qian Chen; David M. Hoover; Patricia Staley; Kenneth D. Tucker; Jacek Lubkowski; Joost J. Oppenheim

2003-01-01

185

Antioxidant, antimicrobial and anticancer activity of the lichens Cladonia furcata, Lecanora atra and Lecanora muralis  

PubMed Central

Background The aim of this study is to investigate in vitro antioxidant, antimicrobial and anticancer activity of the acetone extracts of the lichens Cladonia furcata, Lecanora atra and Lecanora muralis. Methods Antioxidant activity was evaluated by five separate methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds and determination of total flavonoid content. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method against six species of bacteria and ten species of fungi. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. Results Of the lichens tested, Lecanora atra had largest free radical scavenging activity (94.7% inhibition), which was greater than the standard antioxidants. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. Extract of Cladonia furcata was the most active antimicrobial agent with minimum inhibitory concentration values ranging from 0.78 to 25 mg/mL. All extracts were found to be strong anticancer activity toward both cell lines with IC50 values ranging from 8.51 to 40.22 ?g/mL. Conclusions The present study shows that tested lichen extracts demonstrated a strong antioxidant, antimicrobial and anticancer effects. That suggest that lichens may be used as as possible natural antioxidant, antimicrobial and anticancer agents to control various human, animal and plant diseases. PMID:22013953

2011-01-01

186

Antioxidant and antimicrobial activity of some lichen species.  

PubMed

The aim of the research is to explore the overall in vitro antioxidant activity, total phenol content, reduction power and antimicrobial activity of the methanol extracts of the lichens Cetraria pinastri, Cladonia digitata, Cladonia fimbriata, Fulgensia fulgens, Ochrolechia parella and Parmelia crinita. The methanol extract of the Cetraria pinastri showed a strong antioxidant activity, whereas the extracts of the species Fulgenesi fulgens, Cladonia fimbriata and Parmelia crinita showed the moderate one and the extract of the species Ochrolechia parella and Cladonia digitata the weak one. The methanol extract of the lichen Cetraria pinastri had the biggest total phenol content (32.9 mg/g of the dry extract). A certain correlation was established between the antioxidant activity and the total phenol content for the researched lichen extracts. The work also explores the antimicrobial activity of the methanol extracts of the mentioned species of lichens against six bacterial and eleven fungi species by the disc-diffusion method and by establishing the minimum inhibitory concentration (MIC). The methanol extracts of the lichens Cetraria pinastri and Parmelia crinita showed the strongest both antibacterial and antifungal activity against most of the tested microorganisms. These researches suggest that the lichens Cetraria prunastri can be used as new sources of the natural antioxidants and the substances with antimicrobial features. PMID:21446633

Rankovi?, B; Rankovi?, D; Mari?, D

2010-01-01

187

A demonstration of the antimicrobial effectiveness of various copper surfaces  

PubMed Central

Background Bacterial contamination on touch surfaces results in increased risk of infection. In the last few decades, work has been done on the antimicrobial properties of copper and its alloys against a range of micro-organisms threatening public health in food processing, healthcare and air conditioning applications; however, an optimum copper method of surface deposition and mass structure has not been identified. Results A proof-of-concept study of the disinfection effectiveness of three copper surfaces was performed. The surfaces were produced by the deposition of copper using three methods of thermal spray, namely, plasma spray, wire arc spray and cold spray The surfaces were then inoculated with meticillin-resistant Staphylococcus aureus (MRSA). After a two hour exposure to the surfaces, the surviving MRSA were assayed and the results compared. The differences in the copper depositions produced by the three thermal spray methods were examined in order to explain the mechanism that causes the observed differences in MRSA killing efficiencies. The cold spray deposition method was significantly more effective than the other methods. It was determined that work hardening caused by the high velocity particle impacts created by the cold spray technique results in a copper microstructure that enhances ionic diffusion, and copper ions are principally responsible for antimicrobial activity. Conclusions This test showed significant microbiologic differences between coatings produced by different spray techniques and demonstrates the importance of the copper application technique. The cold spray technique shows superior anti-microbial effectiveness caused by the high impact velocity imparted to the sprayed particles which results in high dislocation density and high ionic diffusivity. PMID:23537176

2013-01-01

188

In Vitro Antimicrobial Activities of Bakuchiol against Oral Microorganisms  

PubMed Central

Bakuchiol was isolated from the seeds of Psoralea corylifolia, a tree native to China with various uses in traditional medicine, followed by extraction with ether and column chromatography combined with silica gel and octyldecyl silane. In this study, the antimicrobial activities of bakuchiol against some oral microorganisms were evaluated in vitro. The cell growth of Streptococcus mutans was inhibited in a bakuchiol concentration-dependent manner, and growth of S. mutans was completely prevented by 20 ?g of bakuchiol per ml. The bactericidal effect of bakuchiol on S. mutans was dependent on temperature and stable under the following conditions: sucrose, 0 to 10% (wt/vol); pH, 3.0 to 7.0; organic acids (3% [wt/vol] citric and malic acids). Bakuchiol showed bactericidal effects against all bacteria tested, including S. mutans, Streptococcus sanguis, Streptococcus salivarius, Streptococcus sobrinus, Enterococcus faecalis, Enterococcus faecium, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus plantarum, Actinomyces viscosus, and Porphyromonas gingivalis, with MICs ranging from 1 to 4 ?g/ml and the sterilizing concentration for 15 min ranging from 5 to 20 ?g/ml. Furthermore, bakuchiol was also effective against adherent cells of S. mutans in water-insoluble glucan in the presence of sucrose and inhibited the reduction of pH in the broth. Thus, bakuchiol would be a useful compound for development of antibacterial agents against oral pathogens and has great potential for use in food additives and mouthwash for preventing and treating dental caries. PMID:11600349

Katsura, Harumi; Tsukiyama, Ryo-Ichi; Suzuki, Akiko; Kobayashi, Makio

2001-01-01

189

In vitro antimicrobial activities of bakuchiol against oral microorganisms.  

PubMed

Bakuchiol was isolated from the seeds of Psoralea corylifolia, a tree native to China with various uses in traditional medicine, followed by extraction with ether and column chromatography combined with silica gel and octyldecyl silane. In this study, the antimicrobial activities of bakuchiol against some oral microorganisms were evaluated in vitro. The cell growth of Streptococcus mutans was inhibited in a bakuchiol concentration-dependent manner, and growth of S. mutans was completely prevented by 20 microg of bakuchiol per ml. The bactericidal effect of bakuchiol on S. mutans was dependent on temperature and stable under the following conditions: sucrose, 0 to 10% (wt/vol); pH, 3.0 to 7.0; organic acids (3% [wt/vol] citric and malic acids). Bakuchiol showed bactericidal effects against all bacteria tested, including S. mutans, Streptococcus sanguis, Streptococcus salivarius, Streptococcus sobrinus, Enterococcus faecalis, Enterococcus faecium, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus plantarum, Actinomyces viscosus, and Porphyromonas gingivalis, with MICs ranging from 1 to 4 microg/ml and the sterilizing concentration for 15 min ranging from 5 to 20 microg/ml. Furthermore, bakuchiol was also effective against adherent cells of S. mutans in water-insoluble glucan in the presence of sucrose and inhibited the reduction of pH in the broth. Thus, bakuchiol would be a useful compound for development of antibacterial agents against oral pathogens and has great potential for use in food additives and mouthwash for preventing and treating dental caries. PMID:11600349

Katsura, H; Tsukiyama, R I; Suzuki, A; Kobayashi, M

2001-11-01

190

In-vitro Antimicrobial Activities of Some Iranian Conifers.  

PubMed

Male and female leaves and fruits of eleven different taxons of Iranian conifers (Cupressus sempervirens var. horizontalis, C. sempervirens var. sempervirens, C. sempervirens cv. Cereifeormis, Juniperus communis subsp. hemisphaerica, J. excelsa subsp. excelsa, J. excelsa subsp. polycarpos, J. foetidissima, J. oblonga, J. sabina, Platycladus orientalis and Taxus baccata) were collected from different localities of Iran, dried and extracted with methanol. The extracts were tested for their antimicrobial activity against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Candida albicans. The extracts were screened qualitatively using four different methods, the disc diffusion, hole plate, cylinder agar diffusion and agar dilution methods, whereas the minimum inhibitory concentrations (MIC) of each extract were determined by the agar dilution method. The best result was obtained by means of hole plate method in qualitative determination of antimicrobial activities of extracts and the greatest activity was found against S. aureus in all tested methods. PMID:24250573

Afsharzadeh, Maryam; Naderinasab, Mahboobe; Tayarani Najaran, Zahra; Barzin, Mohammad; Emami, Seyed Ahmad

2013-01-01

191

In-vitro Antimicrobial Activities of Some Iranian Conifers  

PubMed Central

Male and female leaves and fruits of eleven different taxons of Iranian conifers (Cupressus sempervirens var. horizontalis, C. sempervirens var. sempervirens, C. sempervirens cv. Cereifeormis, Juniperus communis subsp. hemisphaerica, J. excelsa subsp. excelsa, J. excelsa subsp. polycarpos, J. foetidissima, J. oblonga, J. sabina, Platycladus orientalis and Taxus baccata) were collected from different localities of Iran, dried and extracted with methanol. The extracts were tested for their antimicrobial activity against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Candida albicans. The extracts were screened qualitatively using four different methods, the disc diffusion, hole plate, cylinder agar diffusion and agar dilution methods, whereas the minimum inhibitory concentrations (MIC) of each extract were determined by the agar dilution method. The best result was obtained by means of hole plate method in qualitative determination of antimicrobial activities of extracts and the greatest activity was found against S. aureus in all tested methods. PMID:24250573

Afsharzadeh, Maryam; Naderinasab, Mahboobe; Tayarani Najaran, Zahra; Barzin, Mohammad; Emami, Seyed Ahmad

2013-01-01

192

Antioxidant, antimicrobial and wound healing activities of Boesenbergia rotunda.  

PubMed

The ethanolic extract of Boesenbergia rotunda (L.) Mansf was studied for its wound-healing potential. Since wound healing is interrelated with microbial infection and reactive oxygen species (ROS), this study was conducted to evaluate the antimicrobial and antioxidant activity of B. rotunda. The antimicrobial activity of B. rotunda was studied against six bacterial and two yeast strains using disc diffusion, minimum inhibitory concentration (MIC), and minimum microbicidal concentration (MMC). The B. rotunda extract displayed potential antimicrobial and antifungal activities by inhibiting the Gram-positive bacteria Staphylococcus aureus (ATCC 25923), S. epidermidis, and Bacillus subtilis (ATCC 6633), and the yeasts Candida albicans (ATCC 10231), and Saccharomyces cerevisiae. MIC and MMC values varied from 0.04 to 25 mg/mL and from 0.16 to 25 mg/mL, respectively. The antioxidant activity of B. rotunda was evaluated by measuring the Ferric Reducing/Antioxidant Power (FRAP) and DPPH free radical scavenging activity. The FRAP and DPPH values were 22.2 microM/microg and 76.3 mg/mL, respectively. In the wound-healing studies, the topical application of the B. rotunda extract indicated a significantly increased percentage of wound contraction on day 12 compared with the control group. Histological studies showed the complete epidermis and found collagen fibers and hair follicles in the dermis. The results of the present study support the continued and expanded utilization of B. rotunda in Thai folk medicine. PMID:22908579

Jitvaropas, Rungrat; Saenthaweesuk, Suphaket; Somparn, Nuntiya; Thuppia, Amornnat; Sireeratawong, Seewaboon; Phoolcharoen, Waranyoo

2012-07-01

193

Antioxidant and antimicrobial activities of Tamarix ramosissima  

Microsoft Academic Search

The ethylacetate and water–acetone extracts of Tamarixramosissima were screened for their antioxidant, antibacterial, antifungal and DNA damaging activities through in vitro experiments. All fractions as well as precipitates showed significant antioxidant activity. A known compound tamarixetin (1) was isolated which showed significant DNA damaging activity in mutant yeast bioassay. Results revealed that antioxidant and antibacterial activities were associated with the

N Sultanova; T Makhmoor; Z. A Abilov; Z Parween; V. B Omurkamzinova; Atta-ur-Rahman; M. Iqbal Choudhary

2001-01-01

194

The antimicrobial activity, hydrophobicity and toxicity of sulfonium compounds, and their relationship.  

PubMed

The sulfonium compound is a kind of cationic surfactant as well as a quaternary ammonium which has been used widely around the globe. This study investigated the antimicrobial activity, the hydrophobicity, the toxicity of several sulfoniums and their relationship with the aim of clarifying their antimicrobial activity and toxicity, and, furthermore, of predicting their usefulness availability as antimicrobials. As a result, the antimicrobial activity, expressed as the minimum inhibitory concentration (MIC) of the sulfoniums examined in this study, tended to decrease with the increase of their hydrophobicity, estimated by ClogP, and their antimicrobial activity against the gram-positive bacteria was higher than that against the gram-negative bacteria used in this study. The antimicrobial activities of several sulfoniums against the gram-positive bacteria were higher than those of some common cationic antimicrobials including quaternary ammoniums such as cetylpyridinium chloride (CPC) and benzalkonium chloride (BKC). In contrast, the antimicrobial activities of the sulfoniums against the gram-negative bacteria were lower than those of some common cationic antimicrobials. Meanwhile the toxicity, in particular, the acute dermal irritation/corrosion of the sulfoniums, tended to be lower than that of common cationic antimicrobials which were toxic in many cases indices. These results suggest that the sulfoniums might become useful antimicrobials which are less hazardous to human health than common cationic antimicrobials. PMID:21467626

Hirayama, Michiasa

2011-03-01

195

Pimarane-type diterpenes: antimicrobial activity against oral pathogens.  

PubMed

Seven pimarane type-diterpenes re-isolated from Viguiera arenaria Baker and two semi-synthetic pimarane derivatives were evaluated in vitro against the following main microorganisms responsible for dental caries: Streptococcus salivarius, S. sobrinus, S. mutans, S. mitis, S. sanguinis and Lactobacillus casei. The compounds ent-pimara-8(14),15-dien-19-oic acid (PA); ent-8(14),15-pimaradien-3beta-ol; ent-15-pimarene-8beta,19-diol; ent-8(14),15-pimaradien-3beta-acetoxy and the sodium salt derivative of PA were the most active compounds, displaying MIC values ranging from 2 to 8 microg mL(-1). Thus, this class of compounds seems promising as a class of new effective anticariogenic agents. Furthermore, our results also allow us to conclude that minor structural differences among these diterpenes significantly influence their antimicrobial activity, bringing new perspectives to the discovery of new natural compounds that could be employed in the development of oral care products. PMID:19127247

Porto, Thiago S; Rangel, Rander; Furtado, Niege A J C; de Carvalho, Tatiane C; Martins, Carlos H G; Veneziani, Rodrigo C S; Da Costa, Fernando B; Vinholis, Adriana H C; Cunha, Wilson R; Heleno, Vladimir C G; Ambrosio, Sergio R

2009-01-01

196

Antimicrobial Activities of Isothiocyanates Against Campylobacter jejuni Isolates  

PubMed Central

Food-borne human infection with Campylobacter jejuni is a medical concern in both industrialized and developing countries. Efficient eradication of C. jejuni reservoirs within live animals and processed foods is limited by the development of antimicrobial resistances and by practical problems related to the use of conventional antibiotics in food processes. We have investigated the bacteriostatic and bactericidal activities of two phytochemicals, allyl-isothiocyanate (AITC), and benzyl isothiocyanate (BITC), against 24 C. jejuni isolates from chicken feces, human infections, and contaminated foods, as well as two reference strains NCTC11168 and 81-176. AITC and BITC displayed a potent antibacterial activity against C. jejuni. BITC showed a higher overall antibacterial effect (MIC of 1.25–5??g?mL?1) compared to AITC (MIC of 50–200??g?mL?1). Both compounds are bactericidal rather than bacteriostatic. The sensitivity levels of C. jejuni isolates against isothiocyanates were neither correlated with the presence of a GGT (?-Glutamyl Transpeptidase) encoding gene in the genome, with antibiotic resistance nor with the origin of the biological sample. However the ggt mutant of C. jejuni 81-176 displayed a decreased survival rate compared to wild-type when exposed to ITC. This work determined the MIC of two ITC against a panel of C. jejuni isolates, showed that both compounds are bactericidal rather than bacteriostatic, and highlighted the role of GGT enzyme in the survival rate of C. jejuni exposed to ITC. PMID:22919644

Dufour, Virginie; Alazzam, Bachar; Ermel, Gwennola; Thepaut, Marion; Rossero, Albert; Tresse, Odile; Baysse, Christine

2012-01-01

197

Antimicrobial activity and hydrophobicity of edible whey protein isolate films formulated with nisin and/or glucose oxidase.  

PubMed

The use of edible antimicrobial films has been reported as a means to improve food shelf life through gradual releasing of antimicrobial compounds on the food surface. This work reports the study on the incorporation of 2 antimicrobial agents, nisin (N), and/or glucose oxidase (GO), into the matrix of Whey protein isolate (WPI) films at pH 5.5 and 8.5. The antimicrobial activity of the edible films was evaluated against Listeria innocua (ATCC 33090), Brochothrix thermosphacta (NCIB10018), Escherichia coli (JMP101), and Enterococcus faecalis (MXVK22). In addition, the antimicrobial activity was related to the hydrophobicity and water solubility of the WPI films. The greatest antibacterial activity was observed in WPI films containing only GO. The combined addition of N and GO resulted in films with lower antimicrobial activity than films with N or GO alone. In most cases, a pH effect was observed as greater antimicrobial response at pH 5.5 as well as higher film matrix hydrophobicity. WPI films supplemented with GO can be used in coating systems suitable for food preservation. PMID:23488765

Murillo-Martínez, María M; Tello-Solís, Salvador R; García-Sánchez, Miguel A; Ponce-Alquicira, Edith

2013-04-01

198

Antimicrobial browning-inhibitory effect of flavor compounds in seaweeds  

Microsoft Academic Search

Since ancient times, the antimicrobial properties of seaweeds have been recognized. However, antimicrobial activities of volatile\\u000a compounds in seaweeds have not been explored so far. Here, essential oils from seaweeds including green, brown and red algae\\u000a such as Laminaria japonica, Kjellmaniella crassifolia, Gracilaria verrucosa and Ulva pertusa were prepared by using SDE (simultaneous distillation and extraction) apparatus. Volatile compounds in

Tadahiko Kajiwara; Kenji Matsui; Yoshihiko Akakabe; Takushi Murakawa; Chikako Arai

199

Isolation and Antimicrobial and Antioxidant Evaluation of Bio-Active Compounds from Eriobotrya Japonica Stems  

PubMed Central

Purpose: The present study was carried out to evaluate antimicrobial and antioxidant activities from Eriobotrya japonica stems as well investigation of its chemical composition. Methods: Methanol 80% extract of Eriobotrya japonica stems was tested for antimicrobial activity against bacterial and fungal strains and for antioxidant activity using oxygen radical absorbance capacity (ORAC) and the trolox equivalent antioxidant capacity (TEAC) assays and also total content of polyphenols with phytochemical analysis of the extract were determined. Results: The results showed that the extract has a significant antimicrobial activity, it inhibited significantly the growth of Candida albicans suggesting that it can be used in the treatment of fungal infections, and it showed no effect on the other bacterial and fungal strains, the extract has a good antioxidant activity, it has shown high values of oxygen radical absorbance capacity and trolox equivalent antioxidant capacity, while it showed a low value of polyphenol content. Phytochemical analysis of the extract showed the presence of carbohydrates, terpenes, tannins and flavonoids, further phytochemical analysis resulted in the isolation and identification of three triterpenic acids, oleanolic, ursolic and corosolic acids and four flavonoids, naringenin, quercetin, kaempferol 3-O-?-glucoside and quercetin 3-O-?-rhamnoside. Conclusion: These results may help to discover new chemical classes of natural antimicrobial antioxidant substances. PMID:24409413

Rashed, Khaled Nabih; Butnariu, Monica

2014-01-01

200

In vitro antimicrobial activity of Romanian medicinal plants hydroalcoholic extracts on planktonic and adhered cells.  

PubMed

The aim of this study was to assess the antibacterial and antifungal potential of some Romanian medicinal plants, arnica--Arnica montana, wormwood--Artemisia absinthium and nettle--Urtica dioica. In order to perform this antimicrobial screening, we obtained the vegetal extracts and we tested them on a series of Gram-positive and Gram-negative bacteria, and also against two fungal strains. The vegetal extracts showed antimicrobial activity preferentially directed against the planktonic fungal and bacterial growth, while the effect against biofilm formation and development was demonstrated only against S. aureus and C. albicans. Our in vitro assays indicate that the studied plant extracts are a significant source of natural alternatives to antimicrobial therapy, thus avoiding antibiotic therapy, the use of which has become excessive in recent years. PMID:21717806

Stanciuc, A M; Gaspar, A; Moldovan, L; Saviuc, C; Popa, M; M?ru?escu, L

2011-01-01

201

Antioxidant and antimicrobial activities of Tamarix ramosissima.  

PubMed

The ethylacetate and water-acetone extracts of Tamarix ramosissima were screened for their antioxidant, antibacterial, antifungal and DNA damaging activities through in vitro experiments. All fractions as well as precipitates showed significant antioxidant activity. A known compound tamarixetin (1) was isolated which showed significant DNA damaging activity in mutant yeast bioassay. Results revealed that antioxidant and antibacterial activities were associated with the presence of polyphenolic substances. PMID:11694365

Sultanova, N; Makhmoor, T; Abilov, Z A; Parween, Z; Omurkamzinova, V B; ur-Rahman, A; Choudhary, M I

2001-12-01

202

Composition and antimicrobial activity of Equisetum arvense L. essential oil.  

PubMed

The volatile constituents of the sterile stems of Equisetum arvense L. (Equisetaceae) were investigated for the first time using GC, GC/MS and (13)C-NMR. Twenty-five compounds were identified. Hexahydrofarnesyl acetone (18.34%), cis-geranyl acetone (13.74%), thymol (12.09%) and trans-phytol (10.06%) were the major constituents. A disk diffusion method was used for the evaluation of the antimicrobial activity of this oil against a panel of microorganisms (bacteria: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis; fungi: Aspergillus niger and Candida albicans). The 1:10 dilution of the essential oil of Equisetum arvense L. was shown to possess a broad spectrum of a very strong antimicrobial activity against all tested strains. PMID:16397851

Radulovi?, Niko; Stojanovi?, Gordana; Pali?, Radosav

2006-01-01

203

Guanidylation and Tail Effects in Cationic Antimicrobial Lipopeptoids  

PubMed Central

Background Cationic antimicrobial peptides (CAMPs) are attractive scaffolds for the next generation of antimicrobial compounds, due to their broad spectrum of activity against multi-drug resistant bacteria and the reduced fitness of CAMP-insensitive mutants. Unfortunately, they are limited by poor in vivo performance, including ready cleavage by endogenous serum proteases. Methodology/Principal Findings To explore the potential for peptoid residues to replace well studied CAMP scaffolds we have produced a series of antimicrobial lipopeptoids, with sequences similar to previously reported lipopeptides. The activity of the peptoids was assessed against a panel of clinically relevant and laboratory reference bacteria, and the potential for non-specific binding was determined through hemolytic testing and repeating the antimicrobial testing in the presence of added bovine serum albumin (BSA). The most active peptoids displayed good to moderate activity against most of the Gram positive strains tested and moderate to limited activity against the Gram negatives. Antimicrobial activity was positively correlated with toxicity towards eukaryotic cells, but was almost completely eliminated by adding BSA. Conclusion/Significance The lipopeptoids had similar activities to the previously reported lipopeptides, confirming their potential to act as replacement, proteolytically stable scaffolds for CAMPs. PMID:22844435

Findlay, Brandon; Szelemej, Paul; Zhanel, George G.; Schweizer, Frank

2012-01-01

204

Antioxidant and antimicrobial activities of Morchella conica Pers  

Microsoft Academic Search

Antioxidant capacity and antimicrobial activities of Morchella conica Pers. extracts obtained with ethanol were investigated in this study. Four complementary test systems; namely DPPH free radical scavenging, ?-carotene\\/linoleic acid systems, total phenolic compounds and total flavonoid concentration were used. Inhibition values of M. conica ethanol extracts, buthylated hydroxyanisol (BHA) and ?-tocopherol standards were found to be 96.9, 98.9 and 99.2%,

TURKOGLU A; KIVRAK I; MERCAN N; DURU ME; GEZER K

205

Saliva Enables the Antimicrobial Activity of LL37 in the Presence of Proteases of Porphyromonas gingivalis  

Microsoft Academic Search

Proteolysis is a common microbial virulence mechanism that enables the destruction of host tissue and evasion from host defense mechanisms. Antimicrobial peptides, also known as host defense peptides, are effector molecules of the innate immunity that demonstrate a broad range of antimicrobial and immunoregu- latory activities. Deficiency of the human LL-37 antimicrobial peptide was previously correlated with severe periodontal disease.

Michal Gutner; Stella Chaushu; Daniela Balter; Gilad Bachrach

2009-01-01

206

Antimicrobial activity of essences from labiates.  

PubMed

Bacteria, filamentous fungi and yeasts were subjected to the action of Lavandula officinalis, Melissa officinalis and Rosmarinus officinalis essences in a steam phase, using a microatmospheric technique. Due to the methodology employed, L. officinalis essence was more active in filamentous fungi than the other essential oils studied. All three essences possessed a similar degree of activity against the micro-organisms tested, though a relatively higher activity was seen in the case of M. officinalis. PMID:7630324

Larrondo, J V; Agut, M; Calvo-Torras, M A

1995-01-01

207

Antimicrobial and Cytotoxic Activities of Turbinaria conoides  

Microsoft Academic Search

Brown alga, Turbinaria conoides was successively extracted with n-hexane, cyclohexane, methanol and ethanol:water (1:1). The extracts were evaluated for antibacterial and antifungal activities by disc diffusion method. Minimal inhibitory concentration was determined for active extracts by broth dilution method. The antiviral activity and cytotoxicity of the extracts were tested in human embryonic lung (HEL) cells (herpes simplex virus-1, herpes simplex

J. Agardh; Sadish Kumar Shanmugam; Yatendra Kumar; Khan Mohammad Sardar Yar; Erik De Clercq

208

Antimicrobial activity of fruits of Solanum nigrum and Solanum xanthocarpum.  

PubMed

Current study was conducted to investigate antimicrobial activity of fruit extracts of two Solanaceous plants (Solanum nigrum and Solanum xanthocarpum) found in Pakistan. Petroleum ether, chloroform, dichloromethane, ethyl acetate, acetone, methanol and water were utilized for extraction. The highest percentages of polar components of both the species were extracted by water; little amount of non-polar components by petroleum ether while very low quantities by other solvents. Antimicrobial activities were estimated by measuring zones of inhibition through hole-plate diffusion method, against three species of Gram positive bacteria, five species of Gram negative bacteria and three species of fungi selected for this study. Doses of 5, 10 and 15 mg/mL prepared through methanolic extracts of each plant's powdered fruit material displayed significant zones of inhibition against all three Gram positive bacteria, three of the Gram negative bacteria out of five and against all three fungi. Although these doses exhibited significant zones of inhibition but they are not as potent as standards: ampicillin or amphotericin B. The present study assures the possible potential of antimicrobial as well as antifungal activity of fruit extracts of these plants. PMID:25265821

Abbas, Khizar; Niaz, Uzma; Hussain, Talib; Saeed, M Asif; Javaid, Zeeshan; Idrees, Arfat; Rasool, Shahid

2014-01-01

209

Total antioxidant activity and antimicrobial potency of the essential oil and oleoresin of Zingiber officinale Roscoe  

PubMed Central

Objective To compare in vitro antioxidant and antimicrobial activities of the essential oil and oleoresin of Zingiber officinale Roscoe. Methods The antioxidant activity was evaluated based on the ability of the ginger extracts to scavenge ABTS°+ free radical. The antimicrobial activity was studied by the disc diffusion method and minimal inhibitory concentration was determined by using the agar incorporation method. Results Ginger extracts exerted significant antioxidant activity and dose-depend effect. In general, oleoresin showed higher antioxidant activity [IC50=(1.820±0.034) mg/mL] when compared to the essential oil [IC50=(110.14±8.44) mg/mL]. In terms of antimicrobial activity, ginger compounds were more effective against Escherichia coli, Bacillus subtilis and Staphylococcus aureus, and less effective against Bacillus cereus. Aspergillus niger was least, whereas, Penicillium spp. was higher sensitive to the ginger extracts; minimal inhibitory concentrations of the oleoresin and essential oil were 2 mg/mL and 869.2 mg/mL, respectively. Moreover, the studied extracts showed an important antifungal activity against Candida albicans. Conclusions The study confirms the wide application of ginger oleoresin and essential oil in the treatment of many bacterial and fungal diseases.

Bellik, Yuva

2014-01-01

210

Antimicrobial activity of nanoemulsion in combination with cetylpyridinium chloride in multidrug-resistant Acinetobacter baumannii.  

PubMed

Acinetobacter baumannii has emerged as a serious problematic pathogen due to the ever-increasing presence of antibiotic resistance, demonstrating a need for novel, broad-spectrum antimicrobial therapeutic options. Antimicrobial nanoemulsions are emulsified mixtures of detergent, oil, and water (droplet size, 100 to 800 nm) which have broad antimicrobial activity against bacteria, enveloped viruses, and fungi. Here, we screened the antimicrobial activities of five nanoemulsion preparations against four Acinetobacter baumannii isolates to identify the most suitable preparation for further evaluation. Among them, N5, which contains 10% (vol/vol) Triton X-100, 25% (vol/vol) soybean oil, and 1% (wt/vol) cetylpyridinium chloride (CPC), showed the best efficacy against A. baumannii in both its planktonic and biofilm forms and was selected for further study. Our data demonstrate that, while the killing of planktonic forms of A. baumannii was due to the 1% CPC component of our nanoemulsions, the breakdown of biofilms was achieved via the emulsified oil and detergent fractions. Furthermore, we documented the effect of ethanol and NaCl in combination with N5 on planktonic A. baumannii. In killing curves of N5 combined with other agents (ethanol or NaCl), a synergistic effect of a ? 2-log decrease in CFU/ml was observed. The antibiofilm activity of N5 was confirmed via a cell proliferation test and scanning electron microscopy. The effects of exposure to severe environmental conditions, which simulates the field conditions in Iraq and Afghanistan, were evaluated, and this exposure did not affect the overall antimicrobial activity of N5. These studies lay a solid foundation for the utilization of nanoemulsions against the antibiotic-resistant forms of A. baumannii. PMID:23669390

Hwang, Yoon Y; Ramalingam, Karthikeyan; Bienek, Diane R; Lee, Valerie; You, Tao; Alvarez, Rene

2013-08-01

211

Antimicrobial Activity of Nanoemulsion in Combination with Cetylpyridinium Chloride in Multidrug-Resistant Acinetobacter baumannii  

PubMed Central

Acinetobacter baumannii has emerged as a serious problematic pathogen due to the ever-increasing presence of antibiotic resistance, demonstrating a need for novel, broad-spectrum antimicrobial therapeutic options. Antimicrobial nanoemulsions are emulsified mixtures of detergent, oil, and water (droplet size, 100 to 800 nm) which have broad antimicrobial activity against bacteria, enveloped viruses, and fungi. Here, we screened the antimicrobial activities of five nanoemulsion preparations against four Acinetobacter baumannii isolates to identify the most suitable preparation for further evaluation. Among them, N5, which contains 10% (vol/vol) Triton X-100, 25% (vol/vol) soybean oil, and 1% (wt/vol) cetylpyridinium chloride (CPC), showed the best efficacy against A. baumannii in both its planktonic and biofilm forms and was selected for further study. Our data demonstrate that, while the killing of planktonic forms of A. baumannii was due to the 1% CPC component of our nanoemulsions, the breakdown of biofilms was achieved via the emulsified oil and detergent fractions. Furthermore, we documented the effect of ethanol and NaCl in combination with N5 on planktonic A. baumannii. In killing curves of N5 combined with other agents (ethanol or NaCl), a synergistic effect of a ?2-log decrease in CFU/ml was observed. The antibiofilm activity of N5 was confirmed via a cell proliferation test and scanning electron microscopy. The effects of exposure to severe environmental conditions, which simulates the field conditions in Iraq and Afghanistan, were evaluated, and this exposure did not affect the overall antimicrobial activity of N5. These studies lay a solid foundation for the utilization of nanoemulsions against the antibiotic-resistant forms of A. baumannii. PMID:23669390

Hwang, Yoon Y.; Ramalingam, Karthikeyan; Bienek, Diane R.; Lee, Valerie; You, Tao

2013-01-01

212

Recombinant expression, purification, and antimicrobial activity of a novel hybrid antimicrobial peptide LFT33.  

