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1

Effect of pulmonary surfactant on antimicrobial activity in vitro.  

PubMed

Time-kill curve experiments were performed with linezolid, doripenem, tigecycline, moxifloxacin, and daptomycin against Staphylococcus aureus and with colistin, moxifloxacin, and doripenem against Pseudomonas aeruginosa to evaluate the effect of porcine pulmonary surfactant on antimicrobial activity. Pulmonary surfactant significantly impaired the activities of moxifloxacin and colistin. When antibiotics are being developed for respiratory tract infections, the method described here might be used to preliminarily quantify the effect of pulmonary surfactant on antimicrobial activity. PMID:23877678

Schwameis, R; Erdogan-Yildirim, Z; Manafi, M; Zeitlinger, M A; Strommer, S; Sauermann, R

2013-07-22

2

Super-SERS-active and highly effective antimicrobial Ag nanodendrites.  

PubMed

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 10(13), 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. PMID:22777687

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

2012-07-10

3

Antimicrobial effect of zinc pyrithione  

Microsoft Academic Search

Synopsis The antimicrobial effect of zinc pyrithione has been studied with healthy scalps in relation to its ANTIDANDRUFF effect. Use of zinc pyrithione-containing shampoo sharply reduced the CORNEOCYTE COUNTS, while the similarly active antimicrobial agent, Irgasan DP-300 © had no effect on the corneocyte counts. Quantitative estimation of scalp microorganisms revealed that corresponding to the decrease in dandruff, Pityrospbrum ovale

GENJI IMOKAWA; HARUO SHIMIZU

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.

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

Screening of antimicrobial activity and cytotoxic effects of two Cladonia species.  

PubMed

The present study explores the antimicrobial activity and cytotoxic effects in culture assays of two fruticose soil lichens, Cladonia rangiformis Hoffm. and Cladonia convoluta (Lamkey) Cout., to contribute to possible pharmacological uses of lichens. In vitro antimicrobial activities of methanol and chloroform extracts against two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), two Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus), and the yeast Candida albicans were examined using the paper disc method and through determination of minimal inhibitory concentrations (MICs). The data showed the presence of antibiotic substances in the chloroform and the methanol extracts of the lichen species. The chloroform extracts exhibited more significant antimicrobial activity than the methanol extracts. However, a higher antifungal activity was noted in the methanol extract of C. rangiformis. The maximum antimicrobial activity was recorded for the chloroform extract of C. convoluta against E. coli. The cytotoxic effects of the lichen extracts on human breast cancer MCF-7 cells were evaluated by the trypan blue assay yielding IC50 values of ca. 173 and 167 microg/ml for the extracts from C. rangiformis and C. convoluta, respectively. PMID:23923615

Açikgöz, Birkan; Karalti, Iskender; Ersöz, Melike; Co?kun, Zeynep M; Cobano?lu, Gül?ah; Sesal, Cenk

6

Effect of carbon source on the antimicrobial activity of Corynebacterium kutscheri and Corynebacterium xerosis  

Microsoft Academic Search

In an attempt to screen out new potent antimicrobial substances producing bacteria, Corynebacterium kutscheri NB-1 and Corynebacterium xerosis NB-2 were isolated and were found antagonistic to bacteria and fungi. Antimicrobial substances production of the bacterial strains was greatly influenced by variation of carbon sources. Galactose and glucose strongly enhanced the antimicrobial activity of Corynebacterium kutscheri and Corynebacterium xerosis, respectively. But

Nasser M. El-Banna

7

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

2008-09-25

8

Effects of mono- and disaccharides on the antimicrobial activity of bovine lactoperoxidase system.  

PubMed

The effects of mono- and disaccharides on the antimicrobial activity of the lactoperoxidase (LPO) system against Salmonella Enteritidis were investigated. The results clearly reveal that most of the sugars inhibit the antimicrobial activity of the LPO system. The inhibitory potency varies depending on the structure of sugar. L-Fructose and D-allose were strongly inhibitive to the action of the LPO system, while sucrose was the weakest inhibitor. The decreased antimicrobial activity is due to the reduction of LPO catalytic activity by sugar. An inhibitory kinetic study showed the noncompetitive inhibitor. D-Allose and L-fructose yielded strikingly low K(i) values of 0.36 and 0.42 mM, respectively, while the K(i) values of the other sugars ranged from 1.37 to 3.60 mM. Since LPO activity is inhibited by the saccharides, the sugar content in food should be considered when the LPO system is applied to the preservation of food. PMID:21219776

Al-Baarri, Ahmad Nimatullah; Hayashi, Makoto; Ogawa, Masahiro; Hayakawa, Shigeru

2011-01-01

9

Antimicrobial activities of iodinated polystyrene derivatives.  

PubMed

The antimicrobial activities of insoluble halogenated acetamidomethy1-styrene polymers (prepared by covalent bonding of iodine to polystyrene) were assessed as were the factors determining antimicrobial efficacy. The most active materials were selected from chlorinated or iodinated polymers. Antimicrobial activities were assessed for Escherichia coli (ATCC 25922; American Type Culture Collection, Rockville, MD, U.S.A.), Saccharomyces cerevisiae, and Candida albicans by determining time-course changes in microbial counts in vitro. A 2-iodoacetamidomethylstyrene polymer (No.6-I:-CH2I) was found to have the greatest antimicrobial activity against both bacteria and fungi. No.6-I is the first antimicrobial material that did not make an inhibition hollow in the conventional diffusion test or for which conjugated iodine showed antibacterial activity. This material can be introduced into styrene units on the surface of devices by chemical modification. This material was most active at 37 degrees C. For coated dishes, antimicrobial activity depended on the depth or swollen character of the reactive layer. NO.6-I requires not only a minimum width of polymer layer, but also frequent contact with microbes to have an antimicrobial effect. No.6-I is valuable as a new material because it has strong antimicrobial activity by itself but does not release active iodine. This material is expected to have various applications in implantable clinical devices. PMID:8908329

Lin, K J; Tani, T; Endo, Y; Kodama, M; Teramoto, K

1996-11-01

10

Effects of Various Test Media on the Activities of 21 Antimicrobial Agents against Haemophilus influenzae  

Microsoft Academic Search

As considerable variation in the antimicrobial susceptibility of Haemophilus influenzae has been reported, the effects of various test media on the susceptibility of H. influenzae were studied. MICs were determined by three laboratories for 21 antimicrobial agents against a panel of 100 selected isolates. Testing was performed using a reference NCCLS frozen broth microdilution method with Haemophilus test medium (HTM)

Michael R. Jacobs; Saralee Bajaksouzian; Anne Windau; Peter C. Appelbaum; Gengrong Lin; David Felmingham; Christine Dencer; Laura Koeth; Mendel E. Singer; Caryn E. Good

2002-01-01

11

Antitumor effects, cell selectivity and structure–activity relationship of a novel antimicrobial peptide polybia-MPI  

Microsoft Academic Search

A novel antimicrobial peptide, polybia-MPI, was purified from the venom of the social wasp Polybia paulista. It has potent antimicrobial activity against both Gram-positive and Gram-negative bacteria, but causing no hemolysis to rat erythrocytes. To date, there is no report about its antitumor effects on any tumor cell lines. In this study we synthesized polybia-MPI and studied its antitumor efficacy

Kai-rong Wang; Bang-zhi Zhang; Wei Zhang; Jie-xi Yan; Jia Li; Rui Wang

2008-01-01

12

Effect of Electrical Current on the Activities of Antimicrobial Agents against Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis Biofilms?  

PubMed Central

Bacterial biofilms are resistant to conventional antimicrobial agents. Prior in vitro studies have shown that electrical current (EC) enhances the activities of aminoglycosides, quinolones, and oxytetracycline against Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus epidermidis, Escherichia coli, and Streptococcus gordonii. This phenomenon, known as the bioelectric effect, has been only partially defined. The purpose of this work was to study the in vitro bioelectric effect on the activities of 11 antimicrobial agents representing a variety of different classes against P. aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and S. epidermidis. An eight-channel current generator/controller and eight chambers delivering a continuous flow of fresh medium with or without antimicrobial agents and/or EC to biofilm-coated coupons were used. No significant decreases in the numbers of log10 CFU/cm2 were seen after exposure to antimicrobial agents alone, with the exception of a 4.57-log-unit reduction for S. epidermidis and trimethoprim-sulfamethoxazole. We detected a statistically significant bioelectric effect when vancomycin plus 2,000 microamperes EC were used against MRSA biofilms (P = 0.04) and when daptomycin and erythromycin were used in combination with 200 or 2,000 microamperes EC against S. epidermidis biofilms (P = 0.02 and 0.0004, respectively). The results of these experiments indicate that the enhancement of the activity of antimicrobial agents against biofilm organisms by EC is not a generalizable phenomenon across microorganisms and antimicrobial agents.

del Pozo, Jose L.; Rouse, Mark S.; Mandrekar, Jayawant N.; Sampedro, Marta Fernandez; Steckelberg, James M.; Patel, Robin

2009-01-01

13

Antimicrobial effect of silver particles on bacterial contamination of activated carbon fibers.  

PubMed

Even though activated carbon fiber (ACF) filters have been widely used in air cleaning for the removal of hazardous gaseous pollutants, because of their extended surface area and high adsorption capacity, bacteria may breed on the ACF filters as a result of their good biocompatibility; ACF filters can themselves become a source of bioaerosols. In this study, silver particles were coated onto an ACF filter, using an electroless deposition method and their efficacy for bioaerosol removal was tested. First, various surface analyses, including scanning electron microscopy, inductively coupled plasma and X-ray diffraction were carried out to characterize the prepared ACF filters. Filtration and antimicrobial tests were then performed on the filters. The results showed that the silver-deposited ACF filters were effective for the removal of bioaerosols by inhibition of the survival of microorganisms, whereas pristine ACF filters were not. Two bacteria, Bacillus subtilis and Escherichia coli, were completely inhibited within 10 and 60 min, respectively. Electroless silver deposition did not influence the physical characteristics of ACF filters such as pressure drop and filtration efficiency. The gas adsorptive ability of the silver-deposited ACF filter, as represented by the micropore specific surface area, decreased by about 20% compared to the pristine filter because of the blockage of the ACF micropores by silver particles. Therefore, the amount of silver particles on the ACF filters needs to be optimized to avoid excessive reduction of their adsorptive characteristics and to show effective antimicrobial activity. PMID:18351101

Yoon, Ki Young; Byeon, Jeong Hoon; Park, Chul Woo; Hwang, Jungho

2008-02-15

14

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

15

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

16

Antimicrobial activity in gorgonian corals (Coelenterata, Octocorallia)  

NASA Astrophysics Data System (ADS)

Coral surfaces are often colonized by bacteria and other microbes that may be pathogenic as well as surface-fouling. To test the hypothesis that corals possess antimicrobial properties, both polar and non-polar extracts from eight species of gorgonian corals were assayed against five species of bacteria. Antimicrobial activity was most apparent in the non-polar fractions, which inhibited bacterial growth in all but one of the 40 interactions assayed (8 coralsx5 bacteria). Polar extracts were effective in less than 40% (14/40) of the interactions assayed. The levels of antimicrobial activity varied significantly among the gorgonian corals and was also dependent on the species of bacteria. Generally, marine bacteria were less sensitive to the extracts than were non-marine species. Differences in selerite content among the gorgonians did not influence the levels of extract antimicrobial activity.

Kim, K.

1994-05-01

17

Antimicrobial activities of squalamine mimics.  

PubMed Central

We investigated the antimicrobial properties of compounds with structural features that were designed to mimic those of squalamine, an antibiotic isolated from the stomach of the dogfish shark. The mimics, like squalamine, are sterol-polyamine conjugates. Unlike squalamine, the mimics were simple to prepare, at high yield, from readily available starting materials. Several squalamine mimics showed activity against gram-negative rods, gram-positive cocci including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and fungi. Some had little or no hemolytic activity. The hydrophobicity of the sterol backbone and the length and the cationic charge of the side chains appeared to be critical determinants of activity. One of the squalamine mimics, SM-7, was bactericidal against Escherichia coli, Pseudomonas aeruginosa, and S. aureus; its activity was decreased by divalent or monovalent cations and by bovine serum albumin. Subinhibitory concentrations of SM-7 markedly enhanced the antimicrobial activity of rifampin against gram-negative rods. These results suggest that the compounds may disrupt an outer membrane of gram-negative rods. Squalamine mimics are a new class of broad-spectrum antimicrobial agents. The antagonism of their activity by serum and albumin and their hemolytic properties may limit their use as systemic agents. The squalamine mimics, because of their potencies, broad spectra of antimicrobial activity, and potential for systemic toxicity, appear to be good candidates for development as topical antimicrobial agents.

Kikuchi, K; Bernard, E M; Sadownik, A; Regen, S L; Armstrong, D

1997-01-01

18

Antimicrobial activities of squalamine mimics.  

PubMed

We investigated the antimicrobial properties of compounds with structural features that were designed to mimic those of squalamine, an antibiotic isolated from the stomach of the dogfish shark. The mimics, like squalamine, are sterol-polyamine conjugates. Unlike squalamine, the mimics were simple to prepare, at high yield, from readily available starting materials. Several squalamine mimics showed activity against gram-negative rods, gram-positive cocci including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and fungi. Some had little or no hemolytic activity. The hydrophobicity of the sterol backbone and the length and the cationic charge of the side chains appeared to be critical determinants of activity. One of the squalamine mimics, SM-7, was bactericidal against Escherichia coli, Pseudomonas aeruginosa, and S. aureus; its activity was decreased by divalent or monovalent cations and by bovine serum albumin. Subinhibitory concentrations of SM-7 markedly enhanced the antimicrobial activity of rifampin against gram-negative rods. These results suggest that the compounds may disrupt an outer membrane of gram-negative rods. Squalamine mimics are a new class of broad-spectrum antimicrobial agents. The antagonism of their activity by serum and albumin and their hemolytic properties may limit their use as systemic agents. The squalamine mimics, because of their potencies, broad spectra of antimicrobial activity, and potential for systemic toxicity, appear to be good candidates for development as topical antimicrobial agents. PMID:9210661

Kikuchi, K; Bernard, E M; Sadownik, A; Regen, S L; Armstrong, D

1997-07-01

19

Characterization of chemoselective surface attachment of the cationic peptide melimine and its effects on antimicrobial activity.  

PubMed

Antimicrobial peptides (AMPs) are promising alternatives to current treatments for bacterial infections. However, our understanding of the structural-functional relationship of tethered AMPs still requires further investigation to establish a general approach for obtaining consistent antimicrobial surfaces. In this study, we have systematically examined the effects of surface orientation of a broad-spectrum synthetic cationic peptide, melimine, on its antibacterial activity against Gram-positive and Gram-negative bacteria. The attachment of melimine to maleimide-functionalized glass was facilitated by addition of a single cysteine amino acid into the peptide sequence at the N-terminus (CysN) or C-terminus (CysC), or at position 13 (Cys13, approximately central). The successful attachment of the modified melimine was monitored using X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS) with principle component analysis. The ToF-SIMS analysis clearly demonstrated structural difference between the three orientations. The peptide density for the modified surfaces was found to be between 3.5-4.0×10(-9)molcm(-2) using a modified Bradford assay. The ability of the surfaces to resist Pseudomonas aeruginosa and Staphylococcus aureus colonization was compared using fluorescence confocal microscopy. Reductions in total P. aeruginosa and S. aureus adhesion of 70% (p<0.001) and 83% (p<0.001), respectively, after 48h were observed for the melimine samples when compared to the blank control. We found that melimine attached via the N-terminus was the most effective in reducing total bacterial adhesion and bacterial viability with two- and four times (p<0.001) more activity than melimine attached via the C-terminus for P. aeruginosa and S. aureus, respectively. Furthermore, for Cys13, despite having the highest measured peptide density of the three surfaces, the higher concentration did not confer the greatest antibacterial effect. This highlights the importance of orientation of the peptides on the surface to efficacy. Our results suggest that the optimal orientation of the cationic residues is essential for maximum surface activity, whereby the optimal activity is obtained when the cationic portion is more available to interact with colonizing bacteria. PMID:22842034

Chen, Renxun; Willcox, Mark D P; Cole, Nerida; Ho, Kitty K K; Rasul, Riaz; Denman, John A; Kumar, Naresh

2012-07-27

20

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.

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

2011-01-01

21

Dissociation of the antimicrobial activity of bacitracin USP from its renovascular effects.  

PubMed Central

Bacitracin is a nephrotoxic antibiotic that has recently been shown to induce contractile effects in aortas isolated from rabbits by stimulating receptors for 5-hydroxytryptamine (5-HT). The possible renovascular actions of this antibiotic were investigated. Bacitracin USP increased the vascular resistance in a concentration-dependent manner (9 to 175 micrograms/ml) in rat kidneys perfused with a constant flow of Krebs solution. This was significantly inhibited by 5-HT antagonists, but only partially at the higher bacitracin concentration. An antagonist of the chemotactic peptide fMet-Leu-Phe failed to influence the pressor effect of bacitracin in rat kidneys. Indomethacin modestly reduced the effect of all potent pressor agents in the rat organ. Bacitracin USP was separated in several fractions by using C18 reverse-phase chromatography. Two distinct fractions were vasoconstrictive when infused in rat kidneys; both fractions were 5-HT mimetics. These peaks were different from the major antibiotic peak, bacitracin A, which was identified by using analytical high-pressure liquid chromatography, mass spectrometry, and inhibition of Micrococcus luteus growth. The less polar vasoactive peak corresponded to at least two minor peptides of the bacitracin family. The most abundant of these vasoactive peptides had no direct contractile effect on an aorta isolated from a rabbit, but a preliminary metabolic study in rat kidneys suggests that it is apparently transformed into a potent 5-HT agonist that is active on the aorta preparation. Bacitracin A, the major constituent of bacitracin with antimicrobial activity, had no vasoconstrictor effect in the test systems that we used; however, we did rule out the possibility that the renovascular stimulants found in the bacitracin mixture do not derive spontaneously or by biotransformation from the antibacterial forms of bacitracin.

Drapeau, G; Petitclerc, E; Toulouse, A; Marceau, F

1992-01-01

22

Stereoisomeric effect on antimicrobial activity of a series of quaternary ammonium salts  

Microsoft Academic Search

Two homologous series of diastereoisomeric racemic ±cis and ±traps-N,N-dimethyl-N-alkyl-2-benzoyloxycyclohexylmethylammonium bromides with the number of carbon atoms in the alkyl chain from six to twenty (m=6,8...20) were synthesised. Their structures have been elucidated by IR, UV and in some cases also with 1H and 13C NMR spectrometry. The title compounds were assayed for their antimicrobial activity on microorganisms S. aureus, E.

Fridrich Gregan; Jarmila Oremusová; Milan Remko; Juraj Gregan; Dušan Mlynar?ík

1998-01-01

23

Effect of gamma irradiation on the antimicrobial and free radical scavenging activities of Glycyrrhiza glabra root  

Microsoft Academic Search

The efficacy of gamma irradiation as a method of decontamination for food and herbal materials is well established. In the present study, Glycyrrhiza glabra roots were irradiated at doses 5, 10, 15, 20 and 25kGy in a cobalt-60 irradiator. The irradiated and un-irradiated control samples were evaluated for phenolic contents, antimicrobial activities and DPPH scavenging properties. The result of the

Khanzadi Fatima Khattak; Thomas James Simpson

2010-01-01

24

Antimicrobial Activities of Squalamine Mimics  

Microsoft Academic Search

We investigated the antimicrobial properties of compounds with structural features that were designed to mimic those of squalamine, an antibiotic isolated from the stomach of the dogfish shark. The mimics, like squalamine, are sterol-polyamine conjugates. Unlike squalamine, the mimics were simple to prepare, at high yield, from readily available starting materials. Several squalamine mimics showed activity against gram- negative rods,

KEN KIKUCHI; EDWARD M. BERNARD; ANDRZEJ SADOWNIK; STEVEN L. REGEN; DONALD ARMSTRONG

1997-01-01

25

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

26

Regulation of IDO Activity by Oxygen Supply: Inhibitory Effects on Antimicrobial and Immunoregulatory Functions  

PubMed Central

Tryptophan is an essential amino acid for human beings as well as for some microorganisms. In human cells the interferon-? (IFN-?) inducible enzyme indoleamine 2,3-dioxygenase (IDO) reduces local tryptophan levels and is therefore able to mediate broad-spectrum effector functions: IDO activity restricts the growth of various clinically relevant pathogens such as bacteria, parasites and viruses. On the other hand, it has been observed that IDO has immunoregulatory functions as it efficiently controls the activation and survival of T-cells. Although these important effects have been analysed in much detail, they have been observed in vitro using cells cultured in the presence of 20% O2 (normoxia). Such high oxygen concentrations are not present in vivo especially within infected and inflamed tissues. We therefore analysed IDO-mediated effects under lower oxygen concentrations in vitro and observed that the function of IDO is substantially impaired in tumour cells as well as in native cells. Hypoxia led to reduced IDO expression and as a result to reduced production of kynurenine, the downstream product of tryptophan degradation. Consequently, effector functions of IDO were abrogated under hypoxic conditions: in different human cell lines such as tumour cells (glioblastoma, HeLa) but also in native cells (human foreskin fibroblasts; HFF) IDO lost the capacity to inhibit the growth of bacteria (Staphylococcus aureus), parasites (Toxoplasma gondii) or viruses (herpes simplex virus type 1). Additionally, IDO could no longer efficiently control the proliferation of T-cells that have been co-cultured with IDO expressing HFF cells in vitro. In conclusion, the potent antimicrobial as well as immunoregulatory functions of IDO were substantially impaired under hypoxic conditions that pathophysiologically occurs in vivo.

Keil, Eric; Woite, Claudia; Ernst, Joachim F.; Benzin, Anika E.; Rupp, Jan; Daubener, Walter

2013-01-01

27

The antimicrobial activity of phenoxyethanol in vaccines.  

PubMed

The activity of the antimicrobial preservatives, phenoxyethanol and thiomersal, were compared in diphtheria, tetanus and pertussis (adsorbed) vaccine. Both chemicals were equally effective in inactivating challenge doses of Gram-negative and Gram-positive micro-organisms, as well as a yeast. PMID:7764595

Lowe, I; Southern, J

1994-02-01

28

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

29

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

30

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

PubMed

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 3month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4wt.%) 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

2013-02-26

31

Effects of various pressing programs and yields on the antioxidant activity, antimicrobial activity, phenolic content and colour of pomegranate juices.  

PubMed

Pomegranate juice (PJ) samples were produced with three different pressing programs: (1) 1.2-4.8 bar for 25 min, (2) 1.2-2.4 bar for 15 min and (3) 1.2-1.8 bar for 5.5 min. Respective juice yields were 39.2%, 33.2% and 27.2%. Effects of pressing pressure-time and yield on total phenolic (TP) content, condensed tannin (CT) content, monomeric anthocyanin (MA) content, antioxidant activity (AOA) and antimicrobial activity (AMA) of the samples were determined. Strong positive linear correlations were found between the pressing pressure with AOA (r=0.973) and TP content (r=0.979), while negative logarithmic correlations were found between pressing pressure with the contents of CT (r=-0.778) and MA (r=-0.955). Among 12 microorganisms tested, Bacillus megaterium, Bacillus subtilis, Staphyloccocus aureus and Pseudomonas sp. were found to be sensitive to juice samples. However, increasing pressing pressure and yield did not lead to a significant change on the AMAs of the juices. PMID:23411313

Türky?lmaz, Meltem; Ta??, ?eref; Dereli, Ufuk; Özkan, Mehmet

2012-12-05

32

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

33

Effect of repetitive lysine-tryptophan motifs on the bactericidal activity of antimicrobial peptides.  

PubMed

Previous studies identified lysine- and tryptophan-rich sequences within various cationic antimicrobial peptides. In the present study, we synthesized a series of peptides composed of lysine (K)-tryptophan (W) repeats (KW)( n ) (where n equals 2, 3, 4 or 5) with amidation of the C-terminal to increase cationicity. We found that increases in chain length up to (KW)(4) enhanced the peptides' antibacterial activity; (KW)(5) exhibited somewhat less bactericidal activity than (KW)(4). Cytotoxicity, measured as lysis of human red blood cells, also increased with increasing chain length. With (KW)(5), reduced antibacterial activity and increased cytotoxicity correlated with greater hydrophobicity and self-aggregation in the aqueous environment. The peptides acted by inducing rapid collapse of the bacterial transmembrane potential and induction of membrane permeability. The mode of interaction of the peptides and the phosphate groups of lipopolysaccharide was dependent upon the peptides' ability to permeate the membrane. Longer peptides [(KW)(4) and (KW)(5)] but not shorter peptides [(KW)(2) and (KW)(3)] strongly bound and partially inserted into negatively charged, anionic lipid bilayers. These longer peptides also induced membrane permeabilization and aggregation of lipid vesicles. The peptides had a disordered structure in aqueous solution, and only (KW)(4) and (KW)(5) displayed a folded conformation on lipid membranes. Moreover, (KW)(4) destroyed and agglutinated bacterial cells, demonstrating its potential as an antimicrobial agent. Collectively, the results show (KW)(4) to be the most efficacious peptide in the (KW)( n ) series, exhibiting strong antibacterial activity with little cytotoxicity. PMID:22914980

Gopal, Ramamourthy; Seo, Chang Ho; Song, Peter I; Park, Yoonkyung

2012-08-23

34

Magnesium Based Materials and their Antimicrobial Activity  

NASA Astrophysics Data System (ADS)

The overall goals of this body of work were to characterize the antimicrobial properties of magnesium (Mg) metal and nano-magnesium oxide (nMgO) in vitro, to evaluate the in vitro cytotoxicity of Mg metal, and to incorporate MgO nanoparticles into a polymeric implant coating and evaluate its in vitro antimicrobial properties. In the course of this work it was found that Mg metal, Mg-mesh, and nMgO have in vitro antimicrobial properties that are similar to a bactericidal antibiotic. For Mg metal, the mechanism of this activity appears to be related to an increase in pH (i.e. a more alkaline environment) and not an increase in Mg2+. Given that Mg-mesh is a Mg metal powder, the assumption is that it has the same mechanism of activity as Mg metal. The mechanism of activity for nMgO remains to be elucidated and may be related to a combination of interaction of the nanoparticles with the bacteria and the alkaline pH. It was further demonstrated that supernatants from suspensions of Mg-mesh and nMgO had the same antimicrobial effect as was noted when the particles were used. The supernatant from Mg-mesh and nMgO was also noted to prevent biofilm formation for two Staphylococcus strains. Finally, poly-epsilon-caprolactone (PCL) composites of Mg-mesh (PCL+Mg-mesh) and nMgO (PCL+nMgO) were produced. Coatings applied to screws inhibited growth of Escherichia coli and Pseudomonas aeruginosa and in thin disc format inhibited the growth of Staphylococcus aureus in addition to the E. coli and P. aeruginosa. Pure Mg metal was noted to have some cytotoxic effect on murine fibroblast and osteoblast cell lines, although this effect needs to be characterized further. To address the need for an in vivo model for evaluating implant associated infections, a new closed fracture osteomyelitis model in the femur of the rat was developed. Magnesium, a readily available and inexpensive metal was shown to have antimicrobial properties that appear to be related to its corrosion products and that nMgO has similar effects. Incorporation of nMgO into a PCL composite was easily achieved and revealed similar, although not identical antimicrobial results. This work has provided a strong foundation and methodology for further evaluation of Mg based materials and their antimicrobial properties.