PubMed

With great therapeutic potential against antibiotic-resistant bacteria, viruses, and even parasites, antimicrobial peptides (AMPs) have received increased interest as pharmaceutical agents in recent years. It is a worthy yet challenging work to carry out the implement and improvement of AMPs production using bioengineering techniques. In the present study, a novel hybrid peptide LFT33 was designed derived from LfcinB and thanatin. The cDNA fragment encoding LFT33 with preferred codons of Escherichia coli was chemically synthesized and ligated into the vector pET32a(+) to express the LFT33 fusion protein. The fusion protein was successfully expressed in soluble form in E. coli induced under optimized conditions. After purification by affinity chromatography, the fusion protein was cleaved successfully by enterokinase and released the peptide LFT33. About 0.5 mg of the recombinant LFT33 was obtained by reversed-phase high performance liquid chromatography from 1 l of culture medium. Mass spectrometry analysis of the purified recombinant LFT33 demonstrated that the molecular weight perfectly matched the calculated mass (4,195 Da). The recombinant peptide LFT33 caused an increase in antimicrobial activity (IC(50)?=?16-64 ?g/ml) against given strains and did not show hemolytic activity for human erythrocytes. The results indicated that the hybrid peptide LFT33 could serve as a promising candidate for pharmaceutical agents. PMID:22189867

Feng, Xingjun; Liu, Chunlong; Guo, Jiayin; Song, Xueying; Li, Jing; Xu, Wenshan; Li, Zhongqiu

2012-09-01

213

Antibacterial activity of the recombinant antimicrobial peptide Ib-AMP4 from Impatiens balsamina and its synergy with other antimicrobial agents against drug resistant bacteria.  

PubMed

Ib-AMP4 is an antimicrobial peptide of Impatiens balsamina (Balsaminaceae). Ib-AMP4 was produced as a recombinant peptide and in this study its antimicrobial activity against human bacterial pathogens was investigated. Ib-AMP4 was bactericidal against both Gram positive and Gram negative bacteria with MIC values between 0.49 and 3.5 microM in sensitive species. A genuine synergistic effect was achieved when IB-AMP4 was employed in combination with the plant monoterpene thymol against drug-resistant Klebsiella pneumoniae (KPC) ATCC700603, or with the antibiotics vancomycin or oxacillin against Enterococcus faecalis (VRE) ATCC51299. PMID:23923648

Fan, X; Reichling, J; Wink, M

2013-07-01

214

Antimicrobial activity of Wedelia trilobata crude extracts.  

PubMed

A biological screening of activity against Gram-positive and Gram-negative bacteria, yeasts, and fungi of crude extracts from Wedelia trilobata is reported. The n-hexane extract showed antibacterial activity against Bacillus subtilis, Mycobacterium smegmatis, Staphylococcus aureus, and Staphylococcus epidermidis (Gram-positive bacteria); along with Proteus vulgaris, Pseudomonas aeruginosa, Salmonella group C, Salmonella paratyphi, and Shigella sonnei (Gram-negative bacteria). The ethyl acetate extract was active only against Salmonella group C; and the aqueous extract was inactive against the tested bacteria. None of the tested extracts showed biological activity against the yeasts (Candida albicans, Candida tropicalis, Rhodotorula rubra) or the fungi (Aspergillus flavus, Aspergillus niger, Mucor sp., Trichophyton rubrum). PMID:10374253

Taddei, A; Rosas-Romero, A J

1999-05-01

215

Synthesis, characterization, antimicrobial activity and carbonic anhydrase enzyme inhibitor effects of salicilaldehyde-N-methyl p-toluenesulfonylhydrazone and its Palladium(II), Cobalt(II) complexes  

NASA Astrophysics Data System (ADS)

We report the synthesis of the ligand, salicilaldehyde-N-methyl p-toluenesulfonylhydrazone (salptsmh) derived from p-toluenesulfonicacid-1-methylhydrazide (ptsmh) and its Pd(II) and Co(II) metal complexes were synthesized for the first time. The structure of the ligand and their complexes were investigated using elemental analysis, magnetic susceptibility, molar conductance and spectral (IR, NMR and LC-MS) measurements. Salptsmh has also been characterized by single crystal X-ray diffraction. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The complexes were found to have general composition [ML2]. The results of elemental analysis showed 1:2 (metal/ligand) stoichiometry for all the complex. Magnetic and spectral data indicate a square planar geometry for Pd(II) complex and a distorted tetrahedral geometry for Co(II) complexes. The ligand and its metal chelates have been screened for their antimicrobial activities using the disk diffusion method against the selected Gram positive bacteria: Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Gram negative bacteria: Eschericha coli, Pseudomonas aeruginosa, Klebsiella pneumonia. The inhibition activities of these compounds on carbonic anhydrase II (CA II) and carbonic anhydrase I (CA I) have been investigated by comparing IC50 and Ki values and it has been found that Pd(II) complex have more enzyme inhibition efficiency than salptsmh and Co(II) complex.

Alyar, Saliha; Adem, ?evki

2014-10-01

216

Synthesis, characterization, antimicrobial activity and carbonic anhydrase enzyme inhibitor effects of salicilaldehyde-N-methyl p-toluenesulfonylhydrazone and its Palladium(II), Cobalt(II) complexes.  

PubMed

We report the synthesis of the ligand, salicilaldehyde-N-methyl p-toluenesulfonylhydrazone (salptsmh) derived from p-toluenesulfonicacid-1-methylhydrazide (ptsmh) and its Pd(II) and Co(II) metal complexes were synthesized for the first time. The structure of the ligand and their complexes were investigated using elemental analysis, magnetic susceptibility, molar conductance and spectral (IR, NMR and LC-MS) measurements. Salptsmh has also been characterized by single crystal X-ray diffraction. (1)H and (13)C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The complexes were found to have general composition [ML2]. The results of elemental analysis showed 1:2 (metal/ligand) stoichiometry for all the complex. Magnetic and spectral data indicate a square planar geometry for Pd(II) complex and a distorted tetrahedral geometry for Co(II) complexes. The ligand and its metal chelates have been screened for their antimicrobial activities using the disk diffusion method against the selected Gram positive bacteria: Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Gram negative bacteria: Eschericha coli, Pseudomonas aeruginosa, Klebsiella pneumonia. The inhibition activities of these compounds on carbonic anhydrase II (CA II) and carbonic anhydrase I (CA I) have been investigated by comparing IC50 and Ki values and it has been found that Pd(II) complex have more enzyme inhibition efficiency than salptsmh and Co(II) complex. PMID:24835932

Alyar, Saliha; Adem, ?evki

2014-10-15

217

Spermicidal activity of the safe natural antimicrobial peptide subtilosin.  

PubMed

Bacterial vaginosis (BV), a condition affecting millions of women each year, is primarily caused by the gram-variable organism Gardnerella vaginalis. A number of organisms associated with BV cases have been reported to develop multidrug resistance, leading to the need for alternative therapies. Previously, we reported the antimicrobial peptide subtilosin has proven antimicrobial activity against G. vaginalis, but not against the tested healthy vaginal microbiota of lactobacilli. After conducting tissue sensitivity assays using an ectocervical tissue model, we determined that human cells remained viable after prolonged exposures to partially-purified subtilosin, indicating the compound is safe for human use. Subtilosin was shown to eliminate the motility and forward progression of human spermatozoa in a dose-dependent manner, and can therefore be considered a general spermicidal agent. These results suggest subtilosin would be a valuable component in topical personal care products aimed at contraception and BV prophylaxis and treatment. PMID:18923673

Sutyak, Katia E; Anderson, Robert A; Dover, Sara E; Feathergill, Kenneth A; Aroutcheva, Alla A; Faro, Sebastian; Chikindas, Michael L

2008-01-01

218

Spermicidal Activity of the Safe Natural Antimicrobial Peptide Subtilosin  

PubMed Central

Bacterial vaginosis (BV), a condition affecting millions of women each year, is primarily caused by the gram-variable organism Gardnerella vaginalis. A number of organisms associated with BV cases have been reported to develop multidrug resistance, leading to the need for alternative therapies. Previously, we reported the antimicrobial peptide subtilosin has proven antimicrobial activity against G. vaginalis, but not against the tested healthy vaginal microbiota of lactobacilli. After conducting tissue sensitivity assays using an ectocervical tissue model, we determined that human cells remained viable after prolonged exposures to partially-purified subtilosin, indicating the compound is safe for human use. Subtilosin was shown to eliminate the motility and forward progression of human spermatozoa in a dose-dependent manner, and can therefore be considered a general spermicidal agent. These results suggest subtilosin would be a valuable component in topical personal care products aimed at contraception and BV prophylaxis and treatment. PMID:18923673

Sutyak, Katia E.; Anderson, Robert A.; Dover, Sara E.; Feathergill, Kenneth A.; Aroutcheva, Alla A.; Faro, Sebastian; Chikindas, Michael L.

2008-01-01

219

A new probiotic cheese with antioxidative and antimicrobial activity.  

PubMed

The aim of our study was to develop an original probiotic cheese based on the Estonian open-texture, smear-ripened, semisoft cheese "Pikantne." Cheese was produced by two methods using cheese starter cultures (Probat 505) in combination with 0.04% of probiotic Lactobacillus fermentum strain ME-3 (10(9) cfu/mL) with high antimicrobial activity and antioxidative properties. The probiotic Lactobacillus was added into milk simultaneously with starter cultures (cheese A) and into drained curd (cheese B). After addition of probiotic L. fermentum ME-3, the cheese composition, flavor, and aroma were comparable to the control cheese (score values = 4.5, 4.2, and 3.7 for control cheese, cheese A, and cheese B, respectively). Cheese A, which had good sensory properties, was chosen for further testing of viability and probiotic properties. The probiotic strain was found to withstand the technological processing of cheese, surviving and sustaining moderate antimicrobial and high antioxidative activity throughout ripening and storage (the ripened cheese contained approximately 5 x 10(7) cfu/g viable ME-3 cells), although the viability of the ME-3 strain incorporated into the cheese showed a slight decrease between d 24 and 54 after cheese preparation. Semisoft cheese "Pikantne" serves as a suitable carrier of antimicrobial and antioxidative L. fermentum ME-3. PMID:15328213

Songisepp, E; Kullisaar, T; Hütt, P; Elias, P; Brilene, T; Zilmer, M; Mikelsaar, M

2004-07-01

220

Antimicrobial Activities of Synthetic Bismuth Compounds against Clostridium difficile  

PubMed Central

Clostridium difficile is a major nosocomial pathogen responsible for pseudomembranous colitis and many cases of antibiotic-associated diarrhea. Because of potential relapse of disease with current antimicrobial therapy protocols, there is a need for additional and/or alternative antimicrobial agents for the treatment of disease caused by C. difficile. We have synthesized a systematic series of 14 structurally simple bismuth compounds and assessed their biological activities against C. difficile and four other gastrointestinal species, including Helicobacter pylori. Here, we report on the activities of six compounds that exhibit antibacterial activities against C. difficile, and some of the compounds have MICs of less than 1 ?g/ml. Also tested, for comparison, were the activities of bismuth subcitrate and ranitidine bismuth citrate obtained from commercial sources. C. difficile and H. pylori were more sensitive both to the synthetic bismuth compounds and to the commercial products than were Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis, and the last three species were markedly resistant to the commercial bismuth salts. Testing with human foreskin fibroblast cells revealed that some of the synthetic compounds were more cytotoxic than others. Killing curves for C. difficile treated with the more active compounds revealed rapid death, and electron microscopy showed that the bismuth of these compounds was rapidly incorporated by C. difficile. Energy dispersive spectroscopy X-ray microanalysis of C. difficile cells containing electron-dense material confirmed the presence of internalized bismuth. Internalized bismuth was not observed in C. difficile treated with synthetic bismuth compounds that lacked antimicrobial activity, which suggests that the uptake of the metal is required for killing activity. The nature of the carrier would seem to determine whether bismuth is transported into susceptible bacteria like C. difficile. PMID:10049270

Mahony, D. E.; Lim-Morrison, S.; Bryden, L.; Faulkner, G.; Hoffman, P. S.; Agocs, L.; Briand, G. G.; Burford, N.; Maguire, H.

1999-01-01

221

Antimicrobial activity of certain Indian medicinal plants used in folkloric medicine  

Microsoft Academic Search

Fifty medicinal plants belonging to 26 families were studied for their antimicrobial activity. Among 50 plants tested, 72% showed antimicrobial activity. About 22 plant extracts from 15 families exhibited activity against both Gram-positive and Gram-negative bacteria. Fourteen plants belonging to 11 families did not show activity against any of the bacteria tested. Only nine plant extracts showed antifungal activity. The

D. Srinivasan; Sangeetha Nathan; T. Suresh; P. Lakshmana Perumalsamy

2001-01-01

222

Antimicrobial Activity of Propolis on Oral Microorganisms  

Microsoft Academic Search

.   Formation of dental caries is caused by the colonization and accumulation of oral microorganisms and extracellular polysaccharides\\u000a that are synthesized from sucrose by glucosyltransferase of Streptococcus mutans. The production of glucosyltransferase from oral microorganisms was attempted, and it was found that Streptococcus mutans produced highest activity of the enzyme. Ethanolic extracts of propolis (EEP) were examined whether EEP inhibit

Yong K. Park; Michel H. Koo; José A. S. Abreu; Masaharu Ikegaki; Jaime A. Cury; Pedro L. Rosalen

1998-01-01

223

Enhanced antimicrobial activity of peptide-cocktails against common bacterial contaminants of ex vivo stored platelets.  

PubMed

Bacterial contamination of blood components such as ex vivo-stored platelets is a major safety risk in transfusion medicine. We have recently shown that synthetic antimicrobial peptides named PD1-PD4 derived from the thrombin-induced human platelet-derived antimicrobial proteins, and repeats of Arg-Trp (RW1-RW5) demonstrate microbicidal activity against selected bacteria and viruses. In the present study, we selected PD3, PD4, RW2, RW3 and RW4 and evaluated each individual peptide and their various combinations to see whether the cocktail regimen enhances the antimicrobial activity above and over the individual peptides. Stored platelet or plasma samples spiked with known titres of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillus cereus were treated with either individual peptides or with peptides in various combinations. Analyses revealed that individual peptides show moderate microbicidal activity (10- to 100-fold reduction) against the tested bacteria relative to their combined regimen. The peptide combinations (RW2 + RW4, RW2 + RW3 + RW4 and PD4 + RW3 + RW4) on the other hand enhanced the microbicidal activity (c.10 000-fold reduction) and revealed a minimal inhibitory concentration of 5 ?M. Time-kill kinetics indicated that these three peptide combinations exhibited enhanced antimicrobial activity bringing about a 100-fold reduction of bacterial titres within 20 min of incubation. The present study therefore demonstrates the synergistic effect of antimicrobial peptides when used in combinations and provides a proof-of-concept of its potential application as a molecular tool towards pathogen reduction and further extends the possibility of using peptide combinatorial therapeutics as broad-spectrum antibiotics or as alternatives to combat drug-resistant bacteria. PMID:23926880

Mohan, K V K; Rao, S Sainath; Gao, Y; Atreya, C D

2014-01-01

224

In vitro antimicrobial activity of ethanolic fractions of Cryptolepis sanguinolenta  

PubMed Central

Background Following claims that some plants have antimicrobial activities against infectious microbes, the in vitro antimicrobial activities of different solvent fractions of ethanolic extract of Cryptolepis sanguinolenta were evaluated against eight standard bacteria and clinical isolates. Methods The solvent partitioning protocol involving ethanol, petroleum ether, chloroform, ethyl acetate and water, was used to extract various fractions of dried pulverized Cryptolepis sanguinolenta roots. Qualitative phyto-constituents screening was performed on the ethanol extract, chloroform fraction and the water fraction. The Kirby Bauer disk diffusion method was employed to ascertain the antibiogram of the test organisms while the agar diffusion method was used to investigate the antimicrobial properties of the crude plant extracts. The microplate dilution method aided in finding the MICs while the MBCs were obtained by the method of Nester and friends. The SPSS 16.0 version was used to analyze the percentages of inhibitions and bactericidal activities. Results The phytochemical screening revealed the presence of alkaloids, reducing sugars, polyuronides, anthocyanosides and triterpenes. The ethanol extract inhibited 5 out of 8 (62.5%) of the standard organisms and 6 out of 8 (75%) clinical isolates. The petroleum ether fraction inhibited 4 out of 8 (50%) of the standard microbes and 1 out of 8 (12.5%) clinical isolates. It was also observed that the chloroform fraction inhibited the growth of all the organisms (100%). Average inhibition zones of 14.0?±?1.0?mm to 24.67?±?0.58?mm was seen in the ethyl acetate fraction which halted the growth of 3 (37.5%) of the standard organisms. Inhibition of 7 (87.5%) of standard strains and 6 (75%) of clinical isolates were observed in the water fraction. The chloroform fraction exhibited bactericidal activity against all the test organisms while the remaining fractions showed varying degrees of bacteriostatic activity. Conclusion The study confirmed that fractions of Cryptolepis sanguinolenta have antimicrobial activity. The chloroform fraction had the highest activity, followed by water, ethanol, petroleum ether and ethyl acetate respectively. Only the chloroform fraction exhibited bactericidal activity and further investigations are needed to ascertain its safety and prospects of drug development. PMID:22709723

2012-01-01

225

Comparative in vitro antimicrobial activity of Chinese medicinal herbs.  

PubMed

Eighteen herbs used in the treatment of infectious diseases in traditional Chinese medicine were evaluated for in vitro activity against ten microbial pathogens. Lyophilized teas were tested by the agar dilution technique at 100-1600 micrograms/ml. Eleven of the preparations were active against at least one microorganism and six of these were active against at least three of the test isolates. Huangqin (Scutellaria sp.) and Huanglian (Coptis sp.) were each active against five of the isolates. Huangqin inhibited Klebsiella pneumoniae and Proteus vulgaris at 200 micrograms/ml. Huangqin alone showed strong activity against Mycobacterium smegmatis (less than or equal to 100 micrograms/ml) and Candida albicans (200 micrograms/ml). The antimicrobial activity of various teas, prepared with equal weights of herbs, could be compared against a particular pathogen by considering both the percentage of water-soluble material in the herbs and the minimum inhibitory concentrations of the filtered, lyophilized decoctions. PMID:3724208

Franzblau, S G; Cross, C

1986-03-01

226

Study of antimicrobial effects of vancomycin loaded PLGA nanoparticles against enterococcus clinical isolates.  

PubMed

Researchers have demonstrated that antimicrobial agents in nanoparticle (NP) forms have better activities. Vancomycin (VCM), as a glycopeptide antibiotic with antimicrobial activity against gram positive bacteria, is poorly absorbed from the intestinal tract. Enterococcus is a genus of bacteria that became resistant to a wide range of antibiotics in last decades, and cause severe infections in hospitalized patients. This paper describes preparation of VCM--loaded poly (lactic-co-glycolic acid) (PLGA) NPs and compares the antimicrobial effects with drug solution against clinical Enterococcus isolates. VCM-loaded PLGA NPs were fabricated by W1/O/W2 solvent evaporation method. The comparison of obtained Minimum Inhibitory Concentration (MIC) values showed a significant decrease in the antimicrobial effect of VCM -loaded NPs. Results also indicated that the potency of the NPs against VCM resistant isolates of Enterococcus was less than VCM susceptible isolates. The reduced antimicrobial effect of formulated NPs in invitro condition is perhaps related to the strong electrostatic linkage between hydrophilic drug (VCM) and hydrophobic polymer (PLGA) that lead to the slow release of the antibiotic from polymeric NPs. PMID:24307271

Lotfipour, F; Abdollahi, S; Jelvehgari, M; Valizadeh, H; Hassan, M; Milani, M

2014-07-01

227

In vitro antimicrobial activity against Pseudomonas aeruginosa and acute oral toxicity of marine algae Gracilaria changii  

Microsoft Academic Search

Methanol extract of the Gracilaria changii has been screened for antimicrobial activity against Pseudomonas aeruginosa. Antimicrobial activities were carried out using disc diffusion assay and broth dilution method against P. aeruginosa. The methanol extract of G. changii showed a good antimicrobial activity against P. aeruginosa with MIC (Minimum Inhibitory Concentration) value of 6.25mg\\/ml. Exposure of P. aeruginosa cells to 6.25mg\\/ml

Sreenivasan Sasidharan; Ibrahim Darah; Mohd Kassim Mohd Jain Noordin

2010-01-01

228

The Antimicrobial Activity, Mosquito Larvicidal Activity, Antioxidant Property and Tyrosinase Inhibition of Piper betle  

Microsoft Academic Search

The essential oil and methanolic and aqueous extracts of Piper betle L. were assayed for their anti- microbial activity, mosquito larvicidal activity, antioxidant property and mushroom tyrosinase inhibition. The methanolic and aquaous extracts showed strong activity against the yeasts: C. albicans ,a ndM. pachydermatis. The crude essential oil exhibited a broad-spectrum strong antimicrobial activity against all test organisms. The strongest

Li-Ching Morgan Row; Jiau-Ching Ho

229

Antimicrobial activity of seven hypericum entities from central Italy.  

PubMed

Methanol-acetone extracts from aerial parts of seven entities of the genus Hypericum [H. perforatum L. subsp. perforatum, H. perforatum L. subsp. veronense (Schrank) Ces., H. montanum L., H. hyssopifolium Chaix, H. hirsutum L., H. hircinum L. subsp. majus (Aiton) N. Robson, H. tetrapterum Fr.] growing in the Appennino Umbro-Marchigiano (central Italy) were tested in vitro for their antimicrobial activity against two Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis), two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and the yeast Candida albicans, by the Kirby-Bauer agar diffusion method. The two H. perforatum subspecies were particularly active against Gram-positive and Gram-negative bacteria, supporting the use of these plants in the traditional medicine of central Italy to treat wounds, skin and infectious diseases. However significant values of inhibition were given also by H. hirsutum against S. aureus and P. aeruginosa, and by H. hyssopifolium, H. hircinum subsp. majus and H. tetrapterum against C. albicans. These results suggest that hypericin and hyperforin are the main components responsible for antimicrobial activity, but not the only ones, as other extracts, showing a low level of these compounds, possess evident activity. Isolation of pure compounds from the most active extracts is in progress. PMID:17516331

Cecchini, Cinzia; Cresci, Alberto; Coman, Maria Magdalena; Ricciutelli, Massimo; Sagratini, Gianni; Vittori, Sauro; Lucarini, Domenico; Maggi, Filippo

2007-06-01

230

Evaluation of three medicinal plants for anti-microbial activity.  

PubMed

Herbal remedies have a long history of use for gum and tooth problems such as dental caries. The present microbiological study was carried out to evaluate the antimicrobial efficacy of three medicinal plants (Terminalia chebula Retz., Clitoria ternatea Linn., and Wedelia chinensis (Osbeck.) Merr.) on three pathogenic microorganisms in the oral cavity (Streptococcus mutans, Lactobacillus casei, and Staphylococcus aureus). Aqueous extract concentrations (5%, 10%, 25%, and 50%) were prepared from the fruits of Terminalia chebula, flowers of Clitoria ternatea, and leaves of Wedelia chinensis. The antimicrobial efficacy of the aqueous extract concentrations of each plant was tested using agar well diffusion method and the size of the inhibition zone was measured in millimeters. The results obtained showed that the diameter of zone of inhibition increased with increase in concentration of extract and the antimicrobial efficacy of the aqueous extracts of the three plants was observed in the increasing order - Wedelia chinensis < Clitoria ternatea < Terminalia chebula. It can be concluded that the tested extracts of all the three plants were effective against dental caries causing bacteria. PMID:23723653

Pratap, Gowd M J S; Manoj, Kumar M G; Sai, Shankar A J; Sujatha, B; Sreedevi, E

2012-07-01

231

Antimicrobial activity of confertifolin from Polygonum hydropiper.  

PubMed

Confertifolin (6,6,9a-trimethyl-4,5,5a,6,7,8,9,9a-octahydronaphtho[1,2-c] furan-3 (1H)-one) was isolated from the essential oil of Polygonum hydropiper L. (Polygonaceae) leaves using column chromatography. Confertifolin showed activity both in bacteria and fungi. The lowest MIC for bacteria was observed against Enterococcus faecalis (31.25 microg/mL). Significant MIC for fungi was observed against Scopulariopsis sp (7.81 microg/mL), Curvularia lunata (7.81 microg/mL), Epidermophyton floccosum (7.81 microg/mL), Trichophyton mentagrophytes (16.62 microg/mL), Trichophyton rubrum (MTCC 296) (16.62 microg/mL), Aspergillus niger (31.25 microg/mL), Botrytis cinerea (31.25 microg/mL) Magnaporthe grisea (62.5 microg/mL), Trichophyton simii (125 microg/mL) and Trichophyton rubrum (clinical isolate) (125 microg/mL). PMID:20645838

Duraipandiyan, Veeramuthu; Indwar, Francis; Ignacimuthu, Savarimuthu

2010-02-01

232

In vitro antimicrobial activity of potash alum.  

PubMed

This study reports the bactericidal activity of potash alum when added to water, against various epidemic causing enteric pathogens like Vibrio cholerae 01, V. cholerae 0139 and Shigella dysenteriae 1 by lowering the pH of water (from 6.0 to 4.0). Growth of the enteric pathogens was monitored in vitro by inoculating broth cultures of the different organisms in distilled water containing increasing concentrations of potash alum and quantitatively determining the concentration of viable organisms over a 48 h period by the standard plate count method. Controls constituted cultures of each organism grown in the absence of potash alum. The pH of alum administered water was measured in each test tube before inoculation of organisms. Potash alum was found to inhibit growth (10(5) viable count per ml) of most of the organisms examined, particularly V. cholerae 01 and V. cholerae 0139 in a dose dependent fashion. Reduction of colony forming units was observed in presence of 0.25 g/dl of alum after 5 h and no growth was noticed after 24 h. PMID:8783521

Dutta, S; De, S P; Bhattacharya, S K

1996-07-01

233

Water Soluble Usnic Acid-Polyacrylamide Complexes with Enhanced Antimicrobial Activity against Staphylococcus epidermidis  

PubMed Central

Usnic acid, a potent antimicrobial and anticancer agent, poorly soluble in water, was complexed to novel antimicrobial polyacrylamides by establishment of strong acidic-base interactions. Thermal and spectroscopic analysis evidenced a molecular dispersion of the drug in the polymers and a complete drug/polymer miscibility for all the tested compositions. The polymer/drug complexes promptly dissolved in water and possessed a greater antimicrobial activity against Staphylococcus epidermidis than both the free drug and the polymer alone. The best results were obtained with the complex based on the lowest molecular weight polymer and containing a low drug content. Such a complex showed a larger inhibition zone of bacterial growth and a lower minimum inhibitory concentration (MIC) with respect to usnic acid alone. This improved killing effect is presumably due to the reduced size of the complexes that allows an efficient cellular uptake of the antimicrobial complexes. The killing effect extent seems to be not significantly dependent on usnic acid content in the samples. PMID:23549269

Francolini, Iolanda; Taresco, Vincenzo; Crisante, Fernanda; Martinelli, Andrea; D'Ilario, Lucio; Piozzi, Antonella

2013-01-01

234

Synthesis and antimicrobial activity of novel 5-aminoimidazole-4-carboxamidrazones.  

PubMed

A mild and simple method was developed to prepare a series of fifteen 5-aminoimidazole 4-carboxamidrazones, starting from the easily accessible 5-amino-4-cyanoformimidoyl imidazoles. The antimicrobial activity of these novel amidrazones was screened against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Pseudomonas aeruginosa) bacteria and Candida sp. (Candida albicans, Candida krusei, Candida parapsilosis). Only a subset of compounds displayed fair-moderate activity against S. aureus and E. coli but all exhibited activity against Candida sp. The three most potent antifungal compounds were further tested against Cryptococcus neoformans, Aspergillus fumigatus and three dermatophytes (Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum gypseum). These three hit compounds strongly inhibited C. krusei and C. neoformans growth, although their activity on filamentous fungi was very weak when compared to the activity on yeasts. PMID:25193230

Ribeiro, Ana I; Gabriel, Carla; Cerqueira, Fátima; Maia, Marta; Pinto, Eugénia; Sousa, João Carlos; Medeiros, Rui; Proença, M Fernanda; Dias, Alice M

2014-10-01

235

Chitosan-hydroxycinnamic acid conjugates: preparation, antioxidant and antimicrobial activity.  

PubMed

In this study, the antioxidant and antimicrobial activities of chitosan-caffeic acid, chitosan-ferulic acid, and chitosan-sinapic acid conjugates with different grafting ratios were investigated. The synthesized chitosan-hydroxycinnamic acid conjugates were verified by performing (1)H NMR and differential scanning calorimetry analysis. The antioxidant activities of the conjugates were increased compared to the unmodified chitosan, by 1.79-fold to 5.05-fold (2,2-diphenyl-1-picrylhydrazyl scavenging assay), 2.44-fold to 4.12-fold (hydrogen peroxide scavenging assay), 1.34-fold to 3.35-fold (ABTS(+) radical scavenging assay), and also exhibited an increased reducing power. The conjugates also showed excellent lipid peroxidation inhibition abilities in a linoleic acid emulsion system. The conjugates exhibited antimicrobial activity against 15 clinical isolates, two standard methicillin-resistant Staphylococcus aureus (MRSA) and three standard methicillin-susceptible S. aureus strains, as well as eight foodborne pathogens. Additionally, the conjugates showed no cytotoxic activity towards human Chang liver and mouse macrophage RAW264.7 cells. PMID:24262532

Lee, Dae-Sung; Woo, Ji-Young; Ahn, Chang-Bum; Je, Jae-Young

2014-04-01

236

Assessment of antimicrobial activity of coffee brewed in three different ways from different origins  

Microsoft Academic Search

The antimicrobial effect against pathogens such as Staphylococcus aureus, Enterecoccus faecalis, Listeria monocytogenes, Pseudomonas aeruginosa, Escherichia coli and Salmonella\\u000a choleraesius was determined in four types of coffee (Coffea arabica L. cv. Colombia, decaffeinated cv. Colombia, cv. Ethiopia and cv. Kenya). Coffee was seen to have significant activity against\\u000a the growth of food spoilage bacteria. Among the Gram-positive bacteria, coffee was

Magdalena Martínez-Tomé; Antonia Ma Jiménez-Monreal; Laura García-Jiménez; Luis Almela; Luis García-Diz; Miguel Mariscal-Arcas; M. Antonia Murcia

237

The essential oil of Senecio graveolens ( Compositae): chemical composition and antimicrobial activity tests  

Microsoft Academic Search

The chemical composition of the essential oil obtained from Senecio graveolens (Compositae) was analyzed by GLC–MS and the components identified were: isovaleraldehyde, ?-pinene, ?-phellandrene, ?-terpinene, p-cymene, sabinene, ?-terpinene, 1-methyl-4-isopropenylbenzene, terpinolene, terpinen-4-ol, piperitenone, ?- and ?-eudesmol. The investigation by the agar-well diffusion method of the antimicrobial activity of the essential oil proved that it has antibacterial effects on Micrococcus luteus ATCC

Cristina Pérez; Alicia Mariel Agnese; José Luis Cabrera

1999-01-01

238

Design of nanoemulsion-based delivery systems of natural antimicrobials: Effect of the emulsifier  

Microsoft Academic Search

This work aims at investigating the effect of the nanoemulsion delivery systems on the antimicrobial activity of different essential oil components.Carvacrol, limonene and cinnamaldehyde were encapsulated in the sunflower oil droplets of nanoemulsions prepared by high pressure homogenization and stabilized by different emulsifiers: (a) lecithin, (b) pea proteins, (c) sugar ester and (d) a combination of Tween 20 and glycerol

Francesco Donsì; Marianna Annunziata; Mariarosaria Vincensi; Giovanna Ferrari

239

Natural antimicrobials: Effect of Microgard™ and nisin against Listeria innocua in liquid cheese whey  

Microsoft Academic Search

Antimicrobial activity of Microgard™ individually or in combination with nisin against Listeria innocua in liquid cheese whey (LCW) was investigated. Microgard™ did not reduce the initial count of L. innocua during storage at 7, 12, 20 and 25°C, and showed a response similar to the untreated whey. In comparison, nisin exhibited an immediate bactericidal effect that was followed by regrowth

Mariana von Staszewski; Rosa J. Jagus

2008-01-01

240

Pharmacological Assessment of the Medicinal Potential of Acacia mearnsii De Wild.: Antimicrobial and Toxicity Activities  

PubMed Central

Acacia mearnsii De Wild. (Fabaceae) is a medicinal plant used in the treatment of microbial infections in South Africa without scientific validation of its bioactivity and toxicity. The antimicrobial activity of the crude acetone extract was evaluated by both agar diffusion and macrobroth dilution methods while its cytotoxicity effect was assessed with brine shrimp lethality assay. The study showed that both bacterial and fungal isolates were highly inhibited by the crude extract. The MIC values for the gram-positive bacteria (78.1–312.5) ?g/mL, gram-negative bacteria (39.1–625) ?g/mL and fungal isolates (625–5000) ?g/mL differ significantly. The bacteria were more susceptible than the fungal strains tested. The antibiosis determination showed that the extract was more (75%) bactericidal than bacteriostatic (25%) and more fungicidal (66.67%) than fungistatic (33.33%). The cytotoxic activity of the extract was observed between 31.25 ?g/mL and 500 ?g/mL and the LC50 value (112.36 ?g/mL) indicates that the extract was nontoxic in the brine shrimp lethality assay (LC50 > 100 ?g/mL). These results support the use of A. mearnsii in traditional medicine for treatment of microbial infections. The extract exhibiting significant broad spectrum antimicrobial activity and nontoxic effects has potential to yield active antimicrobial compounds. PMID:22605976

Olajuyigbe, Olufunmiso O.; Afolayan, Anthony J.

2012-01-01

241

Antimicrobial and antioxidant activities of the essential oil and various extracts of Salvia tomentosa Miller (Lamiaceae)  

Microsoft Academic Search

This study was designed to examine the in vitro antimicrobial and antioxidant activities of the essential oil and various extracts (prepared by using solvents of varying polarity) of Salvia tomentosa (Miller). The essential oil was particularly found to possess strong antimicrobial activity while other non-polar extracts and subfractions showed moderate activities while polar extracts remained almost inactive. GC and GC\\/MS

Bektas Tepe; Dimitra Daferera; Atalay Sokmen; Munevver Sokmen; Moschos Polissiou

2005-01-01

242

Antimicrobial activity of propolis samples from two different regions of Anatolia  

Microsoft Academic Search

Antimicrobial activity of two propolis samples from Kazan and Marmaris regions in Turkey were investigated by the disc diffusion method. Antimicrobial activity was tested with four different ethanolic extracts (30, 50, 70, and 96% ethanol) of each sample against seven Gram positive, four Gram negative bacteria and one fungus culture. The activity was found to be mainly due to caffeic

Murat Kartal; Sulhiye Y?ld?z; Serdar Kaya; Semra Kurucu; Gülaçt? Topçu

2003-01-01

243

Proceedings of the Sudden Oak Death Third Science Symposium Antimicrobial Activity of Extracts and Select  

E-print Network

Proceedings of the Sudden Oak Death Third Science Symposium 375 Antimicrobial Activity of Extracts a microplate reader (Kuhajek and others 2003). Antimicrobial activity of all test compounds was analyzed occidentalis Hook.) were also tested and found to be equally active, but not investigated further until now

Standiford, Richard B.

244

Antimicrobial activity of Chinese medicine herbs against common bacteria in oral biofilm. A pilot study.  

PubMed

Twenty traditional Chinese medicines (TCM) were evaluated for their antimicrobial activity against four common oral bacteria. TCMs were tested for sensitivity against Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis. Aliquots of suspension of each bacterial species were inoculated onto a horse blood agar plate with TCMs soaked separately on 6mm paper disks. The plates were incubated for 48h anaerobically and the mean diameters of growth inhibition of three different areas obtained. 0.2% (w/v) chlorhexidine was used as a positive control. Broth microdilution assay was used to determine minimum inhibitory concentration and minimum bactericidal concentration. Fructus armeniaca mume was effective against all four bacteria. Thirteen TCMs demonstrated antimicrobial activity against Porphyromonas gingivalis, including Cortex magnoliae officinalis, Cortex phellodendri, Flos caryophylli, Flos lonicerae japonicae, Fructus armeniaca mume, Fructus forsythiae suspensae, Herba cum radice violae yedoensitis, Herba menthae haplocalycis, Pericarpium granati, Radix et rhizoma rhei, Radix gentianae, Ramulus cinnamomi cassia and Rhizoma cimicifugae. Cortex phellodendri showed antimicrobial activity against Streptococcus mutans, while Radix et rhizoma rhei was effective against Streptococcus mitis and Streptococcus sanguis. Fructus armeniaca mume had inhibitory effects against Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis in vitro. PMID:20418062

Wong, R W K; Hägg, U; Samaranayake, L; Yuen, M K Z; Seneviratne, C J; Kao, R

2010-06-01

245

In vitro antimicrobial activity of an experimental dentifrice based on ricinus communis.  

PubMed

This study evaluated the antimicrobial activity of a Ricinus communis-based experimental dentifrice for denture hygiene against the following standard strains: Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, Candida albicans and Candida glabrata. The minimum inhibitory concentration (MIC) assay was performed with R. communis in pure oil at 2.5%. Only E. coli was not inhibited by R. communis, but the MIC (0.0781%) was effective against the other microorganisms. From these results it was determined the R. communis concentrations for experimental dentifrices, 1, 2, 5 and 10%, which were evaluated by the test-well diffusion in agar. The commercial dentifrices Colgate, Trihydral and Corega Brite were tested for comparative purposes. The diameter of the zones of bacterial growth inhibition produced around the wells was measured (in mm) with a rule under reflected light. Data were analyzed statistically by analysis of variance and Tukey's post-hoc test (?=0.05). Neither the commercial nor the experimental dentifrices were effective against E. coli. The experimental dentifrices containing R. communis at 2, 5 and 10% presented action against S. mutans, S. aureaus and E. faecallis. The experimental dentifrices showed no antimicrobial activity against Candida spp. and E. coli in any of the tested concentrations. Trihydral was the most effective. Comparing the experimental dentifrices, the product with 10% R. communis produced the largest zones of bacterial growth inhibition and had similar antimicrobial activity to the commercial dentifrices, except against S. aureus. PMID:25252252

Leite, Vanessa Maria Fagundes; Pinheiro, Juliana Barchelli; Pisani, Marina Xavier; Watanabe, Evandro; de Souza, Raphael Freitas; Paranhos, Helena de Freitas Oliveira; Lovato-Silva, Cláudia Helena

2014-07-01

246

Antimicrobial activity of cationic peptides in endodontic procedures  

PubMed Central

Objectives: The present study aimed to investigate the antimicrobial and biofilm inhibition activity of synthetic antimicrobial peptides (AMPs) against microbes such as Enterococcus faecalis, Staphylococcus aureus, and Candida albicans which are involved in endodontic infections. Materials and Methods: Agar diffusion test was done to determine the activity of peptides. The morphological changes in E. faecalis and reduction in biofilm formation after treatment with peptides were observed using scanning electron microscope. The efficacy of peptides using an ex vivo dentinal model was determined by polymerase chain reaction and confocal laser scanning microscopy. Platelet aggregation was done to determine the biocompatibility of peptides. Results: Among 11 peptides, two of the amphipathic cationic peptides were found to be highly active against E. faecalis, S. aureus, C. albicans. Efficacy results using dentinal tubule model showed significant reduction in microbial load at 400 ?m depth. The peptides were also biocompatible. Conclusion: These results suggest that synthetic AMPs have the potential to be developed as antibacterial agents against microorganisms involved in dental infections and thus could prevent the spread and persistence of endodontic infections improving treatment outcomes and teeth preservation. PMID:24966779

Winfred, Sofi Beaula; Meiyazagan, Gowri; Panda, Jiban J.; Nagendrababu, Venkateshbabu; Deivanayagam, Kandaswamy; Chauhan, Virander S.; Venkatraman, Ganesh

2014-01-01

247

Antimicrobial activity of PLUNC protects against Pseudomonas aeruginosa infection  

PubMed Central

Epithelial antimicrobial activity may protect the lung against inhaled pathogens. The bactericidal/permeability-increasing protein family has demonstrated antimicrobial activity in vitro. PLUNC (palate, lung and nasal epithelium carcinoma associated) is a 25 kDa secreted protein that shares homology with bactericidal/permeability-increasing proteins and is expressed in nasopharyngeal and respiratory epithelium. The objective of this study was to determine whether PLUNC can limit Pseudomonas aeruginosa infection in mice. Transgenic mice (Scgb1a1-hPLUNC) were generated in which human PLUNC (hPLUNC) was directed to the airway epithelium with the Scgb1a1 promoter. The human PLUNC protein (hPLUNC) was detected in the epithelium throughout the trachea and bronchial airways and in bronchoalveolar lavage fluid (BALF). BALF from transgenic mice exhibited higher antibacterial activity than that from wild type littermates in vitro. Following in vivo P. aeruginosa challenge, Scgb1a1-hPLUNC transgenic mice displayed enhanced bacterial clearance. This was accompanied by a decrease in neutrophil infiltration and cytokine levels. More importantly, the over-expressed hPLUNC in Scgb1a1-hPLUNC transgenic mouse airway significantly enhanced mouse survival against P. aeruginosa induced respiratory infection. These data indicate that PLUNC is a novel antibacterial protein that likely plays a critical role in airway epithelium mediated innate immune response. PMID:21632717

Lukinskiene, Lina; Liu, Yang; Reynolds, Susan D.; Steele, Chad; Stripp, Barry R.; Leikauf, George D.; Kolls, Jay K.; Di, Y. Peter

2011-01-01

248

Preliminary phytochemical screening, antimicrobial and antioxidant activities of Euphorbia milli.  

PubMed

Euphorbia milii is a Pakistani herb used for various infectious diseases. In this study we have carried out phytochemical, antibacterial and antioxidant investigation of different extracts/fractions. Phytochemical studies showed the presence of cardiac glycosides, steroids/phytosterols, anthocyanin, proteins, terpenoids, flavonoids and tannins. Susceptibility testing by well diffusion assay of its chloroform and methanol fractions revealed good antimicrobial activity against Klebsiella pneumonia and Staph epidermis. Ethyl acetate fraction of roots also exhibited considerable antimicrobial activity against most of tested pathogens. Various fractions (Hexane, chloroform, methanol and water) of E. milii were screen for their antioxidant potential using DPPH radical scavenging assay at different concentrations among these, chloroform fraction exhibited good scavenging activity. The IR spectroscopy of the various extracts/fractions indicated the presence of OH, saturated CH stretching, C=C, C=O, NO2, C-N, Ar-O, C-O- and R-O-Stretching respectively. The findings provide helpful evidence for the use of E. milii in traditional medicines. PMID:25015465

Rauf, Abdur; Khan, Ajmal; Uddin, Nizam; Akram, Muhammad; Arfan, Mohammad; Uddin, Ghias; Qaisar, Muhammad

2014-07-01

249

Biosynthesis and Antimicrobial Activity of Semiconductor Nanoparticles against Oral Pathogens  

PubMed Central

Dental care is an essential phenomenon in human health. Oral pathogens can cause severe break which may show the way to serious issues in human disease like blood circulation and coronary disease. In the current study, we demonstrated the synthesis and antimicrobial activity of cadmium sulphide and zinc sulphide nanoparticles against oral pathogens. The process for the synthesis of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles is fast, novel, and ecofriendly. Formation of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles was confirmed by surface plasmon spectra using UV-Vis spectrophotometer. The morphology of crystalline phase of nanoparticles was determined from transmission electron microscopy (TEM) and X-ray diffraction (XRD) spectra. The average size of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles was in the range of 10?nm to 25?nm and 65?nm, respectively, and the observed morphology was spherical. The results indicated that the proteins, which contain amine groups, played a reducing and controlling responsibility during the formation of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles in the colloidal solution. The antimicrobial activity was assessed against oral pathogens such as Streptococcus sp. Staphylococcus sp. Lactobacillus sp., and Candida albicans and these results confirmed that the sulphide nanoparticles are exhibiting good bactericidal activity. PMID:24860280

Malarkodi, C.; Rajeshkumar, S.; Paulkumar, K.; Vanaja, M.; Gnanajobitha, G.; Annadurai, G.

2014-01-01

250

Antimicrobial activity of selected South African medicinal plants  

PubMed Central

Background Nearly 3,000 plant species are used as medicines in South Africa, with approximately 350 species forming the most commonly traded and used medicinal plants. In the present study, twelve South African medicinal plants were selected and tested for their antimicrobial activities against eight microbial species belonging to fungi, Mycobacteria, Gram-positive and Gram-negative bacteria. Methods The radiometric respiratory technique using the BACTEC 460 system was used for susceptibility testing against Mycobacterium tuberculosis, and the liquid micro-broth dilution was used for other antimicrobial assays. Results The results of the minimal inhibitory concentration (MIC) determinations indicated that the methanol extracts from Acacia karoo, Erythrophleum lasianthum and Salvia africana were able to prevent the growth of all the tested microorganisms. All other samples showed selective activities. MIC values below 100??g/ml were recorded with A. karoo, C. dentate, E. lasianthum, P. obligun and S. africana on at least one of the nine tested microorganisms. The best activity (MIC value of 39.06??g/ml) was noted with S. africana against E. coli, S. aureus and M. audouinii, and Knowltonia vesitoria against M. tuberculosis. Conclusion The overall results of the present work provide baseline information for the possible use of the studied South African plant extracts in the treatment of microbial infections. PMID:22704594

2012-01-01

251

Antimicrobial and antifungal effects of tissue conditioners containing a photocatalyst.  

PubMed

This study examined the antimicrobial/antifungal ability of a tissue conditioner containing a photocatalyst for Escherichia coli, Streptococcus mutans, Staphylococcus aureus and Candida albicans. The photocatalyst was mixed with tissue conditioners powders at concentrations of 0, 10, 15, and 20 wt%. Tissue conditioners powders containing a photocatalyst were mixed with liquid to make test specimens. Test specimens inoculated by each microorganism were irradiated by ultraviolet light for 0-, 2- and 4 hours. The antimicrobial/antifungal effects were evaluated by the CFU technique. The CFU values of each microorganism for tissue conditioners containing a photocatalyst showed significant decrease following UV-irradiation. The improvement in antimicrobial/antifungal effects was concomitant with the increase of the mixing ratio and the irradiation time. Therefore, the results indicated that tissue conditioners containing a photocatalyst might have photocatalytic ability. PMID:21946490

Uchimaru, Masayuki; Sakai, Takako; Moroi, Ryoji; Shiota, Susumu; Shibata, Yukie; Deguchi, Mikito; Sakai, Hidetaka; Yamashita, Yoshihisa; Terada, Yoshihiro

2011-01-01

252

Anthelmintic and antimicrobial activity of methanolic and aqueous extracts of Euphorbia helioscopia L.  

PubMed

The aim of this study was to evaluate the anthelmintic and antimicrobial efficacy of Euphorbia helioscopia crude extracts. A worm motility inhibition assay and egg hatch assay were used for in vitro study, and a faecal egg count reduction assay was used for in vivo study. The in vitro study revealed anthelmintic effects of crude methanolic extracts of E. helioscopia on live Haemonchus contortus worms as evident from their paralysis and/or death at 8 h after exposure. Different concentrations (12.5 mg?ml(-1), 25 mg?ml(-1) and 50 mg?ml(-1)) of aqueous and methanolic extracts were used against H. contortus which exhibited dose-dependent anthelmintic effects on H. contortus. Different extracts of E. helioscopia on percent inhibitory egg hatching was very low as compared to levamisole. The antimicrobial activity of extracts ranging from 100 to 500 mg?ml(-1) screened by disc diffusion method against four selected bacterial (Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas multocida and Escherichia coli) and two fungal strains (Aspergillus flavus and Candida albicans) was also dose dependent with the extract showing more inhibitory effects against S. aureus and E. coli and a minimum inhibitory effect against A. flavus. It is concluded that the entire plant of E. helioscopia possesses significant anthelmintic and antimicrobial activity and could be a potential alternative for treating cases of helminth infections in ruminants. PMID:23065392

Lone, Bashir A; Bandh, Suhaib A; Chishti, Mohammad Zahoor; Bhat, Fayaz Ahmad; Tak, Hidayatullah; Nisa, Humeera

2013-03-01

253

Comparative antimicrobial activities of aerosolized sodium hypochlorite, chlorine dioxide, and electrochemically activated solutions evaluated using a novel standardized assay.  

PubMed

The main aim of this study was to develop a standardized experimental assay to enable differential antimicrobial comparisons of test biocidal aerosols. This study represents the first chlorine-matched comparative assessment of the antimicrobial activities of aerosolized sodium hypochlorite, chlorine dioxide, and electrochemically activated solution (ECAS) to determine their relative abilities to decontaminate various surface-associated health care-relevant microbial challenges. Standard microbiological challenges were developed by surface-associating typed Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis spores, or a clinical methicillin-resistant S. aureus (MRSA) strain on stainless steel, polypropylene, or fabric. All test coupons were subjected to 20-min biocidal aerosols of chlorine-matched (100 ppm) sodium hypochlorite, chlorine dioxide, or ECAS within a standard aerosolization chamber using a commercial humidifier under defined conditions. Biocidal treatment type and material surface had a significant effect on the number of microorganisms recovered from various material surfaces following treatment exposure. Under the conditions of the assay, the order of antimicrobial efficacy of biocidal aerosol treatment was as follows: ECAS > chlorine dioxide > sodium hypochlorite. For all biocides, greater antimicrobial reductions were seen when treating stainless steel and fabric than when treating plastic-associated microorganisms. The experimental fogging system and assay protocol designed within this study were shown capable of differentiating the comparative efficacies of multiple chlorine-matched biocidal aerosols against a spectrum of target organisms on a range of test surface materials and would be appropriate for testing other biocidal aerosol treatments or material surfaces. PMID:23459480

Thorn, R M S; Robinson, G M; Reynolds, D M

2013-05-01

254

Comparative Antimicrobial Activities of Aerosolized Sodium Hypochlorite, Chlorine Dioxide, and Electrochemically Activated Solutions Evaluated Using a Novel Standardized Assay  

PubMed Central

The main aim of this study was to develop a standardized experimental assay to enable differential antimicrobial comparisons of test biocidal aerosols. This study represents the first chlorine-matched comparative assessment of the antimicrobial activities of aerosolized sodium hypochlorite, chlorine dioxide, and electrochemically activated solution (ECAS) to determine their relative abilities to decontaminate various surface-associated health care-relevant microbial challenges. Standard microbiological challenges were developed by surface-associating typed Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis spores, or a clinical methicillin-resistant S. aureus (MRSA) strain on stainless steel, polypropylene, or fabric. All test coupons were subjected to 20-min biocidal aerosols of chlorine-matched (100 ppm) sodium hypochlorite, chlorine dioxide, or ECAS within a standard aerosolization chamber using a commercial humidifier under defined conditions. Biocidal treatment type and material surface had a significant effect on the number of microorganisms recovered from various material surfaces following treatment exposure. Under the conditions of the assay, the order of antimicrobial efficacy of biocidal aerosol treatment was as follows: ECAS > chlorine dioxide > sodium hypochlorite. For all biocides, greater antimicrobial reductions were seen when treating stainless steel and fabric than when treating plastic-associated microorganisms. The experimental fogging system and assay protocol designed within this study were shown capable of differentiating the comparative efficacies of multiple chlorine-matched biocidal aerosols against a spectrum of target organisms on a range of test surface materials and would be appropriate for testing other biocidal aerosol treatments or material surfaces. PMID:23459480

Thorn, R. M. S.; Robinson, G. M.

2013-01-01

255

Mixed monolayer of DPPC and lysine-based cationic surfactants: an investigation into the antimicrobial activity.  

PubMed

In this paper, we report studies which aim to elucidate the mechanisms involved in the antimicrobial activity of three cationic lysine-based surfactants: LLM, LALM, and C6 (LL)2. To this end, a simple membrane model (i.e., 1,2-dipalmitoyl-sn-phosphatidylcholine, DPPC) was used to explore the monolayer properties at the air/liquid interface. Compression ?-A isotherms of mixtures of DPPC/lysine surfactants at different pH showed an expansion of the DPPC monolayer, suggesting cationic lysine surfactant/DPPC interactions, which strongly depend on surfactant structure and hydrophobic interactions. Antimicrobial activity of the three surfactants has also been assessed with transmission electron microscopy, observing the effects on Staphylococcus aureus and Escherichia coli . The three surfactants caused various kinds of damage to the bacteria tested, such as structural alterations, leakage of internal material, and cell destruction. PMID:23750883

Colomer, Aurora; Perez, Lourdes; Pons, Ramon; Infante, Maria Rosa; Perez-Clos, Dani; Manresa, Angels; Espuny, Maria Jose; Pinazo, Aurora

2013-06-25

256

Antimicrobial Activity of Artemisia absinthium Against Surgical Wounds Infected by Staphylococcus aureus in a Rat Model.  

PubMed

The wound infection is one of the frequent complications in patients undergoing surgical operations. Staphylococcus aureus is the most common cause of surgical wounds. Artemisia absinthium has been shown to bear strong antimicrobial activity, especially against Gram-positive pathogens. This study was designed to investigate the antimicrobial effects of A. absinthium against surgical wounds infected by S. aureus in a rat model. Twenty male Sprague-Dawley rats were divided randomly into two equal groups of treated and control rats. A circular incision was created on the dorsal inter-scapular region of each rat. After skin wounding, rats were inoculated locally with 1 × 10(4) CFU of S. aureus at sites of skin wounds. The extract was applied topically twice a day throughout the experiment. Animals of the control group were left untreated. Results have revealed that topical application of A. absinthium extract on the infected wound sites produced significant antibacterial activity against S. aureus. PMID:24293717

Moslemi, Hamid Reza; Hoseinzadeh, Hesamoddin; Badouei, Mahdi Askari; Kafshdouzan, Khatereh; Fard, Ramin Mazaheri Nezhad

2012-12-01

257

Antimicrobial activity of cobalt imidazolate metal-organic frameworks.  

PubMed

Two cobalt imidazolate metal-organic frameworks were evaluated as a bactericidal material against the growth of the Gram-negative bacteria Pseudomonas putida and Escherichia coli. Under the most unfavourable conditions, within the exponential growth phase and in the culture media for both microorganisms, the growth inhibition reached over 50% for concentrations of biocidal material in the 5-10mgL(-1) range. The release of metal gives excellent durability with the antibacterial effect persisting after 3months. Both cobalt-based materials can be prepared with simple, cheap and easily accessible commercial ligands, leading to a more affordable possible future application as antimicrobial materials. PMID:25065809

Aguado, Sonia; Quirós, Jennifer; Canivet, Jerome; Farrusseng, David; Boltes, Karina; Rosal, Roberto

2014-10-01

258

General Principles of Antimicrobial Therapy  

PubMed Central

Antimicrobial agents are some of the most widely, and often injudiciously, used therapeutic drugs worldwide. Important considerations when prescribing antimicrobial therapy include obtaining an accurate diagnosis of infection; understanding the difference between empiric and definitive therapy; identifying opportunities to switch to narrow-spectrum, cost-effective oral agents for the shortest duration necessary; understanding drug characteristics that are peculiar to antimicrobial agents (such as pharmacodynamics and efficacy at the site of infection); accounting for host characteristics that influence antimicrobial activity; and in turn, recognizing the adverse effects of antimicrobial agents on the host. It is also important to understand the importance of antimicrobial stewardship, to know when to consult infectious disease specialists for guidance, and to be able to identify situations when antimicrobial therapy is not needed. By following these general principles, all practicing physicians should be able to use antimicrobial agents in a responsible manner that benefits both the individual patient and the community. PMID:21282489

Leekha, Surbhi; Terrell, Christine L.; Edson, Randall S.

2011-01-01

259

Antimicrobial activities of Gloriosa superba Linn (Colchicaceae) extracts.  

PubMed

The methanol extract of the rhizomes of Gloriosa superba Linn (Colchicaceae) and its subsequent fractions in different solvent systems were screened for antibacterial and antifungal activities. Excellent antifungal sensitivity was expressed by the n-butanol fraction against Candida albicans and Candida glaberata (up to 90%) and against Trichophyton longifusus (78%) followed by the chloroform fraction against Microsporum canis (80%). In the antibacterial bioassay, the crude extract and subsequent fractions showed mild to moderate antibacterial activities. Chloroform fraction displayed highest antibacterial sensitivity against Staphylococcus aureous (88%) followed by the crude extract (59%). The total phenol content of the crude extract and fractions of the plant expressed no significant correlation with the antimicrobial activities. PMID:18615278

Khan, Haroon; Khan, Murad Ali; Mahmood, Tahira; Choudhary, Muhammad Iqbal

2008-12-01

260

The in vitro antimicrobial activities of the essential oils of some Lamiaceae species from Turkey.  

PubMed

In this study, antimicrobial activities of the essential oils obtained by using the hydrodistillation method from some lamiaceous plants--Mentha longifolia (L.) Hudson ssp. longifolia, M. longifolia (L.) Hudson ssp. typhoides (Briq.) Harley var. typhoides, Mentha pulegium L., Salvia fruticosa Miller, Salvia tomentosa Miller, Calamintha nepeta (L.) Savi ssp. glandulosa (Req.) P.W. Ball, Nepeta cadmea Boiss., Lavandula stoechas L. ssp. stoechas, and Ziziphora tenuior L.--were determined by using the disc diffusion method. The plants used in this study were collected from different localities of Mu?la Province, Turkey. All the essential oils isolated from the plants were very effective against Gram-positive and Gram-negative bacteria, which included multiple-antibiotic resistant strains, except Pseudomonas aeruginosa ATCC 27853 and Pseudomonas fluorescens MU 87. The essential oils of the plant species, except S. tomentosa and S. fruticosa, were very effective against Candida albicans. The antimicrobial activities varied depending on the species, subspecies, or variety. In fact, essential oils of some plants belonging to the same taxa but collected from different localities showed different levels of antimicrobial activities. PMID:19735193

Sarac, Nurdan; Ugur, Aysel

2009-08-01

261

In vitro antimicrobial activity of natural toxins and animal venoms tested against Burkholderia pseudomallei  

PubMed Central

Background Burkholderia pseudomallei are the causative agent of melioidosis. Increasing resistance of the disease to antibiotics is a severe problem in treatment regime and has led to intensification of the search for new drugs. Antimicrobial peptides are the most ubiquitous in nature as part of the innate immune system and host defense mechanism. Methods Here, we investigated a group of venoms (snakes, scorpions and honey bee venoms) for antimicrobial properties against two strains of Gram-negative bacteria Burkholderia pseudomallei by using disc-diffusion assay for in vitro susceptibility testing. The antibacterial activities of the venoms were compared with that of the isolated L-amino acid oxidase (LAAO) and phospholipase A2 (PLA2s) enzymes. MICs were determined using broth dilution method. Bacterial growth was assessed by measurement of optical density at the lowest dilutions (MIC 0.25 mg/ml). The cell viability was measured using tetrazolium salts (XTT) based cytotoxic assay. Results The studied venoms showed high antimicrobial activity. The venoms of C. adamanteus, Daboia russelli russelli, A. halys, P. australis, B. candidus and P. guttata were equally as effective as Chloramphenicol and Ceftazidime (30 ?g/disc). Among those tested, phospholipase A2 enzymes (crotoxin B and daboiatoxin) showed the most potent antibacterial activity against Gram-negative (TES) bacteria. Naturally occurring venom peptides and phospholipase A2 proved to possess highly potent antimicrobial activity against Burkholderia pseudomallei. The XTT-assay results showed that the cell survival decreased with increasing concentrations (0.05–10 mg/mL) of Crotalus adamanteus venom, with no effect on the cell viability evident at 0.5 mg/mL. Conclusion This antibacterial profile of snake venoms reported herein will be useful in the search for potential antibacterial agents against drug resistant microorganisms like B. pseudomallei. PMID:16784542

Perumal Samy, R; Pachiappan, A; Gopalakrishnakone, P; Thwin, Maung M; Hian, Yap E; Chow, Vincent TK; Bow, Ho; Weng, Joseph T

2006-01-01

262

Characterization of essential oil from Citrus aurantium L. flowers: antimicrobial and antioxidant activities.  

PubMed

Citrus aurantium L. essential oil is commonly used as a flavouring agent. In the present study, the essential oil of fresh Citrus aurantium L. (CaEO) flowers cultivated in North East of Tunisia (Nabeul) was analyzed by GC-FID and GC-MS. 33 compounds were identified, representing 99% of the total oil. Limonene (27.5%) was the main component followed by E-nerolidol (17.5%), ?-terpineol (14%), ?-terpinyl acetate (11.7%) and E. E-farnesol (8%). The antimicrobial activity of the CaEO was evaluated against a panel of 13 bacteria and 8 fungal strains using agar diffusion and broth microdilution methods. Results have shown that the CaEO exhibited moderate to strong antimicrobial activity against the tested species. The investigation of the mode of action of the CaEO by the time-kill curve showed a drastic bactericidal effect after 5 min using a concentration of 624 ?g/ml. The antioxidant activities of the CaEO were assayed by DPPH and beta carotene tests. Results showed that CaEO displayed an excellent DPPH scavenging ability with an IC?? of 1.8 ?g/ml and a strong Beta-carotene bleaching inhibition after 120 min of incubation with an IC?? of 15.3 ?g/ml. The results suggested that the CaEO possesses antimicrobial and antioxidant properties, and is therefore a potential source of active ingredients for food and pharmaceutical industry. PMID:24088513

Ben Hsouna, Anis; Hamdi, Naceur; Ben Halima, Nihed; Abdelkafi, Slim

2013-01-01

263

Antimicrobial activity of metal based nanoparticles against microbes associated with diseases in aquaculture.  

PubMed

The emergence of diseases and mortalities in aquaculture and development of antibiotics resistance in aquatic microbes, has renewed a great interest towards alternative methods of prevention and control of diseases. Nanoparticles have enormous potential in controlling human and animal pathogens and have scope of application in aquaculture. The present investigation was carried out to find out suitable nanoparticles having antimicrobial effect against aquatic microbes. Different commercial as well as laboratory synthesized metal and metal oxide nanoparticles were screened for their antimicrobial activities against a wide range of bacterial and fungal agents including certain freshwater cyanobacteria. Among different nanoparticles, synthesized copper oxide (CuO), zinc oxide (ZnO), silver (Ag) and silver doped titanium dioxide (Ag-TiO2) showed broad spectrum antibacterial activity. On the contrary, nanoparticles like Zn and ZnO showed antifungal activity against fungi like Penicillium and Mucor species. Since CuO, ZnO and Ag nanoparticles showed higher antimicrobial activity, they may be explored for aquaculture use. PMID:24888333

Swain, P; Nayak, S K; Sasmal, A; Behera, T; Barik, S K; Swain, S K; Mishra, S S; Sen, A K; Das, J K; Jayasankar, P

2014-09-01

264

Essential oils and isolated compounds from Lippia alba leaves and flowers: Antimicrobial activity and osteoclast apoptosis.  