Robinson, Duane Allan

35

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.

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

2012-01-01

36

Antimicrobial activity of glucoprotamin-containing disinfectants.  

PubMed

Introduction of a new antimicrobial agent as a drug--for treatment of infections or as a disinfectant and antiseptic, may result in the occurrence of resistance mechanisms against this agent among microorganisms. Two disinfectants of different composition--Incidin Plus for surface disinfection and Sekusept Plus for medical devices disinfection, both containing glucoprotamin as the active substance, were investigated in this study in order to analyze their antimicrobial activity. Standard bacterial and fungal strains recommended by European Standards, established by European Standardization Committee for testing bactericidal and fungicidal activity of chemical disinfectants were used in the study. Furthermore, 60 clinical bacterial strains with different susceptibility to antibiotics and chemotherapeutics, mostly multiresistant, isolated from different specimens from hospitalized patients were analyzed. In addition, 184 fungal clinical strains isolated from hospitalized patients and outpatients were also included in this study. Antimicrobial activity was evaluated according to EN 1040:2005 --using bacterial strains and according to EN 1275:2005--using fungal strains. Glucoprotamin proved to be a very effective and rapidly acting bactericidal and fungicidal agent. Low concentration of glucoprotamin--0.5% showed to be very effective (1 min) against clinical bacterial isolates. Incidin Plus was also very effective (5 min) against clinical fungal isolates. PMID:20380145

Tyski, Stefan; Grzybowska, Wanda; Grzeszczuk, Sabina; Leszczy?ski, Piotr; Staniszewska, Monika; Röhm-Rodowald, Ewa; Jakimiak, Bozena

2009-01-01

37

Antimicrobial activity of Gymnema sylvestre leaf extract  

Microsoft Academic Search

The ethanolic extract of Gymnema sylvestre leaves demonstrated antimicrobial activity against Bacillus pumilis, B. subtilis, Pseudomonas aeruginosa and Staphylococcus aureus and inactivity against Proteus vulgaris and Escherichiacoli.

R. K. Satdive; P. Abhilash; Devanand P. Fulzele

2003-01-01

38

Metabolic changes of Phomopsis longicolla fermentation and its effect on antimicrobial activity against Xanthomonas oryzae.  

PubMed

Bacterial blight, an important and potentially destructive bacterial disease in rice caused by Xanthomonas oryzae pv. oryzae (Xoo), has recently developed resistance to the available antibiotics. In this study, mass spectrometry (MS)-based metabolite profiling and multivariate analysis were employed to investigate the correlation between time-dependent metabolite changes and antimicrobial activities against Xoo over the course of Phomopsis longicolla S1B4 fermentation. Metabolites were clearly differentiated based on fermentation time into phase 1 (days 4-8) and phase 2 (days 10-20) in the principal component analysis (PCA) plot. The multivariate statistical analysis showed that the metabolites contributing significantly for phases 1 and 2 were deacetylphomoxanthone B, monodeacetylphomoxanthone B, fusaristatin A, and dicerandrols A, B, and C as identified by liquid chromatography-mass spectrometry (LC-MS), and dimethylglycine, isobutyric acid, pyruvic acid, ribofuranose, galactofuranose, fructose, arabinose, hexitol, myristic acid, and propylstearic acid were identified by gas chromatography-mass spectrometry (GC-MS)-based metabolite profiling. The most significantly different secondary metabolites, especially deacetylphomoxanthone B, monodeacetylphomoxanthone B, and dicerandrol A, B and C, were positively correlated with antibacterial activity against Xoo during fermentation. PMID:23412059

Choi, Jung Nam; Kim, Jiyoung; Ponnusamy, Kannan; Lim, Chaesung; Kim, Jeong Gu; Muthaiya, Maria John; Lee, Choonghwan

2013-02-01

39

Antimicrobial and antiplasmid activities of essential oils  

Microsoft Academic Search

The antimicrobial and antiplasmid activities of essential oils (orange oil, eucalyptus oil, fennel oil, geranium oil, juniper oil, peppermint oil, rosemary oil, purified turpentine oil, thyme oil, Australian tea tree oil) and of menthol, the main component of peppermint oil, were investigated. The antimicrobial activities were determined on the Gram (+) Staphylococcus epidermidis and the Gram (?) Escherichia coli F'lac

Zsuzsanna Schelz; Joseph Molnar; Judit Hohmann

2006-01-01

40

Measuring Antimicrobial Activity Against Biofilm Bacteria  

Microsoft Academic Search

Standardization of methodology and interpretation has proved essential to scientific progress in studies of the activity of antimicrobial agents against planktonic bacteria. Current studies of antimicrobial activity against biofilm bacteria lack standardization of methodology. The principles applied to standardization of methods for planktonic bacteria can serve as a template in developing standards for studying biofilm bacteria. Such standards are essential

J. Curtin; M. Cormican

2003-01-01

41

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

42

Flexibility is a mechanical determinant of antimicrobial activity for amphipathic cationic ?-helical antimicrobial peptides.  

PubMed

Antimicrobial peptides (AMPs) are recognized as the potential substitutions for common antibiotics. Flexibility has been demonstrated to be a dominant on antimicrobial activity of an AMP, similar to the structural parameters such as hydrophobicity and hydrophobic moment as well as positive charge. To better understand the effect of flexibility on antimicrobial activity, we herein examined seventy-eight peptides derived from nine different species. Defined as a weighted average of amino acid flexibility indices over whole residue chain of AMP, flexibility index was used to scale the peptide flexibility and indicated to be a reflection of mechanical properties such as tensile and flexural rigidities. The results demonstrated that flexibility index is relevant to but different from other structural properties, may enhance activity against Escherichia coli for stiff clustered peptides or reduce activity against E. coli for flexible clustered peptides, and its optimum occurs at about -0.5. This effect of flexibility on antimicrobial activity may be involved to the antimicrobial actions, such as stable peptide-bound leaflet formation and sequent stress concentration in target cell membrane, mechanically. The present results provide a new insight in understanding antimicrobial actions and may be useful in seeking for a new structure-activity relationship for cationic and amphipathic ?-helical peptides. PMID:23806649

Liu, Li; Fang, Ying; Wu, Jianhua

2013-06-24

43

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.

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

2013-01-01

44

Antimicrobial activity of extractives of Solidago microglossa.  

PubMed

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. PMID:16843619

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

2006-05-24

45

Effects of Slime Produced by Clinical Isolates of Coagulase-Negative Staphylococci on Activities of Various Antimicrobial Agents  

Microsoft Academic Search

A novel in vitro semiquantitative method was developed to investigate the influence of staphylococcal slime on the activities of 22 antimicrobial agents. Pefloxacin, teicoplanin, and vancomycin demonstrated remarkable decreases in efficacy: 30, 52, and 63%, respectively. The activity of rifampin was not significantly reduced (0.99%), whereas all other agents tested were modestly affected (<15% decrease). These data could be influential

MARIA SOULI; HELEN GIAMARELLOU

1998-01-01

46

Influence of substituent effects on spectroscopic properties and antimicrobial activity of 5-(4'-substituted phenylazo)-2-thioxothiazolidinone derivatives.  

PubMed

5-(4'-substituted phenylazo)-2-thioxothiazolidinone derivatives (HL(n)) have been synthesized and characterized by elemental analysis, spectra (IR, electronic and (1)H NMR). The IR spectral data indicate that the compounds can exist in two resonance structures. The synthesized ligands were screened for their antimicrobial activity against four bacterial species, two Gram positive bacteria (Bacillus cereus and Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae) as well as against some species various of fungi; Aspergillus niger, Penicillium chrysogenum, Penicillium italicum and Fusarium oxysporium. The results showed that most these ligands are good antibacterial agents against B. cereus and S. aureus and antifungal agents against A. niger and F. oxysporium. HL(3) was found to be the most effect compound against all tested microorganisms. The size of clear zone were ordered as follows p-(OCH(3) < CH(3) < H < Cl < NO(2)) as expected from Hammett's constant ?(R). PMID:22968655

Abou-Dobara, M I; El-Sonbati, A Z; Morgan, Sh M

2012-09-12

47

Antimicrobial activity of Gymnema sylvestre leaf extract.  

PubMed

The ethanolic extract of Gymnema sylvestre leaves demonstrated antimicrobial activity against Bacillus pumilis, B. subtilis, Pseudomonas aeruginosa and Staphylococcus aureus and inactivity against Proteus vulgaris and Escherichia coli. PMID:14630178

Satdive, R K; Abhilash, P; Fulzele, Devanand P

2003-12-01

48

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.

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

1986-01-01

49

Antimicrobial activity of Miconia species (Melastomataceae).  

PubMed

This work evaluated the antimicrobial activity of the methanol and chloroform extracts of the leaves of Miconia cabucu, Miconia rubiginosa, and Miconia stenostachya using the disc-diffusion method. The results obtained showed that the methanol extracts of the leaves of M. rubiginosa and M. stenostachya and the chloroform extract of the leaves of M. cabucu presented antimicrobial activity against the tested microorganisms. PMID:18361747

Rodrigues, Juliana; Michelin, Danielle Carvalho; Rinaldo, Daniel; Zocolo, Guilherme Julião; dos Santos, Lourdes Campaner; Vilegas, Wagner; Salgado, Hérida Regina Nunes

2008-03-01

50

Effects of exercise intensity on salivary antimicrobial proteins and markers of stress in active men  

Microsoft Academic Search

In the present study, we assessed the effects of exercise intensity on salivary immunoglobulin A (s-IgA) and salivary lysozyme (s-Lys) and examined how these responses were associated with salivary markers of adrenal activation. Using a randomized design, 10 healthy active men participated in three experimental cycling trials: 50% maximal oxygen uptake ([Vdot]O2max), 75%[Vdot]O2max, and an incremental test to exhaustion. The

Judith E. Allgrove; Elisa Gomes; John Hough; Michael Gleeson

2008-01-01

51

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.

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

2011-01-01

52

Antimicrobial effect of phlorotannins from marine brown algae.  

PubMed

Marine organisms exhibit a rich chemical content that possess unique structural features as compared to terrestrial metabolites. Among marine resources, marine algae are a rich source of chemically diverse compounds with the possibility of their potential use as a novel class of artificial food ingredients and antimicrobial agents. The objective of this brief review is to identify new candidate drugs for antimicrobial activity against food-borne pathogenic bacteria. Bioactive compounds derived from brown algae are discussed, namely phlorotannins, that have anti-microbial effects and therefore may be useful to explore as potential antimicrobial agents for the food and pharmaceutical industries. PMID:22735502

Eom, Sung-Hwan; Kim, Young-Mog; Kim, Se-Kwon

2012-06-23

53

Effects of Slime Produced by Clinical Isolates of Coagulase-Negative Staphylococci on Activities of Various Antimicrobial Agents  

PubMed Central

A novel in vitro semiquantitative method was developed to investigate the influence of staphylococcal slime on the activities of 22 antimicrobial agents. Pefloxacin, teicoplanin, and vancomycin demonstrated remarkable decreases in efficacy: 30, 52, and 63%, respectively. The activity of rifampin was not significantly reduced (0.99%), whereas all other agents tested were modestly affected (<15% decrease). These data could be influential in the treatment of implant-associated infections caused by slime-producing staphylococci.

Souli, Maria; Giamarellou, Helen

1998-01-01

54

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

55

Synergistic effect and antibiofilm activity between the antimicrobial peptide coprisin and conventional antibiotics against opportunistic bacteria.  

PubMed

Coprisin is a 43-mer defensin-like peptide from the dung beetle, Copris tripartitus. In this study, we tested its minimum inhibitory concentration and performed combination assays to confirm the antibacterial susceptibility of coprisin and synergistic effects with antibiotics. The synergistic effects were evaluated by testing the effects of coprisin in combination with ampicillin, vancomycin, and chloramphenicol. The results showed that coprisin possessed antibacterial properties and had synergistic activities with the antibiotics. To understand the synergistic mechanism(s), we conducted hydroxyl radical assays. Coprisin alone and in combination with antibiotics generated hydroxyl radicals, which are highly reactive oxygen forms and the major property of bactericidal agents. Furthermore, the antibiofilm effect of coprisin alone and in combination with antibiotics was investigated. Biofilm formation is the source of many relentless and chronic bacterial infections. The results indicated that coprisin alone and in combination with antibiotics also had antibiofilm activity. Therefore, we conclude that coprisin has the potential to be used as a combinatorial therapeutic agent for the treatment of infectious diseases caused by bacteria. PMID:23053486

Hwang, In-sok; Hwang, Jae-Sam; Hwang, Ji Hong; Choi, Hyemin; Lee, Eunjung; Kim, Yangmee; Lee, Dong Gun

2012-09-30

56

Effects of exercise intensity on salivary antimicrobial proteins and markers of stress in active men.  

PubMed

In the present study, we assessed the effects of exercise intensity on salivary immunoglobulin A (s-IgA) and salivary lysozyme (s-Lys) and examined how these responses were associated with salivary markers of adrenal activation. Using a randomized design, 10 healthy active men participated in three experimental cycling trials: 50% maximal oxygen uptake (VO2max), 75%VO2max, and an incremental test to exhaustion. The durations of the trials were the same as for a preliminary incremental test to exhaustion (22.3 min, sx = 0.8). Timed, unstimulated saliva samples were collected before exercise, immediately after exercise, and 1 h after exercise. In the incremental exhaustion trial, the secretion rates of both s-IgA and s-Lys were increased. An increase in s-Lys secretion rate was also observed at 75%VO2max. No significant changes in saliva flow rate were observed in any trial. Cycling at 75%VOmax and to exhaustion increased the secretion of alpha-amylase and chromogranin A immediately after exercise; higher cortisol values at 75%VO2max and in the incremental exhaustion trial compared with 50%VO2max were observed 1 h immediately after exercise only. These findings suggest that short-duration, high-intensity exercise increases the secretion rate of s-IgA and s-Lys despite no change in the saliva flow rate. These effects appear to be associated with changes in sympathetic activity and not the hypothalamic - pituitary - adrenal axis. PMID:18344136

Allgrove, Judith E; Gomes, Elisa; Hough, John; Gleeson, Michael

2008-04-01

57

Antimicrobial activity of Loranthus micranthus harvested from kola nut tree.  

PubMed

Various solvent extracts of Loranthus micranthus exhibited varying degrees of antimicrobial activity. Only the petroleum ether extract showed antifungal activity. The methanol extract showed the best antimicrobial activity against Escherichia coli and Bacillus subtilis. PMID:16257495

Osadebe, P O; Akabogu, I C

2005-10-28

58

Synergistic antimicrobial activities of natural essential oils with chitosan films.  

PubMed

The synergistic antimicrobial activities of three natural essential oils (i.e., clove bud oil, cinnamon oil, and star anise oil) with chitosan films were investigated. Cinnamon oil had the best antimicrobial activity among three oils against Escherichia coli , Staphylococcus aureus , Aspergillus oryzae , and Penicillium digitatum . The chitosan solution exhibited good inhibitory effects on the above bacteria except the fungi, whereas chitosan film had no remarkable antimicrobial activity. The cinnamon oil-chitosan film exhibited a synergetic effect by enhancing the antimicrobial activities of the oil, which might be related to the constant release of the oil. The cinnamon oil-chitosan film had also better antimicrobial activity than the clove bud oil-chitosan film. The results also showed that the compatibility of cinnamon oil with chitosan in film formation was better than that of the clove bud oil with chitosan. However, the incorporated oils modified the mechanical strengths, water vapor transmission rate, moisture content, and solubility of the chitosan film. Furthermore, chemical reaction took place between cinnamon oil and chitosan, whereas phase separation occurred between clove bud oil and chitosan. PMID:22034912

Wang, Lina; Liu, Fei; Jiang, Yanfeng; Chai, Zhi; Li, Pinglan; Cheng, Yongqiang; Jing, Hao; Leng, Xiaojing

2011-11-09

59

Multidrug Pump Inhibitors Uncover Remarkable Activity of Plant Antimicrobials  

PubMed Central

Plant antimicrobials are not used as systemic antibiotics at present. The main reason for this is their low level of activity, especially against gram-negative bacteria. The reported MIC is often in the range of 100 to 1,000 ?g/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. Major plant pathogens belong to the gram-negative bacteria, which makes the low level of activity of plant antimicrobials against this group of microorganisms puzzling. Gram-negative bacteria have an effective permeability barrier, comprised of the outer membrane, which restricts the penetration of amphipathic compounds, and multidrug resistance pumps (MDRs), which extrude toxins across this barrier. It is possible that the apparent ineffectiveness of plant antimicrobials is largely due to the permeability barrier. We tested this hypothesis in the present study by applying a combination of MDR mutants and MDR inhibitors. A panel of plant antimicrobials was tested by using a set of bacteria representing the main groups of plant pathogens. The human pathogens Pseudomonas aeruginosa, Escherichia coli, and Salmonella enterica serovar Typhimurium were also tested. The results show that the activities of the majority of plant antimicrobials were considerably greater against the gram-positive bacteria Staphylococcus aureus and Bacillus megaterium and that disabling of the MDRs in gram-negative species leads to a striking increase in antimicrobial activity. Thus, the activity of rhein, the principal antimicrobial from rhubarb, was potentiated 100- to 2,000-fold (depending on the bacterial species) by disabling the MDRs. Comparable potentiation of activity was observed with plumbagin, resveratrol, gossypol, coumestrol, and berberine. Direct measurement of the uptake of berberine, a model plant antimicrobial, confirmed that disabling of the MDRs strongly increases the level of penetration of berberine into the cells of gram-negative bacteria. These results suggest that plants might have developed means of delivering their antimicrobials into bacterial cells. These findings also suggest that plant antimicrobials might be developed into effective, broad-spectrum antibiotics in combination with inhibitors of MDRs.

Tegos, George; Stermitz, Frank R.; Lomovskaya, Olga; Lewis, Kim

2002-01-01

60

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.

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

2009-01-01

61

Antimicrobial and antibiofilm activity of pleurocidin against cariogenic microorganisms.  

PubMed

Dental caries is a common oral bacterial infectious disease of global concern. Prevention and treatment of caries requires control of the dental plaque formed by pathogens such as Streptococcus mutans and Streptococcus sobrinus. Pleurocidin, produced by Pleuronectes americanus, is an antimicrobial peptide that exerts broad-spectrum activity against pathogenic bacteria and fungi. Moreover, pleurocidin shows less hemolysis and is less toxic than other natural peptides. In the present study, we investigated whether pleurocidin is an effective antibiotic peptide against common cariogenic microorganisms and performed a preliminary study of the antimicrobial mechanism. We assayed minimal inhibitory concentration (MIC), minimal bactericide concentration (MBC) and bactericidal kinetics and performed a spot-on-lawn assay. The BioFlux system was used to generate bacterial biofilms under controllable flow. Fluorescence microscopy and confocal laser scanning microscopy (CLSM) were used to analyze and observe biofilms. Scanning electron microscopy was used to observe the bacterial membrane. MIC and MBC results showed that pleurocidin had different antimicrobial activities against the tested oral strains. Although components of saliva could affect antimicrobial activity, pleurocidin dissolved in saliva still showed antimicrobial effects against oral microorganisms. Furthermore, pleurocidin showed a favorable killing effect against BioFlux flow biofilms in vitro. Our findings suggest that pleurocidin has the potential to kill dental biofilms and prevent dental caries. PMID:21703317

Tao, Rui; Tong, Zhongchun; Lin, Yuan; Xue, Yunpeng; Wang, Wei; Kuang, Rong; Wang, Ping; Tian, Yu; Ni, Longxing

2011-06-15

62

Antimicrobial activity of caO nanoparticles.  

PubMed

The high degree of microbial diseases and their multidrug resistant properties make the researchers to develop new class of antimicrobial agents. A modern and innovative approach of drug development is the use of metallic nanoparticles as new formulations of antimicrobial agents. In this study, microwave irradiated CaO nanoparticles (CaO-NPs) were used to determine their antimicrobial efficacy against gram negative and gram positive bacteria, as well as pathogenic yeast. The physiochemical properties of CaO-NPs were characterized by means of X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The nanoparticles consist of well dispersed agglomerates of grains with a narrow size distribution of 14-24 nm. The prepared CaO-NPs showed much higher antimicrobial activity against Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus epidermidis (MTCC 435) in comparision to Candida tropicalis (NCIM 3110). The minimum inhibitory concentration (MIC) value of CaO-NPs was found within the range of 2-8 mM for all the above tested strains. This bioactive nanoparticle also inhibits the biofilm formation and may have future applications cheap and non toxic as antimicrobial drug for skin care product development. PMID:23980504

Roy, Arup; Gauri, Samiran S; Bhattacharya, Madhusmita; Bhattacharya, Jayanta

2013-09-01

63

[Antimicrobial stewardship].  

PubMed

The purpose of the antimicrobial stewardship is to make an effort so that it tries to draw out the maximum effect by using the antimicrobial agent and to decrease the risk of side-effect, and suppress the emergence of antimicrobial resistant organisms. Antimicrobial stewardship is an activity to achieve these goals. Antimicrobial stewardship must be regarded as quality control and risk management procedure in the medical institution. Enough authorization to medical staff by the executive of the hospital is indispensable for the achievement of proper use of antimicrobial agents. Additionally, the manager of the hospital should give enough resources to support this activity. PMID:22413535

Ohmagari, Norio

2012-02-01

64

Antimicrobial Activities of Essential Oils of Nepal  

Microsoft Academic Search

The volatile components of two essential oils obtained from plants indigenous to Nepal, anthopogon (Rhododendron anthopogon) and Curcuma zedoaria oils, and four oils, chamomile (Chamomilla recutita), French basil (Ocimum basilicum), cornmint (Mentha canadensis) and palmarosa (Cymbopogon martini var. martini), which are exotic but produced in Nepal, were analyzed with GC\\/MS and the antimicrobial activity of all the six oils were

Minoba Yonzon; Dong Jin Lee; Toshihiro Yokochi; Yasuhiro Kawano; Toro Nakahara

2005-01-01

65

Antimicrobial activity of resin acid derivatives  

Microsoft Academic Search

The wide potential of resin acids as bioactive agents gave rise to a growing effort in the search for new applications of the natural forms and their derivatives. In some of these compounds, the antimicrobial activity is associated to the presence in the molecules of functional groups such as the hydroxyl, aldehyde, and ketone or to their cis or trans

Sonia Savluchinske-Feio; Maria João Marcelo Curto; Bárbara Gigante; J. Carlos Roseiro

2006-01-01

66

Antiulcer and antimicrobial activity of Anogeissus latifolia  

Microsoft Academic Search

Ethnobotanically, the bark of Anogeissus latifolia (Roxb. ex DC.) Wall. ex Guill. & Perr.(Combretaceae) has been reported to be used in the treatment of various disorders including stomach and skin diseases. We studied the antiulcer potential and antimicrobial activity of the 50% aqueous alcoholic extract in order to validate ethnobotanical claims regarding the plant use in the above-mentioned disorders. Gastroprotective

R. Govindarajan; M. Vijayakumar; M. Singh; Ch. V. Rao; A. Shirwaikar; A. K. S. Rawat; P. Pushpangadan

2006-01-01

67

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

68

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

69

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

70

Antimicrobial activity of grapefruit seed and pulp ethanolic extract  

Microsoft Academic Search

2 Antibacterial and antifungal activity of ethanolic extract of grapefruit (Citrus paradisi Macf., Rutaceae) seed and pulp was examined against 20 bacterial and 10 yeast stra- ins. The level of antimicrobial effects was established using an in vitro agar assay and standard broth dilution sus- ceptibility test. The contents of 3.92% of total polyphenols and 0.11% of flavonoids were determined

ZDENKA CVETNI; SANDA VLADIMIR-KNE

2004-01-01

71

Antimicrobial activity of alcohols from Musca domestica.  

PubMed

Information on the stimulatory and inhibitory effects of cuticular alcohols on growth and virulence of insecticidal fungi is unavailable. Therefore, we set out to describe the content of cuticular and internal alcohols in the body of housefly larvae, pupae, males and females. The total cuticular alcohols in larvae, males and females of Musca domestica were detected in comparable amounts (4.59, 3.95 and 4.03 ?g g(-1) insect body, respectively), but occurred in smaller quantities in pupae (2.16 ?g g(-1)). The major free alcohol in M. domestica larvae was C(12:0) (70.4%). Internal alcohols of M. domestica larvae were not found. Among cuticular pupae alcohols, C(12:0) (31.0%) was the most abundant. In the internal lipids of pupae, only five alcohols were identified in trace amounts. The most abundant alcohol in males was C(24:0) (57.5%). The percentage content of cuticular C(24:0) in males and females (57.5 and 36.5%, respectively) was significantly higher than that of cuticular lipids in larvae and pupae (0.9 and 5.6%, respectively). Only two alcohols were present in the internal lipids of males in trace amounts (C(18:0) and C(20:0)). The most abundant cuticular alcohols in females were C(24:0) (36.5%) and C(12:0) (26.8%); only two alcohols (C(18:0) and C(20:0)) were detected in comparable amounts in internal lipids (3.61±0.32 and 5.01±0.42 ?g g(-1), respectively). For isolated alcohols, antimicrobial activity against 10 reference strains of bacteria and fungi was determined. Individual alcohols showed approximately equal activity against fungal strains. C(14:0) was effective against gram-positive bacteria, whereas gram-negative bacteria were resistant to all tested alcohols. Mixtures of alcohols found in cuticular lipids of larvae, pupae, males and females of M. domestica generally presented higher antimicrobial activity than individual alcohols. In contrast, crude extracts containing both cuticular and internal lipids showed no antifungal activity against the entomopathogenic fungus Conidiobolus coronatus, which efficiently kills adult house flies. PMID:22693023

Go??biowski, Marek; Dawgul, Ma?gorzata; Kamysz, Wojciech; Bogu?, Mieczys?awa I; Wieloch, Wioletta; W?óka, Emilia; Paszkiewicz, Monika; Przybysz, El?bieta; Stepnowski, Piotr

2012-06-12

72

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

73

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

2011-08-23

74

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.