PubMed

In the present study, essential oils extracted from the leaves and flowers of Lippia alba (Mill.) N.E.Br. (L. alba) were analyzed for their antimicrobial activity and their effects on osteoclasts. The periodontal pathogens, Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans; ATCC 43717), Fusobacterium nucleatum (F. nucleatum; ATCC 25586) and Porphyromonas gingivalis (P. gingivalis); ATCC 33277) were used in antimicrobial activity assays for determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC), whereas Bacteroides fragilis (B. fragilis; ATCC 25285) was used as the control microorganism. Osteoclast (OC) apoptosis was assessed by TUNEL assay and Fas receptor expression was detected by immunocytochemistry. The analysis of antimicrobial activity revealed that P. gingivalis had the lowest MIC values, whereas A. actinomycetemcomitans had the highest. L. alba essential oils were found to be toxic to human cells, although the compounds, carvone, limonene and citral, were non-toxic and induced apoptosis in the OCs. This study demonstrates that L. alba has potential biotechnological application in dentistry. In fact periodontal disease has a multifactorial etiology, and the immune response to microbial challenge leads to osteoclast activation and the resorption of the alveolar bone, resulting in tooth loss. PMID:25384405

Lima Juiz, Paulo José; Lucchese, Angelica Maria; Gambari, Roberto; Piva, Roberta; Penolazzi, Letizia; Di Ciano, Martina; Uetanabaro, Ana Paula Trovatti; Silva, Franceli; Avila-Campos, Mario Julio

2015-01-01

265

Phenolic compounds from the leaf extract of artichoke (Cynara scolymus L.) and their antimicrobial activities.  

PubMed

A preliminary antimicrobial disk assay of chloroform, ethyl acetate, and n-butanol extracts of artichoke (Cynara scolymus L.) leaf extracts showed that the n-butanol fraction exhibited the most significant antimicrobial activities against seven bacteria species, four yeasts, and four molds. Eight phenolic compounds were isolated from the n-butanol soluble fraction of artichoke leaf extracts. On the basis of high-performance liquid chromatography/electrospray ionization mass spectrometry, tandem mass spectrometry, and nuclear magnetic resonance techniques, the structures of the isolated compounds were determined as the four caffeoylquinic acid derivatives, chlorogenic acid (1), cynarin (2), 3,5-di-O-caffeoylquinic acid (3), and 4,5-di-O-caffeoylquinic acid (4), and the four flavonoids, luteolin-7-rutinoside (5), cynaroside (6), apigenin-7-rutinoside (7), and apigenin-7-O-beta-D-glucopyranoside (8), respectively. The isolated compounds were examined for their antimicrobial activities on the above microorganisms, indicating that all eight phenolic compounds showed activity against most of the tested organisms. Among them, chlorogenic acid, cynarin, luteolin-7-rutinoside, and cynaroside exhibited a relatively higher activity than other compounds; in addition, they were more effective against fungi than bacteria. The minimum inhibitory concentrations of these compounds were between 50 and 200 microg/mL. PMID:15563206

Zhu, Xianfeng; Zhang, Hongxun; Lo, Raymond

2004-12-01

266

Enhanced cellular uptake by "pharmaceutically oriented devices" of new simplified analogs of Linezolid with antimicrobial activity.  

PubMed

The aim of the present study was to enhance cellular uptake of simplified analogs of Linezolid by their incorporation into suitable delivery devices in order to improve the antimicrobial activity of these novel synthesized oxazolidin-2-one derivatives. The oxazolidin-2-one derivatives were synthesized by developing a rather simple one-pot reaction starting from oxiranylmethanol and several primary amines. Three delivery devices were prepared by following different synthetic approaches, such as single-step free radical grafting, precipitation polymerization and nano-emulsion. Finally, the antimicrobial activity of the novel synthesized compounds, without any vehicle and after their incorporation into the delivery devices, was evaluated against Escherichia coli and Saccharomyces cerevisiae by performing time-kill analyses. The synthesized oxazolidinones exhibited modest antimicrobial activity against E. coli and S. cerevisiae (MIC 16 ?g/mL). A good activity was, instead, highlighted after their incorporation into the prepared delivery devices (lecithin-based nano-emulsion, poly(N-vinyl-pyrrolidone)-methacrylic acid grafted copolymer and spherical polymeric nanoparticles) (MIC?4 ?g/mL). The incorporation into suitable vehicles, indeed, reduced by 4 times the normal MICs of the newly synthesized oxazolilidin-2-ones and represents an effective strategy to overcome cellular penetration constraints. PMID:24296047

Parisi, Ortensia Ilaria; Fiorillo, Marco; Caruso, Anna; Cappello, Anna Rita; Saturnino, Carmela; Puoci, Francesco; Panno, Antonella; Dolce, Vincenza; El-Kashef, Hussein; Sinicropi, Maria Stefania

2014-01-30

267

Antimicrobial and antioxidant activities of Cortex Magnoliae Officinalis and some other medicinal plants commonly used in South-East Asia  

PubMed Central

Background Eight medicinal plants were tested for their antimicrobial and antioxidant activities. Different extraction methods were also tested for their effects on the bioactivities of the medicinal plants. Methods Eight plants, namely Herba Polygonis Hydropiperis (Laliaocao), Folium Murraya Koenigii (Jialiye), Rhizoma Arachis Hypogea (Huashenggen), Herba Houttuyniae (Yuxingcao), Epipremnum pinnatum (Pashulong), Rhizoma Typhonium Flagelliforme (Laoshuyu), Cortex Magnoliae Officinalis (Houpo) and Rhizoma Imperatae (Baimaogen) were investigated for their potential antimicrobial and antioxidant properties. Results Extracts of Cortex Magnoliae Officinalis had the strongest activities against M. Smegmatis, C. albicans, B. subtilis and S. aureus. Boiled extracts of Cortex Magnoliae Officinalis, Folium Murraya Koenigii, Herba Polygonis Hydropiperis and Herba Houttuyniae demonstrated greater antioxidant activities than other tested medicinal plants. Conclusion Among the eight tested medicinal plants, Cortex Magnoliae Officinalis showed the highest antimicrobial and antioxidant activities. Different methods of extraction yield different spectra of bioactivities. PMID:19038060

Chan, Lai Wah; Cheah, Emily LC; Saw, Constance LL; Weng, Wanyu; Heng, Paul WS

2008-01-01

268

Bioprotective properties of Dragon's blood resin: In vitro evaluation of antioxidant activity and antimicrobial activity  

PubMed Central

Background Food preservation is basically done to preserve the natural characteristics and appearance of the food and to increase the shelf life of food. Food preservatives in use are natural, chemical and artificial. Keeping in mind the adverse effects of synthetic food preservatives, there is a need to identify natural food preservatives. The aims of this study were to evaluate in vitro antioxidant and antimicrobial activities of Dragon's blood resin obtained from Dracaena cinnabari Balf f., with a view to develop safer food preservatives. Methods In this study, three solvents of varying polarity were used to extract and separate the medium and high polarity compounds from the non-polar compounds of the Dragon's blood resin. The extracts were evaluated for their antimicrobial activity against the food borne pathogens. The antioxidant activities of the extracts were assessed using DPPH and ABTS radical scavenging, FRAP, metal chelating and reducing power assays. Total phenolics, flavonoids and flavonols of extracts were also estimated using the standard methods. Results Phytochemical analysis of extracts revealed high phenolic content in CH2Cl2 extract of resin. Free radical scavenging of CH2Cl2 extract was found to be highest which is in good correlation with its total phenolic content. All test microorganisms were also inhibited by CH2Cl2 extract. Conclusions Our result provide evidence that CH2Cl2 extract is a potential source of natural antioxidant compounds and exhibited good inhibitory activity against various food borne pathogens. Thus, CH2Cl2 extract of Dragon's blood resin could be considered as possible source of food preservative. PMID:21329518

2011-01-01

269

Antimicrobial Activity of Terminalia catappa, Manilkara zapota and Piper betel Leaf Extract  

PubMed Central

Aqueous and methanol extract of the leaves of Terminalia catappa L., Manilkara zapota L. and Piper betel L. were evaluated for antibacterial activity against 10 Gram positive, 12 Gram negative bacteria and one fungal strain, Candida tropicalis. Piperacillin and gentamicin were used as standards for antibacterial assay, while fluconazole was used as standard for antifungal assay. The three plants showed different degree of activity against the microorganisms investigated. The methanolic extract was considerably more effective than aqueous extract in inhibiting the investigated microbial strains. The most active antimicrobial plant was Piper betel. PMID:20046756

Nair, R.; Chanda, Sumitra

2008-01-01

270

Relationship of Chemical Structure and Antimicrobial Activity of Alkyl Amides and Amines  

PubMed Central

Contrary to the limited effects of alkyl amides and their corresponding N-derivatives, alkyl amines affected both gram-positive and gram-negative organisms. As with other alkyl derivatives the most sensitive gram-negative bacteria were usually more resistant than the most resistant gram-positive bacteria. Compounds with a chain-length of 11 to 15 are most active. Although some of the general properties relating the activity of fatty acids to their antimicrobial action are similar to those of amine compounds, the amines are unique in that monounsaturation does not increase compound activity. The possible modes of action of these compounds are discussed. PMID:4670442

Kabara, Jon J.; Conley, Anthony J.; Truant, Joseph P.

1972-01-01

271

Antimicrobial Activity of Terminalia catappa, Manilkara zapota and Piper betel Leaf Extract.  

PubMed

Aqueous and methanol extract of the leaves of Terminalia catappa L., Manilkara zapota L. and Piper betel L. were evaluated for antibacterial activity against 10 Gram positive, 12 Gram negative bacteria and one fungal strain, Candida tropicalis. Piperacillin and gentamicin were used as standards for antibacterial assay, while fluconazole was used as standard for antifungal assay. The three plants showed different degree of activity against the microorganisms investigated. The methanolic extract was considerably more effective than aqueous extract in inhibiting the investigated microbial strains. The most active antimicrobial plant was Piper betel. PMID:20046756

Nair, R; Chanda, Sumitra

2008-01-01

272

Antimicrobial activity and cellular toxicity of nanoparticle-polymyxin B conjugates  

NASA Astrophysics Data System (ADS)

We investigate the antimicrobial activity and cytotoxicity to mammalian cells of conjugates of the peptide antibiotic polymyxin B (PMB) to Au nanoparticles and CdTe quantum dots. Au nanoparticles fully covered with PMB are identical in antimicrobial activity to the free drug alone, whereas partially-conjugated Au particles show decreased effectiveness in proportion to the concentration of Au. CdTe-PMB conjugates are more toxic to Escherichia coli than PMB alone, resulting in a flattening of the steep PMB dose-response curve. The effect is most pronounced at low concentrations of PMB, with a greater effect on the concentration required to reduce growth by half (IC50) than on the concentration needed to inhibit all growth (minimum inhibitory concentration, MIC). The Gram positive organism Staphylococcus aureus is resistant to both PMB and CdTe, showing minimal increased sensitivity when the two are conjugated. Measurement of reactive oxygen species (ROS) generation shows a significant reduction in photo-generated hydroxyl and superoxide radicals with CdTe-PMB as compared with bare CdTe. There is a corresponding reduction in toxicity of QD-PMB versus bare CdTe to mammalian cells, with nearly 100% survival in fibroblasts exposed to bactericidal concentrations of QD-PMB. The situation in bacteria is more complex: photoexcitation of the CdTe particles plays a small role in IC50 but has a significant effect on the MIC, suggesting that at least two different mechanisms are responsible for the antimicrobial action seen. These results show that it is possible to create antimicrobial agents using concentrations of CdTe quantum dots that do not harm mammalian cells.

Park, Soonhyang; Chibli, Hicham; Wong, Jody; Nadeau, Jay L.

2011-05-01

273

Antiradical, antimicrobial and cytotoxic activities of commercial beetroot pomace.  

PubMed

The by-product of food processing is often utilized as feed, and for the preparation of dietary fiber and biofuel. However, these products are also promising sources of bioactive antioxidants and color giving compounds, which could be used as additives in the food, pharmaceutical and cosmetic industry. The aim of this study was to investigate the phytochemical profile, and the antiradical, antimicrobial and cytotoxic activities of industrial beetroot pomace extract (BPE). The content of phenolics (45.68 mg gallic acid equivalents g(-1)), flavonoids (25.89 mg rutin equivalents g(-1)) and betalains (4.09 mg betanin g(-1); 7.32 mg vulgaxanthin I g(-1)) were determined spectrophotometrically. The antiradical activity on DPPH (EC(50)(DPPH·) = 0.0797 mg ml(-1)), hydroxyl (EC(50)(·OH) = 0.0655 mg ml(-1)) and superoxide anion (EC(50)(O2·-) = 1.0625 mg ml(-1)) radicals were measured by electron spin resonance (ESR) spectroscopy. The antimicrobial activity was determined using the agar-well diffusion method. Gram(-) bacteria (Salmonella typhimurium, Citrobacter freundii) and Gram(+) bacteria, (Staphylococcus aureus, Staphylococcus sciuri, Bacillus cereus) showed high susceptibility, while yeasts and moulds were resistant. BPE exhibits cytotoxic properties against Ehrlich carcinoma (EAC) cells in vivo due to induction of oxidative stress. The largest decreases in EAC cell numbers were observed in the pre-treated male (approximately 53%) and female (approximately 47%) mice, and also the EAC cell viability was decreased after administration of BPE. The activities of the antioxidant enzymes, xanthine oxidase (XOD) and peroxidase (Px), were significantly different between the untreated EAC control group and all other groups that were treated with BPE. The XOD and Px activities were very low in untreated malignant cells, but increased significantly after administration of BPE. Our results show that BPE holds promise in the food industry as a source of bioactive compounds. PMID:23423147

Vuli?, Jelena J; Cebovi?, Tatjana N; Canadanovi?, Vladimir M; Cetkovi?, Gordana S; Djilas, Sonja M; Canadanovi?-Brunet, Jasna M; Veli?anski, Aleksandra S; Cvetkovi?, Dragoljub D; Tumbas, Vesna T

2013-04-30

274

Antimicrobial activity of Pleurotus eryngii var. ferulae grown on various agro-wastes  

Microsoft Academic Search

In this study, the antimicrobial activity of Pleurotus eryngii var. ferulae grown on various agro- wastes were investigated. The antimicrobial activity from the extract of P. eryngii var. ferulae which was obtained from various culture medium was evaluated according to the disk diffusion method by using Bacillus megaterium DSM 32, Staphylococcus aureus COWAN 1, Escherichia coli ATCC 25922, Klebsiella pneumoniae

Mehmet Akyuz; Sevda Kirbag

275

The Synthesis and Antimicrobial Activity of Heterocyclic Derivatives Michelle B. Kim,  

E-print Network

natural product. Preliminary experiments demonstrate that the indole analogues do not target the bacterialThe Synthesis and Antimicrobial Activity of Heterocyclic Derivatives of Totarol Michelle B. Kim: The synthesis and antimicrobial activity of hetero- cyclic analogues of the diterpenoid totarol are described

Weibel, Douglas B.

276

Preliminary Phytochemical Analysis and Antimicrobial Activity of Some Weeds collected from Marathwada Region  

Microsoft Academic Search

The aqueous and ethanolic extracts of selected weeds such as Portulaca oleracea L. (Portulaceae), Cardiospermum helicacabum L. (Sapindaceae), Euphorbia hirta L. (Euphorbiaceae), Crotalaria retusa L. (Fabaceae) and Euphorbia heterophylla L. (Euphorbiaceae) were screened for phytochemical analysis and antimicrobial activity. The antimicrobial activities were tested against two gram-positive bacteria (Bacillus subtilis, Staphylococus aureus), one gram-negative bacterium (Pseudomonas aeruginosa) and a mould

Dhole JA; Dhole NA; Lone KD; Bodke SS; Rajarshi Shahu

2011-01-01

277

Antimicrobial activity of L. plantarum, isolated from a traditional lactic acid fermentation of table olives  

E-print Network

Health Antimicrobial activity of L. plantarum, isolated from a traditional lactic acid fermentation obtained from culture supernatant was active against Enterococcus faecalis and against natural com during culture stationary phase. In the presence of lactic acid (pH 3.7), these antimicrobial

Boyer, Edmond

278

Antimicrobial, anti-inflammatory, anti-ulcer and antioxidant activities of Carlina acanthifolia root essential oil  

Microsoft Academic Search

The root of Carlina acanthifolia All. (Asteraceae) has been traditionally used in the treatment of various disorders including stomach and skin diseases. We studied antimicrobial, anti-inflammatory, anti-ulcer and antioxidant activities of Carlina acanthifolia root essential oil, in order to validate some of the ethnopharmacological claims. Antimicrobial activity was tested on 15 bacteria and three strains of fungi using the agar

Sofija ?or?evi?; Silvana Petrovi?; Silva Dobri?; Marina Milenkovi?; Dragana Vu?i?evi?; Slavica Žiži?; Jelena Kuki?

2007-01-01

279

Antimicrobial Activity and Composition of the Essential Oil of Cymbopogon Olivieri (Boiss.) Bor from Iran  

Microsoft Academic Search

The in vitro antimicrobial activity of the essential oil isolated from the aerial parts of Cymbopogon Olivieri (Boiss.) Bor, an aromatic grass of Iran was tested against three Gram- negative and four Gram-positive bacteria and also three fungi. The results of the bioassays showed that the oil has a remarkable antimicrobial activity. Bacillus subtilis and Candida albicans were more sensitive

Ali Sonboli; Mohammad Hossein Mirjalili; Morteza Yousefzadic

280

Structural Dissection of a Highly Knotted Peptide Reveals Minimal Motif with Antimicrobial Activity*S  

E-print Network

that understanding the structural features responsible for the activity of these natural products (11­14) may provideStructural Dissection of a Highly Knotted Peptide Reveals Minimal Motif with Antimicrobial Activity in nature. We have undertaken the structural dissection of a highly knotted, cysteine-rich plant thionin

Pompeu Fabra, Universitat

281

In vitro antimicrobial activity of peroxide-based bleaching agents.  

PubMed

Antibacterial activity of 4 commercial bleaching agents (Day White, Colgate Platinum, Whiteness 10% and 16%) on 6 oral pathogens (Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis, Candida albicans, Lactobacillus casei, and Lactobacillus acidophilus) and Staphylococcus aureus were evaluated. A chlorhexidine solution was used as a positive control, while distilled water was the negative control. Bleaching agents and control materials were inserted in sterilized stainless-steel cylinders that were positioned under inoculated agar plate (n = 4). After incubation according to the appropriate period of time for each microorganism, the inhibition zones were measured. Data were analyzed by 2-way analysis of variance and Tukey test (a = 0.05). All bleaching agents and the chlorhexidine solution produced antibacterial inhibition zones. Antimicrobial activity was dependent on peroxide-based bleaching agents. For most microorganisms evaluated, bleaching agents produced inhibition zones similar to or larger than that observed for chlorhexidine. C albicans, L casei, and L acidophilus were the most resistant microorganisms. PMID:17625621

Napimoga, Marcelo Henrique; de Oliveira, Rogério; Reis, André Figueiredo; Gonçalves, Reginaldo Bruno; Giannini, Marcelo

2007-06-01

282

Antimicrobial activity of whey protein based edible films incorporated with oregano, rosemary and garlic essential oils  

Microsoft Academic Search

The use of edible films to release antimicrobial constituents in food packaging is a form of active packaging. Antimicrobial properties of spice extracts are well known, however their application to edible films is limited. In this study, antimicrobial properties of whey protein isolate (WPI) films containing 1.0–4.0% (wt\\/vol) ratios of oregano, rosemary and garlic essential oils were tested against Escherichia

A. C. Seydim; G. Sarikus

2006-01-01

283

Chemical composition and antimicrobial activity of Satureja hortensis and Trachyspermum copticum essential oil  

PubMed Central

Background and Objectives The aim of this study was to evaluate the chemical composition and antimicrobial activity of Satureja hortensis and Trachyspermum copticum essential oils against different kinds of microorganisms in vitro. Material and Methods The antimicrobial activity was evaluated by micro broth dilution assay and the chemical composition of essential oils was analyzed by GC and GC/MS. Results Thymol, p-cymene, ?-terpinene and carvacrol were the main components of S. hortensis oil while thymol, ?-terpinene, and o-cymene were the major components of T. copticum oil. Two essential oils exhibited strong antimicrobial activity but the antimicrobial activity of T. copticum oil was higher than that of S. hortensis oil. Conclusion Thymol as a main component of oils plays an important role in antimicrobial activity. PMID:22530088

Mahboubi, M; Kazempour, N

2011-01-01

284

Total phenolic content, antioxidant and antimicrobial activities of some medicinal plants.  

PubMed

Crude extracts from Inula aucherana, Fumaria officinalis, Crocus sativus, Vicum album, Tribulus terestris, Polygonatum multiflorum, Alkanna tinctoria and Taraxacum officinale were screened for their in vitro antioxidant and antimicrobial properties. Total phenolic content of extracts from these plants were also determined. beta-carotene bleaching assay and Folin-Ciocalteu reagent were used to determine total antioxidant activity and total phenols of plant extracts. Antimicrobial activity was determined by using disk diffusion assay. Antioxidant activity and total phenolic content varied among plants used and Viscum album and Crocus sativus had the highest antioxidant (82.23%) and total phenolic content (42.29 mgGAE/g DW), respectively. The methanol extracts from Vicum album and Alkanna tinctoria showed antimicrobial activity against 9 out of 32 microorganisms, however extract from Inula aucherana showed antimicrobial activity against 15 out of 32 microorganisms. The results provided evidence that the studied plant might indeed be potential sources of natural antioxidant and antimicrobial agents. PMID:19168430

Sengul, Memnune; Yildiz, Hilal; Gungor, Neva; Cetin, Bulent; Eser, Zeynep; Ercisli, Sezai

2009-01-01

285

Antimicrobial activity of endodontic sealers based on calcium hydroxide and MTA.  

PubMed

The aim of this study was to evaluate the antimicrobial activity of a new root canal sealer containing calcium hydroxide (Acroseal) and the root canal sealer based on MTA (Endo CPM Sealer), in comparison with traditional sealers (Sealapex, Sealer 26 and Intrafill) and white MTA-Angelus, against five different microorganism strains. The materials and their components were evaluated after manipulation, employing the agar diffusion method. A base layer was made using Müller-Hinton agar (MH) and wells were made by removing agar. The materials were placed into the wells immediately after manipulation. The microorganisms used were: Micrococcus luteus (ATCC9341), Staphylococcus aureus (ATCC6538), Pseudomonas aeruginosa (ATCC27853), Candida albicans (ATCC 10231), and Enterococcus faecalis (ATCC 10541). The plates were kept at room temperature for 2 h for prediffusion and then incubated at 37 degrees C for 24 h. The results showed that Sealapex and its base paste, Sealer 26 and its powder, Endo CPM Sealer and its powder, white MTA and its powder all presented antimicrobial activity against all strains. Intrafill and its liquid presented antimicrobial activity against all strains except P. aeruginosa and Acroseal was effective only against M. luteus and S. aureus. PMID:19177851

Tanomaru, Juliane M G; Tanomaru-Filho, Mário; Hotta, Juliana; Watanabe, Evandro; Ito, Izabel Y

2008-01-01

286

Antiproliferative, antimicrobial and apoptosis inducing effects of compounds isolated from Inula viscosa.  

PubMed

The antiproliferative and antimicrobial effects of thirteen compounds isolated from Inula viscosa (L.) were tested in this study. The antiproliferative activity was tested against three cell lines using the MTT assay. The microdilution method was used to study the antimicrobial activity against two Gram positive bacteria, two Gram negative bacteria and one fungus. The apoptotic activity was determined using a TUNEL colorimetric assay. Scanning electron microscopy was used to study the morphological changes in treated cancer cells and bacteria. Antiproliferative activity was observed in four flavonoids (nepetin, 3,3'-di-O-methylquercetin, hispidulin, and 3-O-methylquercetin). 3,3'-di-O-Methylquercetin and 3-O-methylquercetin showed selective antiproliferative activity against MCF-7 cells, with IC(50) values of 10.11 and 11.23 µg/mL, respectively. Both compounds exert their antiproliferative effect by inducing apoptosis as indicted by the presence of DNA fragmentation, nuclear condensation, and formation of apoptotic bodies in treated cancer cells. The antimicrobial effect of Inula viscosa were also noticed in 3,3'-di-O-methylquercetin and 3-O-methyquercetin that inhibited Bacillus cereus at MIC of 62.5 and 125 µg/mL, respectively. Salmonella typhimurium was inhibited by both compounds at MIC of 125 µg/mL. 3,3'-di-O-Methylquercetin induced damage in bacterial cell walls and cytoplasmic membranes. Methylated quercetins isolated from Inula viscosa have improved anticancer and antimicrobial properties compared with other flavonoids and are promising as potential anticancer and antimicrobial agents. PMID:22418930

Talib, Wamidh H; Zarga, Musa H Abu; Mahasneh, Adel M

2012-01-01

287

Antimicrobial and inhibitory enzyme activity of N-(benzyl) and quaternary N-(benzyl) chitosan derivatives on plant pathogens.  

PubMed

Chemical modification of a biopolymer chitosan by introducing quaternary ammonium moieties into the polymer backbone enhances its antimicrobial activity. In the present study, a series of quaternary N-(benzyl) chitosan derivatives were synthesized and characterized by (1)H-NMR, FT-IR and UV spectroscopic techniques. The antimicrobial activity against crop-threatening bacteria Agrobacterium tumefaciens and Erwinia carotovora and fungi Botrytis cinerea, Botryodiplodia theobromae, Fusarium oxysporum and Phytophthora infestans were evaluated. The results proved that the grafting of benzyl moiety or quaternization of the derivatives onto chitosan molecule was successful in inhibiting the microbial growth. Moreover, increase water-solubility of the compounds by quaternization significantly increased the activity against bacteria and fungi. Exocellular enzymes including polygalacturonase (PGase), pectin-lyase (PLase), polyphenol oxidase (PPOase) and cellulase were also affected at 1000 mg/L. These compounds especially quaternary-based chitosan derivatives that have good inhibitory effect should be potentially used as antimicrobial agents in crop protection. PMID:25037402

Badawy, Mohamed E I; Rabea, Entsar I; Taktak, Nehad E M

2014-10-13

288

Synthesis and antimicrobial activity of novel amphiphilic aromatic amino alcohols.  

PubMed

We report in this work the preparation and in vitro antimicrobial evaluation of novel amphiphilic aromatic amino alcohols synthesized by reductive amination of 4-alkyloxybenzaldehyde with 2-amino-2-hydroxymethyl-propane-1,3-diol. The antibacterial activity was determined against four standard strains (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa) and 21 clinical isolates of methicillin-resistant Staphylococcus aureus. The antifungal activity was evaluated against four yeast (Candida albicans, Candida tropicalis, Candida glabrata and Candida parapsilosis). The results obtained showed a strong positive correlation between the lipophilicity and the antibiotic activity of the tested compounds. The best activities were obtained against the Gram-positive bacteria (MIC=2-16?gml(-1)) for the five compounds bearing longer alkyl chains (4c-g; 8-14 carbons), which were also the most active against Candida (MIC=2-64?gml(-1)). Compound 4e exhibited the highest levels of inhibitory activity (MIC=2-16?gml(-1)) against clinical isolates of MRSA. A concentration of twice the MIC resulted in bactericidal activity of 4d against 19 of the 21 clinical isolates. PMID:23587426

de Almeida, Angelina M; Nascimento, Thiago; Ferreira, Bianca S; de Castro, Pedro P; Silva, Vânia L; Diniz, Claúdio G; Le Hyaric, Mireille

2013-05-15

289

Antimicrobial effect of silver-doped phosphate-based glasses.  

PubMed

In this study a range of phosphate-based glasses (PBG) doped with silver have been investigated for their antimicrobial activities. In disk diffusion assays, these compositions demonstrated microbistatic effects against a range of organisms including Staphylococcus aureus, Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and Candida albicans. The data obtained from the above studies allowed for an additional range of PBG containing lower amounts of silver to be studied for their effects on the growth and viability of S. aureus, E. coli, and C. albicans. PBG containing 3 and 5 mol % Ag were bactericidal for S. aureus and E. coli and significantly decreased the growth rate of C. albicans. A decrease in the dissolution rates of the glasses was seen with increasing Ag content over the range of concentrations investigated. Overall, 3 mol % Ag incorporated into the PBG investigated was sufficient to mount a potent antibacterial effect against the test organisms, and these compositions also gave excellent long-term release of Ag ions into the medium. PMID:16826601

Ahmed, I; Ready, D; Wilson, M; Knowles, J C

2006-12-01

290

Contact-active antimicrobial and potentially self-polishing coatings based on cellulose.  

PubMed

A contact-active antimicrobial coating is described that is only degraded in the presence of cellulase, which is an extracellular enzyme of numerous microbial strains. Antimicrobial DDA was grafted to a cellulose backbone via a polymeric spacer. The antimicrobial activity of the coatings, their biodegradability and their self-polishing potential were investigated. It was found that all coatings were antimicrobially active against Staphylococcus aureus. Coatings with high DS and long polymeric spacers degraded in water, while coatings with low DS and short spacers were not hydrolyzed even in the presence of cellulase. One coating was found to be selectively degradable by cellulase and recovered most of its antimicrobial activity after overloading and subsequent treatment with cellulase. PMID:20945436

Bieser, Arno M; Thomann, Yi; Tiller, Joerg C

2011-01-10

291

Quantitative structure-activity relationships of antimicrobial fatty acids and derivatives against Staphylococcus aureus *  

PubMed Central

Fatty acids and derivatives (FADs) are resources for natural antimicrobials. In order to screen for additional potent antimicrobial agents, the antimicrobial activities of FADs against Staphylococcus aureus were examined using a microplate assay. Monoglycerides of fatty acids were the most potent class of fatty acids, among which monotridecanoin possessed the most potent antimicrobial activity. The conventional quantitative structure-activity relationship (QSAR) and comparative molecular field analysis (CoMFA) were performed to establish two statistically reliable models (conventional QSAR: R 2=0.942, Q 2 LOO=0.910; CoMFA: R 2=0.979, Q 2=0.588, respectively). Improved forecasting can be achieved by the combination of these two models that provide a good insight into the structure-activity relationships of the FADs and that may be useful to design new FADs as antimicrobial agents. PMID:22302421

Zhang, Hui; Zhang, Lu; Peng, Li-juan; Dong, Xiao-wu; Wu, Di; Wu, Vivian Chi-Hua; Feng, Feng-qin

2012-01-01

292

Chemical composition, cytotoxicity effect and antimicrobial activity of Ceratonia siliqua essential oil with preservative effects against Listeria inoculated in minced beef meat  

Microsoft Academic Search

The present study describes the phytochemical profile and the protective effects of Ceratonia siliqua pods essential oil (CsEO), a food and medicinal plant widely distributed in Tunisia. Twenty five different components were identified in the CsEO. Among them, the major detected components were: Nonadecane, Heneicosane , Naphthalene, 1,2-Benzenedicarboxylic acid dibutylester, Heptadecane, Hexadecanoic acid, Octadecanoic acid, 1,2-Benzenedicarboxylic acid, Phenyl ethyl tiglate,

Anis Ben Hsouna; Mohamed Trigui; Riadh Ben Mansour; Raoudha Mezghani Jarraya; Mohamed Damak; Samir Jaoua

2011-01-01

293

Antimicrobial activity of de novo designed cationic peptides against multi-resistant clinical isolates.  

PubMed

Antibiotic resistance is one of the main problems concerning public health or clinical practice. Antimicrobial peptides appear as good candidates for the development of new therapeutic drugs. In this study we de novo designed a group of cationic antimicrobial peptides, analyzed its physicochemical properties, including its structure by circular dichroism and studied its antimicrobial properties against a panel of clinical isolates expressing different mechanisms of resistance. Three cationic alpha helical peptides exhibited antimicrobial activity comparable to, or even better than the comparator omiganan (MBI-226). PMID:24269514

Faccone, Diego; Veliz, Omar; Corso, Alejandra; Noguera, Martin; Martínez, Melina; Payes, Cristian; Semorile, Liliana; Maffía, Paulo Cesar

2014-01-01

294

Chemical analysis of Greek pollen - Antioxidant, antimicrobial and proteasome activation properties  

PubMed Central

Background Pollen is a bee-product known for its medical properties from ancient times. In our days is increasingly used as health food supplement and especially as a tonic primarily with appeal to the elderly to ameliorate the effects of ageing. In order to evaluate the chemical composition and the biological activity of Greek pollen which has never been studied before, one sample with identified botanical origin from sixteen different common plant taxa of Greece has been evaluated. Results Three different extracts of the studied sample of Greek pollen, have been tested, in whether could induce proteasome activities in human fibroblasts. The water extract was found to induce a highly proteasome activity, showing interesting antioxidant properties. Due to this activity the aqueous extract was further subjected to chemical analysis and seven flavonoids have been isolated and identified by modern spectral means. From the methanolic extract, sugars, lipid acids, phenolic acids and their esters have been also identified, which mainly participate to the biosynthetic pathway of pollen phenolics. The total phenolics were estimated with the Folin-Ciocalteau reagent and the total antioxidant activity was determined by the DPPH method while the extracts and the isolated compounds were also tested for their antimicrobial activity by the dilution technique. Conclusions The Greek pollen is rich in flavonoids and phenolic acids which indicate the observed free radical scavenging activity, the effects of pollen on human fibroblasts and the interesting antimicrobial profile. PMID:21699688

2011-01-01

295

Evaluation of antimicrobial activity of silver nanoparticles for carboxymethylcellulose film applications in food packaging.  

PubMed

In this study, silver nanoparticles were prepared and incorporated into carboxymethylcellulose films to evaluate the antimicrobial activity for food packaging applications. The techniques carried out for material characterization were: infrared spectroscopy and thermal analysis for the silver nanoparticles and films, as well as particle size distribution for the nanoparticles and water vapor permeability for the films. The antimicrobial activity of silver nanoparticles prepared by casting method was investigated. The minimum inhibitory concentration (MIC) value of the silver nanoparticles to test Gram-positive (Enterococcus faecalis) and Gram-negative (Escherichia coli) microorganisms was carried out by the serial dilution technique, tested in triplicate to confirm the concentration used. The results were developed using the Mcfarland scale which indicates that the presence or absence of turbidity tube demonstrates the inhibition of bacteria in relation to the substance inoculated. It was found that the silver nanoparticles inhibited the growth of the tested microorganisms. The carboxymethylcellulose film embedded with silver nanoparticles showed the best antimicrobial effect against Gram-positive (E. faecalis) and Gram-negative (E. coli) bacteria (0.1 microg cm(-3)). PMID:24758059

Siqueira, Maria C; Coelho, Gustavo F; de Moura, Márcia R; Bresolin, Joana D; Hubinger, Silviane Z; Marconcini, José M; Mattoso, Luiz H C

2014-07-01

296

Assessment of antimicrobial activity of nanosized Ag doped TiO(2) colloids.  

PubMed

In the present research, the antimicrobial effects of nanosized silver (Ag) doped TiO(2) colloidal solutions prepared using a sol-gel technique were investigated. In order to determine the solution characteristics, the turbidity, viscosity and pH of the colloidal solutions were measured. Differential thermal analysis-thermogravimetry equipment was used to determine the chemical structures and reaction types of the films formed from these solutions. The morphology of Ag doped TiO(2) nanoparticles was evaluated by atomic force microscopy. The disc diffusion method was employed to explore antimicrobial activity, and the Broth Microdilution method was used to obtain MIC values of nanosized Ag doped TiO(2) colloidal solutions against the test microorganisms Escherichia coli, Staphylococcus aureus, Candida albicans, Bacillus subtilis, and Salmonella typhimurium. It was found that the silver doped TiO(2) nanoparticles inhibited the growth and multiplication of the test microorganisms, including the fungus C. albicans. Antimicrobial activity was observed against all tested microorganisms at a very low concentration of 1.125-2.81 ?g/ml of nano silver in 1-25 % Ag-TiO(2) solutions. PMID:22806159

Ya?a, Ihsan; Lkhagvajav, Natsag; Koizhaiganova, Meruyert; Celik, Erdal; Sar?, Ozcan

2012-07-01

297

Chemical composition, antimicrobial and antioxidant activities of essential oil from Gnaphlium affine.  

PubMed

The chemical composition of the essential oil from Gnaphlium affine was determined, and its antimicrobial and antioxidant activities were evaluated. Twenty-four compounds, representing 94.95% of the amount of total oil, were identified by gas chromatography-mass spectrometry (GC-MS) analysis. Main constituents of the essential oil were found to be eugenol (18.24%), linalool (10.62%), trans-caryophyllene (8.86%), ?-terpineol (5.97%), p-cymene (5.75%), hexadecanoic acid (5.63%), ?-cadinene (4.98%), ?-cadinene (4.22%), ?-humulene (3.22%), and (-)-?-elemene (3.15%). The essential oil revealed a remarkable antimicrobial effect against the tested food-borne microorganisms with the MIC and MBC values in the ranges of 0.2-1.56 ?g/ml and 0.39-3.13 ?g/ml, respectively. The essential oil showed a potent antioxidant activity in ABTS radical scavenging, lipid peroxidation and reducing power assay. It was suggested that the essential oil from G. affine may be a new potential source as natural antimicrobial and antioxidant agents applied in food systems. PMID:21414372

Zeng, Wei-Cai; Zhu, Rui-Xue; Jia, Li-Rong; Gao, Hong; Zheng, Yue; Sun, Qun

2011-06-01

298

Alarin but not its alternative-splicing form, GALP (Galanin-like peptide) has antimicrobial activity  

SciTech Connect

Highlights: • Alarin inhibits the growth of E. coli but not S. aureus. • Alarin’s potency is comparable to LL-37 in inhibiting the growth of E. coli. • Alarin can cause bacterial membrane blebbing. • Alalin does not induce hemolysis on erythrocytes. -- Abstract: Alarin is an alternative-splicing form of GALP (galanin-like peptide). It shares only 5 conserved amino acids at the N-terminal region with GALP which is involved in a diverse range of normal brain functions. This study seeks to investigate whether alarin has additional functions due to its differences from GALP. Here, we have shown using a radial diffusion assay that alarin but not GALP inhibited the growth of Escherichia coli (strain ML-35). The conserved N-terminal region, however, remained essential for the antimicrobial activity of alarin as truncated peptides showed reduced killing effect. Moreover, alarin inhibited the growth of E. coli in a similar potency as human cathelicidin LL-37, a well-studied antimicrobial peptide. Electron microscopy further showed that alarin induced bacterial membrane blebbing but unlike LL-37, it did not cause hemolysis of erythrocytes. In addition, alarin is only active against the gram-negative bacteria, E. coli but not the gram-positive bacteria, Staphylococcus aureus. Thus, these data suggest that alarin has potentials as an antimicrobial and should be considered for the development in human therapeutics.

Wada, Akihiro, E-mail: a-wada@nagasaki-u.ac.jp [Department of Bacteriology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)] [Department of Bacteriology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan); Wong, Pooi-Fong [Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur (Malaysia)] [Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur (Malaysia); Hojo, Hironobu [Department of Applied Biochemistry, Institute of Glycoscience, Tokai University, Kanagawa 2591292 (Japan)] [Department of Applied Biochemistry, Institute of Glycoscience, Tokai University, Kanagawa 2591292 (Japan); Hasegawa, Makoto [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Shiga 5260829 (Japan)] [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Shiga 5260829 (Japan); Ichinose, Akitoyo [Electron Microscopy Shop Central Laboratory, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)] [Electron Microscopy Shop Central Laboratory, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan); Llanes, Rafael [Institute Pedro Kouri, Havana (Cuba)] [Institute Pedro Kouri, Havana (Cuba); Kubo, Yoshinao [Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 8528523 (Japan)] [Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 8528523 (Japan); Senba, Masachika [Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)] [Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan); Ichinose, Yoshio [Kenya Research Station, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)] [Kenya Research Station, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)

2013-05-03

299

Preliminary Screening of Endophytic Fungi from Medicinal Plants in Malaysia for Antimicrobial and Antitumor Activity  

PubMed Central

The screening of antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria, yeast and fungi was carried out on isopropanol extracts prepared from 121 isolates of endophytic fungi isolated from medicinal plants in Malaysia. Sensitivity was found to vary among the microorganisms. Bacillus subtilis, Saccharomyces cerevisiae and Alternaria sp. were susceptible to extracts from three, two and two isolates of endophytic fungi, respectively. None were found effective against Salmonella typhimurium. Sixteen endophytic fungal isolates tested were also found to exhibit antitumor activity in the yeast cell-based assay. PMID:22844221

Radu, Son; Kqueen, Cheah Yoke

2002-01-01

300

Examination of antimicrobial activity of selected non-antibiotic drugs.  

PubMed

A variety of pharmaceutical preparations, which are applied in the management of non-infectious diseases, have shown in vitro some antimicrobial activity. These drugs are called "non-antibiotics". The aim of this study was to detect and characterize the antimicrobial activity of non-antibiotic drugs, selected from the preparations analysed during state control performed in the National Institute of Public Health in Poland. Over 180 of pharmaceutical preparations were randomly chosen from different groups of drugs. A surveillance study was performed on standard ATCC microbial strains used for drug control: S. aureus, E. coli, P. aeruginosa and C. albicans. It was shown that the drugs listed below inhibited growth of at least one of the examined strains: Actonel 5 mg tabl. (risedronate), Aldan 10 mg tabl. (amlodipine), Aleras 10 mg tabl. (cetirisine), Aspicam 15 mg tabl. (meloxicam), Baikadent 6 mg/g gel (flavons of Scutellariae), Debretin 100 mg tabl. (trimebutine), Ferro-Duo 100 mg tabl. (ferrum), Gastrovent 145 mg caps. (bismuth citrate), Ibum 200 mg caps., Upfen 200 mg tabl. (ibuprofen), Lastet 100 mg caps. (etoposide), Legalon 70 mg tabl. (sylimarin), Madopar 125 tabl. (benserazide, levodopa), Moxenil 100 mg tabl. (nimesulide), Neurotin 800 mg tabl. (gabapentin), Propranolol 40 mg tabl. (propranolol), Rexetin 20 mg tabl. (paroxetine), Salipax 20 mg caps. (fluoxetine), Selofen 10 mg caps. (zaleplon) Stenorol 0.6% powder (halofuginone), Stimuloton 50 mg tabl. (sertraline), Superoptim 0.3 mg tabl. (hipericine), Uversan 50 mg tabl. (arbutine from Arctostaphylos uva ursi). S. aureus strain was susceptible to the most of the drugs listed above. The lowest inhibitory concentration was found for sertraline and hipericine (0.16 and 0.075 mg/mL, respectively). PMID:15909927

Kruszewska, Hanna; Zareba, Tomasz; Tyski, Stefan

2004-12-01

301

Antimicrobial activity and phytochemical analysis of crude extracts and essential oils from medicinal plants.  

PubMed

We aimed to establish a phytochemical analysis of the crude extracts and performed GC-MS of the essential oils (EOs) of Eugenia uniflora L. (Myrtaceae) and Asteraceae species Baccharis dracunculifolia DC, Matricaria chamomilla L. and Vernonia polyanthes Less, as well as determining their antimicrobial activity. Establishment of the minimal inhibitory concentrations of the crude extracts and EOs against 16 Staphylococcus aureus and 16 Escherichia coli strains from human specimens was carried out using the dilution method in Mueller-Hinton agar. Some phenolic compounds with antimicrobial properties were established, and all EOs had a higher antimicrobial activity than the extracts. Matricaria chamomilla extract and E. uniflora EO were efficient against S. aureus strains, while E. uniflora and V. polyanthes extracts and V. polyanthes EO showed the best antimicrobial activity against E. coli strains. Staphylococcus aureus strains were more susceptible to the tested plant products than E. coli, but all natural products promoted antimicrobial growth inhibition. PMID:22007687

Silva, N C C; Barbosa, L; Seito, L N; Fernandes, A

2012-01-01

302

Induction and antimicrobial activity of platelet basic protein derivatives in human monocytes  

Microsoft Academic Search

The antimicrobial activity of a number of chemokines has recently come into focus of research about innate immunity. We have previ- ously shown that platelet basic protein (PBP), which gives rise to several antimicrobial peptides of platelets, is also expressed in human monocytes. In the present studies, we show that exposure of hu- man monocytes to bacteria or microbial compo-

Andreas Schaffner; Charles C. King; Dominik Schaer; Donald G. Guiney

2004-01-01

303

Activity of an Antimicrobial Peptide Mimetic against Planktonic and Biofilm Cultures of Oral Pathogens  

Microsoft Academic Search

Antimicrobial peptides (AMPs) are naturally occurring, broad-spectrum antimicrobial agents that have recently been examined for their utility as therapeutic antibiotics. Unfortunately, they are expensive to produce and are often sensitive to protease digestion. To address this problem, we have examined the activity of a peptide mimetic whose design was based on the structure of magainin, exhibiting its amphiphilic structure. We

Nicholas Beckloff; Danielle Laube; Tammy Castro; David Furgang; Steven Park; David Perlin; Dylan Clements; Haizhong Tang; Richard W. Scott; Gregory N. Tew; Gill Diamond

2007-01-01

304

Characterization of a Fish Antimicrobial Peptide: Gene Expression, Subcellular Localization, and Spectrum of Activity  

Microsoft Academic Search

Antimicrobial peptides are proposed to act as the first line of mucosal host defense by exerting broad- spectrum microbicidal activity against pathogenic microbes. Pleurocidin, a new 25-residue linear antimicrobial peptide, was recently isolated from the skin secretions of winter flounder (Pleuronectes americanus). The present study identifies the cDNA and gene encoding pleurocidin. The pleurocidin gene comprises four exons. Its upstream

ALEXANDER M. COLE; RABIH O. DAROUICHE; DIANA LEGARDA; NANCY CONNELL; GILL DIAMOND

2000-01-01

305

Correlation of Antimicrobial Activities of Various Essential Oils and Their Main Aromatic Volatile Constituents  

Microsoft Academic Search

The pure aromatic volatiles p-cymene, carvacrol, eugenol and thymol as well as commercial essential oils of Cinnamomum zeylanicum, Origanum vulgare, Pimenta dioica, Pimenta racemosa, Satureja hortensis, Syzygium aromaticum, Thymus vulgaris and Trachyspermum ammi were investigated concerning antimicrobial activities. Therefore, these samples and, as reference substances, synthetic antibiotics and the natural antimicrobial components carveol, m-, o- and p-cresol were tested against

Martina Höferl; Gerhard Buchbauer; Leopold Jirovetz; Erich Schmidt; Albena Stoyanova; Zapriana Denkova; Alexander Slavchev; Margit Geissler

2009-01-01

306

Antimicrobial and antioxidant activities of Melissa officinalis L. (Lamiaceae) essential oil.  

PubMed

The present study describes antimicrobial and free radical scavenging capacity (RSC) together with the effects on lipid peroxidation (LP) of Melissa officinalis essential oil. The chemical profile of essential oil was evaluated by the means of gas chromatography-mass spectrometry (GC-MS) and thin-layer chromatography (TLC). RSC was assessed measuring the scavenging activity of essential oil on the 2,2-diphenyl-1-picrylhydrazyl (DPPH(*)) and OH(*) radicals. The effect on LP was evaluated following the activities on Fe(2+)/ascorbate and Fe(2+)/H(2)O(2) systems of induction. The antimicrobial activity was tested against 13 bacterial strains and six fungi. The examined essential oil exhibited very strong RSC, reducing the DPPH radical formation (IC(50) = 7.58 microg/mL) and OH radical generation (IC(50) = 1.74 microg/mL) in a dose-dependent manner. According to the GC-MS and TLC (dot-blot techniques), the most powerful scavenging compounds were monoterpene aldehydes and ketones (neral/geranial, citronellal, isomenthone, and menthone) and mono- and sesquiterpene hydrocarbons (E-caryophyllene). Very strong inhibition of LP, particularly in the Fe(2+)/H(2)O(2) system of induction (94.59% for 2.13 microg/mL), was observed in both cases, also in a dose-dependent manner. The most effective antibacterial activity was expressed on a multiresistant strain of Shigella sonei. A significant rate of antifungal activity was exhibited on Trichophyton species. PMID:15113145

Mimica-Dukic, Neda; Bozin, Biljana; Sokovic, Marina; Simin, Natasa

2004-05-01

307

Antimicrobial activity of extractable conifer heartwood compounds toward Phytophthora ramorum.  

PubMed

Ethyl acetate extracts from heartwood of seven western conifer trees and individual volatile compounds in the extracts were tested for antimicrobial activity against Phytophthora ramorum. Extracts from incense and western redcedar exhibited the strongest activity, followed by yellow-cedar, western juniper, and Port-Orford-cedar with moderate activity, and no activity for Douglas-fir and redwood extracts. Chemical composition of the extracts varied both qualitatively and quantitatively among the species with a total of 37 compounds identified by mass spectrometry. Of the 13 individual heartwood compounds bioassayed, three showed strong activity with a Log(10) EC(50) less than or equal to 1.0 ppm (hinokitiol, thymoquinone, and nootkatin), three expressed moderate activity ranging from 1.0-2.0 ppm (nootkatol, carvacrol, and valencene-11,12-diol), four compounds had weak activity at 2.0-3.0 ppm [alpha-terpineol, valencene-13-ol, (+)-beta-cedrene, (-)-thujopsene], and three had no activity [(+)-cedrol, delta-cadinene, and methyl carvacrol]. All of the most active compounds contained a free hydroxyl group, except thymoquinone. The importance of a free hydroxyl was demonstrated by the tremendous difference in activity between carvacrol (Log(10) EC(50) 1.81 +/- 0.08 ppm) and methyl carvacrol (Log(10) EC(50) >3.0 ppm). A field trial in California, showed that heartwood chips from redcedar placed on the forest floor for 4 months under Umbellularia californica (California bay laurel) with symptoms of P. ramorum leaf blight significantly limited the accumulation of P. ramorum DNA in the litter layer, compared with heartwood chips from redwood. PMID:17929093

Manter, Daniel K; Kelsey, Rick G; Karchesy, Joseph J

2007-11-01

308

Antimicrobial activity of the extract of stem bark of diplotropis ferruginea benth.  

PubMed

This is the first report about the antibacterial activity of Diplotropis ferruginea Benth. In this study, the ethanol extract of D. ferruginea was tested for its antimicrobial activity against strains gram-positive and gram-negative. In order to determine the minimal inhibitory concentration, assays were carried out by micro dilution method. The extract was screened for antimicrobial activity, and it showed antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. PMID:22224034

Cerqueira, Gs; Rocha, Nfm; Almeida, Jrgs; de Freitas, Apf; Lima, Eo; Filho, Jmb; de Freitas, Rm; Diniz, Melo Mff

2011-10-01

309

Relationship between peptide structure and antimicrobial activity as studied by de novo designed peptides.  

PubMed

As fundamental components in innate immunity, antimicrobial peptides (AMPs) hold great potentials in the treatment of persistent infections involving slow-growing or dormant bacteria in which, selective inhibition of prokaryotic bacteria in the context of eukaryotic cells is not only an essential requirement, but also a critical challenge in the development of antimicrobial peptides. To identify the sequence and structural properties critical for antimicrobial activity, a series of peptides varying in sequence, length, hydrophobicity/charge ratio, and secondary structure, were designed and synthesized. Their antimicrobial activities were then tested using Escherichia coli and HEK293 cells, together with several index activities against model membrane, including liposome leakage, fusion, and aggregation. While no evident correlation between the antimicrobial activity and the property of the peptides was observed, common activities against model membrane were nevertheless identified for the active antimicrobial peptides: mediating efficient membrane leakage, negligible membrane fusion and liposome aggregation. Therefore, in addition to identifying one highly active antimicrobial peptide, our study further sheds light on the design principle for these molecules. PMID:25157672

Sun, Jianbo; Xia, Yuqiong; Li, Dong; Du, Quan; Liang, Dehai

2014-12-01

310

Lack of antimicrobial bactericidal activity in Mycobacterium abscessus.  

PubMed

Antibiotic therapy of infections caused by the emerging pathogen Mycobacterium abscessus is challenging due to the organism's natural resistance toward most clinically available antimicrobials. We investigated the bactericidal activity of antibiotics commonly administered in M. abscessus infections in order to better understand the poor therapeutic outcome. Time-kill curves were generated for clinical M. abscessus isolates, Mycobacterium smegmatis, and Escherichia coli by using antibiotics commonly categorized as bactericidal (amikacin and moxifloxacin) or bacteriostatic (tigecycline and linezolid). In addition, the impact of aminoglycoside-modifying enzymes on the mode of action of substrate and nonsubstrate aminoglycosides was studied by using M. smegmatis as a model organism. While amikacin and moxifloxacin were bactericidal against E. coli, none of the tested compounds showed bactericidal activity against M. abscessus. Further mechanistic investigations of the mode of action of aminoglycosides in M. smegmatis revealed that the bactericidal activity of tobramycin and gentamicin was restored by disruption of the chromosomal aac(2') gene in the mycobacterial genome. The lack of bactericidal antibiotics in currently recommended treatment regimens provides a reasonable explanation for the poor therapeutic outcome in M. abscessus infection. Our findings suggest that chromosomally encoded drug-modifying enzymes play an important role in the lack of aminoglycoside bactericidal activity against rapidly growing mycobacteria. PMID:24752273

Maurer, Florian P; Bruderer, Vera L; Ritter, Claudia; Castelberg, Claudio; Bloemberg, Guido V; Böttger, Erik C

2014-07-01

311

Antimicrobial activity of essential oils and other plant extracts.  

PubMed

The antimicrobial activity of plant oils and extracts has been recognized for many years. However, few investigations have compared large numbers of oils and extracts using methods that are directly comparable. In the present study, 52 plant oils and extracts were investigated for activity against Acinetobacter baumanii, Aeromonas veronii biogroup sobria, Candida albicans, Enterococcus faecalis, Escherichia col, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype typhimurium, Serratia marcescens and Staphylococcus aureus, using an agar dilution method. Lemongrass, oregano and bay inhibited all organisms at concentrations of < or = 2.0% (v/v). Six oils did not inhibit any organisms at the highest concentration, which was 2.0% (v/v) oil for apricot kernel, evening primrose, macadamia, pumpkin, sage and sweet almond. Variable activity was recorded for the remaining oils. Twenty of the plant oils and extracts were investigated, using a broth microdilution method, for activity against C. albicans, Staph. aureus and E. coli. The lowest minimum inhibitory concentrations were 0.03% (v/v) thyme oil against C. albicans and E. coli and 0.008% (v/v) vetiver oil against Staph. aureus. These results support the notion that plant essential oils and extracts may have a role as pharmaceuticals and preservatives. PMID:10438227

Hammer, K A; Carson, C F; Riley, T V

1999-06-01

312

Retention of antimicrobial activity in plaque and saliva following mouthrinse use in vivo.  

PubMed

The aim of this study was to determine the contribution of plaque and saliva towards the prolonged activity, also called substantivity, of three antimicrobial mouthrinses (Listerine®, Meridol®, Crest Pro Health®), used in combination with a toothpaste (Prodent Coolmint®). Volunteers brushed for 4 weeks with a toothpaste without antimicrobial claims, while during the last 2 weeks half of the volunteers used an antimicrobial mouthrinse in addition to brushing. At the end of the experimental period, plaque and saliva samples were collected 6 h after oral hygiene, and bacterial concentrations and viabilities were determined. The contribution of plaque and saliva towards substantivity was assessed by combining plaque obtained after mechanical cleaning only with plaque and saliva obtained after additional use of an antimicrobial rinse. Subsequently, resulting viabilities of the combined plaques were determined. The viabilities of plaque samples after additional rinsing with mouthrinses were lower than of plaque obtained after mechanical cleaning only, regardless of the rinse involved. Moreover, plaque collected 6 h after rinsing with antimicrobial mouthrinses contained a surplus of antimicrobial activity. Only Listerine showed decreased viability in saliva, but none of the mouthrinses showed any residual antimicrobial activity in saliva. The findings indicate that plaque left behind after mechanical cleaning contributes to the prolonged substantivity of antimicrobial mouthrinses. PMID:20838045

Otten, M P T; Busscher, H J; van der Mei, H C; Abbas, F; van Hoogmoed, C G

2010-01-01

313

Draft Genome Sequence of Paenibacillus sp. Strain MSt1 with Broad Antimicrobial Activity, Isolated from Malaysian Tropical Peat Swamp Soil  

PubMed Central

We report the draft genome sequence of Paenibacillus sp. strain MSt1, which has broad-range antimicrobial activity, isolated from tropical peat swamp soil. Genes involved in antimicrobial biosynthesis are found to be present in this genome. PMID:25301658

Ong, Kuan Shion; Yule, Catherine M.; Gan, Han Ming; Lee, Sui Mae

2014-01-01

314

IN VITRO AND IN VIVO STUDY OF AN ANTIMICROBIAL ACTIVITY DISPLAYED BY THE REDMOUTH DISEASE AGENT, YERSINIA RUCKERI  

E-print Network

IN VITRO AND IN VIVO STUDY OF AN ANTIMICROBIAL ACTIVITY DISPLAYED BY THE REDMOUTH DISEASE AGENT of an antimicrobial factor secretion by Y ruckeri. As it was not possible to detail in a short note all our attempts

Paris-Sud XI, Université de

315

Membrane-disruptive abilities of h-hairpin antimicrobial peptides correlate with conformation and activity: A 31  

E-print Network

the number of cationic charges for antimicrobial activity. This study indicates that 31 P NMR lineshapes of uniaxially aligned membranes are well correlated with antimicrobial activity, and can be used as a diagnosticMembrane-disruptive abilities of h-hairpin antimicrobial peptides correlate with conformation

Hong, Mei

316

Further in vitro evaluation of antimicrobial activity of the marine sesquiterpene hydroquinone avarol.  

PubMed

This work extends in vitro screening of antimicrobial activity of the sesquiterpene hydroquinone avarol, a main secondary metabolite of the Mediterranean sponge species Dysidea avara. The antimicrobial activity was in part evaluated by microdilution method against selected bacterial and fungal strains. Additionally, the screening included evaluation of anti-quorum sensing (anti-QS) effects. At a different extent avarol was proven to be active against all the microorganisms tested (MIC 0.002-0.008 mg/mL and MBC 0.004-0.016 mg/mL; MIC 0.004-0.015 mg/mL and MFC 0.008-0.030 mg/mL; respectively). This marine natural product also showed moderate anti-QS effects, reducing Pseudomonas aeruginosa PAO1 biofilm formation (75%), its twitching and protrusions motilities as well as pyocianin production (39%). According to the best of our knowledge, this is the first report both on avarol anti Gram-negative bacterial activity and anti-QS effects. PMID:25213366

Pejin, Boris; Iodice, Carmine; Tommonaro, Giuseppina; Stanimirovic, Bojana; Ciric, Ana; Glamoclija, Jasmina; Nikolic, Milos; De Rosa, Salvatore; Sokovic, Marina

2014-01-01

317

Antimicrobial Activity of High-Mobility-Group Box 2: a New Function to a Well-Known Protein  

PubMed Central

The human intestinal tract is highly colonized by a vast number of microorganisms. Despite this permanent challenge, infections remain rare, due to a very effective barrier defense system. Essential effectors of this system are antimicrobial peptides and proteins (AMPs), which are secreted by intestinal epithelial and lymphoid cells, balance the gut microbial community, and prevent the translocation of microorganisms. Several antimicrobial proteins have already been identified in the gut. Nonetheless, we hypothesized that additional AMPs are yet to be discovered in this setting. Using biological screening based on antimicrobial function, here we identified competent antibacterial activity of high-mobility-group box 2 (HMGB2) against Escherichia coli. By recombinant expression, we confirmed this biologically new antimicrobial activity against different commensal and pathogenic bacteria. In addition, we demonstrated that the two DNA-binding domains (HMG boxes A and B) are crucial for the antibiotic function. We detected HMGB2 in several gastrointestinal tissues by mRNA analysis and immunohistochemical staining. In addition to the nuclei, we also observed HMGB2 in the cytoplasm of intestinal epithelial cells. Furthermore, HMGB2 was detectable in vitro in the supernatants of two different cell types, supporting an extracellular function. HMGB2 expression was not changed in inflammatory bowel disease but was detected in certain stool samples of patients, whereas it was absent from control individuals. Taken together, we characterized HMGB2 as an antimicrobial protein in intestinal tissue, complementing the diverse repertoire of gut mucosal defense molecules. PMID:23877675

Kuchler, Robert; Schroeder, Bjoern O.; Jaeger, Simon U.; Stange, Eduard F.

2013-01-01

318

Antiviral and antimicrobial activities of three sesquiterpene lactones from Centaurea solstitialis L. ssp. solstitialis.  

PubMed

Three sesquiterpene lactones (centaurepensin = chlorohyssopifolin A, chlorojanerin and 13-acetyl solstitialin A) isolated from the aerial parts of Centaurea solstitialis L. ssp. solstitialis (Asteraceae) were investigated for antimicrobial and antiviral activities. For the antimicrobial activity assessment, both standard and isolated strains of Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. parapsilosis were employed by the microdilution method. Herpes simplex type-1, a DNA virus, and Parainfluenza, an RNA virus, were employed for the determination of the antiviral activity of these three sesquiterpene lactones using Vero cell lines. Ampicilline, ofloxocine, ketoconazole, fluconazole, acyclovir and oseltamivir were used as the reference drugs. 13-Acetyl solstitialin A displayed remarkable antibacterial activity against isolated strains of E. faecalis at 1 microg/ml concentration, which was close to the effective concentrations of ampicillin. The same compound also showed significant activity against the DNA virus, being as potent as the reference compound acyclovir at maximum and minimum concentrations of 16-<0.00006 microg/ml. This is the first report showing that 13-acetyl solstitialin A possesses significant antiviral activity. PMID:17614269

Ozçelik, Berrin; Gürbüz, Ilhan; Karaoglu, Taner; Ye?ilada, Erdem

2009-01-01

319

Vaccines: A Cost-Effective Strategy to Contain Antimicrobial Resistance  

Microsoft Academic Search

\\u000a There is rapid spread of infectious disease globally. Emergence of antimicrobial resistance has made it difficult to contain\\u000a the spread and the associated escalating costs of treatment. Rational use of antibiotics and an effective infection control\\u000a strategy in health-care facilities can reduce the growing spread of infectious disease dramatically but these are often not\\u000a possible in developing countries due to

Richard A. Adegbola; Debasish Saha

320

Evaluating the Antimicrobial Activity of Methonolic Extract of Rhus Succedanea Leaf Gall  

PubMed Central

Introduction: The worldwide increased bacterial resistance to antibiotics and the undesirable side effects associated with constant use of synthetic drugs has prompted the search for novel antimicrobial agents, particularly those manufactured from plants. This study is designed to ascertain the antibacterial potential of Rhus succedanea leaf gall extracts on the growth of gram-positive and gram–negative bacteria. Methods: The methanolic and hexane extract of different concentrations (100, 250, and 500 ?g/ml) were prepared and their antibacterial efficacy was tested against clinical isolates of Escherichia coli, Salmonella typhi, Micrococcus luteus, and Staphylococcus aureus using agar well diffusion method and the size of inhibition zone was measured in millimeters. Results: The methanol and hexane extracts differed significantly in their antimicrobial activity with methanol extract showing a potent inhibitory activity in the range of 16±2 to 23±1, which was almost equal to the values of ciprofloxacin (25±3), used as a standard. Further, the methanol extract was mostly potent and effective in inhibiting the growth of gram-negative bacteria, namely, E. coli, when compared to gram –positive bacteria stains, which are responsible for antimicrobial activities. The phytochemical screening showed positive results for the presence of steroids, triterpenes, alkaloids, and carbohydrates. Conclusion: The potent antibacterial activity of Rhus succedanea leaf gall extracts indicates its useful therapeutic application against bacterial infection. Furthermore, this study indicates that the extract might be exploited as natural drug for the treatment of infectious diseases and could be useful in understanding the relations between traditional cures and current medications. PMID:24455483

Shrestha, Savitri; Subaramaihha, Sundara Rajan; Subbaiah, Sujan Ganapathy Pasura; Eshwarappa, Ravi Shankara Birur; Lakkappa, Dhananjaya Bhadrapura

2013-01-01

321

Determination and Characterization of the Antimicrobial Activity of the Fermented Tea Kombucha  

Microsoft Academic Search

Early reports onKombucha, a traditional fermented tea beverage, suggested that it has antimicrobial activity against a spectrum of organisms, and that concentrates of unfermented tea components also have anti microbial properties. Therefore, the focus of this study was to determine and characterizeKombucha'santimicrobial activity using an absorbent disc method. Antimicrobial activity was observed in the fermented samples containing 33 g\\/L total

C. J Greenwalt; R. A Ledford; KH Steinkraus

1998-01-01

322

Composition and in vitro antimicrobial activity of Populus buds and poplar-type propolis  

Microsoft Academic Search

The antibacterial activity of propolis has been widely investigated. Since reports dealing with antimicrobial activity of\\u000a the origin of propolis are not available, this study was carried out aiming to analyse the in vitro antimicrobial activity\\u000a of the methanol extracts of poplar type propolis and Populus (Populus nigra, P. alba, P. tremuloides) buds as its sources against standard strains of a panel of

Gülhan Vardar-Ünlü; Sibel Silici; Mehmet Ünlü

2008-01-01

323

In vitro activities of 10 antimicrobial agents against bacterial vaginosis-associated anaerobic isolates from pregnant Japanese and Thai women.  