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

75

The Antimicrobial Activity of Liposomal Lauric Acids Against Propionibacterium acnes  

PubMed Central

This study evaluated the antimicrobial activity of lauric acid (LA) and its liposomal derivatives against Propionibacterium acnes (P. acnes), the bacterium that promotes inflammatory acne. First, the antimicrobial study of three free fatty acids (lauric acid, palmitic acid and oleic acid) demonstrated that LA gives the strongest bactericidal activity against P. acnes. However, a setback of using LA as a potential treatment for inflammatory acne is its poor water solubility. Then the LA was incorporated into a liposome formulation to aid its delivery to P. acnes. It's demonstrated that the antimicrobial activity of LA was not only well maintained in its liposomal derivatives but also enhanced at low LA concentration. In addition, the antimicrobial activity of LA-loaded liposomes (LipoLA) mainly depended on the LA loading concentration per single liposomes. Further study found that the LipoLA could fuse with the membranes of P. acnes and release the carried LA directly into the bacterial membranes, thereby killing the bacteria effectively. Since LA is a natural compound that is the main acid in coconut oil and also resides in human breast milk and liposomes have been successfully and widely applied as a drug delivery vehicle in the clinic, the LipoLA developed in this work holds great potential of becoming an innate, safe and effective therapeutic medication for acne vulgaris and other P. acnes associated diseases.

Yang, Darren; Pornpattananangkul, Dissaya; Nakatsuji, Teruaki; Chan, Michael; Carson, Dennis; Huang, Chun-Ming; Zhang, Liangfang

2009-01-01

76

Factors affecting antimicrobial activity of MUC7 12-mer, a human salivary mucin-derived peptide  

Microsoft Academic Search

BACKGROUND: MUC7 12-mer (RKSYKCLHKRCR), a cationic antimicrobial peptide derived from the human low-molecular-weight salivary mucin MUC7, possesses potent antimicrobial activity in vitro. In order to evaluate the potential therapeutic application of the MUC7 12-mer, we examined the effects of mono- and divalent cations, EDTA, pH, and temperature on its antimicrobial activity. METHODS: Minimal Inhibitory Concentrations (MICs) were determined using a

Guo-Xian Wei; Alexander N Campagna; Libuse A Bobek

2007-01-01

77

Antimicrobial activity of antihypertensive food-derived peptides and selected alanine analogues.  

PubMed

This study evaluated four food-derived peptides with known antihypertensive activities for antimicrobial activity against pathogenic microorganisms, and assessed structure-function relationships using alanine analogues. The peptides (EVSLNSGYY, barley; PGTAVFK, soybean; TTMPLW, ?-casein; VHLPP, ?-zein) and the six alanine substitution peptides of PGTAVFK were synthesised, characterised and evaluated for antimicrobial activity using the bacteria, Escherichia coli, Staphylococcus aureus, and Micrococcus luteus and the yeast, Candida albicans. The peptides TTMPLW and PGTAVFK inhibited growth of all four microorganisms tested, with activities of a similar order of magnitude to ampicillin and ethanol controls. EVSLNSGYY inhibited the growth of the bacteria, but VHLPP showed no antimicrobial activity. The alanine analogue, PGAAVFK showed the highest overall antimicrobial activity and PGTAVFA showed no activity; overall, the activities of the analogues were consistent with their structures. Some peptides with antihypertensive activity also show antimicrobial activity, suggesting that food-derived peptides may exert beneficial effects via a number of mechanisms. PMID:24176365

McClean, Stephen; Beggs, Louise B; Welch, Robert W

2013-09-25

78

In Vitro Antimicrobial Activity of Cinoxacin Against 2,968 Clinical Bacterial Isolates  

PubMed Central

Cinoxacin demonstrated effective in vitro antimicrobial activity against the Enterobacteriaceae, but negligible activity against Pseudomonas aeruginosa and gram-positive cocci. The activity of cinoxacin was slightly greater than that of nalidixic acid.

Jones, R. N.; Fuchs, P. C.

1976-01-01

79

Antimicrobial activity of some Indian medicinal plants.  

PubMed

The antimicrobial potential of seventy-seven extracts from twenty-four plants was screened against eight bacteria and four pathogenic fungi, using microbroth dilution assay. Lowest concentration of the extract, which inhibits any visual microbial growth after treatment with p-iodonitrotetrazolium violet, was considered to be minimum inhibitory concentration (MIC). Water extracts of Acacia nilotica, Justicia zelanica, Lantana camara and Saraca asoca exhibited good activity against all the bacteria tested and the MIC was recorded in range of 9.375-37.5 microg/ml and 75.0-300.0 microg/ml against the bacterial and fungal pathogens, respectively. The other extracts of Phyllanthus urinaria, Thevetia nerifolia, Jatropha gossypifolia Saraca asoca, Tamarindus indica, Aegle marmelos, Acacia nilotica, Chlorophytum borivilianum, Mangifera indica, Woodfordia fruticosa and Phyllanthus emblica showed antimicrobial activity in a range of 75-1200 microg/ml. PMID:20161895

Dabur, Rajesh; Gupta, Amita; Mandal, T K; Singh, Desh Deepak; Bajpai, Vivek; Gurav, A M; Lavekar, G S

2007-02-16

80

Antimicrobial activity of ruthenium-based intercalators.  

PubMed

Multidrug resistance of bacterial pathogens is a major problem and there is a clear need for the development of new types of antibiotics. Here we investigated the antimicrobial activity of ruthenium(II) based DNA-intercalating complexes. These complexes were found to have no activity in vitro against the Gram-negative bacterium Escherichia coli, but the complexes were clearly active against the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus. In vivo activity has also been demonstrated for one of the compounds using a simple infection model, the nematode Caenorhabditis elegans. Importantly, this also showed that the compound tested was not toxic to the nematodes. PMID:21182937

Bolhuis, Albert; Hand, Lorna; Marshall, Julia E; Richards, Adair D; Rodger, Alison; Aldrich-Wright, Janice

2010-12-21

81

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

82

Evaluation of antimicrobial activity of Rasaka Bhasma.  

PubMed

Rasaka, one among the Maharasas, has been indicated in various diseases like Netrarogas, Prameha, etc. Lately, the use of Rasaka bhasma has been declined as an identification of Rasaka. The present study aims to prepare Rasaka bhasma from two different samples of Rasaka and undertake comparative antimicrobial activity study against Gram-positive and Gram-negative organisms by agar disk diffusion method. PMID:22131722

Shubha, H S; Hiremath, R S

2010-04-01

83

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.

Jung, Sascha; Sonnichsen, Frank D.; Hung, Chien-Wen; Tholey, Andreas; Boidin-Wichlacz, Celine; Haeusgen, Wiebke; Gelhaus, Christoph; Desel, Christine; Podschun, Rainer; Waetzig, Vicki; Tasiemski, Aurelie; Leippe, Matthias; Grotzinger, Joachim

2012-01-01

84

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

85

Phenolic antioxidants from clonal oregano ( Origanum vulgare) with antimicrobial activity against Helicobacter pylori  

Microsoft Academic Search

Phenolic phytochemicals consumed via our diet are good sources of natural antioxidants. These phenolic metabolites have beneficial effects on human health, including inhibition of mutagenesis and carcinogenesis. In addition some phenolic phytochemicals have also been shown to have antimicrobial and antifungal activity. Oregano (Origanum vulgare L.) is an important Mediterranean herb rich in phenolic compounds with antioxidant and antimicrobial activity.

Sung-Sook Chun; Dhiraj A. Vattem; Yuan-Tong Lin; Kalidas Shetty

2005-01-01

86

Structure and antimicrobial activities of benzoyl phenyl-thiosemicarbazone-chitosans.  

PubMed

Previously, we had prepared acetyl phenyl-thiosemicarbazone derivatives of chitosan, and their antimicrobial activities were analyzed. The purpose of the present study was to further assess the relationship between the structure and antimicrobial activities of benzoyl phenyl-thiosemicarbazone-chitosan. Ten new benzoyl phenyl-thiosemicarbazone-chitosans were prepared and their structures were characterized by FT-IR and elemental analysis. The antimicrobial experiment against four species of bacteria and four crop-threatening pathogenic fungi were conducted based on the derivatives of chitosan with different molecular weight at different concentrations. The results indicated that the antimicrobial activities of benzoyl phenyl-thiosemicarbazone derivatives are much better than that of pure CS. The value of the minimum inhibition concentration (MIC) and the minimum bactericidal concentration (MBC) of the derivatives against Escherichia coli was 7.03 and 225 ?g mL(-1) respectively. All of the derivatives had significant inhibiting effect on the investigated fungi in the concentration of 50-500 ?g mL(-1), and the maximum inhibitory index was 94.74%. These results indicate that the derivatives have potential ability used as antibacterial reagent in agricultural field. PMID:22266384

Zhong, Zhimei; Aotegen, Bayaer; Xu, Hui; Zhao, Shuang

2012-01-14

87

Antimicrobial activity and synergism of some substituted flavonoids  

Microsoft Academic Search

Natural and synthetic substituted chalcones, flavones and flavanones were tested for antibacterial activity. In order to determine\\u000a synergism, new combinations of substituted flavonoids against Staphylococcus aureus, Escherichia coli and Enterobacter aerogenes were assayed. The results allow us to establish relationships between antimicrobial effect of the compounds and membrane\\u000a structures of these microorganisms. When flavonoid combinations were employed a stronger effect

M. A. Alvarez; N. B. Debattista; N. B. Pappano

2008-01-01

88

Antioxidant and antimicrobial activities of native Rosa sp. from British Columbia, Canada.  

PubMed

Indigenous traditional knowledge and western science have revealed the potential for significant nutritional and therapeutic benefits among natural antioxidants. We investigated antioxidant and antimicrobial activity of rose hip extracts (Rosa nutkana, Rosa pisocarpa and Rosa woodsii) from wild British Columbia populations using liposome oxidation and disc diffusion assays. All extracts exhibited strong antioxidant activity. R. nutkana pericarp extracts contained high phenolic concentrations and showed greater antioxidant and antimicrobial activity than seed extracts. R. woodsii seed extracts had a higher phenolic concentration and greater antioxidant activity than pericarp extracts. Antioxidant activity was correlated with antimicrobial activity, and both extracts showed antimicrobial activity against yeast and Gram-positive bacteria. Our study is the first to demonstrate the antioxidant and antimicrobial properties of wild British Columbia roses. The effectiveness of selected species compared with standards demonstrates the significance of this natural resource to the continued health of human populations, and the need for conservation practices. PMID:17514536

Yi, Ocksook; Jovel, Eduardo M; Towers, G H Neil; Wahbe, Tanya R; Cho, Dongwuk

2007-05-01

89

Molecular design, structures, and activity of antimicrobial Peptide-mimetic polymers.  

PubMed

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; Kuroda, Kenichi

2013-07-05

90

Antimicrobial activity of marine sponge Clathria indica (Dendy, 1889).  

PubMed

Sponges are sessile filter feeders that have developed efficient defense mechanisms against foreign invaders such as viruses, bacteria or eukaryotic organisms. Antimicrobial peptides are known as major components of the innate immune defense system in marine invertebrates. The aim of the present work was to study the antimicrobial properties of the Indian sponge Clathria indica with special reference to the identification of antimicrobial peptides. Crude methanolic extract and its chloroform, n-butanol and aqueous fractions were tested against 16 human pathogens which include eleven bacteria with four of them being multidrug resistant and five pathogenic fungi. All fractions showed effective antibacterial activity against common and multidrug-resistant Salmonella typhi and antifungal activity against C. albicans and C. neoformans. However, they were ineffective against Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes and Staphylococcus aureus. Chloroform fraction being the most potent among the fractions tested on chemical investigation was indicative of the presence of peptides as evidenced by ninhydrin positive spots on TLC and presence of peptide bonds by NMR. Its ESI-MS showed presence of several peptides in the range of m/z 850 to 980. Structure of three peptides has been tentatively assigned by ESI-MS/MS or tandem mass analysis, on the basis of the amino acid sequence established. The results clearly show that the sponge C. indica represent an interesting source of marine invertebrates-derived antimicrobial peptides in the development of new strategies to treat various infectious diseases. PMID:22096990

Ravichandran, S; Wahidullah, S; D'Souza, L; Anbuchezhian, R M

91

Screening of some Siberian medicinal plants for antimicrobial activity  

Microsoft Academic Search

The antimicrobial activity of crude ethanolic extracts of 16 Siberian medicinal plants was tested against five species of microorganisms: Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Of the 16 plants tested, 12 showed antimicrobial activity against one or more species of microorganisms. The most active antimicrobial plants were Bergenia crassifolia,Chelidonium majus,Rhaponticum carthamoides,Sanguisorba officinalis, and Tussilago farfara.

L. Kokoska; Z. Polesny; V. Rada; A. Nepovim; T. Vanek

2002-01-01

92

Comparative antimicrobial activities of Emblica officinalis and Ocimum sanctum.  

PubMed

The aqueous and successive extracts of the fruit pulp of Emblica officinalis and fresh leaves and stems of Ocimum sanctum were prepared and evaluated for antimicrobial activity. The successive extracts such as petroleum ether,chloroform, ethyl acetate and methanol were prepared by successive solvent extraction method and aqueous extract by maceration process and screened for antimicrobial activity against gram positive bacteria Staphylococcus aureus, gram negative bacteria E.coli and fungal strains of Candida species by using agar cup plate method. The extracts showed different degree of activity against pathogenic microbes. The results obtained were compared with standard drugs Amoxicillin (10?g) and Amphotericin B(10?g). The methanolic extract of Emblica officinalis was found to be more effective than the leaf and stem extracts of Ocimum sanctum in inhibiting all the microbial strains. PMID:22557261

Vijayalakshmi, S; Arunkumar, V; Anju, D; Gunasundari, P; Moorthy, P; Chandrasekharan, A K

2007-10-01

93

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

94

Antimicrobial activity of Curcuma zedoaria and Curcuma malabarica tubers  

Microsoft Academic Search

The antimicrobial activity of extracts of Curcuma zedoaria and Curcuma malabarica tubers was tested against six bacterial and two fungal strains using the agar well diffusion and broth dilution methods. Petroleum ether, hexane, chloroform, acetone and ethanol extracts exhibited antibacterial as well as antifungal activity. Acetone and hexane extracts of both tubers showed comparable antimicrobial activity as indicated by minimum

B. Wilson; G. Abraham; V. S. Manju; M. Mathew; B. Vimala; S. Sundaresan; B. Nambisan

2005-01-01

95

Quaternized Chitosan as an Antimicrobial Agent: Antimicrobial Activity, Mechanism of Action and Biomedical Applications in Orthopedics  

PubMed Central

Chitosan (CS) is a linear polysaccharide with good biodegradability, biocompatibility and antimicrobial activity, which makes it potentially useful for biomedical applications, including an antimicrobial agent either alone or blended with other polymers. However, the poor solubility of CS in most solvents at neutral or high pH substantially limits its use. Quaternary ammonium CS, which was prepared by introducing a quaternary ammonium group on a dissociative hydroxyl group or amino group of the CS, exhibited improved water solubility and stronger antibacterial activity relative to CS over an entire range of pH values; thus, this quaternary modification increases the potential biomedical applications of CS in the field of anti-infection. This review discusses the current findings on the antimicrobial properties of quaternized CS synthesized using different methods and the mechanisms of its antimicrobial actions. The potential antimicrobial applications in the orthopedic field and perspectives regarding future studies in this field are also considered.

Tan, Honglue; Ma, Rui; Lin, Chucheng; Liu, Ziwei; Tang, Tingting

2013-01-01

96

[Antimicrobial activities of ceftriaxone against fresh, clinically isolated strains].  

PubMed

In order to evaluate antimicrobial activity of ceftriaxone (CTRX), minimum inhibitory concentrations (MICs) of CTRX and control drugs were determined against clinically isolated strains including those from purulent meningitis and liver and biliary tract infections in 1995. The results are summarized as follows; 1. MIC90 of CTRX was 0.05 micrograms/ml against benzylpenicillin (PCG)-insensitive Streptococcus pneumoniae or PCG-resistant S. pneumoniae and it was < or = 0.025 micrograms/ml against beta-lactamase producing strains of Haemophilus influenzae. Antimicrobial activities of CTRX against these strains were stronger than control drugs. 2. MIC distribution of CTRX was in a lower concentration range than those of ceftazidime and flomoxef against extend broad-spectrum beta-lactamase (EBLA)-producing Escherichia coli and Klebsiella pneumoniae subsp. pneumoniae. 3. These results suggested that CTRX will be effective against community-acquired pneumonia, purulent meningitis and liver & biliary tract infections. PMID:8851307

Suzuki, Y; Koguchi, M; Tanaka, S; Fukayama, S; Ishihara, R; Deguchi, K; Oda, S; Nakane, Y; Fukumoto, T

1996-01-01

97

Antiendotoxin activity of cationic peptide antimicrobial agents.  

PubMed Central

The endotoxin from gram-negative bacteria consists of a molecule lipopolysaccharide (LPS) which can be shed by bacteria during antimicrobial therapy. A resulting syndrome, endotoxic shock, is a leading cause of death in the developed world. Thus, there is great interest in the development of antimicrobial agents which can reverse rather than promote sepsis, especially given the recent disappointing clinical performance of antiendotoxin therapies. We describe here two small cationic peptides, MBI-27 and MBI-28, which have both antiendotoxic and antibacterial activities in vitro and in vivo in animal models. We had previously demonstrated that these peptides bind to LPS with an affinity equivalent to that of polymyxin B. Consistent with this, the peptides blocked the ability of LPS and intact cells to induce the endotoxic shock mediator, tumor necrosis factor (TNF), upon incubation with the RAW 264.7 murine macrophage cell line. MBI-28 was equivalent to polymyxin B in its ability to block LPS induction of TNF by this cell line, even when added 60 min after the TNF stimulus. Furthermore, MBI-28 offered significant protection in a galactosamine-sensitized mouse model of lethal endotoxic shock. This protection correlated with the ability of MBI-28 to reduce LPS-induced circulating TNF by nearly 90% in this mouse model. Both MBI-27 and MBI-28 demonstrated antibacterial activity against gram-negative bacteria in vitro and in vivo against Pseudomonas aeruginosa infections in neutropenic mice.

Gough, M; Hancock, R E; Kelly, N M

1996-01-01

98

Antimicrobial activity of grapefruit seed and pulp ethanolic extract.  

PubMed

Antibacterial and antifungal activity of ethanolic extract of grapefruit (Citrus paradisi Macf., Rutaceae) seed and pulp was examined against 20 bacterial and 10 yeast strains. The level of antimicrobial effects was established using an in vitro agar assay and standard broth dilution susceptibility test. The contents of 3.92% of total polyphenols and 0.11% of flavonoids were determined spectrometrically in crude ethanolic extract. The presence of flavanones naringin and hesperidin in the extract was confirmed by TLC analysis. Ethanolic extract exibited the strongest antimicrobial effect against Salmonella enteritidis (MIC 2.06%, m/V). Other tested bacteria and yeasts were sensitive to extract concentrations ranging from 4.13% to 16.50% (m/V). PMID:15610620

Cvetni?, Zdenka; Vladimir-Knezevi?, Sanda

2004-09-01

99

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

2006-05-30

100

ANTIMICROBIAL ACTIVITY OF ALLICIN AGAINST HONEY BEE PATHOGENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Allicin is the chief anti-microbial compound produced in garlic. It has been extensively studied for activities against human and food-born pathogens. In this study, the antimicrobial activity of allicin (Allisure (TM) Liquid) was tested against a number of bacterial and fungal pathogens (Paenibac...

101

The antimicrobial activity of liposomal lauric acids against Propionibacterium acnes  

Microsoft Academic Search

This study evaluated the antimicrobial activity of lauric acid (LA) and its liposomal derivatives against Propionibacterium acnes (P. acnes), the bacterium that promotes inflammatory acne. First, the antimicrobial study of three free fatty acids (lauric acid, palmitic acid and oleic acid) demonstrated that LA gives the strongest bactericidal activity against P. acnes. However, a setback of using LA as a

Darren Yang; Dissaya Pornpattananangkul; Teruaki Nakatsuji; Michael Chan; Dennis Carson; Chun-Ming Huang; Liangfang Zhang

2009-01-01

102

Antimicrobial activity of Citrox® bioflavonoid preparations against oral microorganisms  

Microsoft Academic Search

Background Citrox® is a formulation of soluble bioflavonoids obtained from citrus fruits. The non-toxic and antimicrobial properties of natural bioflavonoids are well documented, and consequently there has been interest in the therapeutic application of these substances.Objective To determine the antimicrobial activity of two Citrox® formulations (BC30 and MDC30) with different bioflavonoid combinations against a range of oral microorganisms.Methods The antimicrobial

M. A. O. Lewis; M. J. Wilson; D. W. Williams; S. J. Hooper

2011-01-01

103

Antimicrobial activity and enterococcus faecalis biofilm formation on chlorhexidine varnishes  

PubMed Central

Objective: To evaluate, in vitro, the antimicrobial activity and biofilm formation of three chlorhexidine varnishes in four Enterococcus faecalis strains: E. faecalis ATCC 29212, E. faecalis EF-D1 (from failed endodontic treatment), E. faecalis 072 (cheese) and E. faecalis U-1765 (nosocomial infection), and one Enterococcus durans strain (failed endodontic treatment). Study Design: The direct contact test was used to study the antimicrobial activity. Bacterial suspensions were exposed for one hour to EC40, Cervitec (CE) and Cervitec Plus (CEP) varnishes. “Eradication” was defined as 100% bacterial kill. The formation of enterococci biofilms was tested on the surface of the varnishes after 24 hours of incubation and expressed as percentage of biofilm reduction. Results: EC40 eradicated all strains except E. faecalis ATCC 29212, where 98.78% kill was achieved. CE and CEP showed antimicrobial activity against all the strains, but most clearly against E. durans and E. faecalis 072. EC40 completely inhibited the formation of biofilm of E. faecalis ATCC 29212, E. faecalis 072 and E. durans. CE and CEP led to over 92% of biofilm reduction, except in the case of E. faecalis U-1765 on CEP (76.42%). Conclusion: The three varnishes studied were seen to be effective in killing the tested strains of enterococci and in inhibiting the formation of biofilm, the best results being observed with EC40. Key words:Biofilm, chlorhexidine varnish, direct contact test, Enterococcus durans, Enterococcus faecalis, intracanal medication.

Ferrer-Luque, Carmen M.; Gonzalez-Rodriguez, Maria P.; Navarro-Escobar, Esther; de Freitas, Marcia F.A.; Baca, Pilar

2012-01-01

104

Prediction of antimicrobial activity of synthetic peptides by a decision tree model.  

PubMed

Antimicrobial resistance is a persistent problem in the public health sphere. However, recent attempts to find effective substitutes to combat infections have been directed at identifying natural antimicrobial peptides in order to circumvent resistance to commercial antibiotics. This study describes the development of synthetic peptides with antimicrobial activity, created in silico by site-directed mutation modeling using wild-type peptides as scaffolds for these mutations. Fragments of antimicrobial peptides were used for modeling with molecular modeling computational tools. To analyze these peptides, a decision tree model, which indicated the action range of peptides on the types of microorganisms on which they can exercise biological activity, was created. The decision tree model was processed using physicochemistry properties from known antimicrobial peptides available at the Antimicrobial Peptide Database (APD). The two most promising peptides were synthesized, and antimicrobial assays showed inhibitory activity against Gram-positive and Gram-negative bacteria. Colossomin C and colossomin D were the most inhibitory peptides at 5 ?g/ml against Staphylococcus aureus and Escherichia coli. The methods described in this work and the results obtained are useful for the identification and development of new compounds with antimicrobial activity through the use of computational tools. PMID:23455341

Lira, Felipe; Perez, Pedro S; Baranauskas, José A; Nozawa, Sérgio R

2013-03-01

105

Synthesis, antimicrobial and anticancer activity of new thiosemicarbazone derivatives.  

PubMed

Thiosemicarbazones of p-aminobenzoic acid (PABA) were synthesized and tested for their antimicrobial and anticancer activity. Hydroxamate derivatives 4a-4l were found to have better antimicrobial and anticancer activity than their acid counterpart. Compound 4d was found to have good antimicrobial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Vibrio cholerae, and Bacillus subtilis with IC(50) value of about 1 µM. Compound 4f showed potent antifungal activity against Candida albicans (IC(50) ?= 1.29 µM) and compound 4h showed potent anticancer activity (IC(50) ?= 0.07 µM). PMID:21290424

Kulandaivelu, Umasankar; Padmini, Valisakka Gari; Suneetha, Kyatham; Shireesha, Boyapati; Vidyasagar, Jannu Vincent; Rao, Tadikonda Rama; K N, Jayaveera; Basu, Arijit; Jayaprakash, Venkatesan

2010-11-25

106

Chemical properties and antioxidant and antimicrobial activities of Slovenian propolis.  