PubMed

The in vitro activities of 10 antimicrobial agents against 159 bacterial vaginosis-associated anaerobic isolates from pregnant Japanese and Thai women were determined. Clindamycin, imipenem, cefmetazole, amoxicillin, amoxicillin-clavulanate, and metronidazole were highly active against all anaerobic isolates except Prevotella bivia and Mobiluncus species, which were resistant to amoxicillin and metronidazole, respectively. Cefotiam, ceftazidime, and ofloxacin were variably effective, while cefaclor was the least effective agent. PMID:9333068

Puapermpoonsiri, S; Watanabe, K; Kato, N; Ueno, K

1997-10-01

324

Characterization of ?-carrageenan films incorporated plant essential oils with improved antimicrobial activity.  

PubMed

Antioxidant and antimicrobial kappa-carrageenan-based films containing different concentrations of Zataria multiflora Boiss (ZEO) and Mentha pulegium (MEO) essential oils were developed, and their water vapor permeability (WVP), optical, microstructure, antioxidant and antimicrobial properties were characterized. ZEO and MEO decreased the WVP of the emulsified films; for example, 3% ZEO reduced WVP by around 80%. Increasing the content of ZEO or MEO from 1% to 3% (v/v) increased values for elongation at break from 37.43% to 44.74% and from 36.09% to 41.25% respectively. Carrageenan-composite films were less resistant to breakage, more flexible and more opaque with lower gloss. These properties were related to the film's microstructure as analyzed by atomic force microscopy and scanning electron microscopy. ZEO affected the antioxidant properties of the films more markedly than MEO, e.g., ZEO containing films showed DPPH radical scavenging of 80.6% which were two-fold higher than those having MEO. The films' antimicrobial activities were increased by incorporating essential oils, particularly ZEO, which were more effective against the bacteria in the direct-contact method than a vapor phase. S. aureus was found to be the most sensitive bacterium to either ZEO or MEO, followed by B. cereus and E. coli. A highest inhibition zone of 544.05 mm(2) was observed for S. aureus around the films incorporated with 3% (v/v) ZEO. The total inhibitory zone of 3% (v/v) MEO formulated films was 20.43 for S. typhimurium and 10.15 mm(2) for P. aeruginosa. These results revealed that ZEO and MEO have good potential to be incorporated into ?-carrageenan to make antimicrobial and antioxidant edible films for food applications. PMID:24299814

Shojaee-Aliabadi, Saeedeh; Hosseini, Hedayat; Mohammadifar, Mohammad Amin; Mohammadi, Abdorreza; Ghasemlou, Mehran; Hosseini, Seyede Marzieh; Khaksar, Ramin

2014-01-30

325

Psychotropic effects of antimicrobials and immune modulation by psychotropics: implications for neuroimmune disorders  

PubMed Central

SUMMARY Antimicrobial compounds and psychotropic medications often share overlapping mechanisms of actions and pharmacological effects. The immune system appears to be an important site of interaction as several antimicrobials display neurological and, at times, direct psychotropic effects, while psychotropics have shown significant immunomodulatory properties. The isoniazid class of antibiotics for example has been shown to possess monoamine oxidase activity, while selective serotonin reuptake inhibitors have shown significant effects on leukocyte populations. As the importance of the immune system's role in CNS homeostasis and disease continues to move to the forefront of neuropsychiatric research, these shared pharmacological effects may provide an important insight, elucidating the complexities in neuroimmune pathophysiology and guiding the development of potential treatments. PMID:23148142

Obregon, Demian; Parker-Athill, Ellisa Carla; Tan, Jun; Murphy, Tanya

2012-01-01

326

In vitro antimicrobial activity of ten medicinal plants against clinical isolates of oral cancer cases  

PubMed Central

Background Suppression of immune system in treated cancer patients may lead to secondary infections that obviate the need of antibiotics. In the present study, an attempt was made to understand the occurrence of secondary infections in immuno-suppressed patients along with herbal control of these infections with the following objectives to: (a) isolate the microbial species from the treated oral cancer patients along with the estimation of absolute neutrophile counts of patients (b) assess the in vitro antimicrobial activity medicinal plants against the above clinical isolates. Methods Blood and oral swab cultures were taken from 40 oral cancer patients undergoing treatment in the radiotherapy unit of Regional Cancer Institute, Pt. B.D.S. Health University, Rohtak, Haryana. Clinical isolates were identified by following general microbiological, staining and biochemical methods. The absolute neutrophile counts were done by following the standard methods. The medicinal plants selected for antimicrobial activity analysis were Asphodelus tenuifolius Cav., Asparagus racemosus Willd., Balanites aegyptiaca L., Cestrum diurnum L., Cordia dichotoma G. Forst, Eclipta alba L., Murraya koenigii (L.) Spreng. , Pedalium murex L., Ricinus communis L. and Trigonella foenum graecum L. The antimicrobial efficacy of medicinal plants was evaluated by modified Kirby-Bauer disc diffusion method. MIC and MFC were investigated by serial two fold microbroth dilution method. Results Prevalent bacterial pathogens isolated were Staphylococcus aureus (23.2%), Escherichia coli (15.62%), Staphylococcus epidermidis (12.5%), Pseudomonas aeruginosa (9.37%), Klebsiella pneumonia (7.81%), Proteus mirabilis (3.6%), Proteus vulgaris (4.2%) and the fungal pathogens were Candida albicans (14.6%), Aspergillus fumigatus (9.37%). Out of 40 cases, 35 (87.5%) were observed as neutropenic. Eight medicinal plants (A. tenuifolius, A. racemosus, B. aegyptiaca, E. alba, M. koenigii, P. murex R. communis and T. foenum graecum) showed significant antimicrobial activity (P < .05) against most of the isolates. The MIC and MFC values were ranged from 31 to 500 ?g/ml. P. aeruginosa was observed highest susceptible bacteria (46.6%) on the basis of susceptible index. Conclusion It can be concluded that treated oral cancer patients were neutropenic and prone to secondary infection of microbes. The medicinal plant can prove as effective antimicrobial agent to check the secondary infections in treated cancer patients. PMID:21599889

2011-01-01

327

Expression of mouse beta defensin 2 in escherichia coli and its broad-spectrum antimicrobial activity.  

PubMed

Mature mouse beta defensin 2 (mBD2) is a small cationic peptide with antimicrobial activity. Here we established a prokaryotic expression vector containing the cDNA of mature mBD2 fused with thioredoxin (TrxA), pET32a-mBD2. The vector was transformed into Escherichia Coli (E. coli) Rosseta-gami (2) for expression fusion protein. Under the optimization of fermentation parameters: induce with 0.6 mM isopropylthiogalactoside (IPTG) at 34°C in 2×YT medium and harvest at 6 h postinduction, fusion protein TrxA-mBD2 was high expressed in the soluble fraction (>95%). After cleaved fusion protein by enterokinase, soluble mature mBD2 was achieved 6 mg/L with a volumetric productivity. Purified recombinant mBD2 demonstrated clear broad-spectrum antimicrobial activity for fungi, bacteria and virus. The MIC of antibacterial activity of against Staphylococcus aureus was 50 ?g/ml. The MIC of against Candida albicans (C. albicans) and Cryptococcus neoformans (C. neoformans) was 12.5?g/ml and 25?g/ml, respectively. Also, the antimicrobial activity of mBD2 was effected by NaCl concentration. Additionally, mBD2 showed antiviral activity against influenza A virus (IAV), the protective rate for Madin-Darby canine kidney cells (MDCK) was 93.86% at the mBD2 concentration of 100 ?g/ml. These works might provide a foundation for the following research on the mBD2 as therapeutic agent for medical microbes. PMID:24031740

Gong, Tianxiang; Li, Wanyi; Wang, Yueling; Jiang, Yan; Zhang, Qiang; Feng, Wei; Jiang, Zhonghua; Li, Mingyuan

2011-07-01

328

Evaluation of the Antimicrobial Activity of Lysostaphin-Coated Hernia Repair Meshes?  

PubMed Central

Bacterial infections by antibiotic-resistant Staphylococcus aureus strains are among the most common postoperative complications in surgical hernia repair with synthetic mesh. Surface coating of medical devices/implants using antibacterial peptides and enzymes has recently emerged as a potentially effective method for preventing infections. The objective of this study was to evaluate the in vitro antimicrobial activity of hernia repair meshes coated by the antimicrobial enzyme lysostaphin at different initial concentrations. Lysostaphin was adsorbed on pieces of polypropylene (Ultrapro) mesh with binding yields of ?10 to 40% at different coating concentrations of between 10 and 500 ?g/ml. Leaching of enzyme from the surface of all the samples was studied in 2% (wt/vol) bovine serum albumin in phosphate-buffered saline buffer at 37°C, and it was found that less than 3% of adsorbed enzyme desorbed from the surface after 24 h of incubation. Studies of antibacterial activity against a cell suspension of S. aureus were performed using turbidity assay and demonstrated that the small amount of enzyme leaching from the mesh surface contributes to the lytic activity of the lysostaphin-coated samples. Colony counting data from the broth count (model for bacteria in wound fluid) and wash count (model for colonized bacteria) for the enzyme-coated samples showed significantly decreased numbers of CFU compared to uncoated samples (P < 0.05). A pilot in vivo study showed a dose-dependent efficacy of lysostaphin-coated meshes in a rat model of S. aureus infection. The antimicrobial activity of the lysostaphin-coated meshes suggests that such enzyme-leaching surfaces could be efficient at actively resisting initial bacterial adhesion and preventing subsequent colonization of hernia repair meshes. PMID:21709102

Satishkumar, Rohan; Sankar, Sriram; Yurko, Yuliya; Lincourt, Amy; Shipp, John; Heniford, B. Todd; Vertegel, Alexey

2011-01-01

329

Total Phenolic, Total Flavonoids, Antioxidant and Antimicrobial Activities of Scrophularia Striata Boiss Extracts  

PubMed Central

Background Scrophularia striata (Scrophulariaceae family) is an herbaceous plant that is traditionally used for treatment of microbial infections. Objectives Antimicrobial and antioxidant activity of different extracts (methanolic, ethanolic, aqueous and ethyl acetate) from S. striata aerial parts was evaluated. Materials and Methods The antimicrobial activity of different extracts from S. striata was evaluated against a large number of bacteria and fungi by micro broth dilution. Total phenolic and flavonoid contents were measured and their antioxidant activities evaluated by DPPH assay and beta carotene linoleic acid test. Results Antimicrobial screening exhibited the positive relation between the total phenolic content and its antimicrobial activity but their antioxidant activity had a negative relation. Conclusions Further studies are recommended against clinical isolate of sensitive bacteria and deep investigation on flavonoid and phenolic compounds of S. striata and detecting the antioxidant portion in aqueous extract. PMID:24624181

Mahboubi, Mohaddese; Kazempour, Nastaran; Boland Nazar, Ali Reza

2013-01-01

330

Study of the chemical composition and antimicrobial activities of ethanolic extracts from roots of Scutellaria baicalensis Georgi.  

PubMed

Scutellaria baicalensis Georgi (SBG), commonly named Huangqin, showed strong in vitro antimicrobial effects. However, limited research is available to systematically evaluate the effects of extraction methods on the phytochemical composition of SBG and its associated antimicrobial effects. In addition, limited studies have tested SBG as a natural antimicrobial agent on fresh produce such as tomatoes. In the current study, powered roots of SBG were extracted with 60, 80, and 100% ethanol, and their antiviral and antibacterial activities were evaluated. SBG ethanol extracts (SBGEEs) at 6.25 mg/mL showed limited antiviral activities against coliphage MS2 and hepatitis A virus. The SBG 80% ethanol extract (SBG80%EE) exhibited the lowest minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) against six foodborne pathogens. SBG80%EE had the highest contents of flavonoids and phenolic acids determined by high-performance liquid chromatography (HPLC). Among these bioactive compounds, ferulic acid had the lowest MIC and MBC values, 0.4 and 1.0 mg/mL, respectively, followed by baicalein and baicalin. Washing with SBG80%EE (12.5 mg/mL) resulted in >1 log reduction of Salmonella enterica serovars Typhimurium, Kentucky, Senftenberg, and Enteritidis on surface-inoculated grape tomatoes. None of SBGEE solutions changed the total phenolic content, color, or pH values of grape tomatoes. The quantification of these antimicrobial flavonoids and phenolic acids is important to maintain the quality and antimicrobial efficacy of SBG extracts. In addition, the application of SBG on tomatoes has provided valuable insights on the potential usage of this antimicrobial extract. PMID:21866919

Lu, Yingjian; Joerger, Rolf; Wu, Changqing

2011-10-26

331

Evaluation of in vitro antioxidant, antimicrobial, genotoxic and anticancer activities of lichen Cetraria islandica.  

PubMed

In this study, the antioxidant, antimicrobial, genotoxic and anticancer activities of Cetraria islandica methanol extract were determined by using free radical and superoxide anion scavenging activity, reducing power, determination of total phenolic compounds and flavonoid contents, broth microdilution minimal inhibitory concentration against five bacterial and five fungal species, cytokinesis block micronucleus (MN) assay on peripheral blood lymphocytes (PBLs) and the microculture tetrazolium test on FemX (human melanoma) and LS174 (human colon carcinoma) cell lines. As a result of the study, we found that C. islandica methanol extract exhibited moderate free-radical-scavenging activity with IC50 values 678.38 ?g/ml. Moreover, the tested extract had effective reducing power and superoxide anion radical scavenging. The minimal inhibitory concentration values against the tested microorganisms ranged from 0.312 to 5 mg/ml. The extract increased MN frequency in a dose dependent manner, but it was significant in higher tested concentrations (50, 100 and 200 ?g/ml). No significant differences were observed between NDI values in all treatments and untreated PBLs. In addition, the tested extract had strong anticancer activity towards both cell lines with IC50 values of 22.68 and 33.74 ?g/ml. It can be concluded that the tested extract exhibited a certain level of in vitro antioxidant, antimicrobial, genotoxic and anticancer activities. PMID:24590925

Gruji?i?, Darko; Stoši?, Ivana; Kosani?, Marijana; Stanojkovi?, Tatjana; Rankovi?, Branislav; Miloševi?-Djordjevi?, Olivera

2014-10-01

332

Synthesis, characterization and antimicrobial activity of some novel benzimidazole derivatives  

PubMed Central

A series of novel N-((1H-benzoimidazol-1-yl) methyl)-4-(1-phenyl-5-substituted-4, 5-dihydro-1-benzoimidazol-1-yl) methyl)-4-(1-phenyl-5-substituted-4, 5-dihydro-1H-pyrazol-3-yl) benzenamine were synthesized by treating various 1-(4-((1H-benzoimidazol-1-yl) methylamino) phenyl)-3-substitutedprop-2-en-1-one with phenyl hydrazine in the presence of sodium acetate through a simple ring closure reaction. The starting material, 1-(4-((1H-benzoimidazol-1-yl) methylamino) phenyl)-3-substitutedprop-2-en-1-one,-benzoimidazol-1-yl) methylamino) phenyl)-3-substitutedprop-2-en-1-one, was synthesized from o-phenylenediamine by a multistep synthesis. All the synthesized compounds were characterized by spectroscopic means and elemental analyses. The title compounds were investigated for in vitro antibacterial and antifungal properties against some human pathogenic microorganisms by employing the agar streak dilution method using Ciprofloxacin and Ketoconazole as standard drugs. All title compounds showed activity against the entire strains of microorganism. Structural activity relationship studies reveal that compounds possessing an electron-withdrawing group display better activity than the compounds containing electron-donating groups, whereas the unsubstituted derivatives display moderate activity. Based on the results obtained, N-((1H-benzoimidazol-1-yl) methyl)-4-(1-phenyl-5-(4-(trifluoromethyl) phenyl)-4,5-dihydro-1H-pyrazol-3-yl) benzenamine 5i was found to be very active compared with the rest of the compounds and standard drugs that were subjected to antimicrobial assay. PMID:24696814

Krishnanjaneyulu, Immadisetty Sri; Saravanan, Govindaraj; Vamsi, Janga; Supriya, Pamidipamula; Bhavana, Jarugula Udaya; Sunil Kumar, Mittineni Venkata

2014-01-01

333

Antimicrobial, antioxidant and cytotoxic activities of propolis from Melipona orbignyi (Hymenoptera, Apidae).  

PubMed

Propolis from stingless bees is well known for its biologic properties; however, few studies have demonstrated these effects. Therefore, this study aimed to investigate the chemical composition and antimicrobial, antioxidant and cytotoxic activities of propolis from the stingless bee Melipona orbignyi, found in Mato Grosso do Sul, Brazil. The chemical composition of the ethanol extract of propolis (EEP) indicated the presence of aromatic acids, phenolic compounds, alcohols, terpenes and sugars. The EEP was active against the bacterium Staphylococcus aureus and the fungus Candida albicans. The EEP showed antioxidant activity by scavenging free radicals and inhibiting hemolysis and lipid peroxidation in human erythrocytes incubated with an oxidizing agent. Additionally, EEP promoted cytotoxic activity and primarily necrotic death in K562 erythroleukemia cells. Taken together, these results indicate that propolis from M. orbignyi has therapeutic potential for the treatment and/or prevention of diseases related to microorganism activity, oxidative stress and tumor cell proliferation. PMID:24412556

Campos, Jaqueline Ferreira; dos Santos, Uilson Pereira; Macorini, Luis Fernando Benitez; de Melo, Adriana Mary Mestriner Felipe; Balestieri, José Benedito Perrella; Paredes-Gamero, Edgar Julian; Cardoso, Claudia Andrea Lima; de Picoli Souza, Kely; dos Santos, Edson Lucas

2014-03-01

334

Effect of naturally occurring antimicrobials and chemical preservatives on the growth of Aspergillus Parasiticus  

Microsoft Academic Search

Effect of water activity (aw, 0.99), pH (4.5) and their interaction on the growth inhibition of Aspergillus parasiticus was studied on potato dextrose agar (PDA) using various antimicrobial agents (citral, carvacrol, eugenol, cineole, thymol\\u000a guaiacol, vanillin, anethol, potassium sorbate and sorbic acid). The results demonstrate that colony diameter (mm) exhibited\\u000a a constant increase with time (zero order kinetics) for all

Prathesha Pillai; K. Ramaswamy

335

Short communication: Combined antimicrobial activity of reuterin and diacetyl against foodborne pathogens.  

PubMed

Reuterin (?-hydroxypropionialdehyde) is a broad-spectrum antimicrobial substance produced by some strains of Lactobacillus reuteri during anaerobic fermentation of glycerol. Some of these strains are able to survive and produce reuterin in cheese and yogurt when added as adjuncts to the starter. Similarly, in fermented dairy foods, other inhibitory compounds such as lactic acid and diacetyl are produced during fermentation. In this work, we studied the combined effect of reuterin and diacetyl under different pH conditions against Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes. Results from agar spot assays showed that the antimicrobial activity of reuterin-producing strains against the gram-negative bacteria tested was enhanced as the concentration of diacetyl increased to 50mg/kg, and was higher under acidic conditions (pH 5.0) for the 3 pathogenic strains. The combination of reuterin and diacetyl had an additive effect against L. monocytogenes only at diacetyl concentrations of 50mg/kg and pH 5.0. In addition, growth kinetics studies showed that the combination of 1 activity unit (AU)/mL of reuterin with 100mg/kg diacetyl increased the lag time of the 3 pathogens. In milk, synergistic antimicrobial activity was observed with the combination of 1AU/mL reuterin and 50 or 100mg/kg of diacetyl on the gram-negative strains tested, and with 1AU/mL reuterin and 100mg/kg of diacetyl on L. monocytogenes. The greatest inhibition of the 3 pathogens was achieved in acidified milk at pH 5.0 with reuterin (1AU/mL) and diacetyl (100mg/kg). Based on these results, the combination of reuterin and diacetyl in acidified dairy products could be a promising strategy to control food pathogens in these products. PMID:25087026

Langa, S; Martín-Cabrejas, I; Montiel, R; Landete, J M; Medina, M; Arqués, J L

2014-10-01

336

Activity of the antimicrobial polypeptide piscidin 2 against fish ectoparasites.  

PubMed

Abstract The antiparasitic effects of piscidin 2, an antimicrobial polypeptide (AMPP) first isolated from mast cells of hybrid striped bass, were tested against three protistan ectoparasites of marine fish (the ciliates Cryptocaryon irritans and Trichodina sp., and the dinoflagellate Amyloodinium ocellatum) and one ciliate ectoparasite of freshwater fish (Ichthyophthirius multifiliis). I. multifiliis was the most susceptible parasite, with all theronts killed at 6.3 microg mL(-1) piscidin 2. The most resistant parasite was Trichodina, where a few cells were killed at 12.5 microg mL(-1), but several were still alive even at 100 microg mL(-1). C. irritans was of intermediate sensitivity, with some theronts killed at 12.5 microg mL(-1) and all killed at 25 microg mL(-1). High parasite density apparently exhausted the piscidin 2 before it could attain its maximal effect, but surviving parasites were often visibly damaged. The lower efficacy of piscidin 2 against marine parasites compared with the freshwater ciliate might be related to the inhibitory effects of high sea water cation levels. The tissue concentration of piscidins estimated in healthy hybrid striped bass gill (40 microg mL(-1)) suggests that piscidin 2 is lethal to the parasites tested at physiological concentrations and is thus an important component of innate defence in fish expressing this type of AMPP. PMID:18471098

Colorni, A; Ullal, A; Heinisch, G; Noga, E J

2008-06-01

337

PLASMOSE - antimicrobial effects of modular atmospheric plasma sources  

PubMed Central

The technological potential of non-thermal plasmas for the antimicrobial treatment of heat sensitive materials is well known and has been documented in a great number of research activities, but the realisation of industrial plasma-based decontamination processes remains a great challenge. One of the reasons for this situation is the fact that an antimicrobial treatment process needs to consider all properties of the product to be treated as well as the requirements of the complete procedure, e.g. a reprocessing of a medical instrument. The aim of the BMBF-funded network project PLASMOSE is to demonstrate the applicability of plasma-based processes for the antimicrobial treatment on selected, heat sensitive products. Modular and selective plasma sources, driven at atmospheric pressure are used. This basic approach shall combine the technological advantages of atmospheric pressure plasmas (avoidance of vacuum devices and batch processing) with the flexibility and handling properties of modular devices. Two different objectives were selected: the outer surface treatment of medical products and the treatment of hollow packaging for pharmaceutical products. The outer surface treatment of medical products, in particular catheters for intracardial electrophysiological studies, is investigated by means of RF-driven plasma jets in argon. Due to its compact design they are predestined for modularisation and can be adapted to nearly any complex 3-dimensional structure as given by the medical products. The realisation of an antimicrobial treatment process of hollow packaging for pharmaceutical products has quite different demands. Such a process is needed to be implemented in in-line filling procedures and to work without additional process gases. The idea is to use an atmospheric air, microwave-driven self propagating discharge. The plasma process is optimized for the decontamination of 200 ml bottles by field simulation studies combined with optical emissions spectroscopy and micro-biological tests. PMID:20204116

Ehlbeck, Jorg; Brandenburg, Ronny; von Woedtke, Thomas; Krohmann, Udo; Stieber, Manfred; Weltmann, Klaus-Dieter

2008-01-01

338

Investigation of antimicrobial activity of photothermal therapeutic gold/copper sulfide core/shell nanoparticles to bacterial spores and cells  

PubMed Central

Background Au/CuS core/shell nanoparticles (NPs) were designed as a new type of transducer agent for photothermal therapy (PTT), with attractive features of easy preparation, low cost and small size for targeting. This paper studied for the first time the intrinsic antimicrobial activity of Au/CuS NPs to B. anthracis spores and cells in addition to its PTT effect. Results It was found that Au/CuS NPs were highly efficient in inactivating B. anthracis cells, but not effective to the spores. Treatment with NPs at ~0.83 ?M for 30 min achieved a 7 log reduction in viable cells. The antimicrobial effect was both NPs concentration and treatment time dependent. SEM imaging and the efflux of DNA test demonstrated the damage of cell membrane after NPs treatment, yet further research is necessary to fully understand the precise inactivation mechanism. Conclusions The Au/CuS NPs had strong antimicrobial activity to B. anthracis cells, which showed a great potential to be an effective antimicrobial agent to bacterial cells. PMID:24963345

2014-01-01

339

Antimicrobial and cytotoxic activities screening of some Brazilian medicinal plants used in Governador Valadares district  

Microsoft Academic Search

Ethanol extracts from medicinal plants commonly used by Governador Valadares people were tested for antimicrobial activity and cytotoxicity (BST assay). The field survey was conducted during the years 1997-2000 by means of direct interviews with healing men (\\

Beatriz Gonçalves Brasileiro; Virgínia Ramos Pizziolo; Délio Soares Raslan; Claudia Mashrouah Jamal; Dâmaris Silveira

2006-01-01

340

Antimicrobial activity of licorice flavonoids against methicillin-resistant Staphylococcus aureus  

Microsoft Academic Search

Nineteen flavonoids isolated from licorice (Glycyrrhiza glabra, G. inflata and G. uralensis) were tested for their antimicrobial activities against methicillin sensitive Staphylococcus aureus, methicillin resistant S. aureus, Micrococcus luteus, Bacillussubtilis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa.

Toshio Fukai; Ai Marumo; Kiyoshi Kaitou; Toshihisa Kanda; Sumio Terada; Taro Nomura

2002-01-01

341

Antimicrobial Activity of Selected Phytochemicals against Escherichia coli and Staphylococcus aureus and Their Biofilms  

PubMed Central

Abstract Bacteria can be resistant to multiple antibiotics and we are fast approaching a time when antibiotics will not work on some bacterial infections. New antimicrobial compounds are urgently necessary. Plants are considered the greatest source to obtain new antimicrobials. This study aimed to assess the antimicrobial activity of four phytochemicals—7-hydroxycoumarin (7-HC), indole-3-carbinol (I3C), salicylic acid (SA) and saponin (SP)—against Escherichia coli and Staphylococcus aureus, either as planktonic cells or as biofilms. These bacteria are commonly found in hospital-acquired infections. Some aspects on the phytochemicals mode of action, including surface charge, hydrophobicity, motility and quorum-sensing inhibition (QSI) were investigated. In addition, the phytochemicals were combined with three antibiotics in order to assess any synergistic effect. 7-HC and I3C were the most effective phytochemicals against E. coli and S. aureus. Both phytochemicals affected the motility and quorum-sensing (QS) activity, which means that they can play an important role in the interference of cell-cell interactions and in biofilm formation and control. However, total biofilm removal was not achieved with any of the selected phytochemicals. Dual combinations between tetracycline (TET), erythromycin (ERY) and ciprofloxacin (CIP) and I3C produced synergistic effects against S. aureus resistant strains. The overall results demonstrates the potential of phytochemicals to control the growth of E. coli and S. aureus in both planktonic and biofilm states. In addition, the phytochemicals demonstrated the potential to act synergistically with antibiotics, contributing to the recycling of old antibiotics that were once considered ineffective due to resistance problems.

Monte, Joana; Abreu, Ana C.; Borges, Anabela; Simões, Lúcia Chaves; Simões, Manuel

2014-01-01

342

Chemical Composition and Antimicrobial Activity of the Essential Oil of Kumquat (Fortunella crassifolia Swingle) Peel  

PubMed Central

The aim of this study was to determine the main constituents of the essential oil isolated from Fortunella crassifolia Swingle peel by hydro-distillation, and to test the efficacy of the essential oil on antimicrobial activity. Twenty-five components, representing 92.36% of the total oil, were identified by GC-MS analysis. The essential oil showed potent antimicrobial activity against both Gram-negative (E. coli and S. typhimurium) and Gram-positive (S. aureus, B. cereus, B. subtilis, L. bulgaricus, and B. laterosporus) bacteria, together with a remarkable antifungal activity against C. albicans. In a food model of beef extract, the essential oil was observed to possess an effective capacity to control the total counts of viable bacteria. Furthermore, the essential oil showed strongly detrimental effects on the growth and morphological structure of the tested bacteria. It was suggested that the essential oil from Fortunella crassifolia Swingle peel might be used as a natural food preservative against bacteria or fungus in the food industry. PMID:22489157

Wang, Yong-Wei; Zeng, Wei-Cai; Xu, Pei-Yu; Lan, Ya-Jia; Zhu, Rui-Xue; Zhong, Kai; Huang, Yi-Na; Gao, Hong

2012-01-01

343

Antimicrobial activity of the essential oil of Cyclotrichium niveum (Boiss.) Manden. Et Scheng  

Microsoft Academic Search

The present study was designed to examine in vitro antimicrobial and antifungal activities of the essential oil of Cyclotrichium niveum. The major constituents of the essential oil were determined as pulegone (50.46%) and iso-menthone (34.53%). The antimicrobial activity of the oil was also tested against gram-positive and -negative bacteria and fungus using a disc-diffusion method and the minimal inhibitory concentration

Ahmet Alim; Ismihan Goze; Ali Cetin; Ahmet D. Atas; Nilufer Vural; Erol Donmez

344

Myrtus communis essential oil: chemical composition and antimicrobial activities against food spoilage pathogens.  

PubMed

Myrtus communis is a typical plant of the Mediterranean area, which is mainly used as animal and human food and, in folk medicine, for treating some disorders. In the present study, we evaluated in vitro antibacterial and antifungal properties of the essential oils of Myrtus communis (McEO), as well as its phytochemical composition. The GC/MS analysis of the essential oil revealed 17 compounds. Myrtenyl acetate (20.75%), 1,8-cineol (16.55%), ?-pinene (15.59%), linalool (13.30%), limonene (8.94%), linalyl acetate (3.67%), geranyl acetate (2.99%), and ?-terpineol (2.88%) were the major components. The antimicrobial activity of the essential oil was also investigated on several microorganisms. The inhibition zones and minimal inhibitory concentration (MIC) values of bacterial strains were in the range of 16-28?mm and 0.078-2.5?mg/ml, respectively. The inhibitory activity of the McEO against Gram-positive bacteria was significantly higher than against Gram-negative. It also exhibited remarkable activity against several fungal strains. The investigation of the mode of action of the McEO by the time-kill curve against Listeria monocytogenes (food isolate) showed a drastic bactericidal effect after 5?min using a concentration of 312??g/ml. These results evidence that the McEO possesses antimicrobial properties, and it is, therefore, a potential source for active ingredients for food and pharmaceutical industries. PMID:24706627

Ben Hsouna, Anis; Hamdi, Naceur; Miladi, Ramzi; Abdelkafi, Slim

2014-04-01

345

Synthesis of lipophilic tyrosyl esters derivatives and assessment of their antimicrobial and antileishmania activities  

PubMed Central

Background Preparation of tyrosyl lipophilic derivatives was carried out as a response to the food, cosmetic and pharmaceutical industries' increasing demand for new lipophilic antioxidants. Results A large series of tyrosyl esters (TyC2 to TyC18:1) with increasing lipophilicity was synthesized in a good yield using lipase from Candida antarctica (Novozyme 435). Spectroscopic analyses of purified esters showed that the tyrosol was esterified on the primary hydroxyl group. Synthetized compounds were evaluated for either their antimicrobial activity, by both diffusion well and minimal inhibition concentration (MIC) methods, or their antileishmanial activity against Leishmania major and Leishmania infantum parasite species. Among all the tested compounds, our results showed that only TyC8, TyC10 and TyC12 exhibited antibacterial and antileishmanial activities. When MIC and IC50 values were plotted against the acyl chain length of each tyrosyl derivative, TyC10 showed a parabolic shape with a minimum value. This nonlinear dependency with the increase of the chain length indicates that biological activities are probably associated to the surfactant effectiveness of lipophilic derivatives. Conclusion These results open up potential applications to use medium tyrosyl derivatives surfactants, antioxidants, antimicrobial and antileishmanial compounds in cosmetic, food and pharmaceutical industries. PMID:22264330

2012-01-01

346

Synthesis, reactions and antimicrobial activities of 8-ethoxycoumarin derivatives.  