PubMed

The chemical composition as well as the antioxidant and antimicrobial activities of two EtOH extracts of propolis (PEEs) from Slovenia were determined. EtOH was used as extracting solvent at 70 and 96%, providing the extracts PEE70 and PEE96, respectively. The extraction with 70% EtOH was more efficient than that with 96% EtOH, as the PEE70 was richer in total phenolic compounds than the PEE96. The Slovenian propolis was characterized by different phenolic acids and flavonoids. The PEE96 was slightly richer in three specific compounds, i.e., caffeic acid, ferulic acid, and luteolin, while all other substances detected showed higher contents in the PEE70. The PEE70 showed a stronger reducing power and ability to scavenge free radicals and metal ions than the PEE96. Both PEEs were in the main more effective against Gram-positive bacteria than against fungi and Gram-negative bacteria like Salmonella and Escherichia coli, with the exception of Campylobacter. The PEE96 decreased the intracellular oxidation in Saccharomyces cerevisiae in a dose-dependent manner. The antimicrobial activities and antioxidant properties were related to the total phenolic contents. The two PEEs have the potential for use as natural antimicrobial and antioxidant additives in foods. PMID:22899615

Mavri, Ana; Abramovi?, Helena; Polak, Tomaž; Bertoncelj, Jasna; Jamnik, Polona; Smole Možina, Sonja; Jeršek, Barbara

2012-08-01

107

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

2013-06-05

108

Antimicrobial Actions of the Nadph Phagocyte Oxidase and Inducible Nitric Oxide Synthase in Experimental Salmonellosis. I. Effects on Microbial Killing by Activated Peritoneal Macrophages in Vitro  

PubMed Central

The contribution of the NADPH phagocyte oxidase (phox) and inducible nitric oxide (NO) synthase (iNOS) to the antimicrobial activity of macrophages for Salmonella typhimurium was studied by using peritoneal phagocytes from C57BL/6, congenic gp91phox?/?, iNOS?/?, and doubly immunodeficient phox?/?iNOS?/? mice. The respiratory burst and NO radical (NO·) made distinct contributions to the anti-Salmonella activity of macrophages. NADPH oxidase–dependent killing is confined to the first few hours after phagocytosis, whereas iNOS contributes to both early and late phases of antibacterial activity. NO-derived species initially synergize with oxyradicals to kill S. typhimurium, and subsequently exert prolonged oxidase-independent bacteriostatic effects. Biochemical analyses show that early killing of Salmonella by macrophages coincides with an oxidative chemistry characterized by superoxide anion (O2·?), hydrogen peroxide (H2O2), and peroxynitrite (ONOO?) production. However, immunofluorescence microscopy and killing assays using the scavenger uric acid suggest that peroxynitrite is not responsible for macrophage killing of wild-type S. typhimurium. Rapid oxidative bacterial killing is followed by a sustained period of nitrosative chemistry that limits bacterial growth. Interferon ? appears to augment antibacterial activity predominantly by enhancing NO· production, although a small iNOS-independent effect was also observed. These findings demonstrate that macrophages kill Salmonella in a dynamic process that changes over time and requires the generation of both reactive oxidative and nitrosative species.

Vazquez-Torres, Andres; Jones-Carson, Jessica; Mastroeni, Pietro; Ischiropoulos, Harry; Fang, Ferric C.

2000-01-01

109

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

110

Self-aggregation and antimicrobial activity of imidazolium and pyridinium based ionic liquids in aqueous solution.  

PubMed

Two series of long-chain imidazolium and pyridinium based ionic liquids (1-alkyl-3-methylimidazolium and 1-alkylpyridinium bromides) were synthesised and the effect of the alkyl chain length and the nature of the cationic head group on micellization and antimicrobial activity of the ionic liquids (ILs) were investigated. Tensiometry, conductometry, spectrofluorimetry and PGSE-NMR were applied to study the self-aggregation of the amphiphilic ILs in aqueous solution. The ILs investigated displayed surface activity and the characteristic chain length dependence of the micellization process of surfactants. The antimicrobial activity was evaluated against Gram-negative and Gram-positive bacteria and fungi. ILs containing more than eight carbon atoms in the alkyl chain showed antimicrobial activity. Their efficiency as antimicrobial agents increased with the hydrophobicity of the amphiphilic cation being the C(14) homologous the most active compounds. PMID:21186035

Cornellas, Anna; Perez, Lourdes; Comelles, Francesc; Ribosa, Isabel; Manresa, Angeles; Garcia, M Teresa

2010-11-25

111

Enhanced antimicrobial activity of engineered human lysozyme.  

PubMed

Lysozymes contain a disproportionately large fraction of cationic residues, and are thereby attracted toward 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

2010-09-17

112

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.

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

113

Cationic Hydrophobic Peptides with Antimicrobial Activity  

PubMed Central

The MICs of cationic, hydrophobic peptides of the prototypic sequence KKAAAXAAAAAXAAWAAXAAAKKKK-amide (where X is one of the 20 commonly occurring amino acids) are in a low micromolar range for a panel of gram-negative and gram-positive bacteria, with no or low hemolytic activity against human and rabbit erythrocytes. The peptides are active only when the average segmental hydrophobicity of the 19-residue core is above an experimentally determined threshold value (where X is Phe, Trp, Leu, Ile, Met, Val, Cys, or Ala). Antimicrobial activity could be increased by using peptides that were truncated from the prototype length to 11 core residues, with X being Phe and with 6 Lys residues grouped at the N terminus. We propose a mechanism for the interaction between these peptides and bacterial membranes similar to the “carpet model,” wherein the Lys residues interact with the anionic phospholipid head groups in the bacterial membrane surface and the hydrophobic core portion of the peptide is then able to interact with the lipid bilayer, causing disruption of the bacterial membrane.

Stark, Margareta; Liu, Li-Ping; Deber, Charles M.

2002-01-01

114

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.

Hoskin, David W.; Ramamoorthy, Ayyalusamy

2008-01-01

115

Phytochemical properties and antimicrobial activities of combined effect of extracts of the leaves of Garcinia kola, Vernonia amygdalina and honey on some medically important microorganisms  

Microsoft Academic Search

Warm water extracts of the leaves of Garcinia kola and Vernonia amygdalina suspended in honey traditionally employed for the treatment of post circumcision wounds, fresh wounds and chronic skin ulcers was prepared and evaluated for its phytochemical properties and antimicrobial activities. The phytochemical analysis of the preparation revealed the presence of polyphenol, reducing sugars, tannins, glycoside, alkaloids, saponins, flavonoids and

C. I. Mboto; M. E. Eja; A. A Adegoke; G. D. Iwatt; B. E. Asikong; I. Takon; S. M. Udo; M. Akeh

116

Antimicrobial Actions of the NADPH Phagocyte Oxidase and Inducible Nitric Oxide Synthase in Experimental Salmonellosis. I. Effects on Microbial Killing by Activated Peritoneal Macrophages In Vitro  

Microsoft Academic Search

The contribution of the NADPH phagocyte oxidase (phox) and inducible nitric oxide (NO) synthase (iNOS) to the antimicrobial activity of macrophages for Salmonella typhimurium was studied by using peritoneal phagocytes from C57BL\\/6, congenic gp91 phox 2 \\/ 2 , iNOS 2 \\/ 2 , and doubly immunodeficient phox 2 \\/ 2 iNOS 2 \\/ 2 mice. The respiratory burst and

Andrés Vazquez-Torres; Jessica Jones-Carson; Pietro Mastroeni; Harry Ischiropoulos; Ferric C. Fang

117

Antimicrobial activity of saponin fractions of the leaves of Gymnema sylvestre and Eclipta prostrata  

Microsoft Academic Search

The antimicrobial activity of saponin fractions from the leaves of Gymnema sylvestre and Eclipta prostrata was evaluated against pathogenic bacteria and fungi in an in vitro condition. A series of concentrations of crude and pure\\u000a saponin fractions were tested for antimicrobial activity by zone of inhibition method. The pure saponin fractions were found\\u000a to be more effective against tested bacterial pathogens

Venkatesan Gopiesh khanna; Krishnan Kannabiran

2008-01-01

118

Evaluation of the antimicrobial activities of chlorhexidine gluconate, sodium hypochlorite and octenidine hydrochloride in vitro.  

PubMed

The objective of this study was to compare the antimicrobial activity of sodium hypochlorite (NaOCl), chlorhexidine gluconate (CHX) and octenidine hydrochloride (OCT) in different concentrations against endodontic pathogens in vitro. Agar diffusion procedure was used to determine the antimicrobial activity of the tested materials. Enterococcus faecalis, Candida albicans and the mixture of these were used for this study. In the agar diffusion test, 5.25% NaOCl exhibited better antimicrobial effect than the other concentrations of NaOCl for all strains. All concentrations of OCT were effective against C. albicans and E. faecalis. Some 0.2% CHX was ineffective on all microorganisms. Antibacterial effectiveness of all experimental solutions decreased on the mixture of all strains. Decreasing concentrations of NaOCl resulted in significantly reduced antimicrobial effect. PMID:23551508

Tirali, Resmiye E; Bodur, Haluk; Sipahi, Bilge; Sungurtekin, Elif

2010-10-24

119

In vitro hypoglycemic and antimicrobial activities of Senecio leucanthemifolius Poiret  

Microsoft Academic Search

This study reports on the ?-amylase inhibitory and antimicrobial activities of Senecio leucanthemifolius Poiret. Extracts of S. leucanthemifolius were tested for their antimicrobial and antifungal activities against seven different pathogenic microorganisms using the microdilution technique. The ethyl acetate extract exhibited a strong antibiotic activity against Staphylococcus aureus with a MIC value of 31.25?µg?mL, while the n-hexane extract showed a significant

R. Tundis; M. R. Loizzo; G. A. Statti; P. J. Houghton; A. Miljkovic-Brake; F. Menichini

2007-01-01

120

Antimicrobial activity of silicone rubber used in hydrocephalus shunts, after impregnation with antimicrobial substances.  

PubMed Central

Colonisation of cerebrospinal fluid shunts by coagulate-negative staphylococci (Staphylococcus albus) is a serious problem. Because of its possible role in prevention of the condition, the antimicrobial activity of silicone rubber after impregnation with antimicrobial drugs was studied. The method of impregnation used and test methods were found to be important. Formaldehyde-urea condensates gave no activity. Gentamicin sulphate gave activity which was short-lived. Sodium and diethanolamine fusidates and clindamycin hydrochloride gave prolonged activity. A method of impregnation was developed which could be applied to commercially available shunts before use.

Bayston, R; Milner, R D

1981-01-01

121

Effect of preliminary load of macrophages with silicium dioxide on phagocytosis of BCG strain micobacteria by macrophages and antimicrobial activity.  

PubMed

We studied the effect of preliminary loading of peritoneal macrophages with silicium dioxide on in vitro viability, phagocytosis of BCG strain mycobacteria, and the capability to destroy the phagocytosed mycobacterium tuberculosis. It was shown that preliminary loading of macrophages with silicium dioxide did not reduce their viability and stimulated phagocytosis of BCG strain mycobacteria, but reduced their antibacterial activity. PMID:21234459

Arkhipov, S A; Shkurupy, V A; Bugrimova, Yu S

2010-10-01

122

Oxygen limitation favors the production of protein with antimicrobial activity in Pseudoalteromonas sp  

PubMed Central

This study examined the effect of dissolved oxygen concentration on the production of biomass and metabolites with antimicrobial activity of Pseudoalteromonas sp cultured at 0, 150, 250, or 450 revolutions per minute (rev. min-1). Dissolved oxygen (D.O) was monitored during the fermentation process, biomass was quantified by dry weight, and antimicrobial activity was assessed using the disk diffusion method. The bacterium Pseudoalteromonas reached similar concentration of biomass under all experimental agitation conditions, whereas antimicrobial activity was detected at 0 and 150 rev. min-1 registering 0% and 12% of D.O respectively corresponding to microaerophilic conditions. Antibiotic activity was severely diminished when D.O was above 20% of saturation; this corresponded to 250 or 450 rev. min-1. SDS-PAGE electrophoresis revealed a protein with a molecular weight of approximately 80 kilodaltons (kDa) with antimicrobial activity. Pseudoalteromonas is capable of growing under oxic and microaerophilic conditions but the metabolites with antimicrobial activity are induced under microaerophilic conditions. The current opinion is that Pseudoalteromonas are aerobic organisms; we provide additional information on the amount of dissolved oxygen during the fermentation process and its effect on antimicrobial activity.

Lopez, Ruth; Monteon, Victor; Chan, Ernesto; Montejo, Rubi; Chan, Manuel

2012-01-01

123

Antimicrobial activities of three species of family mimosaceae.  

PubMed

The antimicrobial activities of crude methanolic extract of leaves of Acacia nilotica L., Albizia lebbeck L. and Mimosa himalayana Gamble belonging to family mimosaceae were investigated in this research work. Antibacterial activity was studied by agar well diffusion method against one gram-positive Bacillus subtilis and three gram-negative Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumonia. Crude extract of all plants showed best activity against gram-negative bacterial strains while minor inhibition zones were found against gram positive bacterial strains. Antifungal activity of crude plant extract was screened by agar tube dilution method against Aspergillus nigar and Aspergillus flavus. These results showed that these plants extracts have potential against bacterias, while against fungi their activity is not much effective. PMID:22186331

Mahmood, Adeel; Mahmood, Aqeel; Qureshi, Rizwana Aleem

2012-01-01

124

Effect of Antimicrobial Edible Additives on Cassava Starch Biobased Films Characterization  

Microsoft Academic Search

Antimicrobial films appear in response of the searching for more competitive and aggregated value packaging. With the aim of developing packages that, besides active are also biodegradable, this work proposes to study the effect of antimicrobial additives (honey, cinnamon powder, clove powder, orange essential oil, pepper and coffee powder) on the characterization of cassava starch biobased films. The biofilms were

Ana C. L. Attarian; Viviane Kechichian; Pricila Veiga-Santos; Cynthia Ditchfield; Carmen C. Tadini

125

Synthesis, Isolation of Phenazine Derivatives and Their Antimicrobial Activities  

Microsoft Academic Search

Antimicrobial activity of natural phenazine-1-carboxylic acid (PCA) from Pseudomonas aeruginosa TISTR 781 and synthetic phenazine-5,10- dioxide (PDO), prepared by oxidation of the phenazine, were evaluated by in vitro disc diffusion and minimal inhibitory concentration (MIC) methods. The results indicated that both phenazine derivatives differed clearly in their antimicrobial activity. PCA showed better efficacy against growth of Acidovorax avenae subsp. citrulli,

Aunchalee NANSATHIT; Sukanya APIPATTARAKUL; Chanokporn PHAOSIRI; Paweena PONGDONTRI; Saksit CHANTHAI; Chalerm RUANGVIRIYACHAI

2009-01-01

126

Synthetic analogs of anoplin show improved antimicrobial activities.  

PubMed

We present the antimicrobial and hemolytic activities of the decapeptide anoplin and 19 analogs thereof tested against methicillin-resistant Staphylococcus aureus ATCC 33591 (MRSA), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), vancomycin-resistant Enterococcus faecium (ATCC 700221) (VRE), and Candida albicans (ATCC 200955). The anoplin analogs contain substitutions in amino acid positions 2, 3, 5, 6, 8, 9, and 10. We use these peptides to study the effect of altering the charge and hydrophobicity of anoplin on activity against red blood cells and microorganisms. We find that increasing the charge and/or hydrophobicity improves antimicrobial activity and increases hemolytic activity. For each strain tested, we identify at least six anoplin analogs with an improved therapeutic index compared with anoplin, the only exception being Enterococcus faecium, against which only few compounds are more specific than anoplin. Both 2Nal(6) and Cha(6) show improved therapeutic index against all strains tested. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd. PMID:24019229

Munk, Jens K; Uggerhøj, Lars Erik; Poulsen, Tanja J; Frimodt-Møller, Niels; Wimmer, Reinhard; Nyberg, Nils T; Hansen, Paul R

2013-09-09

127

Antimicrobial activity of Mitracarpus scaber extract and isolated constituents.  

PubMed

The antimicrobial activity of a methanol extract and isolated constituents of Mitracarpus scaber, a species used in folk medicine by West African native people, was evaluated against Staphylococcus aureus and Candida albicans strains. The mitracarpus methanol extract possesses both antibacterial and antimycotic activities (minimum inhibitory concentration-MIC 31.25 and 62.50 microg ml-, respectively). This extract was subsequently fractioned and monitored by bioassays leading to the isolation of seven compounds screened for antibacterial and antimycotic activities. Among these compounds, gallic acid and 3,4,5-trimethoxybenzoic acid inhibited the growth of Staph. aureus (MIC 3.90 and 0.97 microg ml-). 4-Methoxyacetophenone and 3,4,5-trimethoxyacetophenone effectively inhibited C. albicans (MIC 1.95 microg ml-). The other compounds (kaempferol-3-O-rutinoside, rutin and psoralen) which were also isolated showed low antibacterial and antimycotic activities (125-500 microg ml-). PMID:10736009

Bisignano, G; Sanogo, R; Marino, A; Aquino, R; D'Angelo, V; Germanò, M P; De Pasquale, R; Pizza, C

2000-02-01

128

Effectiveness of antimicrobial food packaging materials.  

PubMed

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 of such packaging materials is not meant to be a substitute for good sanitation practices, but it should enhance the safety of food as an additional hurdle for the growth of pathogenic and/or spoilage microorganisms. Studies have focused on establishing methods for coating low-density polyethylene film or barrier films with methyl cellulose as a carrier for nisin. These films have significantly reduced the presence of Listeria monocytogenes in solutions and in vacuum packaged hot dogs. Other research has focused on the use of chitosan to inhibit L. monocytogenes and chlorine dioxide sachets for the reduction of Salmonella on modified atmosphere-packaged fresh chicken breasts. Overall, antimicrobial packaging shows promise as an effective method for the inhibition of certain bacteria in foods, but barriers to their commercial implementation continue to exist. PMID:16227182

Cooksey, K

2005-10-01

129

Effective functionalization of multiwalled carbon nanotube with amphiphilic poly(propyleneimine) dendrimer carrying silver nanoparticles for better dispersability and antimicrobial activity.  

PubMed

Two multiwalled carbon nanotube hybrids have been prepared: (a) multiwalled carbon nanotubes (MWCNTs) functionalized with amphiphilic poly(propyleneimine) dendrimer (APPI), viz. MWCNTs-APPI, and (b) silver nanoparticles (AgNPs)-deposited multiwalled carbon nanotubes functionalized with an amphiphilic poly(propyleneimine) dendrimer (MWCNTs-APPI-AgNPs). The degree of covalent functionalization of APPI in MWCNTs and deposition of AgNPs in MWCNTs-APPI were examined by Fourier transform infrared spectroscopy, zeta potential, scanning and high-resolution transmission electron microscopy, energy-dispersive spectroscopy, thermogravimetric analysis, and Raman spectroscopy. The amount of APPI functionalized on MWCNTs determined by thermal gravimetric analysis was about 67% which enables an effective dispersability in aqueous and organic solvents without sonication and these solutions were stable for 6 months without undergoing aggregation of MWCNTs. The electronic properties of the hybrid materials were not altered drastically as verified by the Raman studies. The antimicrobial activities of MWCNTs-APPI and MWCNTs-APPI-AgNPs against three different bacteria, viz. Bacillus subtilis, Staphylococcus aureus, and Escheriachia coli illustrated excellent activity. PMID:21377164

Murugan, E; Vimala, G

2011-03-04

130

Study of the Soil Isolates for Antimicrobial Activity  

PubMed Central

During the process of screening for a potent antimicrobial compound, a new strain was isolated from the soil sample of Thalaikunda village in Ooty, Tamil Nadu. That organism was name as NK2. It was found to be antagonistic to both bacterial and fungal test organisms. Production of antibiotic was more in a newly formulated broth. Antibiotic production reached maximum at the end of the 70 h of fermentation by stirred flask culture. The antimicrobial compound was extracted in n-butanol, ethyl acetate and methanol. Antimicrobial compound, which was produced by the soil isolate NK2 did not showed cytotoxic activity on Vero cell lines.

Srividya, A. R.; Saritha, G. S.; Suresh, B.

2008-01-01

131

Peptidotriazoles with antimicrobial activity against bacterial and fungal plant pathogens.  

PubMed

We designed and prepared peptidotriazoles based on the antimicrobial peptide BP100 (LysLysLeuPheLysLysIleLeuLysTyrLeu-NH(2)) by introducing a triazole ring in the peptide backbone or onto the side chain of a selected residue. These compounds were screened for their in vitro growth inhibition of bacterial and fungal phytopathogens, and for their cytotoxic effects on eukaryotic cells and tobacco leaves. Their proteolytic susceptibility was also analyzed. The antibacterial activity and the hemolysis were influenced by the amino acid that was modified with the triazole as well as by the absence of presence of a substituent in this heterocyclic ring. We identified sequences active against the bacteria Xanthomonas axonopodis pv. vesicatoria, Erwinia amylovora, Pseudomonas syringae pv. syringae (MIC of 1.6-12.5 ?M), and against the fungi Fusarium oxysporum (MIC<6.2-12.5 ?M) with low hemolytic activity (0-23% at 50 ?M), high stability to protease digestion and no phytotoxicity. These peptidotriazoles constitute good candidates to design new antimicrobial agents. PMID:22198367

Güell, Imma; Micaló, Lluís; Cano, Laura; Badosa, Esther; Ferre, Rafael; Montesinos, Emilio; Bardají, Eduard; Feliu, Lidia; Planas, Marta

2011-12-16

132

Factors affecting the antimicrobial activity of ovine-derived cathelicidins against E. coli 0157:H7  

Microsoft Academic Search

Antimicrobial peptides extracted from ovine neutrophils have potential to be high-value by-products of the lamb industry as, for example, a biopreservative for chilled lamb products. This work was carried out to determine the conditions in which ovine peptides are most effective and to assist in product development. The activities of three synthetic ovine-derived antimicrobial peptides tested were not significantly affected

Rachel C. Anderson; Pak-Lam Yu

2005-01-01

133

In vitro antimicrobial activity of four Ficus carica latex fractions against resistant human pathogens (antimicrobial activity of Ficus carica latex).  

PubMed

Methanolic, hexanoïc, chloroformic and ethyl acetate extracts of Ficus carica latex were investigated for their in vitro antimicrobial proprieties against five bacteria species and seven strains of fungi. The green fruit latex was collected from Chott Mariam Souse, Middle East coast of Tunisia. The antimicrobial activity of the extracts was evaluated and based respectively on the inhibition zone using the disc-diffusion assay, minimal inhibition concentration (MIC) for bacterial testing and the method by calculating inhibition percentage (I%) for fungi-inhibiting activities. The methanolic extract had no effect against bacteria except for Proteus mirabilis while the ethyl acetate extract had inhibition effect on the multiplication of five bacteria species (Enterococcus fecalis, Citobacter freundei, Pseudomonas aeruginosa, Echerchia coli and Proteus mirabilis). For the opportunist pathogenic yeasts, ethyl acetate and chlorophormic fractions showed a very strong inhibition (100%); methanolic fraction had a total inhibition against Candida albicans (100%) at a concentration of 500 microg/ml and a negative effect against Cryptococcus neoformans. Microsporum canis was strongly inhibited with methanolic extract (75%) and totally with ethyl acetate extract at a concentration of 750 microg/ml. Hexanoïc extract showed medium results. PMID:20067867

Aref, Houda Lazreg; Salah, Karima Bel Hadj; Chaumont, Jean Pierre; Fekih, Abdelwaheb; Aouni, Mahjoub; Said, Khaled

2010-01-01

134

In vitro antimicrobial activity of pistachio (Pistacia vera L.) polyphenols.  

PubMed

We investigated the antimicrobial properties of polyphenol-rich fractions derived from raw shelled and roasted salted pistachios. American Type Culture Collection (ATCC), food and clinical isolates, of Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Pseudomonas mirabilis), Gram-positive bacteria (Listeria monocytogenes, Enterococcus hirae, Enterococcus faecium, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus), the yeasts Candida albicans and Candida parapsilosis and the fungus Aspergillus niger were used. Pistachio extracts were active against Gram-positive bacteria with a bactericidal effect observed against L. monocytogenes (ATCC strains and food isolates), S. aureus and MRSA clinical isolates. Extracts from raw shelled pistachios were more active than those from roasted salted pistachios. The bactericidal activity of pistachio extracts could be used to help control the growth of some microorganisms in foods to improve safety and may find application as a topical treatment for S. aureus. PMID:23350629

Bisignano, Carlo; Filocamo, Angela; Faulks, Richard M; Mandalari, Giuseppina

2013-02-11

135

Antimicrobial activity of Fabaceae species used in Yucatan traditional medicine  

Microsoft Academic Search

The methanol and water extracts of six Fabaceae species, traditionally used in Mayan medicine for the treatment of diarrhoea and eye infections, were phytochemically screened and tested for in vitro antimicrobial activity. Four species showed activity against Gram positive bacteria, five exhibited some activity against Candidaalbicans, two exhibited activity against Aspergillusniger and only one, Mimosapigra, inhibited growth of Pseudomonasaeruginosa. None

M Rosado-Vallado; W Brito-Loeza; G. J Mena-Rejón; E Quintero-Marmol; J. S Flores-Guido

2000-01-01

136

Single-walled carbon nanotubes exhibit strong antimicrobial activity.  

PubMed

We provide the first direct evidence that highly purified single-walled carbon nanotubes (SWNTs) exhibit strong antimicrobial activity. By using a pristine SWNT with a narrow diameter distribution, we demonstrate that cell membrane damage resulting from direct contact with SWNT aggregates is the likely mechanism leading to bacterial cell death. This finding may be useful in the application of SWNTs as building blocks for antimicrobial materials. PMID:17658863

Kang, Seoktae; Pinault, Mathieu; Pfefferle, Lisa D; Elimelech, Menachem

2007-07-21

137

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.

2012-01-01

138

Antimicrobial activity of catechol and pyrogallol as allelochemicals.  

PubMed

Catechol and pyrogallol are allelochemicals which belong to phenolic compounds synthesized in plants. Their antimicrobial activities were investigated on three bacteria (Pseudomonas putida, Pseudomonas pyocyanea, Corynebacterium xerosis) and two fungi (Fusarium oxysporum, Penicillium italicum) phytopathogenic species as test organisms using the disc diffusion method. Both catechol and pyrogallol were found to have antibacterial effects on all the bacteria used in the study at 5 and 10 mM concentrations. Catechol has also been found to have an antifungal effect on the fungi used in the study, whereas no antifungal effects of pyrogallol were observed. The most sensitive species among the bacteria was P. putida which was inhibited by the allelochemicals even at 1 mM concentration. PMID:17137106

Kocaçali?kan, Ismail; Talan, Ismet; Terzi, Irfan

139

Antimicrobial effects of quaternary phosphonium salt intercalated clay minerals on Escherichia coli and Staphylococci aureus.  

PubMed

The aim of this research was to determine the antimicrobial properties and influence factors of four clay minerals intercalated by quaternary phosphonium salt (tetradecyl tributyl phosphonium bromide, TDTB) on antimicrobial effects. Escherichia coli (E. coli) and Staphylococci aureus (S. aureus) were chosen for Minimal Inhibitory Concentration (MIC) tests to evaluate the antimicrobial activities of organ-clay minerals. The properties of organ-clay minerals were analyzed by FTIR, XRD, TEM, Z-Average and Zeta potential, and the releasing amount of TDTB into the broth was measured by ICP. The results showed that montmorillonites-TDTB inhibited the growth of E. coli and S. aureus, and the MICs were 200 ± 20 and 80 ± 15 mg/L, respectively. The amount of TDTB released into the broth was 3.42 ± 0.71%. According to the properties of organ-clay mineral, it was indicated that the antimicrobial activities of organ-clay mineral were the synergic effect of the releasing amount of TDTB, Zeta potential, particle size and distribution. The organ-clay mineral with the larger releasing amount of TDTB, the higher Zeta potential, the same particle size with bacterial size and the narrower size distribution exhibited better antimicrobial activity. The present study demonstrated the properties of organ-clay minerals effected their antimicrobial activities, provided theoretically guidance to promote the antimicrobial activity of clay minerals. PMID:21536418

Wu, Ting; Xie, A-Gui; Tan, Shao-Zao; Cai, Xiang

2011-04-14

140

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

141

Synthesis and antimicrobial activities of new pyridinium and benzimidazolium chlorides  

Microsoft Academic Search

A novel class of pyridinium and benzimidazolium chloride has been obtained in high yield. The antimicrobial activities of three homologous series of pyridinium and benzimidazolium chlorides against cocci, rods, fungi and bacillus have been measured. The antimicrobial activities of N,N?-bis[3-(1-alkoxymethyl)pyridinium chloride]methylenediamines, 1-undecyloxymethyl-3-(1-benzimidazolmethylamino)pyridinium, 1-undecyloxymethyl- and 1-dodecyloxymethyl-3-[1(benzotriazol-1-yl)methylamino]pyridinium chlorides exhibited strong activity and wide antibacterial spectra similar to the activity of benzalkonium chloride.

Juliusz Pernak; Jarostaw Rogo?a; Ilona Mirska

2001-01-01

142

Antimicrobial activity investigation on Wuyiencin fractions of different polarity.  

PubMed

The aim of this study was to evaluate the antimicrobial activity of Wuyiencin fractions with different polarities against six indicator microorganisms: Rhodotorula rubra, Bacillus subtilis, Bacillus megaterium, Escherichia coli, Cladosporium fulvum and Staphylococcus aureus. The fermentation broth of Wuyiencin was submitted to AB-8 macroporous adsorptive resin and fractionated with solvents of different polarity. The fraction eluted with water had remarkably antimicrobial activity against all the microorganisms investigated except for C. fulvum and S. aureus (MIC active components. The fraction eluted with methanol showed potential antimicrobial activity against all the test microorganisms except for R.rubra, with MIC values of 0.5 and 2 mg/mL. In conclusion, fractions eluted with water and methanol, respectively, represent the main active-part of Wuyiencin, and could be emphasized for agricultural applications in the future. PMID:20657470

Cui, Zengjie; Zhang, Kecheng; She, Gaimei; Lin, Yinni; Sun, Lei; Cheng, Yan; Tan, Beibei

2010-04-29

143

Cytotoxic and antimicrobial activity of selected Cameroonian edible plants  

PubMed Central

Background In Cameroon, the use of edible plants is an integral part of dietary behavior. However, evidence of the antimicrobial as well as the cytotoxic effects of many of them has not been investigated. In the present study, aqueous and methanol extracts from barks, seeds, leaves and roots of three Cameroonian edible plants namely Garcina lucida, Fagara heitzii and Hymenocardia lyrata were evaluated for their cytotoxic and antimicrobial activities. Methods Antibacterial and antifungal activities were assessed by the broth micro-dilution method meanwhile the cytotoxicity was performed using sulphorhodamine B assay (SRB) against the human leukemia THP-1, the alveolar epithelial A549, prostate cancer PC-3, breast adenocarcinoma MCF-7 and cervical cancer HeLa cell lines. Results The minimum inhibitory concentration (MIC) values of the seven tested extracts ranged from 62.5 ?g/ml to 1000 ?g/ml. The methanol (MeOH) extract from the roots of H. lyrata showed the highest antibacterial activity against Gram-positive bacteria S. aureus and S. epidermitis. The best antifungal activity was obtained with the MeOH extract from the leaves of G. lucida against C. tropicalis (MIC value of 62.5 ?g/ml). The in vitro antiproliferative activity revealed that, extract from the bark of F. heitzii and extract from H. lyrata roots had significant cytotoxic activity on THP-1 (IC50 8.4 ?g/ml) and PC-3 (IC50 9.5 ?g/ml) respectively. Conclusion Our findings suggest that Cameroonian spices herein studied could be potentially useful for the development of therapeutic agents against bacterial infections as well as for prostate and leukemia cancer.

2013-01-01

144

aug-MIA-QSAR modeling of antimicrobial activities and design of multi-target anilide derivatives.  

PubMed

The antibacterial activity against Bacillus subtilis, Staphylococcus aureus and Escherichia coli, as well as the antifungal activity against Aspergillus niger of a series of anilide derivatives have been modeled using augmented multivariate image analysis applied to quantitative structure-activity relationship (aug-MIA-QSAR). This QSAR approach is based on 2D molecular shape, as well as atomic sizes and colors to encode chemical, physical and biological properties. Predictive models with r(2) from 0.65 to 0.83 were used to estimate the antimicrobial activities of novel anilide analogs, which were built from the combination of substructures of the most active antimicrobial compounds along the series. Given the synergistic effect of different substituents to provide new molecules, promising compounds were proposed, highlighting a considerable multi-antimicrobial activity. PMID:23831437

Nunes, Cleiton A; Freitas, Matheus P

2013-07-04

145

Polyhexamethylene biguanide functionalized cationic silver nanoparticles for enhanced antimicrobial activity  

PubMed Central

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.

2012-01-01

146

Antimicrobial peptides: a review of how peptide structure impacts antimicrobial activity  

NASA Astrophysics Data System (ADS)

Antimicrobial peptides (AMPs) have been discovered in insects, mammals, reptiles, and plants to protect against microbial infection. Many of these peptides have been isolated and studied exhaustively to decipher the molecular mechanisms that impart protection against infectious bacteria, fungi, and viruses. Unfortunately, the molecular mechanisms are still being debated within the scientific community but valuable clues have been obtained through structure/function relationship studies1. Biophysical studies have revealed that cecropins, isolated from insects and pigs, exhibit random structure in solution but undergo a conformational change to an amphipathic ?-helix upon interaction with a membrane surface2. The lack of secondary structure in solution results in an extremely durable peptide able to survive exposure to high temperatures, organic solvents and incorporation into fibers and films without compromising antibacterial activity. Studies to better understand the antimicrobial action of cecropins and other AMPs have provided insight into the importance of peptide sequence and structure in antimicrobial activities. Therefore, enhancing our knowledge of how peptide structure imparts function may result in customized peptide sequences tailored for specific applications such as targeted cell delivery systems, novel antibiotics and food preservation additives. This review will summarize the current state of knowledge with respect to cell binding and antimicrobial activity of AMPs focusing primarily upon cecropins.

Soares, Jason W.; Mello, Charlene M.

2004-03-01

147

Iontophoresis generates an antimicrobial effect that remains after iontophoresis ceases.  

PubMed Central

Iontophoresis required chlorine-containing compounds in the medium for effective microbial population reduction and killing. After iontophoresis ceased, the antimicrobial effect generated by iontophoresis remained but slowly decreased. Antimicrobial effects of iontophoresis may be related to the generation of short-lived chlorine-containing compounds.

Davis, C P; Wagle, N; Anderson, M D; Warren, M M

1992-01-01

148

[Antimicrobial activity of Laetiporus sulphureus strains grown in submerged culture].  

PubMed

Cultural conditions for growth and fruit body formation were elaborated to four strains of Laetiporus sulphureus isolated from nature. All strains demonstrated antimicrobial activity against a wide spectrum of gram-positive and gram-negative bacteria during agar and submerged cultivation including methicillin-resistant strain of Staphylococcus aureus (MRSA) and glycopeptide-resistant strain of Leuconostoc mesenteroides. Antifungal activity was not found. The level of antimicrobial activity during submerged cultivation reached maximum after seven days of growth on specific medium with soybean meal and corn liquid; the next four weeks its increasing was not so manifested. Antimicrobial activity correlated with orange pigment secretion and cultural liquid acidification to pH 2.0-2.8 that indicates on acid nature of synthesized products. PMID:12741318

Ershova, E Iu; Tikhonova, O V; Lur'e, L M; Efremenkova, O V; Kamzolkina, O V; Dudnik, Iu V

2003-01-01

149

Antimicrobial effect of tetramethyldithiooxamide and its application as a biocide.  

PubMed

Tetramethyldithiooxamide (TMDTOA) is a stable and effective inhibitor of metal corrosion. The antimicrobial effects of TMDTOA and its metal compounds were investigated with regard to their use as biocides for water treatment. Growth of a variety of strains of bacteria and yeasts was completely inhibited at 400 mumol l-1 TMDTOA or its metal complexes. At 100 mg l-1 there was a 99.99% reduction in the number of viable micro-organisms; this activity persisted for 1-3 months. TMDTOA can be produced cheaply at 98% purity by a novel method, representing an alternative cost-effective water treatment agent combining corrosion-inhibiting and biocide characteristics. PMID:9812392

Tabakova, S V; Kantardjiev, T V; Mircheva, V V

1998-10-01

150

Improvement of the antimicrobial and antioxidant activities of camel and bovine whey proteins by limited proteolysis.  

PubMed

The compositions and structures of bovine and camel milk proteins are different, which define their functional and biological properties. The aim of this study was to investigate the effects of enzymatic hydrolysis of camel and bovine whey proteins (WPs) on their antioxidant and antimicrobial properties. After enzymatic treatment, both the antioxidant and the antimicrobial activities of bovine and camel WPs were improved. The significantly higher antioxidant activity of camel WPs and their hydrolysates as compared with that of bovine WPs and their hydrolysates may result from the differences in amounts and/or in accessibilities of antioxidant amino acid residues present in their primary structures and from the prevalence of alpha-lactalbumin and beta-lactoglobulin as proteolytic substrates in camel and bovine whey, respectively. The results of this study reveal differences in antimicrobial and antioxidant activities between WP hydrolysates of bovine and camel milk and the effects of limited proteolysis on these activities. PMID:20175528

Salami, Maryam; Moosavi-Movahedi, Ali Akbar; Ehsani, Mohammad Reza; Yousefi, Reza; Haertlé, Thomas; Chobert, Jean-Marc; Razavi, Seyed Hadi; Henrich, Robert; Balalaie, Saeed; Ebadi, Seyed Ahmad; Pourtakdoost, Samineh; Niasari-Naslaji, Amir

2010-03-24

151

Chemical Composition of Turmeric Oil (Curcuma longa L. cv. Roma) and its Antimicrobial Activity against Eye Infecting Pathogens  

Microsoft Academic Search

The essential oil from the rhizomes of Roma cultivar of turmeric (Curcuma longa) from Orissa was examined for its antimicrobial activity against the pathogens causing eye infections. The oil was obtained by hydrodistillation extraction method using Clevenger apparatus. Chemical analysis of the oil was done by using gas chromatography and mass spectrometry (GC\\/MS). The antimicrobial effects of oil towards Staphylococcus

Shikha Singh; Bhawani Sankar; Sathpathy Rajesh; Kumar Sahoo; Enketeswara Subudhi; Sanghamitra Nayak

2011-01-01

152

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

153

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.

2013-01-01

154

Effect of Selectively Introducing Arginine and D-Amino Acids on the Antimicrobial Activity and Salt Sensitivity in Analogs of Human Beta-Defensins  

PubMed Central

We have examined the antimicrobial activity of C-terminal analogs of human ?-defensins HBD-1and-3 wherein lysines have been selectively replaced by L- and D-arginines and L-isoleucine substituted with its D-enantiomer. The analogs exhibited antibacterial and antifungal activities. Physiological concentration of NaCl did not attenuate the activity of the peptides against Gram-negative bacteria considerably, while some attenuation of activity was observed against S. aureus. Variable attenuation of activity was observed in the presence of Ca2+ and Mg2+. Introduction of D-amino acids abrogated the need for a disulfide bridge for exhibiting activity. Confocal images of carboxyfluorescein (CF) labeled peptides indicated initial localization on the membrane and subsequent translocation into the cell. Analogs corresponding to cationic rich segments of human defensins substituted with L- and D-arginine, could be attractive candidates for development as future therapeutic drugs.

Olli, Sudar; Rangaraj, Nandini; Nagaraj, Ramakrishnan

2013-01-01

155

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.

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

1997-01-01

156

Phytochemical screening and antimicrobial activity of Coccinia cordifolia L. plant.  

PubMed

The medicinal plant, Coccinia cordifolia L. was analyzed for its chemical composition. The antimicrobial activities of the methanol, water, ethanol and ethyl acetate extracts of Coccinia cordifolia L. plant were evaluated against some Gram positive bacteria (Sarcina lutea, Bacillus subtilis and Staphylococcus aureus), Gram negative bacteria (Salmonella typhi, Shigella dysenteriae and Escherichia coli) and fungi (Candida albicans, Aspergillus niger and Penicillium notatum). Chemical analysis showed that the plant is rich in nutrients, especially antioxidant compounds such as total phenol, vitamin C and ?-carotene. Phytochemical screening showed that the methanolic extract contains the bioactive constituents such as tannins, saponins, phenols, flavonoids and terpenoids. In the methanolic extract of the plant, promising antimicrobial potential was observed against the tested microorganism. Methanolic extract showed highest activity against Shigella dysenteriae, Escherichia coli, Staphylococcus aureus, and Candida albicans compared to the other extracts. Water extract showed less antimicrobial activity as compared to other extractants. PMID:23009991

Khatun, Shahanaz; Pervin, Farzana; Karim, Mohammad Rezaul; Ashraduzzaman, Mohammad; Rosma, Ahmad

2012-10-01

157

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

2012-12-30

158

Antimicrobial effect of sugar osazones and anhydro sugars  

Microsoft Academic Search

The antimicrobial effect of 14 sugar osazones and anhydro sugars was studied with model strains ofMicrococcus luteus, Bacillus licheniformis, Escherichia coli and strainsStaphylococcus aureus andPseudomonas aeruginosa isolated from clinical material. The relationship between the structure of these compounds, their solubility in water and\\u000a 1-octanol and antimicrobial effect was investigated.

J. Zemek; K. Linbk; B. Kadle?íková; Š. Ku?ár; L. Somogyi

1985-01-01

159

Antimicrobial activity of submerged cultures of Chilean basidiomycetes.  

PubMed

This study is part of a screening program aimed at searching for bioactive metabolites from Chilean basidiomycetes. Submerged cultivation of fungal mycelia in liquid media was evaluated for antimicrobial activity. A total of 148 strains were obtained in vitro. The extracts produced from submerged cultures were evaluated against bacteria and fungi. In the primary antimicrobial assay, approximately 60% of the extracts presented positive biological activity. The highest frequencies of active strains were from the orders Agaricales (31.0%), Polyporales (20.6%), Sterales (18.3%), Boletales (11.4%), and Cortinariales (9.1%). Antifungal activity was more pronounced than antibacterial activity. Twelve extracts that exhibited strong antimicrobial activity showed minimum inhibitory concentration (MIC) values of 50?µL/mL against Bacillus brevis and 25?50?µL/mL against Penicillium notatum and Paecilomyces variotii. The biological activity of some strains did not vary considerably, regardless of the substrate or collection site whereas, for others, it showed marked variations. Differences in antimicrobial activities observed in the different fungal genera suggested that the ability to produce bioactive compounds is not homogenously distributed among basidiomycetes. The information obtained from this study reveals that Chilean basidiomycetes are able to generate small and/or large variations in the normal pathway of compounds production. Thus, it is necessary to evaluate this biological and chemical wealth, which could be an unsuspected reservoir of new and potentially useful molecules. PMID:20425689

Aqueveque, Pedro; Anke, Timm; Saéz, Katia; Silva, Mario; Becerra, José

2010-04-27

160

Preparation and antimicrobial activity of scleraldehyde from Schizophyllum commune  

Microsoft Academic Search

The present study investigates the antimicrobial activity of oxidized schizophyllan (scleraldehyde) against Gram-positive and Gram-negative bacteria by diffusion and tube dilution analysis. Schizophyllan is a natural polysaccharide produced by fungi of the genus Schizophyllum. Periodate oxidation specifically cleaves the vicinal glycols in scleraldehyde to form their dialdehyde derivatives. The antibacterial activity exhibited by scleraldehyde was defined using various tests such

Gladstone Christopher Jayakumar; Swarna V. Kanth; B. Chandrasekaran; J. Raghava Rao; B. U. Nair

2010-01-01

161

Antimicrobial activity of plant extract Ankaferd Blood Stopper ®  

Microsoft Academic Search

The in vitro antimicrobial activity of Ankaferd Blood Stopper® (ABS) was assessed on 102 clinical isolates from both Gram negative and Gram positive bacteria and four standard strains, including MRSA ATCC 43300, MSSA ATCC 25923, P. aeruginosa ATCC 27853 and E. coli ATCC 35218. ABS was significantly active against all bacteria investigated.

Nuriye Tasdelen Fisgin; Yeliz Tanriverdi Cayci; Ahmet Yilmaz Coban; Duzgun Ozatli; Esra Tanyel; Belma Durupinar; Necla Tulek

2009-01-01

162

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

163

Antimicrobial activity of Guinea-Bissau traditional remedies  

Microsoft Academic Search

The ethanolic extracts of twelve plants selected through ethnomedical survey in Guinea-Bissau were investigated for their in vitro antimicrobial properties over ten bacteria and Candida albicans, using agar diffusion and dilution methods. All the tested extracts showed some activity against at least one of the bacteria. Most of the extracts (79%) showed activity against Staphylococcus aureus and only one (Cryptolepis

O. Silva; A. Duarte; J. Cabrita; M. Pimentel; A. Diniz; E. Gomes

1996-01-01

164

Broad-spectrum antimicrobial activity of the reactive compounds generated in vitro by Manduca sexta phenoloxidase  

Microsoft Academic Search

Although quinone production and melanin formation are widely recognized as an integral part of the insect defense system, experimental evidence is lacking that the proteolytic activation of prophenoloxidase participates in the direct killing of invading microbes—active phenoloxidase generates quinones that polymerize to form melanin. Here, we report the antimicrobial effect of reactive intermediates produced in phenoloxidase-catalyzed reactions. After being treated

Picheng Zhao; Jiajing Li; Yang Wang; Haobo Jiang

2007-01-01

165

Antimicrobial activity of bark extracts of Syzygium jambos (L.) Alston (Myrtaceae)  

Microsoft Academic Search

Syzygium jambos (L.) Alston (Myrtaceae) is a widespread medicinal plant traditionally used in sub-Saharan Africa to treat infectious diseases. Acetone and aqueous extracts from the bark of S. jambos were tested for antimicrobial activity in vitro by the agar dilution method in petri dishes. Both extracts showed some activity against the tested micro-organisms. They proved to be particularly effective on

Corine Djadjo Djipa; Michel Delmée; Joëlle Quetin-Leclercq

2000-01-01

166

Antimicrobial activity of chitosan films containing nisin, peptide P34, and natamycin  

Microsoft Academic Search

The antimicrobial effect of edible chitosan films containing nisin, peptide P34, and natamycin was investigated. The activity of chitosan films was tested against Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enteritidis, Clostridium perfringens, Lactobacillus acidophilus, Aspergillus phoenicis, and Penicillium stoloniferum. The addition of nisin and P34 significantly increased the activity against bacteria. Films containing natamycin showed similar inhibition

Nisia Cé; Caciano P. Z. Noreña; Adriano Brandelli

2012-01-01

167

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

2012-05-17

168

Screening of antimicrobial activity of Cistus ladanifer and Arbutus unedo extracts.  

PubMed

In this work, the in vitro antimicrobial activity of different crude extracts obtained from Cistus ladanifer L. and Arbutus unedo L. was investigated. The ethanol, methanol and acetone/water extracts of Cistus ladanifer and Arbutus unedo were prepared using different extraction methods and their antimicrobial activities against reference strains, including three Gram-positive, five Gram-negative and three yeasts, and against clinical isolates of Helicobacter pylori and methicillin-resistant Staphylococcus aureus, were investigated. All the extracts inhibited more than one microorganism; moreover all of them presented antimicrobial activity against the Gram-positive bacteria, Klebsiella pneumonia, Candida tropicalis and Helicobacter pylori. It is noteworthy that the most considerable in vitro effect was observed against Helicobacter pylori. These inhibitory effects can be considered relevant to the development of new agents for inclusion in the treatment or prevention of infections by the tested strains. PMID:22077559

Ferreira, S; Santos, J; Duarte, A; Duarte, A P; Queiroz, J A; Domingues, F C

2011-11-14

169

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

2013-02-16

170

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

2011-02-01

171

Effects of antimicrobial peptides of neutrophils on tumor and normal host cells in culture  

Microsoft Academic Search

We carried out a study of the effects of two structurally different cationic antimicrobial peptides of cathelicidin family,\\u000a porcine protegrin 1 (PG1) and caprine Bac5 on selected tumor and normal mammalian cells in vitro. Protegrins are amphiphilic\\u000a ?-hairpin molecules having broad-spectrum antimicrobial activity due to their marked membranolytic effects. Bac5 belongs to\\u000a a group of proline-rich peptides, which adopt a

O. V. Shamova; G. A. Sakuta; D. S. Orlov; V. V. Zenin; G. I. Stein; N. I. Kolodkin; I. V. Afonina; V. N. Kokryakov

2007-01-01

172

Measuring antimicrobial peptide activity on epithelial surfaces in cell culture.  

PubMed

To more accurately assess the activity and role of epithelial cell-derived antimicrobial peptides in their native settings, it is essential to perform assays at the surfaces under relevant conditions. In order to carry this out, we utilize three-dimensional cultures of airway and gingival epithelium, which are grown at an air-liquid interface. Under these conditions, the cultures can be subjected to challenge with a variety of factors known to cause an increase in antimicrobial peptide gene expression. The functional relevance of this induction can then be assessed by quantifying antibacterial activity either directly on the surface of the cells or using the fluid secreted onto the apical surface of the cultures. The relative contribution of the peptides can also be measured by pre-incubation of the secreted fluid with specific inhibitory antibodies. Thus, a relatively inexpensive in vitro model can be used to evaluate the role of antimicrobial peptides in mucosal epithelium. PMID:20094876

Diamond, Gill; Yim, Sunghan; Rigo, Isaura; McMahon, Laura

2010-01-01

173

Evaluation of antimicrobial activity of selected plant extracts by rapid XTT colorimetry and bacterial enumeration  

Microsoft Academic Search

The aim of this study was to screen and evaluate the antimicrobial activity of indigenous Jordanian plant extracts, dissolved in dimethylsulfoxide, using the rapid XTT assay and viable count methods. XTT rapid assay was used for the initial screening of antimicrobial activity for the plant extracts. Antimicrobial activity of potentially active plant extracts was further assessed using the “viable plate

Amal G. Al-Bakri; Fatma U. Afifi

2007-01-01

174

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

175

Salvia officinalis L. essential oils: effect of hydrodistillation time on the chemical composition, antioxidant and antimicrobial activities  

Microsoft Academic Search

Salvia officinalis L. oils were isolated from the plant's commercial dried aerial parts, by hydrodistillation, with different distillation times. The essential oils were analysed by gas chromatography and gas chromatography–mass spectrometry. The antioxidant ability was measured using a free radical scavenging activity assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH), a thiobarbituric acid reactive substances (TBARS) assay, a deoxyribose assay for the scavenging of

G. Miguel; C. Cruz; M. L. Faleiro; M. T. F. Simões; A. C. Figueiredo; J. G. Barroso; L. G. Pedro

2011-01-01

176

Effect of Plant Age on Endophytic Bacterial Diversity of Balloon Flower ( Platycodon grandiflorum ) Root and Their Antimicrobial Activities  

Microsoft Academic Search

Balloon flower (Platycodon grandiflorum) is widely cultivated vegetable and used as a remedy for asthma in East Asia. Experiments were conducted to isolate endophytic\\u000a bacteria from 1-, 3-, and 6-year-old balloon flower roots and to analyze the enzymatic, antifungal, and anti-human pathogenic\\u000a activities of the potential endophytic biocontrol agents obtained. Total 120 bacterial colonies were isolated from the interior\\u000a of

Jong Min Kim; Myoung Geun Yun; Ji Joong Cho; Eun Jin Kim; Young Han Lee; Han Dae Yun

2010-01-01

177

Antimicrobial Activity of the Volatile Oil of Nigella sativa Linneaus Seeds  

PubMed Central

The antimicrobial activity of the volatile oil of Nigella sativa Linneaus seeds was studied. The antimicrobial principle has been isolated, identified as thymohydroquinone, and found to be active against gram-positive bacteria and yeasts.

Toama, Mohamed A.; El-Alfy, Taha S.; El-Fatatry, Hamed M.

1974-01-01

178

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

2010-03-01

179

[Antimicrobially effective compounded medications. Clinical value and critical comments].  