PubMed

Condensation of 3-acetyl-8-ethoxycoumarin (3) with thiosemicarbazide gave ethylidenehydrazinecarbothioamide 5, which was transformed into the thiazolidin-4-one derivatives 6,7. Interaction of 3 with DMF/POCl(3) gave b-chloroacroline derivative 8. Treatment of 3 with malononitrile gave benzo[c]chromone and 2-aminobenzonitrile derivatives 9 and 10, respectively with respect to the reaction conditions. Condensation of 3-(2-bromoacetyl)-8-ethoxycoumarin (4) with o-phenylenediamine gave 3-(quioxaline-2-yl)-8-ethoxycoumarin hydrobromide (11), while 4 reacted with 2-aminopyridine to give chromenopyridopyrimidine derivative 12. Condensation of 4 with potassium thio-cyanate/methanol gave an unexpected derivative, 2H-chromeno-3-carboxy(methyl-carbonimidic)thioanhydride 16, which upon treatment with (NH(2))(2)·H(2)O gave 3-ethoxy-2-hydroxybenzaldehyde azine 19. Interaction of 4 with thiourea derivatives gave thiazole derivatives 20a-c. The structures of the newly synthesized compounds were confirmed by their spectra data. The newly synthesized compounds were also screened for their antimicrobial activity. PMID:22258342

Mohamed, Hany M; Abd El-Wahab, Ashraf H F; Ahmed, Kamal A; El-Agrody, Ahmed M; Bedair, Ahmed H; Eid, Fathy A; Khafagy, Mostafa M

2012-01-01

347

Poly-lysine peptidomimetics having potent antimicrobial activity without hemolytic activity.  

PubMed

Diversity of sequence and structure in naturally occurring antimicrobial peptides (AMPs) limits their intensive structure-activity relationship (SAR) study. In contrast, peptidomimetics have several advantages compared to naturally occurring peptide in terms of simple structure, convenient to analog synthesis, rapid elucidation of optimal physiochemical properties and low-cost synthesis. In search of short antimicrobial peptides using peptidomimetics, which provide facile access to identify the key factors involving in the destruction of pathogens through SAR study, a series of simple and short peptidomimetics consisting of multi-Lys residues and lipophilic moiety have been prepared and found to be active against several Gram-negative and Gram-positive bacteria containing methicillin-resistant Staphylococcus aureus (MRSA) without hemolytic activity. Based on the SAR studies, we found that hydrophobicity, +5 charges of multiple Lys residues, hydrocarbon tail lengths and cyclohexyl group were crucial for antimicrobial activity. Furthermore, membrane depolarization, dye leakage, inner membrane permeability and time-killing kinetics revealed that bacterial-killing mechanism of our peptidomimetics is different from the membrane-targeting AMPs (e. g. melittin and SMAP-29) and implied our peptidomimetics might kill bacteria via the intracellular-targeting mechanism as done by buforin-2. PMID:24961649

Ahn, Mija; Jacob, Binu; Gunasekaran, Pethaiah; Murugan, Ravichandran N; Ryu, Eun Kyoung; Lee, Ga-hyang; Hyun, Jae-Kyung; Cheong, Chaejoon; Kim, Nam-Hyung; Shin, Song Yub; Bang, Jeong Kyu

2014-09-01

348

Antimicrobial and anti-inflammatory activity of chitosan-alginate nanoparticles: a targeted therapy for cutaneous pathogens.  

PubMed

Advances in nanotechnology have demonstrated potential application of nanoparticles (NPs) for effective and targeted drug delivery. Here we investigated the antimicrobial and immunological properties and the feasibility of using NPs to deliver antimicrobial agents to treat a cutaneous pathogen. NPs synthesized with chitosan and alginate demonstrated a direct antimicrobial activity in vitro against Propionibacterium acnes, the bacterium linked to the pathogenesis of acne. By electron microscopy (EM) imaging, chitosan-alginate NPs were found to induce the disruption of the P. acnes cell membrane, providing a mechanism for the bactericidal effect. The chitosan-alginate NPs also exhibited anti-inflammatory properties as they inhibited P. acnes-induced inflammatory cytokine production in human monocytes and keratinocytes. Furthermore, benzoyl peroxide (BP), a commonly used antiacne drug, was effectively encapsulated in the chitosan-alginate NPs and demonstrated superior antimicrobial activity against P. acnes compared with BP alone while demonstrating less toxicity to eukaryotic cells. Together, these data suggest the potential utility of topical delivery of chitosan-alginate NP-encapsulated drug therapy for the treatment of dermatologic conditions with infectious and inflammatory components. PMID:23190896

Friedman, Adam J; Phan, Jenny; Schairer, David O; Champer, Jackson; Qin, Min; Pirouz, Aslan; Blecher-Paz, Karin; Oren, Ami; Liu, Phil T; Modlin, Robert L; Kim, Jenny

2013-05-01

349

Antimicrobial activity of bacteriocin-producing lactic acid bacteria isolated from cheeses and yogurts.  

PubMed

The biopreservation of foods using bacteriocinogenic lactic acid bacteria (LAB) isolated directly from foods is an innovative approach. The objectives of this study were to isolate and identify bacteriocinogenic LAB from various cheeses and yogurts and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro as well as on a food commodity.LAB were isolated using MRS and M17 media. The agar diffusion bioassay was used to screen for bacteriocin or bacteriocin-like substances (BLS) producing LAB using Lactobacillus sakei and Listeria innocua as indicator organisms. Out of 138 LAB isolates, 28 were found to inhibit these bacteria and were identified as strains of Enterococcus faecium, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus sakei subsp. sakei using 16S rRNA gene sequencing. Eight isolates were tested for antimicrobial activity at 5°C and 20°C against L. innocua, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, Erwinia carotovora, and Leuconostoc mesenteroides subsp. mesenteroides using the agar diffusion bioassay, and also against Penicillium expansum, Botrytis cinerea and Monilinia frucitcola using the microdilution plate method. The effect of selected LAB strains on L. innocua inoculated onto fresh-cut onions was also investigated.Twenty percent of our isolates produced BLS inhibiting the growth of L. innocua and/or Lact. sakei. Organic acids and/or H2O2 produced by LAB and not the BLS had strong antimicrobial effects on all microorganisms tested with the exception of E. coli. Ent. faecium, Strep. thermophilus and Lact. casei effectively inhibited the growth of natural microflora and L. innocua inoculated onto fresh-cut onions. Bacteriocinogenic LAB present in cheeses and yogurts may have potential to be used as biopreservatives in foods. PMID:22963659

Yang, En; Fan, Lihua; Jiang, Yueming; Doucette, Craig; Fillmore, Sherry

2012-01-01

350

Antimicrobial activity of bacteriocin-producing lactic acid bacteria isolated from cheeses and yogurts  

PubMed Central

The biopreservation of foods using bacteriocinogenic lactic acid bacteria (LAB) isolated directly from foods is an innovative approach. The objectives of this study were to isolate and identify bacteriocinogenic LAB from various cheeses and yogurts and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro as well as on a food commodity. LAB were isolated using MRS and M17 media. The agar diffusion bioassay was used to screen for bacteriocin or bacteriocin-like substances (BLS) producing LAB using Lactobacillus sakei and Listeria innocua as indicator organisms. Out of 138 LAB isolates, 28 were found to inhibit these bacteria and were identified as strains of Enterococcus faecium, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus sakei subsp. sakei using 16S rRNA gene sequencing. Eight isolates were tested for antimicrobial activity at 5°C and 20°C against L. innocua, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, Erwinia carotovora, and Leuconostoc mesenteroides subsp. mesenteroides using the agar diffusion bioassay, and also against Penicillium expansum, Botrytis cinerea and Monilinia frucitcola using the microdilution plate method. The effect of selected LAB strains on L. innocua inoculated onto fresh-cut onions was also investigated. Twenty percent of our isolates produced BLS inhibiting the growth of L. innocua and/or Lact. sakei. Organic acids and/or H2O2 produced by LAB and not the BLS had strong antimicrobial effects on all microorganisms tested with the exception of E. coli. Ent. faecium, Strep. thermophilus and Lact. casei effectively inhibited the growth of natural microflora and L. innocua inoculated onto fresh-cut onions. Bacteriocinogenic LAB present in cheeses and yogurts may have potential to be used as biopreservatives in foods. PMID:22963659

2012-01-01

351

A study of antimicrobial activity, acute toxicity and cytoprotective effect of a polyherbal extract in a rat ethanol-HCl gastric ulcer model  

PubMed Central

Background The decoction of the aerial parts of Rhynchosia recinosa (A.Rich.) Bak. [Fabaceae] is used in combination with the stem barks of Ozoroa insignis Del. (Anacardiaceae), Maytenus senegalensis (Lam.) Excell. [Celastraceae] Entada abyssinica Steud. ex A.Rich [Fabaceae] and Lannea schimperi (Hochst.)Engl. [Anacardiaceae] as a traditional remedy for managing peptic ulcers. However, the safety and efficacy of this polyherbal preparation has not been evaluated. This study reports on the phytochemical profile and some biological activities of the individual plant extracts and a combination of extracts of the five plants. Methods A mixture of 80% ethanol extracts of R. recinosa, O. insignis, M. senegalensis, E. abyssinica and L. schimperi at doses of 100, 200, 400 and 800 mg/kg body wt were evaluated for ability to protect Sprague Dawley rats from gastric ulceration by an ethanol-HCl mixture. Cytoprotective effect was assessed by comparison with a negative control group given 1% tween 80 in normal saline and a positive control group given 40 mg/kg body wt pantoprazole. The individual extracts and their combinations were also tested for antibacterial activity against four Gram negative bacteria; Escherichia coli (ATCC 25922), Salmonella typhi (NCTC 8385), Vibrio cholerae (clinical isolate), and Klebsiella pneumoniae (clinical isolate) using the microdilution method. In addition the extracts were evaluated for brine shrimp toxicity and acute toxicity in mice. Phytochemical tests were done using standard methods to determine the presence of tannins, saponins, steroids, cardiac glycosides, flavonoids, alkaloids and terpenoids in the individual plant extracts and in the mixed extract of the five plants. Results The combined ethanolic extracts of the 5 plants caused a dose-dependent protection against ethanol/HCl induced ulceration of rat gastric mucosa, reaching 81.7% mean protection as compared to 87.5% protection by 40 mg/kg body wt pantoprazole. Both the individual plant extracts and the mixed extracts of 5 plants exhibited weak to moderate antibacterial activity against four G-ve bacteria. Despite Ozoroa insignis being toxic to mice at doses above 1000 mg/kg body wt, the other plant extracts and the combined extract of the 5 plants were tolerated by mice up to 5000 mg/kg body wt. The brine shrimp test results showed the same pattern of toxicity with Ozoroa insignis being the most toxic (LC50?=?10.63 ?g/ml). Phytochemical tests showed that the combined extract of the five plants contained tannins, saponins, steroids, cardiac glycosides, flavonoids and terpenoids. Flavonoids, tannins and terpenoids are known to have antioxidant activity. Conclusion The combined extract of the five plants exhibited a dose-dependent protective activity in the rat ethanol-HCl gastric ulcer model. The extracts also exhibited weak antibacterial activity against four Gram negative bacteria and low acute toxicity in mice and brine shrimps. Although the results support claims by traditional healers who use a decoction of the five plants for treatment of peptic ulcers, more models of gastric ulceration and proper animal toxicity studies are needed to validate possible clinical use of the polyherbal extract. It is also evident that the doses of the crude extracts showing protection of the gastric mucosa are too large for realistic translation to direct clinical application, but further studies using bioassay guided fractionation are important to either identify more practical fractions or active compound/s. PMID:23031266

2012-01-01

352

Composite PLGA/AgNpPGA/AscH Nanospheres with Combined Osteoinductive, Antioxidative, and Antimicrobial Activities  

PubMed Central

The global rise in the resistance of pathogens to conventional antibiotics has created an intensive search for alternative materials with antimicrobial properties. This study is performed with an intention to investigate the combined effects of poly(L-glutamic acid)-capped silver nanoparticles (AgNpPGA) and ascorbic acid (AscH) encapsulated within freeze-dried poly(lactide-co-glycolide) (PLGA) nanospheres to obtain a nanomaterial with simultaneous osteoinductive, antioxidative, and prolonged antimicrobial properties. The influence of PLGA/AgNpPGA/AscH particles on (i) viability and super-oxide production of human umbilical vein endothelial cells in vitro, (ii) morphology and expression of osteogenic markers in osteoblastic MC3T3-E1 cells in vitro, and (iii) antimicrobial activity against a Gram-positive bacterium, methicillin-resistant Staphylococcus aureus, and a Gram-negative bacterium, Escherichia coli, was investigated. PLGA/AgNpPGA/AscH nanoparticles showed a superior and extended antibacterial activity against both types of bacteria. The nanoparticles appeared to be capable of delivering ascorbate to the cells, which was evidenced by the significant decrease in the level of superoxides in human umbilical vein endothelial cells and which could have a therapeutic potential in preventing oxidative stress. PLGA/AgNpPGA/AscH nanoparticles had a positive effect on MC3T3-E1 osteoblastic cells in vitro, promoting: (i) an intimate contact with the cells and preservation of their healthy morphologies; (ii) unreduced cell viability; and (iii) multiple-fold upregulation of two osteogenic markers: osteocalcin and type I procollagen. It is concluded that PLGA/AgNpPGA/AscH nanospheres present a promising new material for the treatment of infections and use in wound dressings and other prophylactic applications. PMID:23984965

Stevanovi?, Magdalena; Uskokovi?, Vuk; Filipovi?, Miloš; Škapin, Sre?o D.; Uskokovi?, Dragan

2014-01-01

353

Plant-based hydrocarbon esters from Tragia involucrata possess antimicrobial and anti-inflammatory activities.  

PubMed

Antimicrobial and anti-inflammatory activities of hydrocarbon esters obtained from Tragia involucrata were evaluated by disk-diffusion (250 µg/ml), and broth-dilution (500-7.8 µg/ml), methods against bacteria. Among the compounds, shellsol showed the most potent activity against Burkholderia pseudomallei (KHW), Aeromonas hydrophila, Staphylococcus aureus, Bacillus subtilis, Streptococcus pyogenes, Klebsiella pneumoniae, Proteus mirabilis, and Streptococcus pneumoniae. Interestingly, vinyl hexylether was active against food-spoilage bacteria (Bacillus cereus and Proteus vulgaris), 2, 4-methyl hexane also exerted antimicrobial activity against K. pneumoniae, S. pyogenes, B. pseudomallei, Alcaligens viscolactis, and Pseudomonas aeruginosa. 2-methylnonane and 2, 6-dimethyl heptane showed only weak activity. For example, shellsol showed bacteriostatic effect (MIC of 7.8 µg/ml) against A. hydrophila, vinyl hexylether (MIC of 15.6 µg/ml) against P. mirabilis, and 2, 4-methyl hexane (MIC of 31.25 µg/ml) on B. pseudomallei. Cytotoxic effects of compounds were assayed in human skin and monkey kidney cells (62.5-2000 µg/ml) by an XTT assay. The vinyl hexylether, 2, 4-dimethyl hexane and shellsol did not show any toxicity up to 1000 µg/ml concentrations. The 2-methylnonane and 2, 6-dimethyl heptane induced morphological changes (e.g. cell disintegration and lysis) of both cell types at a 2000 µg/ml. The vinyl hexylether, 2, 4-dimethyl hexane and shellsol were devoid of toxic effects; however, 2-methylnonane induced weight loss and severe necrosis as evidenced by histopathological and serum biochemical analysis in rats. Interestingly, shellsol showed the maximum inhibition of carrageenan-induced, paw oedema in rats. In conclusion, findings of this study clearly indicate that biologically active hydrocarbon esters, such as shellsol, vinyl hexylether, and 2, 4-dimethyl hexane isolated from T. involucrata, may effectively control the growth of certain food-borne and food-spoilage pathogens. PMID:23713670

Samy, Ramar Perumal; Sethi, Gautam; Chow, Vincent T K; Stiles, Bradley G

2013-04-01

354

The immediate antimicrobial effect of a toothbrush and miswak on cariogenic bacteria: a clinical study.  

PubMed

The aim of this study was to assess the antimicrobial activity of the miswak chewing stick (Salvadora persica) in vivo, especially on streptococcus mutans and lactobacilli. The study was conducted clinically using patients' saliva and measuring the effect of miswak (chewing stick), miswak extract, toothbrush, and normal saline on mutans and lactobacilli. Forty male subjects aged 20-45 years were included in the study; there were four groups of ten subjects each. For the study, 50% of miswak extract (solution) was used. The levels of mutans streptococci and lactobacilli were measured using commercially available Vivacare line CRT (Caries Risk Test) bacteria 2 in 1 kit. The results showed there was a marked reduction of streptococcus mutans among all groups. When the groups were compared, the reduction of streptococcus mutans was significantly greater using miswak in comparison to toothbrushing (p = 0.013), and there was no significant difference for lactobacilli reduction (p = 0.147). It may be concluded miswak has an immediate antimicrobial effect. Streptococcus mutans were more susceptible to miswak antimicrobial activity than lactobacilli. Dietary intake of sugar and oral health status may be considered for controlled clinical trials with special emphasis on the antibacterial activity of miswak on cariogenic bacteria for a longer period of time. A toothbrush with and without toothpaste should be compared with miswak alone. Further research is needed with a larger sample size. PMID:14973564

Almas, Khalid; Al-Zeid, Zuhair

2004-02-15

355

A novel direct contact method for the assessment of the antimicrobial activity of dental cements.  

PubMed

Dental cements are a crucial part of the odontological treatment, however, due to the hazardous nature and reduced biological efficiency of some of the used materials, newer and safer alternatives are needed, particularly so those possessing higher antimicrobial activity than their traditional counterparts. The evaluation of the antimicrobial properties of solid and semi-solid antimicrobials, such as dental cements and gels, is challenging, particularly due to the low sensitivity of the current methods. Thus, the main aim of this study was the evaluation of the antimicrobial activity of a novel chitosan containing dental cement while simultaneous assessing/validating a new, more efficient, method for the evaluation of the antimicrobial activity of solid and gel like materials. The results obtained showed that the proposed method exhibited a higher sensitivity than the standard 96 well microtiter assay and allowed the determination of bactericidal activity. Additionally, it is interesting to note that the chitosan containing cement, which presented higher antimicrobial activity than the traditional zinc oxide/eugenol mix, was capable of inducing a viable count reduction above 5 log of CFU for all of the studied microorganisms. PMID:23541954

Costa, E M; Silva, S; Madureira, A R; Cardelle-Cobas, A; Tavaria, F K; Pintado, M M

2013-06-01

356

[Comparison of in vitro antimicrobial activities of bioaggregate and mineral trioxide aggregate].  

PubMed

Treatment outcome of endodontic perforations depends on successful elimination of the associated microorganisms and infected tissues as well as the effective seal of the root-end or perforation site to prevent future contamination. Ideally, perforation repair material has to be bacteriostatic or bactericidal in order to prevent bacterial contamination as well as good sealing properties and biocompatibility. The aim of this study was to evaluate the antimicrobial effects of BioAggregate (BA) and Mineral Trioxide Aggregate (MTA) on the standard strains of Candida albicans, Enterococcus faecalis, Escherichia coli, Streptococcus mutans, Streptococcus sanguinis and Pseudomonas aeruginosa using the agar disc diffusion test. Colonies of each strains were harvested from the medium and microorganisms were diluted to obtain a suspension of approximately 108 cfu/ml. Petri plates with blood agar base with 5% sheep blood or Sabouraud dextrose agar (for C.albicans) were inoculated with experimental suspensions and BA and MTA discs prepared as 2 mm length and 6 mm diameter were placed. After 24 and 48 hours incubation, the diameters of the zones of inhibition were measured. The results of the disc diffusion tests showed that BA and MTA were effective on the tested microorganisms at 24 and 48 hours incubation periods. BA and MTA showed similar antimicrobial effects on C.albicans and E.coli. BA was more effective than MTA on S.mutans, E.faecalis and P.aeruginosa, however MTA was more effective than BA on S.sanguinis at 48 hours. When the time efficiency of the materials were compared, there was no statistically difference between 24 to 48 hours on E.coli, E.faecalis, S.mutans, S.sanguinis in both two groups (p> 0.05). There was statistically significant decrease 24 to 48 hours on C.albicans in BA and MTA groups and P.aeruginosa in BA group (p< 0.05). It can be concluded that although BA and MTA displayed similar antimicrobial efficacy on the tested microorganisms newly improved material BA demonstrated superior antimicrobial activity than other. PMID:23971930

Cavdar Tetik, Esma Asuman; Dartar Öztan, Meltem; K?yan, Mehmet

2013-07-01

357

Laurel leaf extracts for honeybee pest and disease management: antimicrobial, microsporicidal, and acaricidal activity.  

PubMed

A diverse set of parasites and pathogens affects productivity and survival of Apis mellifera honeybees. In beekeeping, traditional control by antibiotics and molecules of synthesis has caused problems with contamination and resistant pathogens. In this research, different Laurus nobilis extracts are tested against the main honeybee pests through an integrated point of view. In vivo effects on bee survival are also evaluated. The ethanol extract showed minimal inhibitory concentration (MIC) values of 208 to 416 ?g/mL, having the best antimicrobial effect on Paenibacillus larvae among all substances tested. Similarly, this leaf extract showed a significant antiparasitic activity on Varroa destructor, killing 50 % of mites 24 h after a 30-s exposure, and on Nosema ceranae, inhibiting the spore development in the midgut of adult bees ingesting 1?×?10(4) ?g/mL of extract solution. Both ethanol extract and volatile extracts (essential oil, hydrolate, and its main component) did not cause lethal effects on adult honeybees. Thus, the absence of topical and oral toxicity of the ethanol extract on bees and the strong antimicrobial, microsporicidal, and miticidal effects registered in this study place this laurel extract as a promising integrated treatment of bee diseases and stimulates the search for other bioactive phytochemicals from plants. PMID:24288051

Damiani, Natalia; Fernández, Natalia J; Porrini, Martín P; Gende, Liesel B; Álvarez, Estefanía; Buffa, Franco; Brasesco, Constanza; Maggi, Matías D; Marcangeli, Jorge A; Eguaras, Martín J

2014-02-01

358

Antimicrobial activity of binary combinations of natural and synthetic phenolic antioxidants against Enterococcus faecalis.  

PubMed

This study investigated the antimicrobial activity of 3 natural (thymol, carvacrol, and gallic acid) and 2 synthetic [butylated hydroxyanisole (BHA) and octyl gallate] phenolic compounds, individually and in binary combinations, on 4 dairy isolates of Enterococcus faecalis with different virulence factors (?-hemolytic, gelatinase, or trypsin activities; acquired resistance to erythromycin or tetracycline; and natural resistance to gentamicin). A checkerboard technique and a microdilution standardized method were used. All compounds individually tested exhibited antimicrobial activity against E. faecalis, with minimal inhibitory concentrations (MIC) ranging from 30 ?g/mL (octyl gallate) to 3,150 ?g/mL (gallic acid), although no significant differences were detected among strains to each phenolic compound. Carvacrol in combination with thymol or gallic acid, and gallic acid combined with octyl gallate showed partial synergistic inhibition of all E. faecalis strains. The most effective combinations were thymol+carvacrol and gallic acid+octyl gallate, as the MIC for each of these compounds was reduced by 67 to 75% compared with their respective individual MIC. These results highlight the possibility of using combinations of these phenolic compounds to inhibit the growth of potential virulent or spoilage E. faecalis strains by reducing the total amount of additives used in dairy foods. PMID:23769374

Gutiérrez-Fernández, J; García-Armesto, M R; Alvarez-Alonso, R; del Valle, P; de Arriaga, D; Rúa, J

2013-08-01

359

Biosynthesis of silver nanoparticles using Alternanthera sessilis (Linn.) extract and their antimicrobial, antioxidant activities.  

PubMed

The present work focuses the use of the aqueous extract of Alternanthera sessilis Linn. (Amaranthaceae) in producing silver nanoparticles (AgNPs) from silver nitrate aqueous. Phytochemical analysis of the extract revealed the presence of alkaloid, tannins, ascorbic acid, carbohydrates and proteins and they serve as effective reducing and capping agents for converting silver nitrate into nanoparticles. The synthesized silver nanoparticles (AgNPs) were also tested for proteins and ascorbic acid. Its pH was also determined (5.63). The AgNPs obtained was characterized by UV-vis spectroscopy, FT-IR spectroscopy, SEM, Zeta sizer and TG-DSC. SEM images which revealed the presence of various shapes and sizes. FT-IR spectrum showed the AgNPs having a coating of proteins indicating a dual role of bio-molecules responsible for capping and efficient stabilization of the silver nanoparticles. Presence of impurities and melting point profile were screened by TG-DSC analyzer. AgNPs were synthesized from the silver nitrate through the reducing power of ascorbic acid present in A. sessilis leaves. In this study, we also investigated antimicrobial and antioxidant activity of green synthesized AgNPs. The antimicrobial activity is investigated by Bauer et al.'s method. Antioxidant activity was done by DPPH method. PMID:23006568

Niraimathi, K L; Sudha, V; Lavanya, R; Brindha, P

2013-02-01

360

Antimicrobial and antioxidant activities of clove essential oil and eugenyl acetate produced by enzymatic esterification.  

PubMed

This work reports the maximization of eugenyl acetate production by esterification of essential oil of clove in a solvent-free system using Novozym 435 as catalyst. The antimicrobial and antioxidant activities of clove essential oil and eugenyl acetate produced were determined. The conditions that maximized eugenyl acetate production were 60 °C, essential oil of clove to acetic anhydride ratio of 1:5, 150 rpm, and 10 wt% of enzyme, with a conversion of 99.87 %. A kinetic study was performed to assess the influence of substrates' molar ratio, enzyme concentration, and temperature on product yield. Results show that an excess of anhydride, enzyme concentration of 5.5 wt%, 50 °C, and essential oil of clove to acetic anhydride ratio of 1:5 afforded nearly a complete conversion after 2 h of reaction. Comparing the antibacterial activity of the essential oil of clove before and after esterification, we observed a decrease in the antimicrobial activity of eugenyl acetate, particularly with regard to minimum inhibitory concentration (MIC). Both eugenyl acetate and clove essential oil were most effective to the gram-negative than gram-positive bacteria group. The results showed a high antioxidant potential for essential oil before and particularly after the esterification reaction thus becoming an option for the formulation of new antioxidant products. PMID:25104002

Vanin, Adriana B; Orlando, Tainara; Piazza, Suelen P; Puton, Bruna M S; Cansian, Rogério L; Oliveira, Debora; Paroul, Natalia

2014-10-01

361

Quantification, antioxidant and antimicrobial activity of phenolics isolated from different extracts of Capsicum frutescens (Pimenta Malagueta).  

PubMed

This paper presents the quantification, antioxidant and antimicrobial activity of capsaicin, dihydrocapsaicin and the flavonoid chrysoeriol isolated from different extracts (hexane and acetonitrile extracts from whole fruit, peel and seed) of Capsicum frutescens (pimenta malagueta). The acetonitrile extract of the seeds, peel and whole fruits contained capsaicin as a major component, followed in abundance by dihydrocapsaicin and chrysoeriol. The antimicrobial activity of the isolated compounds against seven microorganisms showed chrysoeriol was the most active compound. In the antioxidant test, the acetonitrile extract from the whole fruit showed the highest activity. The antioxidant activity of pimenta malagueta may be correlated with its phenolic content, principally with the most active compound, capsaicin. PMID:24879587

Nascimento, Patrícia L A; Nascimento, Talita C E S; Ramos, Natália S M; Silva, Girliane R; Gomes, José Erick Galindo; Falcão, Rosângela E A; Moreira, Keila A; Porto, Ana L F; Silva, Tania M S

2014-01-01

362

Antimicrobial Prophylaxis in Adults  

PubMed Central

Antimicrobial prophylaxis is commonly used by clinicians for the prevention of numerous infectious diseases, including herpes simplex infection, rheumatic fever, recurrent cellulitis, meningococcal disease, recurrent uncomplicated urinary tract infections in women, spontaneous bacterial peritonitis in patients with cirrhosis, influenza, infective endocarditis, pertussis, and acute necrotizing pancreatitis, as well as infections associated with open fractures, recent prosthetic joint placement, and bite wounds. Perioperative antimicrobial prophylaxis is recommended for various surgical procedures to prevent surgical site infections. Optimal antimicrobial agents for prophylaxis should be bactericidal, nontoxic, inexpensive, and active against the typical pathogens that can cause surgical site infection postoperatively. To maximize its effectiveness, intravenous perioperative prophylaxis should be administered within 30 to 60 minutes before the surgical incision. Antimicrobial prophylaxis should be of short duration to decrease toxicity and antimicrobial resistance and to reduce cost. PMID:21719623

Enzler, Mark J.; Berbari, Elie; Osmon, Douglas R.

2011-01-01

363

Interaction of silver nanoparticles with serum proteins affects their antimicrobial activity in vivo.  

PubMed

The emergence of multidrug-resistant bacteria is a global threat for human society. There exist recorded data that silver was used as an antimicrobial agent by the ancient Greeks and Romans during the 8th century. Silver nanoparticles (AgNPs) are of potential interest because of their effective antibacterial and antiviral activities, with minimal cytotoxic effects on the cells. However, very few reports have shown the usage of AgNPs for antibacterial therapy in vivo. In this study, we deciphered the importance of the chosen methods for synthesis and capping of AgNPs for their improved activity in vivo. The interaction of AgNPs with serum albumin has a significant effect on their antibacterial activity. It was observed that uncapped AgNPs exhibited no antibacterial activity in the presence of serum proteins, due to the interaction with bovine serum albumin (BSA), which was confirmed by UV-Vis spectroscopy. However, capped AgNPs [with citrate or poly(vinylpyrrolidone)] exhibited antibacterial properties due to minimized interactions with serum proteins. The damage in the bacterial membrane was assessed by flow cytometry, which also showed that only capped AgNPs exhibited antibacterial properties, even in the presence of BSA. In order to understand the in vivo relevance of the antibacterial activities of different AgNPs, a murine salmonellosis model was used. It was conclusively proved that AgNPs capped with citrate or PVP exhibited significant antibacterial activities in vivo against Salmonella infection compared to uncapped AgNPs. These results clearly demonstrate the importance of capping agents and the synthesis method for AgNPs in their use as antimicrobial agents for therapeutic purposes. PMID:23877702

Gnanadhas, Divya Prakash; Ben Thomas, Midhun; Thomas, Rony; Raichur, Ashok M; Chakravortty, Dipshikha

2013-10-01

364

Antimicrobial effects of silver zeolite, silver zirconium phosphate silicate and silver zirconium phosphate against oral microorganisms  

PubMed Central

Objective To evaluate the antimicrobial activities of silver inorganic materials, including silver zeolite (AgZ), silver zirconium phosphate silicate (AgZrPSi) and silver zirconium phosphate (AgZrP), against oral microorganisms. In line with this objective, the morphology and structure of each type of silver based powders were also investigated. Methods The antimicrobial activities of AgZ, AgZrPSi and AgZrP were tested against Streptococcus mutans, Lactobacillus casei, Candida albicans and Staphylococcus aureus using disk diffusion assay as a screening test. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the modified membrane method. Scanning electron microscope and X-ray diffraction were used to investigate the morphology and structure of these silver materials. Results All forms of silver inorganic materials could inhibit the growth of all test microorganisms. The MIC of AgZ, AgZrPSi and AgZrP was 10.0 g/L whereas MLC ranged between 10.0–60.0 g/L. In terms of morphology and structure, AgZrPSi and AgZrP had smaller sized particles (1.5–3.0 µm) and more uniformly shaped than AgZ. Conclusions Silver inorganic materials in the form of AgZ, AgZrPSi and AgZrP had antimicrobial effects against all test oral microorganisms and those activities may be influenced by the crystal structure of carriers. These results suggest that these silver materials may be useful metals applied to oral hygiene products to provide antimicrobial activity against oral infection. PMID:23570016

Saengmee-anupharb, Sirikamon; Srikhirin, Toemsak; Thaweboon, Boonyanit; Thaweboon, Sroisiri; Amornsakchai, Taweechai; Dechkunakorn, Surachai; Suddhasthira, Theeralaksna; Kamaguchi, Arihide

2013-01-01

365

Brine shrimp cytotoxicity of Caesalpinia pulcherrima aerial parts, antimicrobial activity and characterisation of isolated active fractions.  