PubMed

Triphenyl-methan dyes, traditionally used in dermatology should be reevaluated with caution. Their use should be limited due to the uncertain pharmacological-toxicological risk-benefit ratio and the lack of pharmacological quality of the raw substances. Sometimes antimicrobial activity is insufficient and the cytotoxic effects, along with the inhibition of wound healing, make these dyes less suitable for topical treatment in dermatology. Chinolinolsulfat (Chinosol) and Clioquinol should be used in low concentrations and only on small areas. Due to their negative benefit-risk profile ethracidinlactate-monohydrate (Rivanol) and phenylmercuri-borate (Mercuchrom) should not be used as topical antimicrobial substances. The present publication is intended to give practical recommendations on compounded medications for topical antimicrobial use. Even though some of the cited compounds must be considered critically, we recommend the topical use of chlorhexidine salts, polihexanide, triclosan, polyvidone iodide and silver compounds. Useful standardised compounded formulations containing these four groups are listed in the NRF (Neues Rezeptur Formularium: New German Pharmacopoeia for compounded medication). PMID:15933865

Eifler-Bollen, R; Fluhr, J W

2005-08-01

180

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

181

The antimicrobial effects of cranberry against Staphylococcus aureus  

Microsoft Academic Search

The antimicrobial effects of the American cranberry (Vaccinium macrocarpon) on a major food-borne pathogen, Staphylococcus aureus, were investigated using commercially obtained Lakewood® organic cranberry juice and Ocean Spray® cranberry juice cocktail and four other berry fruit extracts (acai berry, strawberry, raspberry, and blueberry). The results showed that cranberry is a potent antimicrobial against S. aureus and the most potent among

Poh Yng Lian; T Maseko; M Rhee; K Ng

2012-01-01

182

Comparison of Serum Bactericidal Activity Among Three Antimicrobial Combinations  

PubMed Central

Three antimicrobial combinations, ticarcillin plus cephalothin (T+C), ticarcillin plus gentamicin (T+G), and cephalothin plus gentamicin (C+G), were administered to 105 febrile granulocytopenic cancer patients at the Baltimore Cancer Research Center as part of a multi-institutional prospective randomized antibiotic trial. The sera from 32 of these patients (T+C?10 patients, T+G?10 patients, and C+G?12 patients) obtained 1 h post-antibiotic administration were examined for bactericidal activity against 11 strains each of the most common pathogens infecting the granulocytopenic host: Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus. Each of the three antibiotic regimens produced a high degree of bactericidal activity in these sera against S. aureus and E. coli. P. aeruginosa was equally, although poorly, killed by sera containing ticarcillin (T+G, T+C), whereas C+G produced no measurable serocidal activity (P < 0.05). Sera with C+G killed K. pneumoniae more effectively than T+G; T+C produced the least killing effect of the three regimens against this organism (P < 0.05). The bactericidal activity of the serum from these 32 patients supplements the overall clinical results of the multi-institutional antibiotic trial and suggests that T+G is a useful initial regimen for empiric therapy of febrile episodes in granulocytopenic cancer patients.

Murillo, Jorge; Standiford, Harold C.; Schimpff, Stephen C.; Tatem, Beverly A.

1978-01-01

183

Antimicrobial and antioxidant activities of alcoholic extracts of Rumex dentatus L.  

PubMed

In-vitro antimicrobial and antioxidant activities of various concentrations ranging from 150 to 500 ?g/ml of alcoholic (methanol and ethanol) extracts of Rumex dentatus were analyzed on different clinical bacterial strains (Shigella flexneri, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus) and fungal strains (Aspergillus versicolor, Aspergillus flavus, Acremonium spp., Penicillium dimorphosporum, Candida albicans, Candida kruesie, Candida parapsilosis) using agar disk diffusion method and broth dilution method (MIC and MBC determination) for antimicrobial activity and DPPH (1,1-diphenyl-2-picrylhydrazyl) assay, Riboflavin photo-oxidation assay, deoxyribose assay, lipid peroxidation assay for antioxidant activity. The extracts showed maximum inhibitory effect against K. pneumonia and P. aeruginosa with no activity against S. typhimurium from among the bacterial strains while as in case of the fungal strains the maximum effect was observed against C. albicans by both the extracts. MIC and MBC values determined for active fractions of the extracts against some bacterial strains (S. flexneri, K. pneumonia and E. coli) revealed that the test organisms were inhibited by all the extracts with methanol showing lower values of both MIC and MBC indicating it as a better antimicrobial agent. The antioxidant activity showed that the extracts exhibited scavenging effect in concentration-dependent manner on superoxide anion radicals and hydroxyl radicals leading to the conclusion that the plant has got a broad spectrum antimicrobial and antioxidant activity and could be a potential alternative for treating various diseases. PMID:23415966

Humeera, Nisa; Kamili, Azra N; Bandh, Suhaib A; Amin, Shajr-ul-; Lone, Bashir A; Gousia, Nisa

2013-02-13

184

Poly(ethyleneimines) in dermal applications: Biocompatibility and antimicrobial effects.  

PubMed

Cationic polyamines, such as poly(ethyleneimines) (PEIs), may recommend themselves for antimicrobial applications as they can interact with microbial membranes resulting in their disruption. The purpose of the study was the assessment of biocompatibility and antibacterial activity of PEIs with different architectures (branched (b) and linear (l)) and molar masses (0.8-750kDa). lPEI and bPEI exhibited a strong antibacterial activity against Staphylococcus aureus and Escherichia coli with a more pronounced effect on the Gram-positive bacteria. lPEIs further demonstrated a higher antibacterial efficacy compared to bPEIs but no significant differences between 5 and 25kDa were observed. In accordance, antibacterial activity of bPEI did not specifically depend on molar mass. Only slightly lower minimal inhibitory concentrations (MIC) were observed at 5kDa (S. aureus) and 25kDa (E. coli) in the tests. As PEIs are compelling candidates for use in antimicrobial treatment, two basic aspects have to be investigated: treatment effectiveness and safety. PEIs clearly induced molecular weight dependent cytotoxic effects in vitro. PEIs with low molecular weight (0.8 and 5kDa) exhibited higher biocompatibility. Nonetheless, the results confirmed a low genotoxic potential of lPEI and bPEIs. In conclusion, 2.5kDa-lPEI and 0.8kDa-bPEI can be recommended for use as antimicrobial polymers in dermal applications due to their high biocompatibility with concomitant antibacterial efficacy. PMID:23948135

Wiegand, Cornelia; Bauer, Marius; Hipler, Uta-Christina; Fischer, Dagmar

2013-08-12

185

Chemical constituents from the rhizomes of Smilax glabra and their antimicrobial activity.  

PubMed

Six new phenolic compounds, named smiglabrone A (1), smiglabrone B (2), smilachromanone (3), smiglastilbene (4), smiglactone (5), smiglabrol (6), together with fifty-seven known ones 7-63 were isolated from the rhizomes of Smilax glabra. Their structures were elucidated on the basis of extensive spectroscopic analyses, as well as by comparison with literature data. Twenty-seven of these compounds were obtained from and identified in the genus Smilax for the first time. The absolute configuration of (2S)-1,2-O-di-trans-p-coumaroylglycerol (43) was determined for the first time using the exciton-coupled circular dichroism (ECCD) method. Thirty isolated compounds were evaluated for their antimicrobial activity against three Gram-negative bacteria, three Gram-positive bacteria and one fungus, and the corresponding structure-activity relationships were also discussed. Eighteen compounds were found to be antimicrobial against the microorganisms tested and the minimum inhibitory concentrations (MIC) were in the range of 0.0794-3.09 mM. Among them, compound 1 showed antimicrobial activity against Canidia albicans with MIC value of 0.146 mM, which was stronger than cinchonain Ia with an MIC of 0.332 mM. Compounds 3 and 4 exhibited inhibitory activity against Staphylococcus aureus with MIC values of 0.303 and 0.205 mM, respectively. The results indicated that these antimicrobial constituents of this crude drug might be responsible for its clinical antimicrobial effect. PMID:23698042

Xu, Shuo; Shang, Ming-Ying; Liu, Guang-Xue; Xu, Feng; Wang, Xuan; Shou, Cheng-Chao; Cai, Shao-Qing

2013-05-08

186

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.

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

2011-01-01

187

Synthesis and antimicrobial activities of some sulphur containing chromene derivatives.  

PubMed

A series of 3,3-dimethyl-3Hbenzothieno[3,2-f][1]-benzopyran analogues modified at the pyran 1,2-double bond were synthesized. The corresponding dihydro and (+/-)-cis-diol derivatives were converted into diacetate and cyclic carbonate upon acylation. The title compounds were characterized by spectroscopic analysis and screened for their antimicrobial activity in vitro. PMID:22908574

Serbetçi, Tuba; Birteksöz, Seher; Prado, Soizic; Michel, Sylvie; Tillequin, François

2012-07-01

188

Antimicrobial and antibiofilm activity of pleurocidin against cariogenic microorganisms  

Microsoft Academic Search

Dental caries is a common oral bacterial infectious disease of global concern. Prevention and treatment of caries requires control of the dental plaque formed by pathogens such as Streptococcus mutans and Streptococcus sobrinus. Pleurocidin, produced by Pleuronectes americanus, is an antimicrobial peptide that exerts broad-spectrum activity against pathogenic bacteria and fungi. Moreover, pleurocidin shows less hemolysis and is less toxic

Rui Tao; Zhongchun Tong; Yuan Lin; Yunpeng Xue; Wei Wang; Rong Kuang; Ping Wang; Yu Tian; Longxing Ni

2011-01-01

189

Antitumor, antioxidant and antimicrobial activities of Bersama engleriana (Melianthaceae)  

Microsoft Academic Search

The aim of this study was to evaluate the antitumor, antioxidant and antimicrobial activities as well as the phytochemical composition and the acute toxicity of the methanolic extracts from the roots (BER), stem bark (BEB), leaves (BEL) and wood (BEW) of Bersama engleriana. The crown gall tumor and DPPH radical scavenging assays were used to detect respectively the antitumoral and

Victor Kuete; Armelle Tsafack Mbaveng; Maurice Tsaffack; Véronique Penlap Beng; Francois-Xavier Etoa; Augustin Ephraim Nkengfack; J. J. Marion Meyer; Namrita Lall

2008-01-01

190

Antimicrobial Activity of Some Medicinal Plants from Malaysia  

Microsoft Academic Search

Problem statement: About 32 extracts from eight selected medicinal plants, n amely Pereskia bleo , Pereskia grandifolia , Curcuma aeruginosa Roxb., Curcuma zedoria , Curcuma mangga , Curcuma inodora aff. Blatter , Zingiber officinale var. officinale (jahe gajah) and Zingiber officinale var. rubrum (jahe emprit) used by Malaysia traditional health c are systems were screened for their antimicrobial activity against

Koshy Philip; Sri Nurestri; Abd Malek; Wirakarnain Sani; Sim Kae Shin; Saravana Kumar; Lee Guan Serm; Syarifah N. S. A. Rahman

2009-01-01

191

Study on the antimicrobial activity of Hymatanthus sucuba.  

PubMed

The antimicrobial activity of Hyamatantus sucuba roots methanol extract, fractions prepared from this extract (n-hexane, CHCl(3), EtOAc, and n-butanol) and some isolated compounds were evaluated against some Gram(+) and Gram(-) bacteria and yeasts. PMID:16326031

Morel, A F; Graebner, I B; Porto, C; Dalcol, I I

2005-12-02

192

Antimicrobial Activity of Bacteriocins and Their Applications  

NASA Astrophysics Data System (ADS)

Bacteriocins are peptides or proteins that exert an antimicrobial action against a range of microorganisms. Their production can be related to the antagonism within a certain ecological niche, as the producer strain, being itself immune to its action, generally gains a competitive advantage. Many Gram-positive and Gram-negative microorganisms have been found to produce bacteriocins. The former, and especially the ones produced by lactic acid bacteria, has been the field of intensive research during the last decades mainly due to their properties that account for their suitability in food preservation and the benefits arising from that, and secondarily due to the broader inhibitory spectrum compared to the ones produced by Gramnegative microorganisms.

Drosinos, Eleftherios H.; Mataragas, Marios; Paramithiotis, Spiros

193

Effect of varying pH on the susceptibility of Campylobacter pylori to antimicrobial agents  

Microsoft Academic Search

The susceptibility of 22 clinical isolates ofCampylobacter pylori to eight antimicrobial agents was studied under varying pH conditions. Macrolides (erythromycin, dirythromycin), clindamycin and to a lesser extent quinolones lost efficacy at lowered pH. The activity of ampicillin and metronidazole remained relatively stable throughout the pH range tested. The effect of pH an antimicrobial efficacy may warrant consideration when selecting an

M. L. Grayson; G. M. Eliopoulos; M. J. Ferraro; R. C. Moellering

1989-01-01

194

Extraction, antioxidant and antimicrobial activities of Epimedium acuminatum Franch. polysaccharide.  

PubMed

Polysaccharides from Epimedium acuminatum were extracted by hot water and optimized with response surface methodology. The optimal conditions of the extraction were determined to be the ratio of water to raw material of 29.61, extraction temperature of 85.67°C and extraction time of 3.57 h. Under these optimal conditions, the yield of polysaccharide was 8.21%, which was well matched with the predictive yield (8.23%). Moreover, three purified fractions (EAP40-1, EAP60-1 and EAP80-2) were obtained for further chemical analysis, antioxidant activity analysis and antimicrobial activity analysis. EAP40-1 with molecular weight of 138,884 Da showed the best radical scavenging activity. Meanwhile, EAP60-1 with molecular weight of 114,667 Da was found to exhibit significant antihemolytic activity and antimicrobial activity. PMID:23688459

Cheng, Haoran; Feng, Shiling; Shen, Shian; Zhang, Li; Yang, Ruiwu; Zhou, Yonghong; Ding, Chunbang

2013-03-29

195

Antimicrobial activity of a new series of benzimidazole derivatives.  

PubMed

Due to antimicrobial importance of benzimidazoles and hydrazones, some benzimidazole-hydrazone compounds were synthesized to screen their antimicrobial activity. Structures of the synthesized compounds were elucidated by (1)H-NMR, IR and ES-MS spectral data and elemental analysis. The synthesized benzimidazole-hydrazones exhibited very weak antibacterial activity. However, antifungal activity of some of the synthesized compounds was very notable against Candida species. The compounds displaying important antifungal activity were screened for their toxicity. Artemia salina 96-well assay was used to determine cytotoxicity of the compounds. Tested compounds exhibited toxicity to different extents (LD(50) = 126.33-368.72 ?g/mL). Nevertheless, determination of 3-14 folds higher LD(50) than minimum inhibitory concentration is a significant finding, which demonstrates that the compounds display antifungal activity at non-toxic concentration. PMID:21975803

Özkay, Yusuf; Tunal?, Ya?mur; Karaca, Hülya; I??kda?, Ilhan

2011-10-06

196

Synthesis and antimicrobial activities of 4-purpuromycin derivatives.  

PubMed

Purpuromycin (1) is a natural antibiotic with a broad spectrum of activity encompassing bacteria, fungi and protozoa. A new series of derivatives of 1 was prepared by the modification or replacement of the C-4 hydroxyl group. The physico-chemical characteristics and the in vitro antimicrobial activity of these new semisynthetic purpuromycin derivatives are reported. Attachment of a variety of bulky groups to the C-4 hydroxyl group as well as acylation or mesylation of 1 gave derivatives with significantly reduced antifungal activity, while the antimicrobial activity of these derivatives against Gram-positive and Gram-negative bacteria was only slightly decreased. All compounds were inactive against Escherichia coli. The C-4 epimers showed different in vitro activity as compared with those having the natural configuration, particularly against fungi. PMID:8765673

Trani, A; Dallanoce, C; Ferrari, P; Goldstein, B; Ripamonti, F; Ciabatti, R

1996-07-01

197

[Current animal feeds with antimicrobial activity].  

PubMed

Among the growth-promoting substances and factors contributing to fodder utilization in growing farm animals, also called nutritive, ergotropic means, the antibiotics and some synthetic chemotherapeutics have acquired special importance. To avoid the hazardous effect in humans consuming products of animal origin there should be no residual amounts of these stimulating agents in such products. That is why it has been assumed in a number of countries to use for the same purpose only nutritive means that are not applied as therapeutic agents. Such means should neither induce resistence to antibiotics and chemotherapeutics in microorganism nor should they be resorbed by the alimentary tract (or resorption should be negligible) or they are rapidly eliminated from the animal body, leaving no residual amounts. They should likewise act chiefly against gram-positive organisms, inducing no allergic reactions in the animals. Described are the following nutritive antibiotics: flavophospholipol (bambermycin, menomycin--flavomycin, producing a nutritive effect also in ruminants with a developed forestomach, and rebuilds sensitivity in antibiotic-resistant organisms belonging to Enterobacteriaceae), avoparcin (avotan--also active in ruminants with a developed forestomach), virginiamycin (staphylomycin--escalin, stafac), zincbacitracin (bacipharmin, baciferm), grisin (kormogrisin, of a road spectrum, with an antimycotic effect, raising the fertilization rate and activating phagocitosis), vitamycin-A (vitamycin--active also at retinol deficiency, lambdamycin, nosiheptide (primofax), efrotomycin. Due consideration is given to such chemotherapeutics as nitrovin (payson, paison), carbadox (mecadox, fortigro, of a broad spectrum retained for a longer period in the body of pigs), olaquindox (bio-N-celbar--of a broad spectrum, particularly with regard to gram-negative organisms, applied at present as a therapeutic and prophylactic preparation), cyadox (with a broad sprectrum). The following polyether ionophoric antibiotics are mentioned: monensine (rumensine, elancoban), lassalocide (avatek, lasotek), slinomycin(eustin, ustin, coxistac), lonomycin (emercide), harasine. Dosage rates and other data are given characterising the respective preparations. PMID:7046217

Drumev, D

1981-01-01

198

Antimicrobial activity of some endemic plants growing in the Eastern Black Sea Region, Turkey  

Microsoft Academic Search

The Eastern Black Sea Region has an extensive flora because of ample rainfall lasting all year. In this study, antimicrobial effects of 74 crude extracts of 22 endemic plants were investigated. Among the 30 active crude extracts, water-insoluble crude extracts from Betula medwediewii, Heracleum platytaenium, Primula longipes, Anthemis cretica ssp. argaea and Centaurea helenioides were the prominent ones with their

Kurtulus Buruk; Atalay Sokmen; Faruk Aydin; Murat Erturk

2006-01-01

199

Interactions between high pressure homogenization and antimicrobial activity of lysozyme and lactoperoxidase  

Microsoft Academic Search

It was the objective of this work to evaluate the effect of high pressure homogenization on the activity of antimicrobial enzymes such as lysozyme and lactoperoxidase against a selected group of Gram positive and Gram negative species inoculated in skim milk.Lactobacillus helveticus, Lactobacillus plantarum and Listeria monocytogenes were the most pressure resistant species while Bacillus subtilis, Pseudomonas putida, Salmonella typhimurium,

L. Vannini; R. Lanciotti; D. Baldi; M. E. Guerzoni

2004-01-01

200

Antimicrobial activity and physical properties of chitosan–tapioca starch based edible films and coatings  

Microsoft Academic Search

Antimicrobial activity of edible coating solutions based on chitosan and blends of chitosan–tapioca starch with or without potassium sorbate (KS) addition was studied. The agar well diffusion assay showed an antagonist effect on the efficiency of chitosan against Lactobacillus spp. when KS and\\/or tapioca starch were present. A salmon slice coating assay showed that the chitosan solution was the best

María B. Vásconez; Silvia K. Flores; Carmen A. Campos; Juan Alvarado; Lía N. Gerschenson

2009-01-01

201

Antimicrobial activity of foodborne Paenibacillus and Bacillus spp. against Clostridium botulinum.  

PubMed

The saprophytic Paenibacillus and Bacillus spp. found in cooked chilled foods may have an effect on the growth of Clostridium botulinum, a major microbiological hazard, especially for pasteurized vacuum-packaged products. Culture supernatants of 200 strains of Paenibacillus and Bacillus strains isolated from commercial cooked chilled foods containing vegetables were screened for activity against C. botulinum type A, proteolytic type B, and type E strains in a well diffusion assay. Nineteen strains were positive against C. botulinum. Among those, seven Paenibacillus polymyxa strains showed the highest antibotulinal activity and the largest antimicrobial spectrum against C. botulinum strains. The antibotulinal activity was evaluated throughout the growth of a representative strain of the positive P. polymyxa strains. The antimicrobial activity was detected in the culture supernatant from late-log/early stationary phase of the bacteria, which occurred after 7 to 10 days of incubation at 10 degrees C and after 2 to 3 days at 20 degrees C in nutrient broth and in vegetable purées under aerobic or anaerobic conditions. In co-cultures with the positive strain of P. polymyxa in nutrient broth and vegetable purées, a C. botulinum type E strain was inhibited whenever P. polymyxa reached stationary phase and produced its antimicrobial activity before C. botulinum began its exponential growth phase. The antimicrobial activity of P. polymyxa against C. botulinum was attributed to the production of antimicrobial peptides resistant to high temperature and acidity. Other gram-positive and -negative bacteria (Escherichia coli, Streptococcus mutans, Leuconostoc mesenteroides, and Bacillus subtilis) were also sensitive to these antimicrobial peptides. PMID:12030292

Girardin, Hélène; Albagnac, Christine; Dargaignaratz, Claire; Nguyen-The, Christophe; Carlin, Frédéric

2002-05-01

202

Study of the nanomaterials and their antimicrobial activities  

NASA Astrophysics Data System (ADS)

In the last decade, the world faced huge problems associated with the spread of antimicrobial resistant infections that are essentially untreatable such as methicillin resistant Staphylococcus aureus (MRSA) infection. These infections have begun to occur in both hospital and community environments. Developing new antimicrobial surface coatings can hold a great promise to minimize and control various problems that associated with the spreading of infections and biofilms formation, these coatings can be used in medicine where medical devices associated with severe infections, in construction industry and the in food packaging industry. It has been established that single-walled CNTs exhibit a strong antimicrobial activity and can pierce bacterial cell walls. Recently, nanomaterial structures that made from pure carbon such as CNTs have been seen as promising candidates for many potential applications in Biotechnology and bioscience due to the combination of their extraordinary properties that arise from surface area, light weight, strength, flexibility, unique electrical conductivity and many more novel physical and chemical properties at nanoscale level. CNTs have been used widely in biomedical field including drug delivery, gene therapy and creating new biomedical devices with novel properties. Researchers have now made a first step to add carbon nanotubes to antimicrobial agents list. There are two types of CNTs have been used in biomedical research. The first one is a single-walled carbon nanotube (SWNT) and the second is a multi-walled carbon nanotube (MWNT). Recent in vitro studies suggest that carbon nanotubes have antimicrobial activity and coating CNTs with nickel nanoparticle could enhance the antimicrobial activity of cabon nanotubes. In order to test this hypothesis, nickel nanoparticles were deposited on carbon nanotubes (CNTs) by electrochemical deposition. The carbon nanotubes used in this study were XD-CNTs, SWNTs and Ni-coated CNTs. The structure and the morphology of Ni-coated CNTs were investigated by scanning electron microscopy (SEM), dispersive x-ray analysis (EDX) and thermo gravimetric analysis (TGA). The SEM results revealed that CNTs provide an excellent surface for electrochemical deposition of nanomaterials. Ni nanoparticles were homogeneously electrodeposited on the surfaces of SWNTs. Antimicrobial activity of CNTs was determined by broth dilution method using six different bacterial strains, three strains of gram negative and three strains of gram positive bacteria. The gram positive bacteria include Staphylococcus aureus, Staphylococcus epidermidis and Bacillus subtilis . The gram negative bacteria include Eshericia coli, Klebsiella pneumonia and Pseudomonas aerugenosa. Bactericidal rate was calculated. Based on the results Ni-coated CNTs show much stronger bactericidal property comparing to SWNTs and XD-grade CNTs.

Ramadi, Muntaha

203

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.

2012-01-01

204

Antioxidant, Antimicrobial Activity and Toxicity Test of Pilea microphylla  

PubMed Central

A total of 9 plant extracts were tested, using two different kinds of extracting methods to evaluate the antioxidant and antimicrobial activities from Pilea microphylla (Urticaceae family) and including toxicity test. Antioxidant activity were tested by using DPPH free radical scavenging, also total phenolic contents and total flavonoid contents were determined. Toxicity assay carried out by using brine shrimps. Methanol extract of method I (ME I) showed the highest antioxidant activity at 69.51 ± 1.03. Chloroform extract of method I (CE I) showed the highest total phenolic contents at 72.10 ± 0.71 and chloroform extract of method II (CE II) showed the highest total flavonoid contents at 60.14 ± 0.33. The antimicrobial activity of Pilea microphylla extract was tested in vitro by using disc diffusion method and minimum inhibitory concentration (MIC). The Pilea microphylla extract showed antibacterial activity against some Gram negative and positive bacteria. The extracts did not exhibit antifungal and antiyeast activity. The hexane extract of method I (HE I) was not toxic against brine shrimp (LC50 value was 3880??g/ml). Therefore, the extracts could be suitable as antimicrobial and antioxidative agents in food industry.

Modarresi Chahardehi, Amir; Ibrahim, Darah; Fariza Sulaiman, Shaida

2010-01-01

205

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.

2011-01-01

206

The antimicrobial effects of cranberry against Staphylococcus aureus.  

PubMed

The antimicrobial effects of the American cranberry (Vaccinium macrocarpon) on a major food-borne pathogen, Staphylococcus aureus, were investigated using commercially obtained Lakewood® organic cranberry juice and Ocean Spray® cranberry juice cocktail and four other berry fruit extracts (acai berry, strawberry, raspberry, and blueberry). The results showed that cranberry is a potent antimicrobial against S. aureus and the most potent among the berries studied. The order of percentage inhibition of bacterial growth at the same concentration of phenolic materials as gallic acid equivalents was Lakewood cranberry juice?>?Ocean Spray cranberry juice???blueberry?>?acai berry???raspberry???strawberry. The antimicrobial effect was not due to the acidity of the berries as NaOH-neutralized samples were almost as effective in terms of percentage inhibition of viable cell growth. Solid-phase extraction of cranberry juice using C18 solid phase showed that the antimicrobial effects reside exclusively with the C18-bound materials. PMID:22414934

Lian, Poh Yng; Maseko, T; Rhee, M; Ng, K

2012-03-13

207

Synthesis, tautomerism, and antimicrobial, anti-HCV, anti-SSPE, antioxidant, and antitumor activities of arylazobenzosuberones.  