PubMed

Caesalpinia pulcherrima Swartz. is an ornamental plant, shrub or a small tree belonging to the family Caesalpiniaceae. The plant has been used for the treatment of inflammatory disorders, skin diseases and so on. In this study, the cytotoxicity of the methanol extract of the aerial parts of C. pulcherrima was tested using an Artemia salina (brine shrimp) bioassay. Further, the methanol extract was fractionated by silica gel column chromatography using a solvent gradient of hexane:ethyl acetate:methanol in different ratios and 56 fractions were collected. On the basis of thin layer chromatography profiles, 13 major fractions were obtained, which were tested for antimicrobial activity against 14 microorganisms using the agar disc diffusion method and also tested for their minimal inhibitory concentration and minimal bactericidal concentration values. In terms of cytotoxicity, the extract caused 26% mortality of brine shrimp larvae after 24?h at a concentration of 1000?µg?mL(-1). Fractions 3, 9 and 10 showed significant antimicrobial activities. Phytochemical analysis of these three fractions led to the identification of 11 compounds, and their structures were established by means of gas chromatography-mass spectroscopy techniques. These findings suggest that these bioactive compounds may be useful as potential antimicrobials. Further investigation is needed to establish the mode of action of these bioactive compounds. PMID:21762031

Chanda, Sumitra; Baravalia, Yogesh

2011-12-01

366

Antimicrobial Effects of Helix D-derived Peptides of Human Antithrombin III.  

PubMed

Antithrombin III (ATIII) is a key antiproteinase involved in blood coagulation. Previous investigations have shown that ATIII is degraded by Staphylococcus aureus V8 protease, leading to release of heparin binding fragments derived from its D helix. As heparin binding and antimicrobial activity of peptides frequently overlap, we here set out to explore possible antibacterial effects of intact and degraded ATIII. In contrast to intact ATIII, the results showed that extensive degradation of the molecule yielded fragments with antimicrobial activity. Correspondingly, the heparin-binding, helix d-derived, peptide FFFAKLNCRLYRKANKSSKLV (FFF21) of human ATIII, was found to be antimicrobial against particularly the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Fluorescence microscopy and electron microscopy studies demonstrated that FFF21 binds to and permeabilizes bacterial membranes. Analogously, FFF21 was found to induce membrane leakage of model anionic liposomes. In vivo, FFF21 significantly reduced P. aeruginosa infection in mice. Additionally, FFF21 displayed anti-endotoxic effects in vitro. Taken together, our results suggest novel roles for ATIII-derived peptide fragments in host defense. PMID:25202017

Papareddy, Praveen; Kalle, Martina; Bhongir, Ravi K V; Mörgelin, Matthias; Malmsten, Martin; Schmidtchen, Artur

2014-10-24

367

Evaluation of Composition and Antimicrobial Activity of Supercritical Fluid Extract of Leaves of Vitex negundo  

PubMed Central

Supercritical fluid extract of leaves of Vitex negundo was tested for its antimicrobial potential and was compared with that of ethanol extract, ether extract and hydrodistilled oil of leaves. The chemical constituents of extracts were studied by chromatographic techniques. Extracts were evaluated for antimicrobial potential against bacterial strains like Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and yeast Candida albicans. Extracts showed prominent antibacterial activity against Bacillus subtilis and Staphylococcus aureus. Supercritical fluid extract exhibited good antibacterial potential. PMID:21695000

Nagarsekar, K. S.; Nagarsenker, M. S.; Kulkarni, S. R.

2010-01-01

368

Modular determinants of antimicrobial activity in platelet factor-4 family kinocidins  

Microsoft Academic Search

Mammalian platelets contain an array of antimicrobial peptides, termed platelet microbicidal proteins (PMPs). Human and rabbit PMPs include known chemokines, such as platelet factor-4 (hPF-4); PMP-1 is the rabbit orthologue of hPF-4. Chemokines that also exert direct antimicrobial activity have been termed kinocidins. A consensus peptide domain library representing mammalian PF-4 family members was analyzed to define structural domains contributing

Michael R. Yeaman; Nannette Y. Yount; Alan J. Waring; Kimberly D. Gank; Deborah Kupferwasser; Robert Wiese; Arnold S. Bayer; William H. Welch

2007-01-01

369

Characterization of a heat-stable protein with antimicrobial activity from Arabidopsis thaliana  

Microsoft Academic Search

A heat-stable protein with antimicrobial activity was isolated from Arabidopsis thaliana plants by buffer-soluble extraction and two chromatographic procedures. The results of MALDI-TOF analysis revealed that the isolated protein shares high sequence identity with aspen SP1. To determine the exact antimicrobial properties of this protein, a cDNA encoding the protein was isolated from an A. thaliana leaf cDNA library and

Seong-Cheol Park; Jung Ro Lee; Sun-Oh Shin; Sang Yeol Lee; Kyung-Soo Hahm

2007-01-01

370

Evaluation of antimicrobial activity of the lichens Lasallia pustulata, Parmelia sulcata, Umbilicaria crustulosa , and Umbilicaria cylindrica  

Microsoft Academic Search

The antimicrobial properties of acetone, methanol, and aqueous extracts of the lichens Lasallia pustulata, Parmelia sulcata, Umbilicaria crustulosa, and Umbilicaria cylindrica were studied comparatively in vitro. Antimicrobial activities of the extracts of different lichens were estimated by the\\u000a disk diffusion test for Gram-positive bacteria, Gram-negative bacteria, and fungal organisms, as well as by determining the\\u000a MIC (minimal inhibitory concentration). The

B. Rankovi?; M. Miši?; S. Sukdolak

2007-01-01

371

Effects of arginine density on the membrane-bound structure of a cationic antimicrobial peptide from solid-state NMR  

E-print Network

- phosphate association are two important elements for strong antimicrobial activities of this class is important for the peptide's antimicrobial activity [4­6]. For example, when the -hairpin fold is destroyed by replacing the Cys residues by Ala, the antimicrobial activity is significantly attenuated [7

Hong, Mei

372

Preparation and evaluation of antimicrobial activity of nanosystems for the control of oral pathogens Streptococcus mutans and Candida albicans  

PubMed Central

Background Diseases that affect the buccal cavity are a public health concern nowadays. Chlorhexidine and nystatin are the most commonly used drugs for the control of buccal affections. In the search for more effective antimicrobials, nanotechnology can be successfully used to improve the physical chemical properties of drugs whilst avoiding the undesirable side effects associated with its use. Herein described are studies using nystatin and chlorhexidine with sodium montmorillonite (MMTNa), and chlorhexidine with ?-cyclodextrin and two derivatives methyl-?-cyclodextrin and hydroxypropyl-?-cyclodextrin in the development of antimicrobial nanosystems. Methods The nanosystems were prepared by kneading and solubilization followed by freeze-drying technique. The nanosystems were characterized by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). Nanosystem antimicrobial activity against Streptococcus mutans and Candida albicans strains was evaluated with inhibition halo analysis. Results The nanocarriers MMTNa and cyclodextrins showed good yields. XRPD, FTIR, and DSC analysis confirmed the proposed nanosystems formation and the suitability of the production methods. The nanosystems that showed best antimicrobial effect were chlorhexidine gluconate (CHX) and cyclodextrin inclusion complexes and CHX:MMTNa 60% cation exchange capacity – 24 hours. Conclusion The nanosystem formulations present higher stability for all chlorhexidine inclusion complexes compared with pure chlorhexidine. The nystatin nanosystems have the potential to mask the bitter taste, justifying subsequent in-vivo studies. For these reasons, further studies are being carried out to evaluate their application in professional formulations. PMID:22114490

Pupe, Carolina Goncalves; Villardi, Michele; Rodrigues, Carlos Rangel; Rocha, Helvecio Vinicius Antunes; Maia, Lucianne Cople; de Sousa, Valeria Pereira; Cabral, Lucio Mendes

2011-01-01

373

Cerecidins, Novel Lantibiotics from Bacillus cereus with Potent Antimicrobial Activity  

PubMed Central

Lantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial peptides that are widely produced by Gram-positive bacteria, including many species of the Bacillus group. In the present study, one novel gene cluster coding lantibiotic cerecidins was unveiled in Bacillus cereus strain As 1.1846 through genomic mining and PCR screening. The designated cer locus is different from that of conventional class II lantibiotics in that it included seven tandem precursor cerA genes, one modification gene (cerM), two processing genes (cerT and cerP), one orphan regulator gene (cerR), and two immunity genes (cerF and cerE). In addition, one unprecedented quorum sensing component, comQXPA, was inserted between cerM and cerR. The expression of cerecidins was not detected in this strain of B. cereus, which might be due to repressed transcription of cerM. We constitutively coexpressed cerA genes and cerM in Escherichia coli, and purified precerecidins were proteolytically processed with the endoproteinase GluC and a truncated version of putative serine protease CerP. Thus, two natural variants of cerecidins A1 and A7 were obtained which contained two terminal nonoverlapping thioether rings rarely found in lantibiotics. Both cerecidins A1 and A7 were active against a broad spectrum of Gram-positive bacteria. Cerecidin A7, especially its mutant Dhb13A, showed remarkable efficacy against multidrug-resistant Staphylococcus aureus (MDRSA), vancomycin-resistant Enterococcus faecalis (VRE), and even Streptomyces. PMID:24532070

Wang, Jian; Zhang, Li; Teng, Kunling; Sun, Shutao; Sun, Zhizeng

2014-01-01

374

Cerecidins, novel lantibiotics from Bacillus cereus with potent antimicrobial activity.  

PubMed

Lantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial peptides that are widely produced by Gram-positive bacteria, including many species of the Bacillus group. In the present study, one novel gene cluster coding lantibiotic cerecidins was unveiled in Bacillus cereus strain As 1.1846 through genomic mining and PCR screening. The designated cer locus is different from that of conventional class II lantibiotics in that it included seven tandem precursor cerA genes, one modification gene (cerM), two processing genes (cerT and cerP), one orphan regulator gene (cerR), and two immunity genes (cerF and cerE). In addition, one unprecedented quorum sensing component, comQXPA, was inserted between cerM and cerR. The expression of cerecidins was not detected in this strain of B. cereus, which might be due to repressed transcription of cerM. We constitutively coexpressed cerA genes and cerM in Escherichia coli, and purified precerecidins were proteolytically processed with the endoproteinase GluC and a truncated version of putative serine protease CerP. Thus, two natural variants of cerecidins A1 and A7 were obtained which contained two terminal nonoverlapping thioether rings rarely found in lantibiotics. Both cerecidins A1 and A7 were active against a broad spectrum of Gram-positive bacteria. Cerecidin A7, especially its mutant Dhb13A, showed remarkable efficacy against multidrug-resistant Staphylococcus aureus (MDRSA), vancomycin-resistant Enterococcus faecalis (VRE), and even Streptomyces. PMID:24532070

Wang, Jian; Zhang, Li; Teng, Kunling; Sun, Shutao; Sun, Zhizeng; Zhong, Jin

2014-04-01

375

Antimicrobial effect of diallyl sulphide on Campylobacter jejuni biofilms  

PubMed Central

Objectives Bacterial biofilms pose significant food safety risks because of their attachment to fomites and food surfaces, including fresh produce surfaces. The purpose of this study was to systematically investigate the activity of selected antimicrobials on Campylobacter jejuni biofilms. Methods C. jejuni biofilms and planktonic cells were treated with ciprofloxacin, erythromycin and diallyl sulphide and examined using infrared and Raman spectroscopies coupled with imaging analysis. Results Diallyl sulphide eliminated planktonic cells and sessile cells in biofilms at a concentration that was at least 100-fold less than used for either ciprofloxacin or erythromycin on the basis of molarity. Distinct cell lysis was observed in diallyl sulphide-treated planktonic cells using immunoblot analysis and was confirmed by a rapid decrease in cellular ATP. Two phases of C. jejuni biofilm recalcitrance modes against ciprofloxacin and erythromycin were validated using vibrational spectroscopies: (i) an initial hindered adsorption into biofilm extracellular polymeric substance (EPS) and delivery of antibiotics to sessile cells within biofilms; and (ii) a different interaction between sessile cells in a biofilm compared with their planktonic counterparts. Diallyl sulphide destroyed the EPS structure of the C. jejuni biofilm, after which the sessile cells were killed in a similar manner as planktonic cells. Spectroscopic models can predict the survival of sessile cells within biofilms. Conclusions Diallyl sulphide elicits strong antimicrobial activity against planktonic and sessile C. jejuni and may have applications for reducing the prevalence of this microbe in foods, biofilm reduction and, potentially, as an alternative chemotherapeutic agent for multidrug-resistant bacterial strains. PMID:22550133

Lu, Xiaonan; Samuelson, Derrick R.; Rasco, Barbara A.; Konkel, Michael E.

2012-01-01

376

IL4 and IL13 exposure during mucociliary differentiation of bronchial epithelial cells increases antimicrobial activity and expression of antimicrobial peptides  

Microsoft Academic Search

The airway epithelium forms a barrier against infection but also produces antimicrobial peptides (AMPs) and other inflammatory\\u000a mediators to activate the immune system. It has been shown that in allergic disorders, Th2 cytokines may hamper the antimicrobial\\u000a activity of the epithelium. However, the presence of Th2 cytokines also affects the composition of the epithelial layer which\\u000a may alter its function.

Suzanne Zuyderduyn; Dennis K Ninaber; Jasmijn A Schrumpf; Marianne AJA van Sterkenburg; Renate M Verhoosel; Frans A Prins; Sandra van Wetering; Klaus F Rabe; Pieter S Hiemstra

2011-01-01

377

Chemical composition and antimicrobial activities of the essential oils from three ecotypes of Zataria multiflora  

PubMed Central

Background: Zataria multiflora Boiss. is a traditional and popular spice in Iran. The effects of 3 ecotypes (ECTPs) of Z. multiflora essential oils (EOs) against most common causes of food-borne and nosocomial infections were evaluated. Materials and Methods: The antimicrobial activities of the EOs were examined by broth microdilution method as recommended by the Clinical and Laboratory Standards Institute (CLSI). The chemical compositions of the EOs from 3 ECTPs of Z. multiflora have been analyzed by gas chromatography–mass spectrometry. Results: Analysis of the EOs indicated that 3 chemotypes were present in Z. multiflora, including carvacrol, thymol-carvacrol, and linalool, whereas previous studies have only found carvacrol and thymol. Inhibition studies showed that the tested EOs entirely inhibited the growth of yeasts at concentrations of less than 1 ?L/mL. Moreover, the oils exhibited significant bacteriostatic and bactericidal activities against Gram-positive and Gram-negative bacteria at concentrations ranging from 0.12 to 8 ?L/mL. Conclusion: These results suggest that the EOs from Z. multiflora should be investigated further for possible use in antimicrobial products and food preservatives. PMID:21472080

Zomorodian, K.; Saharkhiz, M. J.; Rahimi, M. J.; Bandegi, A.; Shekarkhar, G.; Bandegani, A.; Pakshir, K.; Bazargani, A.

2011-01-01

378

Antioxidant and antimicrobial activities of essential oil and extracts of Saurauia lantsangensis hu root.  

PubMed

Antioxidant and antimicrobial activities of the essential oil and n-hexane (HEE), chloroform (CHE), ethyl acetate (EAE), and methanol (MEE) extracts, respectively, from the root of Saurauia lantsangensis Hu were investigated. The GC-MS analysis revealed 39 compounds representing 96.41% of the oil containing T-muurolol (13.85%), acetophenone (7.46%), alpha-cadinol (6.26%), methyl palmitate (5.36%), n-hexadecanoic acid (4.31%), torreyol (3.69%), and isospathulenol (3.48%) as major components. Antioxidant activities determined by three various testing systems, i.e., DPPH radical scavenging, superoxide anion radical scavenging, and reducing power assay, increased in the order: HEE < CHE < oil < MEE < EAE. CHE, EAE, MEE and oil exhibited a promising antimicrobial effect determined as the diameter of zones of inhibition (13.3-16.2, 16.5-20.4, 13.5-16.6, and 16.5-22.7 mm), respectively, along with their respective MIC values (500-1000, 125-500, 250-500, and 250-500 microg/ml) against Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli), Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus), and a yeast (Hansenula anomala). PMID:22888533

Zhu, Liang; Zhu, Si-ming; Tian, Ying-juan

2012-01-01

379

Biophysical characterization of antimicrobial peptides activity: from in vitro to ex vivo techniques.  

PubMed

Antimicrobial peptides (AMPs) are evolutionarily conserved components of the innate immune defense system of many living organisms varying from prokaryotes to eukaryotes, including humans. Due to their broad-spectrum activity and low level of induced resistance, these short aminoacid sequences represent a novel class of potential antimicrobial agents. Besides the development of anti-bacterial drugs, AMPs constitute ideal molecular models for the design of molecules with wide-ranging nanomedical applications, such as anti-tumorigenic agents and pharmacological tools to cure channelopaties. Several techniques are currently used to shed light on the mechanisms of action of AMPs, ranging from the characterization of the interaction between peptides and biomimetic membranes and/or intracellular targets, to the study of AMPs effects on pathogens, living cells and tissues. Comprehensive and multiscale studies are crucial to design new AMPs and to identify molecules that can boost their activity. In this minireview we summarize the most recent achievements in AMP-characterization, with a special emphasis on the integration of biophysical approaches, which can synergistically help to bridge the gap between in vitro and ex vivo investigations. PMID:24106959

Aquila, Marco; Benedusi, Mascia; Dell'Orco, Daniele

2013-11-01

380

Design, development and evaluation of chronomodulated drug delivery systems of amoxicillin trihydrate with enhanced antimicrobial activity.  

PubMed

The present studies entail the formulation development and evaluation of chronomodulated drug delivery system of amoxicillin trihydrate (AMT), which comprises of a bilayer tablet containing a delayed release and a sustained release layer. Direct compression method was employed for the preparation of bilayer matrix tablets containing rational blend of polymers, such as Eudragit-L100 D55 as delayed release polymer and HPMCK4M, HPMCK15 and HPMCK100 are sustained release polymers. In- vitro drug release studies of bilayer tablets observed a good sustained release action with time-dependent burst release after a lag-time of 3 hrs. Evaluation of drug release kinetics from sustained release layer of bilayer tablets followed Higuchi model via quasi-Fickian diffusion mechanism. SEM studies revealed formation of pores on sustained release layer, which confirmed the drug release through diffusion and predominantly by surface erosion mechanism. Evaluation of antimicrobial activity showed a decrease in minimum inhibitory concentration of optimized bilayer tablets vis-à-vis conventional marketed formulation. Accelerated stability studies revealed that the optimized bilayer tablet formulation was found to be stable upto the period of 6 months. Solid state characterization employing FT-IR and DSC studies indicated lack of significant interaction of drug with formulation excipients. Thus, the present studies ratify the suitability of chronomodulated bilayer tablets of AMT for effective management of bacterial infections owing to specific time-dependent drug release, higher gastric protection and enhanced antimicrobial activity. PMID:22998051

Beg, Sarwar; Swain, Suryakanta; Gahoi, Sachin; Kohli, Kanchan

2013-04-01

381

Evaluation of the antimicrobial activity of cationic polyethylenimines on dry surfaces.  

PubMed

The antimicrobial activity of cationic N-dodecyl-N-methylpolyethylenimine (PEI+) against S. aureus, A. baumannii, and E. coli was evaluated when the polymer was applied as a coating to various surfaces using a paint-like procedure. Antimicrobial activity of PEI+ as a function of time was determined using an assay for long-term survival involving placement of single drops of various bacterial concentrations on dry surfaces. These data were compared with an assay method where bacteria were applied by spraying and surfaces were incubated overnight under agar. PEI+-coated surfaces were found to be highly bactericidal after 30 min when bacteria were sprayed onto surfaces. However, when bacteria were applied as single drops, PEI+-coated surfaces were less biocidal at short contact times particularly for A. baumannii and E. coli. The observations are explained in the context of the difference in drying time between drops deposited on uncoated surfaces and PEI+-coated surfaces and the sensitivity of bacterial survival to dehydration. These results demonstrate that PEI+-coated surfaces are not effectively biocidal for some types of bacteria under certain conditions and that the method of assaying bactericidal efficiency can greatly affect the results obtained. PMID:19194927

Koplin, Stephen A; Lin, Shirley; Domanski, Tammy

2008-01-01

382

Synthesis, antimicrobial evaluation, and structure-activity relationship of ?-pinene derivatives.  

PubMed

Several (+)- and (-)-?-pinene derivatives were synthesized and evaluated for their antimicrobial activity toward Gram-positive bacteria Micrococcus luteus and Staphylococcus aureus, Gram-negative bacterium Escherichia coli, and the unicellular fungus Candida albicans using bioautographic assays. (+)-?-Pinene 1a showed modest activity against the test organisms, whereas (-)-?-pinene 1b showed no activity at the tested concentration. Of all the ?-pinene derivatives evaluated, the ?-lactam derivatives (10a and 10b) were the most antimicrobial. The increase in the antimicrobial activity of 10a compared to 1a ranged from nearly 3.5-fold (C. albicans) to 43-fold (S. aureus). The mean ± standard deviation for the zone of inhibition (mm) for 10a (C. albicans) was 31.9 ± 4.3 and that for S. aureus was 51.1 ± 2.9. Although (-)-?-pinene 1b was not active toward the test microorganisms, the corresponding ?-lactam 10b, amino ester 13b, and amino alcohol 14b showed antimicrobial activity toward the test microorganisms. The increase in the antimicrobial activity of 10b compared to 1b ranged from 32-fold (S. aureus) to 73-fold (M. luteus). The mean ± standard deviation for the zone of inhibition (mm) for 10b (S. aureus) was 32.0 ± 0.60 and that for M. luteus was 73.2 ± 0.30. PMID:24716724

Dhar, Preeti; Chan, PuiYee; Cohen, Daniel T; Khawam, Fadi; Gibbons, Sarah; Snyder-Leiby, Teresa; Dickstein, Ellen; Rai, Prashant Kumar; Watal, Geeta

2014-04-23

383

Two interdependent mechanisms of antimicrobial activity allow for efficient killing in nylon-3-based polymeric mimics of innate immunity peptides.  

PubMed

Novel synthetic mimics of antimicrobial peptides have been developed to exhibit structural properties and antimicrobial activity similar to those of natural antimicrobial peptides (AMPs) of the innate immune system. These molecules have a number of potential advantages over conventional antibiotics, including reduced bacterial resistance, cost-effective preparation, and customizable designs. In this study, we investigate a family of nylon-3 polymer-based antimicrobials. By combining vesicle dye leakage, bacterial permeation, and bactericidal assays with small-angle X-ray scattering (SAXS), we find that these polymers are capable of two interdependent mechanisms of action: permeation of bacterial membranes and binding to intracellular targets such as DNA, with the latter necessarily dependent on the former. We systemically examine polymer-induced membrane deformation modes across a range of lipid compositions that mimic both bacteria and mammalian cell membranes. The results show that the polymers' ability to generate negative Gaussian curvature (NGC), a topological requirement for membrane permeation and cellular entry, in model Escherichia coli membranes correlates with their ability to permeate membranes without complete membrane disruption and kill E. coli cells. Our findings suggest that these polymers operate with a concentration-dependent mechanism of action: at low concentrations permeation and DNA binding occur without membrane disruption, while at high concentrations complete disruption of the membrane occurs. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova. PMID:24743021

Lee, Michelle W; Chakraborty, Saswata; Schmidt, Nathan W; Murgai, Rajan; Gellman, Samuel H; Wong, Gerard C L

2014-09-01

384

The antimicrobial effects of wood-associated polyphenols on food pathogens and spoilage organisms.  

PubMed

The antimicrobial effects of the wood-associated polyphenolic compounds pinosylvin, pinosylvin monomethyl ether, astringin, piceatannol, isorhapontin, isorhapontigenin, cycloXMe, dHIMP, ArX, and ArXOH were assessed against both Gram-negative (Salmonella) and Gram-positive bacteria (Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus) and yeasts (Candida tropicalis, Saccharomyces cerevisiae). Particularly the stilbenes pinosylvin, its monomethyl ether and piceatannol demonstrated a clear antimicrobial activity, which in the case of pinosylvin was present also in food matrices like sauerkraut, gravlax and berry jam, but not in milk. The destabilization of the outer membrane of Gram-negative microorganisms, as well as interactions with the cell membrane, as indicated by the NPN uptake and LIVE/DEAD viability staining experiments, can be one of the specific mechanisms behind the antibacterial action. L. monocytogenes was particularly sensitive to pinosylvin, and this effect was also seen in L. monocytogenes internalized in intestinal Caco2 cells at non-cytotoxic pinosylvin concentrations. In general, the antimicrobial effects of pinosylvin were even more prominent than those of a related stilbene, resveratrol, well known for its various bioactivities. According to our results, pinosylvin could have potential as a natural disinfectant or biocide in some targeted applications. PMID:23624538

Plumed-Ferrer, Carme; Väkeväinen, Kati; Komulainen, Heli; Rautiainen, Maarit; Smeds, Annika; Raitanen, Jan-Erik; Eklund, Patrik; Willför, Stefan; Alakomi, Hanna-Leena; Saarela, Maria; von Wright, Atte

2013-06-01

385

Effect of antimicrobial activity of Melaleuca alternifolia essential oil on antagonistic potential of Pleurotus species against Trichoderma harzianum in dual culture  

Microsoft Academic Search

Melaleuca alternifolia (tea tree) essential oil was investigated for its “in vitro” ability to control Trichoderma harzianum, a fungal contaminant that causes extensive losses in the cultivation of Pleurotus species. The antifungal activity of M. alternifolia essential oil and antagonist activities between Pleurotus species against three T. harzianum strains were studied in dual-culture experiments on an agar-based medium in which different concentrations of

P. Angelini; R. Pagiotti; B. Granetti

2008-01-01

386

Fabrication of Phaeodactylum tricornutum extract-loaded gelatin nanofibrous mats exhibiting antimicrobial activity.  

PubMed

Microalgae have recently been recognized as a valuable resource for various applications. Phaeodactylum tricornutum is a diatom that lives in marine water and has an unusually high content of lipids. In this study, we added P. tricornutum into a gelatin dope solution to examine the effect of this diatom using electrospinning. The addition of P. tricornutum extracts increased the conductivity of the dope solution but had little effect on the viscosity. Due to the increased conductivity, the fiber diameter was reduced compared with the neat gelatin nanofiber. The loading of P. tricornutum extracts was confirmed using fluorescence microscopy, and the incorporation of lipids was detected through gas chromatography. The P. tricornutum-loaded nanofiber mat exhibited anti-microbial activity against Escherichia coli and multidrug-resistant Staphylococcus aureus (MRSA). The cell viability test showed that the P. tricornutum-loaded nanofiber has no cytotoxicity. We expect that this antimicrobial P. tricornutum-loaded gelatin nanofiber mat can be applied as a wound dressing. PMID:24239540

Kwak, Hyo Won; Kang, Min Ji; Bae, Jin Hee; Hur, Sung Bum; Kim, Ick-Soo; Park, Young Hwan; Lee, Ki Hoon

2014-02-01

387

Antimicrobial activity of acid-hydrolyzed Citrus unshiu peel extract in milk.  

PubMed

Citrus fruit (Citrus unshiu) peels were extracted with hot water and then acid-hydrolyzed using hydrochloric acid. Antimicrobial activities of acid-hydrolyzed Citrus unshiu peel extract were evaluated against pathogenic bacteria, including Bacillus cereus, Staphylococcus aureus, and Listeria monocytogenes. Antilisterial effect was also determined by adding extracts at 1, 2, and 4% to whole, low-fat, and skim milk. The cell numbers of B. cereus, Staph. aureus, and L. monocytogenes cultures treated with acid-hydrolyzed extract for 12h at 35°C were reduced from about 8log cfu/mL to <1log cfu/mL. Bacillus cereus was more sensitive to acid-hydrolyzed Citrus unshiu peel extract than were the other bacteria. The addition of 4% acid-hydrolyzed Citrus unshiu extracts to all types of milk inhibited the growth of L. monocytogenes within 1d of storage at 4°C. The results indicated that Citrus unshiu peel extracts, after acid hydrolysis, effectively inhibited the growth of pathogenic bacteria. These findings indicate that acid hydrolysis of Citrus unshiu peel facilitates its use as a natural antimicrobial agent for food products. PMID:24534507

Min, Keun Young; Kim, Hyun Jung; Lee, Kyoung Ah; Kim, Kee-Tae; Paik, Hyun-Dong

2014-04-01

388

Antimicrobial activity of vanillin against spoilage microorganisms in stored fresh-cut mangoes.  

PubMed

The antimicrobial activity of vanillin against four bacteria (Pantoea agglomerans, Aeromonas enteropelogenes, Micrococcus lylae, and Sphingobacterium spiritovorun), four fungi (Alternaria sp., Aspergillus sp., Penicillium sp., and Fusarium sp.), and three unidentified yeasts isolated from spoiling fresh-cut mango slices was verified in laboratory media adjusted to pH 5.0. MICs of vanillin against the fungi (12.5 to 13.3 mM), bacteria (10 to 13.3 mM), and yeasts (5.0 to 6.7 mM) indicated that all the test species were sensitive to the antimicrobial effects of vanillin. Fresh-cut mango slices were dipped for 1 min in solutions containing 40 and 80 mM vanillin before being packaged in rigid trays and stored at 5 and 10 degrees C to verify the effects of vanillin on the development of the spoilage microflora. Microbiological analysis for up to 14 days of storage revealed that treatment with 80 mM vanillin significantly delayed (P < 0.05) the development of total aerobic bacteria and yeast and mold populations. Vanillin may be a practical preservative for processing fresh-cut mango. PMID:16865911

Ngarmsak, Manatchaya; Delaquis, Pascal; Toivonen, Peter; Ngarmsak, Tipvanna; Ooraikul, Buncha; Mazza, G

2006-07-01

389

Antimicrobial activity of the Anseriform outer eggshell and cuticle  

Microsoft Academic Search

The avian eggshell is a complex, multifunctional biomineral composed of a calcium carbonate mineral phase and an organic phase of lipids and proteins. The outermost layer of the eggshell, the eggshell cuticle, is an organic layer of variable thickness composed of polysaccharides, hydroxyapatite crystals, lipids and glycoprotein. In addition to regulating gas exchanges, the eggshell cuticle may contain antimicrobial elements.

Olivier Wellman-Labadie; Jaroslav Picman; Maxwell T. Hincke

2008-01-01