PubMed

2-Dimethylaminomethylene-1-benzosuberone 1 was coupled with diazotized aniline derivatives to afford a series of the hitherto unreported 2-arylazo-1-benzosuberones 3a-i. The tautomeric structure and the effect of substituents on the tautomeric form (s) of the products 3a-i were discussed. Similar coupling of the enaminone 1 with diazonium salts of heterocyclic amines gave the respective fused azolotriazino-benzosuberones. Some of the newly synthesized compounds showed potent antimicrobial, anti-HCV, antioxidant, antitumor (as topoisomerase I inhibitors), and antimicrobial activities. PMID:19864149

Farghaly, Thoraya A; Abdalla, Mohamed M

2009-10-12

208

Design and Characterization of an Acid-Activated Antimicrobial Peptide  

PubMed Central

Dental caries is a microbial biofilm infection in which the metabolic activities of plaque bacteria result in a dramatic pH decrease and shift the demineralization/ remineralization equilibrium on the tooth surface towards demineralization. In addition to causing a net loss in tooth minerals creation of an acidic environment favors growth of acid enduring and acid generating species, which causes further reduction in the plaque pH. In this study we developed a prototype antimicrobial peptide capable of achieving high activity exclusively at low environmental pH to target bacterial species like Streptococcus mutans that produce acid and thrive under the low pH conditions detrimental for tooth integrity. The features of clavanin A, a naturally occurring peptide rich in histidine and phenylalanine residues with pH-dependent antimicrobial activity, served as a design basis for these prototype “acid-activated peptides” (AAPs). Employing the major cariogenic species S. mutans as a model system, the two AAPs characterized in this study exhibited a striking pH-dependent antimicrobial activity which correlated well with the calculated charge distribution. This type of peptide represents a potential new way to combat dental caries.

Li, Lina; He, Jian; Eckert, Randal; Yarbrough, Daniel; Lux, Renate; Anderson, Maxwell; Shi, Wenyuan

2009-01-01

209

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

210

Antimicrobial and antibiofilm activity of cathelicidins and short, synthetic peptides against Francisella.  

PubMed

Francisella infects the lungs causing pneumonic tularemia. Focusing on the lung's host defense, we have examined antimicrobial peptides as part of the innate immune response to Francisella infection. Interest in antimicrobial peptides, such as the cathelicidins, has grown due their potential therapeutic applications and the increasing problem of bacterial resistance to commonly used antibiotics. Only one human cathelicidin, LL-37, has been characterized. Helical cathelicidins have also been discovered in snakes including the Chinese King Cobra, Naja atra (NA-CATH). Four synthetic 11-residue peptides (ATRA-1, -2, -1A and -1P) containing variations of a repeated motif within NA-CATH were designed. We hypothesized that these smaller synthetic peptides could have excellent antimicrobial effectiveness with shorter length (and less cost), making them strong potential candidates for development into broad-spectrum antimicrobial compounds. We tested the susceptibility of F. novicida to four ATRA peptides, LL-37, and NA-CATH. Two of the ATRA peptides had high antimicrobial activity (microM), while the two proline-containing ATRA peptides had low activity. The ATRA peptides did not show significant hemolytic activity even at high peptide concentration, indicating low cytotoxicity against host cells. NA-CATH killed Francisella bacteria more quickly than LL-37. However, LL-37 was the most effective peptide against F. novicida (EC50=50 nM). LL-37 mRNA was induced in A549 cells by Francisella infection. We recently demonstrated that F. novicida forms in vitro biofilms. LL-37 inhibited F. novicida biofilm formation at sub-antimicrobial concentrations. Understanding the properties of these peptides, and their endogenous expression in the lung could lead to potential future therapeutic interventions for this lung infection. PMID:20399752

Amer, Lilian S; Bishop, Barney M; van Hoek, Monique L

2010-04-23

211

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

2013-03-12

212

Antimicrobial activity of Curcuma zedoaria and Curcuma malabarica tubers.  

PubMed

The antimicrobial activity of extracts of Curcuma zedoaria and Curcuma malabarica tubers was tested against six bacterial and two fungal strains using the agar well diffusion and broth dilution methods. Petroleum ether, hexane, chloroform, acetone and ethanol extracts exhibited antibacterial as well as antifungal activity. Acetone and hexane extracts of both tubers showed comparable antimicrobial activity as indicated by minimum inhibitory concentration (MIC) values, but other extracts of Curcuma malabarica showed significantly lower activity than those of Curcuma zedoaria. The MIC values for different strains and extracts ranged from 0.01 to 0.15 mg/ml in Curcuma zedoaria and from 0.01 to 0.94 mg/ml in Curcuma malabarica. Staphylococcus aureus (Gram positive) was inhibited by Curcuma malabarica but not by Curcuma zedoaria. This study is the first report of the antimicrobial properties of Curcuma malabarica. The findings also support the use of Curcuma zedoaria tubers in traditional medicine for the treatment of bacterial and fungal infections. PMID:15848035

Wilson, B; Abraham, G; Manju, V S; Mathew, M; Vimala, B; Sundaresan, S; Nambisan, B

2005-05-13

213

Effective antimicrobial activity of Cbf-K16 and Cbf-A7 A13 against NDM-1-carrying Escherichia coli by DNA binding after penetrating the cytoplasmic membrane in vitro.  

PubMed

New Delhi metallo-beta-lactamase-1(NDM-1)-carrying isolates, which are resistant to most clinical used antibiotics except for tigecycline and colistin, have been found worldwide. Cathelicidin-BF (BF-30) is found in the venom of the snake Bungarus fasciatus and exhibits broad antimicrobial activity. Cbf-K(16) and Cbf-A(7) A(13) were obtained by mutating Lys(16), Ala(7), and Ala(13) of BF-30, respectively. To investigate their antimicrobial activities against NDM-1 carrying bacteria, recombinant Escherichia coli BL21 (DE3)-NDM-1 with high NDM-1 activity was constructed by inserting the Klebsiella pneumoniae NDM-1 gene (GenBank accession no. HQ328085) into a pET28a vector and transforming it into E. coli BL21 (DE3). The peptides showed effective antimicrobial activities against NDM-1-carrying E. coli, and the minimum inhibitory concentrations of Cbf-K(16) and Cbf-A(7) A(13) were only 4 and 8 µg/ml, whereas those of minimum bactericidal concentrations were 8 and 16 µg/ml, respectively. A time course experiment showed that colony forming unit counts rapidly decreased, and bacteria were thoroughly eliminated within 3 and 6 h by the Cbf-K(16) and Cbf-A(7) A(13) treatments, respectively. The peptides penetrated the bacterial cell membrane and enabled ?-galactosidase leakage, and caused the cytoplasmic membrane to become permeable, and finally bound to the DNA. The genomic DNA of E. coli was completely unable to migrate on an agarose gel after Cbf-K(16) treatment (8 µg/ml). These data demonstrated that Cbf-K(16) and Cbf-A(7) A(13) possess effective antimicrobial activity against drug-resistant strains, including NDM-1 carrying E. coli BL21 (DE3)-NDM-1, by binding to DNA after penetrating the cytoplasmic membrane in vitro, which may have potential therapeutic value for the treatment of NDM-1-carrying bacterial infections. PMID:23389882

Hao, Qingru; Wang, Hui; Wang, Jing; Dou, Jie; Zhang, Min; Zhou, Weidong; Zhou, Changlin

2013-02-07

214

Antimicrobial activity and chemical investigation of Brazilian Drosera.  

PubMed

The antimicrobial activity of three different extracts (hexanic, ethyl acetate, methanol) obtained from Brazilian Drosera species (D. communis, D. montana var. montana, D. brevifolia, D. villosa var. graomogolensis, D. villosa var. villosa, Drosera sp. 1, and Drosera sp. 2 ) were tested against Staphylococcus aureus (ATCC 25923), Enterococcus faecium (ATCC23212), Pseudomonas aeruginosa (ATCC27853), Escherichia coli (ATCC11229), Salmonella choleraesuis (ATCC10708), Klebsiella pneumoniae (ATCC13883), and Candida albicans (a human isolate). Better antimicrobial activity was observed with D. communis and D. montana var. montana ethyl acetate extracts. Phytochemical analyses from D. communis, D. montana var. montana and D. brevifolia yielded 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin); long chain aliphatic hydrocarbons were isolated from D. communis and from D. villosa var. villosa, a mixture of long chain aliphatic alcohols and carboxylic acids, was isolated from D. communis and 3b-O-acetylaleuritolic acid from D. villosa var. villosa. PMID:15654434

Ferreira, Dalva Trevisan; Andrei, César Cornélio; Saridakis, Halha Ostrensky; Faria, Terezinha de Jesus; Vinhato, Elisângela; Carvalho, Kátia Eliane; Daniel, Juliana Feijó Souza; Machado, Sílvio Luiz; Saridakis, Dennis Panayotis; Braz-Filho, Raimundo

2005-01-12

215

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.

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

2012-01-01

216

Antimicrobial Activity of Amine Oxides: Mode of Action and Structure-Activity Correlation  

PubMed Central

The effect of N-alkyl derivatives of saturated heterocyclic amine oxides on the growth and metabolism of microorganisms has been studied. 4-Dodecylmorpholine-N-oxide inhibited the differentiation and growth of Bacillus cereus, of different species of filamentous fungi, and of the yeast Saccharomyces cerevisiae. For vegetative cells, the effect of 4-dodecylmorpholine-N-oxide was lethal. Cells of S. cerevisiae, after interaction with 4-dodecylmorpholine-N-oxide, released intracellular K+ and were unable to oxidize or ferment glucose. The functions of isolated yeast mitochondria were also impaired. 4-Dodecylmorpholine-N-oxide at growth-inhibiting concentrations induced rapid lysis of osmotically stabilized yeast protoplasts, with the rate of lysis a function of temperature and of amine oxide concentration. A study of the relationships between structure, antimicrobial activity, and cytolytic activity was made with a group of structurally different amine oxides involving a series of homologous 4-alkylmorpholine-N-oxides, 1-alkylpiperidine-N-oxides, 1-dodecylpyrrolidine-N-oxide, 1-dodecylperhydroasepine-N-oxide, and N,N-dimethyldodecylamine oxide. Disorganization of the membrane structure after interaction of cells with the tested amine oxides was primarily responsible for the antimicrobial activity of the amine oxides. This activity was found to be dependent on the chain length of the hydrophobic alkyl group and was only moderately influenced by other substituents of the polarized N-oxide group.

Subik, Julius; Takacsova, Gizela; Psenak, Mikulas; Devinsky, Ferdinand

1977-01-01

217

Antimicrobial polymers: mechanism of action, factors of activity, and applications  

Microsoft Academic Search

Complex epidemiological situation, nosocomial infections, microbial contamination, and infection risks in hospital and dental\\u000a equipment have led to an ever-growing need for prevention of microbial infection in these various areas. Macromolecular systems,\\u000a due to their properties, allow one to efficiently use them in various fields, including the creation of polymers with the\\u000a antimicrobial activity. In the past decade, the intensive

Larisa Timofeeva; Natalia Kleshcheva

2011-01-01

218

Antimicrobial Activity of Broth Fermented with Kefir Grains  

Microsoft Academic Search

Kefir grains originate from the Caucasus region and are used for preparing beverages using sugar solution, milk, and fruit\\u000a juice. As long as they are formed by a microbial consortium useful in the intestine, the produced drinks can be called probiotics.\\u000a The aim of this study was to determine the antimicrobial activity during kefir fermentation in sugar broth. Fermentations\\u000a with

Karoline R. Silva; Sheila A. Rodrigues; Lauro Xavier Filho; Álvaro S. Lima

2009-01-01

219

Multidrug Pump Inhibitors Uncover Remarkable Activity of Plant Antimicrobials  

Microsoft Academic Search

Plant antimicrobials are not used as systemic antibiotics at present. The main reason for this is their low level of activity, especially against gram-negative bacteria. The reported MIC is often in the range of 100 to 1,000 g\\/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. Major plant pathogens belong to the gram-negative bacteria,

George Tegos; Frank R. Stermitz; Olga Lomovskaya; Kim Lewis

2002-01-01

220

Antimicrobial activity of pomegranate ( Punica granatum L.) fruit peels  

Microsoft Academic Search

Food-borne diseases such as listeriosis and diseases caused by the emergence of multi-drug resistant pathogens (e.g. Staphylococcus aureus) are globally recognized as environmental hazards to the food supply and human health. Natural inhibitors for pathogenic microorganisms have been explored in many plants. The antimicrobial activity against some food-borne pathogens by various extracts from pomegranate fruit peels was evaluated using both

N. S. Al-Zoreky

2009-01-01

221

Synthesis, antifungal and antimicrobial activity of alkylphospholipids.  

PubMed

The antifungal, antibacterial and haemolytic activity of a series of alkylphosphocholines (e.g., miltefosine) and alkylglycerophosphocholines (e.g., edelfosine) has been investigated. These compound classes exhibit significant antifungal and moderate antibacterial activities. Several new alkylphosphocholine derivatives with amide or ester bonds in the alkyl chain have been synthesised. These compounds show much lower haemolytic activity than miltefosine. Alkylphosphocholines and alkylglycerophosphocholines show significant promise as novel orally available antifungal and antibacterial therapeutics. PMID:17532639

Obando, Daniel; Widmer, Fred; Wright, Lesley C; Sorrell, Tania C; Jolliffe, Katrina A

2007-05-17

222

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

223

Antimicrobial activity of Bridelia ferruginea leaves extracts  

Microsoft Academic Search

Methanol, ethyl acetate, and hexane extracts of Bridelia ferruginea leaves exhibited significant activity against Pseudomonas frutescens, Bacillus subtilis, Echerichia coli, Staphylococcus aureus and Streptococcus faecalis.

E. Talla; D. Djamen; D. R. Djouldé; L. Tatsadjeu; D. Tantoh; J. T. Mbafor; Z. T. Fomum

2002-01-01

224

Antimicrobial activity of Bridelia ferruginea leaves extracts.  

PubMed

Methanol, ethyl acetate, and hexane extracts of Bridelia ferruginea leaves exhibited significant activity against Pseudomonas frutescens, Bacillus subtilis, Echerichia coli, Staphylococcus aureus and Streptococcus faecalis. PMID:12234581

Talla, E; Djamen, D; Djouldé, D; Tatsadjeu, L; Tantoh, D; Mbafor, J T; Fomum, Z T

2002-07-01

225

Kirenol production in hairy root culture of Siegesbeckea orientalis and its antimicrobial activity  

PubMed Central

Background: Despite the excellent anti-inflammatory and anti-rheumatic efficacy associated with kirenol generation, the content of kirenol in Siegesbeckea orientalis is quite low. Objective: This study was designed to establish a reliable kirenol production protocol by transformed root cultures of S. orientalis and to investigate the antimicrobial activities of kirenol, hairy root, and S. orientalis. Materials and Methods: Transformed root cultures of S. orientalis were established by the transformation of Agrobacterium rhizogenes A4. Transgenic status of the roots was confirmed by polymerase chain reaction (PCR) using rolB specific primers. The biomass and kirenol accumulation of hairy root clones were assessed using four different culture media: MS, MS/2, B5, and white. The antimicrobial activities of kirenol, hairy root, and S. orientalis were evaluated by the disc diffusion method. Results: The optimum media for kirenol synthesis was MS. The content of kirenol in transformed hairy roots made up about 80% of that observed in natural leaves of S. orientalis (1.6 mg/g dry weight). All tested samples displayed antimicrobial activity against Gram-positive pathogens including Staphylococcus epidermidis, Staphylococcus aureus, and Acinetobacter baumannii, with MIC ranging from 78 to 625 ?g/mL. Discussion and Conclusion: The high level of kirenol contents was obtained from hairy roots of S. orientalis. Kirenol was effective against gram-positive bacteria. Interestingly, the extract from hairy roots showed a diverse antimicrobial effect from that of kirenol and S. orientalis.

Wang, Jian-Ping; Zhou, Ya-Ming; Zhang, Yong-Hui

2012-01-01

226

Antimicrobial activity of silver nitrate against periodontal pathogens.  

PubMed

Metal ions were evaluated as potential antimicrobial agents suitable for local delivery in the oral cavity for the treatment of periodontitis. Silver nitrate, copper chloride, and zinc chloride were tested for antimicrobial activity in in vitro killing assays conducted in phosphate buffered saline with a series of oral bacteria including gram-negative periodontal pathogens and gram-positive streptococci. Copper and zinc salts failed to exhibit strong and consistent activity against periodontal pathogens. In contrast, silver at a concentration of 0.5 microg/mL produced a 3 log10 reduction in colony forming units (CFU)/mL or greater against all periodontal pathogens tested including Porphyromonas gingivalis, Prevotella intermedia, Prevotella denticola, Bacteroides forsythus, Fusobacterium nucleatum vincentii, Campylobacter gracilis, Campylobacter rectus, Eikenella corrodens, and Actinobacillus actinomycetemcomitans. In comparison, substantially higher concentrations of silver nitrate failed to kill oral streptococci. A silver nitrate concentration of 25 microg/mL produced log10 reductions in CFU/mL of 3.5-5 in killing assays performed in human serum against P. gingivalis, demonstrating the ability of silver to retain activity in a biological medium similar to that encountered in vivo in the periodontal pocket. These results identify silver nitrate, an antimicrobial that may possess advantages over traditional antibiotics, as a potential agent for controlled release local delivery in the oral cavity for the treatment of periodontitis. PMID:11327077

Spacciapoli, P; Buxton, D; Rothstein, D; Friden, P

2001-04-01

227

Antimicrobial activity of essential oil and various extracts of fruits of greater cardamom.  

PubMed

Greater cardamom (Amomum subulatum Roxb. Zingiberaceae) commonly known as "Bari ilaichi" is a well known plant used in Ayurvedic and Unani medicine. It has been used for the treatment of various diseases and disorders like gastric ulcer. Therefore antimicrobial activity of petroleum ether, methanol and aqueous extracts from leaves and roots, essential oil and isolated vasicine from A. vasica were tested against various microorganisms. Antimicrobial activity was done by disc diffusion method. The zone of inhibition observed was compared with that of standard drugs, ciprofloxacin and fluconazole. Minimum inhibitory concentration was determined against microorganisms used in the study. The results of this study reveal that methanol extract of fruits of A. subulatum shows remarkable antimicrobial activity against Escherichia coli whereas in case of other microorganisms used it was found inferior to the standard drug used. Methanol extract of rind showed good antimicrobial activity against Staphylococcus aureus. It was found that the essential oil isolated was effective against majority of microorganisms used viz. Bacillus pumilus, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Saccharomyces cerevisiae. PMID:21695005

Agnihotri, Supriya; Wakode, S

2010-09-01

228

Phytochemical screening, antioxidant, and antimicrobial activities of the crude leaves' extract from Ipomoea batatas (L.) Lam  

PubMed Central

Background: Ipomoea batatas (L.) Lam., popularly known as sweet potato (SP), has played an important role as an energy and a phytochemical source in human nutrition and animal feeding. Ethnopharmacological data show that SP leaves have been effectively used in herbal medicine to treat inflammatory and/or infectious oral diseases in Brazil. The aim of this research was to evaluate the phytochemical, antioxidant, and antimicrobial activities of the crude leaves’ extract of SP leaves. Materials and Methods: The screening was performed for triterpenes/steroids, alkaloids, anthraquinones, coumarins, flavonoids, saponins, tannins, and phenolic acids. The color intensity or the precipitate formation was used as analytical responses to these tests. The total antioxidant capacity was evaluated by the phosphomolybdenum complex method. Antimicrobial activity was made by agar disk and agar well diffusion tests. Results: The phytochemical screening showed positive results for triterpenes/steroids, alkaloids, anthraquinones, coumarins, flavonoids, saponins, tannins, and phenolic acids. Total contents of 345.65, 328.44, and 662.02 mg were respectively obtained for alkaloids, anthraquinones, and phenolic compounds in 100 g of the dry sample. The total antioxidant capacity was 42.94% as compared to ascorbic acid. For antimicrobial studies, no concentration of the SP freeze dried extract was able to inhibit the growth of Streptococcus mutans, S. mitis, Staphylococcus aureus, and Candida albicans in both agar disk and agar well diffusion tests. Conclusions: SP leaves demonstrated the presence of secondary metabolites with potential biological activities. No antimicrobial activity was observed.

Pochapski, Marcia Thais; Fosquiera, Eliana Cristina; Esmerino, Luis Antonio; dos Santos, Elizabete Brasil; Farago, Paulo Vitor; Santos, Fabio Andre; Groppo, Francisco Carlos

2011-01-01

229

Antimicrobial activity of three Mexican Gnaphalium species  

Microsoft Academic Search

The antibacterial activity of the hexane, ethyl acetate and methanol extracts of the flowers, leaves and stems of Gnaphaliumoxyphyllum var. oxyphyllum, G. liebmannii var. monticola and G. viscosum was investigated. The hexane extracts showed in all cases the higher inhibitions, G. oxyphyllum flower extract exhibiting the wider spectrum of activity.

J. Roberto Villagómez-Ibarra; Maricruz Sánchez; Ofelia Espejo; Armida Zúñiga-Estrada; J. Mart??n Torres-Valencia; Pedro Joseph-Nathan

2001-01-01

230

Antimicrobial activity of three Mexican Gnaphalium species.  

PubMed

The antibacterial activity of the hexane, ethyl acetate and methanol extracts of the flowers, leaves and stems of Gnaphalium oxyphyllum var. oxyphyllum, G. liebmannii var. monticola and G. viscosum was investigated. The hexane extracts showed in all cases the higher inhibitions, G. oxyphyllum flower extract exhibiting the wider spectrum of activity. PMID:11543972

Villagómez-Ibarra, J R; Sánchez, M; Espejo, O; Zúñiga-Estrada, A; Torres-Valencia, J M; Joseph-Nathan, P

2001-08-01

231

Antimicrobial activity of new porphyrins of synthetic and natural origin  

NASA Astrophysics Data System (ADS)

Antimicrobial photodynamic inactivation has been successfully used against Gram (+) microorganisms, but most of the photosensitizers (PSs) on Gram (-) bacteria acts weakly. PSs are the natural or synthetic origin dyes, mainly porphyrins. We have synthesized more than 100 new cationic porphyrins and metalloporphyrins with different functional groups (hydroxyethyl, butyl, allyl, methallyl) and metals (cobalt, iron, copper, zinc, silver and other); from the nettle have also been purified pheophytin (a+b) and pheophytin (a) and have synthesized their Ag-and Zn-metalloporphyrins. It was found that in the dark (cytotoxic) mode, the most highly efficiency against microorganisms showed Agmetalloporphyrins of both types of porphyrins (synthetic and natural). Metalloporphyrin of natural origin Ag-pheophytin (a + b) is a strong antibacterial agent and causes 100% death as the Gram (+) microorganisms (St. aureus and MRSA) and the Gram (-) microorganisms (E.coli and Salmonella). It is established that for the destruction of Gram (+) and Gram (-) microorganisms in photodynamic mode cationic water-soluble synthetic metalloporphyrins, especially Zn-TBut4PyP, many times more effective than pheophytins. In vivo conditions on mice established that the best therapeutic activity against various strains of the microorganism St. aureus has the synthetic metalloporphyrin Ag-TBut4PyP. It is significantly more efficient than known drug "Chlorophyllipt" (2.5-3 times) and leads the survival rate of animals up to 50-60%.

Gyulkhandanyan, Grigor V.; Ghazaryan, Robert K.; Paronyan, Marina H.; Ulikhanyan, Ghukas I.; Gyulkhandanyan, Aram G.; Sahakyan, Lida A.

2012-02-01

232

N-cholesteryl amino acid conjugates and their antimicrobial activities.  

PubMed

A series of N-cholesteryl amino acid conjugates have been synthesized using a reductive amination protocol in good yield and purity. All the synthesized conjugates were evaluated for their in vitro antimicrobial activities against Gram positive and Gram negative bacteria. Among the conjugates tested, N-cholesteryl GABA 12 showed the highest potency toward the methicillin-resistant Staphylococcus aureus with the lowest MIC value of 2?g/mL. Hemolytic activities of the compounds 3, 4, 11, and 12 were determined. All compounds tested had no significant hemolytic activity up to >50?g/mL. PMID:23872625

Jadhav, Jyoti R; Kim, Hong-Seok; Kwak, Jin-Hwan

2013-07-18

233

Analysis of the antimicrobial activities of a chemokine-derived peptide (CDAP-4) on Pseudomonas aeruginosa  

SciTech Connect

Chemokines are key molecules involved in the control of leukocyte trafficking. Recently, a novel function as antimicrobial proteins has been described. CCL13 is the only member of the MCP chemokine subfamily displaying antimicrobial activity. To determine Key residues involved in its antimicrobial activity, CCL13 derived peptides were synthesized and tested against several bacterial strains, including Pseudomonas aeruginosa. One of these peptides, corresponding to the C-terminal region of CCL13 (CDAP-4) displayed good antimicrobial activity. Electron microscopy studies revealed remarkable morphological changes after CDAP-4 treatment. By computer modeling, CDAP-4 in {alpha} helical configuration generated a positive electrostatic potential that extended beyond the surface of the molecule. This feature is similar to other antimicrobial peptides. Altogether, these findings indicate that the antimicrobial activity was displayed by CCL13 resides to some extent at the C-terminal region. Furthermore, CDAP-4 could be considered a good antimicrobial candidate with a potential use against pathogens including P. aeruginosa.

Martinez-Becerra, Francisco [Department of Immunology, Instituto de Investigaciones Biomedicas, Universidad Nacional Autonoma de Mexico, Circuito Escolar s/n, Mexico, DF, CP 04510 (Mexico); Silva, Daniel-Adriano [Department of Biochemistry, Facultad de Medicina, Universidad Nacional Autonoma de Mexico (Mexico); Dominguez-Ramirez, Lenin [Department of Biochemistry, Facultad de Medicina, Universidad Nacional Autonoma de Mexico (Mexico); Mendoza-Hernandez, Guillermo [Department of Biochemistry, Facultad de Medicina, Universidad Nacional Autonoma de Mexico (Mexico); Lopez-Vidal, Yolanda [Departamento de Microbiologia y Parasitologia, Facultad de Medicina, Universidad Nacional Autonoma de Mexico (Mexico); Soldevila, Gloria [Department of Immunology, Instituto de Investigaciones Biomedicas, Universidad Nacional Autonoma de Mexico, Circuito Escolar s/n, Mexico, DF, CP 04510 (Mexico); Garcia-Zepeda, Eduardo A. [Department of Immunology, Instituto de Investigaciones Biomedicas, Universidad Nacional Autonoma de Mexico, Circuito Escolar s/n, Mexico, DF, CP 04510 (Mexico)]. E-mail: garciaze@servidor.unam.mx

2007-04-06

234

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

235

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.

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

2008-01-01

236

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

2008-10-09

237

Antimicrobial substances produced by coliform strains active against foodborne pathogens.  

PubMed

In the present study, 31 coliform strains were isolated from salad, cheese, and meat products sold in commercial establishments in Rio de Janeiro city, and were tested for antibiotic resistance and antimicrobial substance production. Thirteen strains (41.9%) were resistant to at least one antibiotic tested, among which one presented resistance to nine different antibiotics. Two strains (6.4%) exhibited inhibitory activity against the indicator strains, Escherichia coli LMIFRJ and Salmonella enterica I. The antimicrobial substances that they produced were sensitive to proteolytic enzymes, suggesting that they might be bacteriocins. The producer strains were identified as Klebsiella ozaenae and Raoultella terrigena. Although they had similar spectrums of action, the bacteriocins were shown to be different. Both of them were able to inhibit E. coli, Klebsiella, Enterobacter, and Salmonella strains, including antibiotic-resistant ones. Our results suggest that these bacteriocins, named klebicin K and raoultellin L, could have potential use against some foodborne pathogens. PMID:19895262

Fleming, Luana Rocha; Bolzan, Dayana Nascimento; Nascimento, Janaína Dos Santos

2010-03-01

238

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

239

Antimicrobial activities of the rhizome extract of Zingiber zerumbet Linn  

PubMed Central

Objective To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet (Z. zerumbet) (L.) Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi. Methods The fresh rhizomes of Zingiber zerumbet were extracted in cold with ethanol (4.0 L) after concentration. The crude ethanol extract was fractionated by petroleum ether and chloroform to form a suspension of ethanol extract (15.0 g), petroleum ether fraction (6.6 g) and chloroform soluble fraction (5.0 g). The crude ethanol extract and its petroleum ether and chloroform fractions were evaluated for antibacterial and antifungal activity against thirteen pathogenic bacteria and three fungi by the disc diffusion method. Commercially available kanamycin (30 µg/disc) was used as standard disc and blank discs impregnated with the respective solvents were used as negative control. Results At a concentration of 400 µg/disc, all the samples showed mild to moderate antibacterial and antifungal activity and produced the zone of inhibition ranging from 6 mm to 10 mm. Among the tested samples, the crude ethanol extract showed the highest activity against Vibrio parahemolyticus (V. parahemolyticus). The minimum inhibitory concentration (MIC) of the crude ethanol extract and its fractions were within the value of 128-256 µg/mL against two Gram positive and four Gram negative bacteria and all the samples showed the lowest MIC value against V. parahemolyticus (128 µg/mL). Conclusions It can be concluded that, potent antibacterial and antifungal phytochemicals are present in ethanol extract of Z. zerumbet (L).

Kader, Golam; Nikkon, Farjana; Rashid, Mohammad Abdur; Yeasmin, Tanzima

2011-01-01

240

In vitro assay for the screening of the plaque-reducing activity of antimicrobial agents.  

PubMed

Bacteria grown in biofilms are less susceptible to antimicrobial agents than planktonic bacteria. One of the most common biofilms in humans is dental plaque. To investigate the antimicrobial activity against dental bacteria grown in biofilms, biofilms were generated with Streptococcus sanguis on hydroxyapatite disks to mimic the tooth surface. After 48 h of aerobic incubation at 37 degrees C in a continuous flow culture, a biofilm consisting of Streptococcus sanguis became visible on the surface of the disks. The disks were removed from the growth chamber and placed in different vessels containing either chlorhexidine digluconate (CAS 55-56-1, 0.1% or 1.0%), polyvinylpyrrolidone iodine (1.5% or 7.5%), or octenidine dihydrochloride (CAS 70775-75-6, 0.05% or 0.1%) for 5 or 30 min. In addition, the antiseptics were applied to the bacterial suspension in the growth chamber. A significant difference was observed in the antimicrobial activity against bacteria in the suspension liquid compared to the bacteria grown in biofilms. The best reduction factors were obtained with chlorhexidine (1.0%, 30 min) for either sessile (3.97 Ig) or planktonic bacteria (> or = 5.58 Ig). Clear relationships between the doses and times of action were found for the assessed agents. Therefore, the authors conclude that the present in vitro assay is a quick and cost-effective model to screen the activity of antimicrobial agents against bacteria grown in biofilms. PMID:12705173

Pitten, Frank-Albert; Doering, Sven; Kramer, Axel; Rosin, Michael

2003-01-01

241

Antimicrobial Activities of Lawsonia inermis - A Review  

Microsoft Academic Search

World is endowed with a rich wealth of medicinal plants. Man cannot survive on this earth for long life without the plant kingdom because the plant products and their active constituents played an important role. There is a widespread belief that green medicines are healthier and more harmless or safer than synthetic ones. Medicinal plants have been used to cure

P. Dinesh Babu; R. S. Subhasree

2009-01-01

242

Antimicrobial activity and cytotoxicity of Cirsium tenoreanum  

Microsoft Academic Search

The methanol and ethyl acetate extracts of the aerial parts of Cirsium tenoreanum, have been evaluated for their phytochemical constituents and antibacterial and cytotoxic properties. Three flavonoids, apigenin, quercetin-3-O-galactoside and kaempferol-3-O-ramnoside, were isolated. The ethyl acetate extract showed a good antiproliferative activity.

Monica Rosa Loizzo; Giancarlo A. Statti; Rosa Tundis; Filomena Conforti; Sebastiano Ando’; Francesco Menichini

2004-01-01

243

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

244

Antimicrobial activity of organic thiosulfates (Bunte salts).  

PubMed

A number of organic thiosulfates (Bunte salts) were prepared from appropriate primary bromides or iodides. In the case of substrates with long aliphatic chains, an addition of benzyltrimethylammonium chloride as phase transfer catalyst was very successful. The Bunte salts obtained were tested for antibacterial and fungicidal activity by means of the agar disc-diffusion method and by assignation of the minimum inhibitory concentrations (MIC). It was found that the microorganisms Proteus vulgaris, Candida albicans and Staphylococcus aureus showed the highest sensitivity. Biological activity of the compounds studied was dependent on the length of the aliphatic chain. Among the investigated compounds, aliphatic thiosulfates with 10-13 carbon atom chain were the most potent. PMID:9547520

Stefa?ska, J Z; Staro?ciak, B J; Orzeszko, A; Kazimierczuk, Z

1998-03-01

245

Importance and efficiency of in-depth antimicrobial activity for the control of listeria development with nisin-incorporated sodium caseinate films  

Microsoft Academic Search

The effect of antimicrobial sodium caseinate-based films was investigated on inhibition of Listeria innocua in cheese. Nisin was incorporated into sorbitol-plasticized sodium caseinate films at 1000IU\\/cm2 and the films were prepared by casting methods. Mini red Babybel® cheese was chosen as a semi-soft cheese model. The antimicrobial activity was studied based on the contact between antimicrobial films and surface-contaminated as

Lan Cao-Hoang; Lydie Grégoire; Aline Chaine; Yves Waché

2010-01-01

246

Exploitation of the antioxidant potential of Geranium macrorrhizum (Geraniaceae): hepatoprotective and antimicrobial activities.  

PubMed

In this study we evaluated in vitro (radical scavenging) and in vivo (hepatoprotective effect) antioxidant activities and antimicrobial properties of the extracts of the above- and underground parts of Geranium macrorrhizum L. (Geraniaceae), an ethnopharmacologically renowned plant species. The antioxidant activity and total phenol and flavonoid contents of four different solvent extracts were evaluated by seven different methods. The methanol extracts, administered i.p. to rats (120-480 mg/kg), were evaluated for hepatoprotective activity in a CCl4-induced hepatotoxicity model. The same extracts were tested for antimicrobial activity against seven bacterial and two fungal species. The administered methanol extracts with the highest antioxidant potential showed a significant dose-dependent hepatoprotective action against CCl4-induced liver damage in both decreasing the levels of liver transaminases and bilirubin and in reducing the extent of morphological malformations of the liver. The leaf methanol extract displayed a very strong antibacterial activity, especially against Staphylococcus aureus, with low minimal inhibitory and bactericidal concentrations. These results justify the frequent use of this plant species in folk medicine. Besides the known astringent effect, one can expect that the observed antimicrobial activity against several human pathogens contributes to the wound healing properties of this plant. PMID:23413565

Radulovi?, Niko S; Stojkovi?, Milan B; Miti?, Snezana S; Randjelovi?, Pavle J; Ili?, Ivan R; Stojanovi?, Nikola M; Stojanovi?-Radi?, Zorica Z

2012-12-01

247

Enhancing antibiofilm efficacy in antimicrobial photodynamic therapy: effect of microbubbles  

NASA Astrophysics Data System (ADS)

In this study, we tested the hypothesis that a microbubble containing photosensitizer when activated with light would enable comprehensive disinfection of bacterial biofilms in infected root dentin by antimicrobial photodynamic therapy (APDT). Experiments were conducted in two stages. In the stage-1, microbubble containing photosensitizing formulation was tested for its photochemical properties. In the stage-2, the efficacy of microbubble containing photosensitizing formulation was tested on in vitro infected root canal model, developed with monospecies biofilm models of Enterococcus faecalis on root dentin substrate. The findings from this study showed that the microbubble containing photosensitizing formulation was overall the most effective formulation for photooxidation, generation of singlet oxygen, and in disinfecting the biofilm bacteria in the infected root canal model. This modified photosensitizing formulation will have potential advantages in eliminating bacterial biofilms from infected root dentin.

Kishen, Anil; George, Saji

2013-02-01

248

Effect of Antimicrobial Peptide-Amide: Indolicidin on Biological Membranes  

PubMed Central

Indolicidin, a cationic antimicrobial tridecapeptide amide, is rich in proline and tryptophan residues. Its biological activity is intensively studied, but the details how indolicidin interacts with membranes are not fully understood yet. We report here an in situ atomic force microscopic study describing the effect of indolicidin on an artificial supported planar bilayer membrane of dipalmitoyl phosphatidylcholine (DPPC) and on purple membrane of Halobacterium salinarum. Concentration dependent interaction of the peptide and membranes was found in case of DPPC resulting the destruction of the membrane. Purple membrane was much more resistant against indolicidin, probably due to its high protein content. Indolicidin preferred the border of membrane disks, where the lipids are more accessible. These data suggest that the atomic force microscope is a powerful tool in the study of indolicidin-membrane interaction.

Vegh, Attila Gergely; Nagy, Krisztina; Balint, Zoltan; Kerenyi, Adam; Rakhely, Gabor; Varo, Gyorgy; Szegletes, Zsolt

2011-01-01

249

Preparation, characterization and in vitro antimicrobial activity of liposomal ceftazidime and cefepime against Pseudomonas aeruginosa strains  

PubMed Central

Pseudomonas aeruginosa is an opportunistic microorganism with the ability to respond to a wide variety of environmental changes, exhibiting a high intrinsic resistance to a number of antimicrobial agents. This low susceptibility to antimicrobial substances is primarily due to the low permeability of its outer membrane, efflux mechanisms and the synthesis of enzymes that promote the degradation of these drugs. Cephalosporins, particularty ceftazidime and cefepime are effective against P. aeruginosa, however, its increasing resistance has limited the usage of these antibiotics. Encapsulating antimicrobial drugs into unilamellar liposomes is an approach that has been investigated in order to overcome microorganism resistance. In this study, antimicrobial activity of liposomal ceftazidime and cefepime against P. aeruginosa ATCC 27853 and P. aeruginosa SPM-1 was compared to that of the free drugs. Liposomal characterization included diameter, encapsulation efficiency and stability. Minimum Inhibitory Concentration (MIC) was determined for free and liposomal forms of both drugs. Minimum Bactericidal Concentration (MBC) was determined at concentrations 1, 2 and 4 times MIC. Average diameter of liposomes was 131.88 nm and encapsulation efficiency for cefepime and ceftazidime were 2.29% end 5.77%, respectively. Improved stability was obtained when liposome formulations were prepared with a 50% molar ratio for cholesterol in relation to the phospholipid. MIC for liposomal antibiotics for both drugs were 50% lower than that of the free drug, demonstrating that liposomal drug delivery systems may contribute to increase the antibacterial activity of these drugs.

Torres, Ieda Maria Sapateiro; Bento, Etiene Barbosa; Almeida, Larissa da Cunha; de Sa, Luisa Zaiden Carvalho Martins; Lima, Eliana Martins

2012-01-01

250

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

251

Novel natural food antimicrobials.  

PubMed

Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry. PMID:22385168

Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

2012-01-01

252

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

253

Evaluation of three medicinal plants for anti-microbial activity  

PubMed Central

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.

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

2012-01-01

254

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

255

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.

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

2013-01-01

256

Antimicrobial effect of oxidized cellulose salts  

Microsoft Academic Search

Antimicrobial properties of oxidized cellulose and its salts in linters (-L) and microsphere (-M) form (OKCEL® H-L, OKCEL® Zn-M, OKCEL® ZnNa-L, OKCEL® ZnNa-M and OKCEL® Ag-L) were tested by a dilution method against a spectrum of microbial strains: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, Bacillus licheniformis, Aspergillus niger, Penicillium chrysogenum, Rhizopus oryzae, Scopulariopsis brevicaulis, Candida albicans and Candida tropicalis. OKCEL®

Jarmila Vytrasova; Andrea Tylsova; Iveta Brozkova; Libor Cervenka; Marcela Pejchalova; Pavel Havelka

2008-01-01

257

Differentiation of borreliacidal activity caused by immune serum or antimicrobial agents by flow cytometry.  

PubMed Central

We demonstrated that borreliacidal activity caused by immune serum and complement can easily be differentiated by flow cytometry from killing activity caused by antimicrobial agents that are commonly used for the treatment of Lyme disease. Assay suspensions containing normal or immune serum were incubated with Borrelia burgdorferi in the presence or absence of ceftriaxone, doxycycline, penicillin, and phosphomycin for 2, 8, 16, and 24 h. Samples containing killing activity were identified by using flow cytometry and acridine orange. In 30 min, the effects of immune serum and complement were easily distinguished from the killing of spirochetes by antimicrobial agents by adding fluorescein isothiocyanate-conjugated goat anti-hamster immunoglobulin. This simple procedure greatly enhanced the usefulness of the borreliacidal assay by eliminating a major source of false-positive reactions.

Liu, Y F; Lim, L C; Schell, K; Lovrich, S D; Callister, S M; Schell, R F

1994-01-01

258

Antimicrobial and antifungal activities of the extracts and essential oils of Bidens tripartita.  

PubMed

The aim of this study was to determine the antibacterial and antifungal properties of the extracts, subextracts and essential oils of Bidens tripartita flowers and herbs. In the study, twelve extracts and two essential oils were investigated for activity against different Gram-positive Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Gram-negative bacteria Escherichia coli, E. coli (beta-laktamase+), Klebsiella pneumoniae (ESBL+), Pseudomonas aeruginosa and some fungal organisms Candida albicans, C. parapsilosis, Aspergillus fumigatus, A. terreus using a broth microdilution and disc diffusion methods. The results obtained indicate antimicrobial activity of the tested extracts (except butanolic extracts), which however did not inhibit the growth of fungi used in this study. Bacteriostatic effect of both essential oils is insignificant, but they have strong antifungal activity. These results support the use of B. tripartita to treat a microbial infections and it is indicated as an antimicrobial and antifungal agent, which may act as pharmaceuticals and preservatives. PMID:19056546

Tomczykowa, Monika; Tomczyk, Micha?; Jakoniuk, Piotr; Tryniszewska, Elzbieta

2008-01-01

259

Chemical composition and antimicrobial activity of the essential oils of Anthemis xylopoda O. Schwarz from Turkey.  

PubMed

The chemical composition and the antimicrobial activity of the essential oils isolated from the leaves (LEO) and flowers (FEO) of Anthemis xylopoda, an endemic taxon of Turkey, were investigated. Borneol was the major constituent of both the oils studied (30.15 and 31.85%, respectively). The antimicrobial activities of both oils were separately evaluated against 13 microorganisms. The disc diffusion method was used for the antimicrobial activity test. Results showed that both oils of Anthemis xylopoda exhibited a significant antimicrobial activity. PMID:15507328

Uzel, A; Guvensen, A; Cetin, E

2004-12-01

260

Synergized antimicrobial activity of eugenol incorporated polyhydroxybutyrate films against food spoilage microorganisms in conjunction with pediocin.  

PubMed

Biopolymers and biopreservatives produced by microorganisms play an essential role in food technology. Polyhydroxyalkanoates and bacteriocins produced by bacteria are promising components to safeguard the environment and for food preservation applications. Polyhydroxybutyrate (PHB)-based antimicrobial films were prepared incorporating eugenol, from 10 to 200 ?g/g of PHB. The films were evaluated for antimicrobial activity against foodborne pathogens, spoilage bacteria, and fungi such as Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Bacillus cereus, Aspergillus flavus, Aspergillus niger, Penicillium sp., and Rhizopus sp. The synergistic antimicrobial activity of the films in the presence of crude pediocin was also investigated. The broth system containing pediocin (soluble form) as well as antimicrobial PHB film demonstrated an extended lag phase and a significant growth reduction at the end of 24 h against the bacteria. Crude pediocin alone could not elicit antifungal activity, while inhibition of growth and sporulation were observed in the presence of antimicrobial PHB film containing eugenol (80 ?g/g) until 7 days in the case of molds, i.e., A. niger, A. flavus, Penicillium sp., and Rhizopus sp. in potato dextrose broth. In the present study, we identified that use of pediocin containing broth in conjunction with eugenol incorporated PHB film could function in synergized form, providing effective hurdle toward food contaminating microorganisms. Furthermore, tensile strength, percent crystallinity, melting point, percent elongation to break, glass transition temperature, and seal strength of the PHB film with and without eugenol incorporation were investigated. The migration of eugenol on exposure to different liquid food simulants was also analyzed using Fourier transform infrared spectroscopy. The study is expected to provide applications for pediocin in conjunction with eugenol containing PHB film to enhance the shelf life of foods in the food industry. PMID:23666640

Narayanan, Aarthi; Neera; Mallesha; Ramana, Karna Venkata

2013-05-12

261

Antimicrobial, antioxidant, and antimutagenic activities of selected marine natural products and tobacco cembranoids.  

PubMed

Multidrug resistance (MDR) in microorganisms is a cause of major concern for clinicians and pharmaceutical industries. Continuous development of new antimicrobial drugs with multiple targets and potentials is expected to efficiently combat MDR in these microorganisms. In a continued exploration of new antimicrobial drug leads, 11 marine natural products, semisynthetic, or related synthetic analogs (1-11) and two tobacco cembranoids (12 and 13) were screened for their antimicrobial, antioxidant, and antimutagenic activities. Eight compounds showed varying levels of both antibacterial and antifungal activities. Compounds such as 17-O-methyllatrunculin-A, verongiaquinol, (1S,2E,4R,6R,7E,11E)-2,7,11-cembratriene-4,6-diol), and manzamine-A showed a broad spectrum of activity, inhibiting six of seven tested bacteria with zone of inhibition diameter from 9 to 30 mm. Four of these active compounds also showed antifungal activity. The findings of the in vitro time-kill assay of the most active compound, verongiaquinol, against Staphylococcus aureus indicated its subinhibitory effect at the level lower than the minimal inhibitory concentration (MIC) values (i.e., 2 and 4 µg/mL). At the MIC (8 µg/mL), bacterial cells were completely killed within 18 hours of incubation. DPPH free radical scavenging activity was demonstrated by five compounds in the range of 89.65-36.19% decolorization. Further, four compounds evaluated for their antimutagenic activity against the directly acting mutagens, methyl methanesulfonate and sodium azide, in Salmonella typhimurium strains, interestingly, showed no sign of mutagenicity. Verongiaquinol and manzamine A, in fact, reduced the mutagenicity by 50-75% at a dose of 5 µg/plate in different test strains. Our study seems to provide some novel antimicrobial leads with strong antioxidant potential and the associated ability of antimutagenicity. PMID:21314466

Aqil, Farrukh; Zahin, Maryam; El Sayed, Khalid A; Ahmad, Iqbal; Orabi, Khaled Y; Arif, Jamal M

2011-04-01

262

Antimicrobial effects of silver nanoparticles against bacterial cells adhered to stainless steel surfaces.  

PubMed

Given the increasing number of antibiotic-resistant bacteria and the need to synthesize new antimicrobials, silver has attracted interest in the scientific community because of its recognized antimicrobial activity. This study aimed to evaluate the antimicrobial effects of silver nanoparticles (NP) obtained by a new method and tested at concentrations of 6 ?g/ml and 60 ?g/ml against the species Staphylococcus aureus, Listeria innocua, Salmonella Choleraesuis, Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus. The ability of these nanoparticles to remove or kill vegetative cells adhered to stainless steel surfaces was also evaluated. We observed that the NP obtained with the new method, concentrated silver nanoparticles (CNP), and silver nanoparticles with added sodium chloride (NPNaCl) had high antimicrobial activities (P < 0.05). We also verified that the most effective condition for the removal of P. aeruginosa cells on stainless steel coupons (10 by 10 mm) was immersion of the surfaces in CNP. The CNP treatment produced a 5-log reduction of the microbial population after 30 to 60 min of immersion. The CNP treatment also performed better than water and sodium carbonate, a compound commonly applied in clean-in-place procedures in the food industry, in removing adherent B. cereus cells from stainless steel cylinders. Therefore, these results suggest that NP synthesized by a new procedure may be used as antimicrobials in the food industry, for example, for the sanitization of utensils that come into contact with foods. PMID:22488058

Araújo, Emiliane A; Andrade, Nélio J; da Silva, Luis Henrique M; Bernardes, Patrícia C; de C Teixeira, Alvaro V N; de Sá, João Paulo N; Fialho, José Felício Q; Fernandes, Patrícia E

2012-04-01

263

Synthesis and antimicrobial activity of newer indole semicarbazones  

Microsoft Academic Search

A series of 1-(2-Oxo-2-phenyl-ethyl)-2-phenyl-1H-indole-3yl)methylene) semicarbazone derivatives (4a–g and 6a–c) were synthesized by the condensation of derivatives of 1-(2-Oxo-2-phenyl-ethyl)-2-phenyl-1H-indole-3-carbaldehyde and semicarbazide in ethanol under microwave irradiation procedure. Both conventional and microwave-irradiated\\u000a syntheses have been carried out to compare their yields and reaction time. The structures of the synthesized compounds were\\u000a confirmed by spectral data. The antimicrobial activities of the synthesized compounds

S. Vijaya Laxmi; B. Rajitha

264

Cyclopeptide alkaloids from Scutia buxifolia Reiss and their antimicrobial activity.  

PubMed

The present study reports a cyclopeptide alkaloid, scutianine M, isolated from the methanolic root bark extract of Scutia buxifolia Reiss (Rhamnaceae) along with six known compounds, scutianines-B, -C, -D, -E, -F, and scutianene D. Its structure was established on the basis of spectroscopic analyses, including application of 2D NMR spectroscopic techniques. As part of a study of the bioactive compounds of medicinal plants from southern Brazil, we also compared the antimicrobial activity of the isolated compounds towards Gram (+), Gram (-) bacteria, and yeasts. PMID:16226284

Morel, Ademir F; Maldaner, Graciela; Ilha, Vinicius; Missau, Fabiana; Silva, Ubiratan F; Dalcol, Ionara I

2005-10-13

265

Antimicrobial activity of some endemic plants growing in the Eastern Black Sea Region, Turkey.  

PubMed

The Eastern Black Sea Region has an extensive flora because of ample rainfall lasting all year. In this study, antimicrobial effects of 74 crude extracts of 22 endemic plants were investigated. Among the 30 active crude extracts, water-insoluble crude extracts from Betula medwediewii, Heracleum platytaenium, Primula longipes, Anthemis cretica ssp. argaea and Centaurea helenioides were the prominent ones with their MIC values. PMID:16716535

Buruk, Kurtulus; Sokmen, Atalay; Aydin, Faruk; Erturk, Murat

2006-04-18

266

Determination of antimicrobial activity and resistance to oxidation of moringa peregrina seed oil.  

PubMed

The antimicrobial activity of the oil extracted with n-hexane from the seeds of Moringa peregrina was tested against Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Candida albicans, C. tropicalis and C. glabrata. The oil proved effective against all of the tested microorganisms. Standard antibiotics (netilmycin, 5-flucytocine, intraconazole and 7-amino-4-methylcoumarin-3-acetic acid) were used for comparison. The resistance to oxidation of the extracted seed oil was also determined. PMID:22367027

Lalas, Stavros; Gortzi, Olga; Athanasiadis, Vasilios; Tsaknis, John; Chinou, Ioanna

2012-02-24

267

Antidiarrhoeal and antimicrobial activities of Emilia coccinea (Sims) G. Don extracts  

Microsoft Academic Search

Emilia coccinea (Sims) G. Don is reported to possess a number of medicinal properties including antidiarrhoeal and antimicrobial activities. The antidiarrhoeal effects of both methanol and aqueous extracts of the leaves of Emilia coccinea were studied in rats against castor oil-induced diarrhoea at the doses of 200, 400 and 600mg\\/kg body weight. The methanol extract, and to a lesser extent

Gerald Ngo Teke; Jules Roger Kuiate; Omer Bébe Ngouateu; Donatien Gatsing

2007-01-01

268

Anti-allergic and anti-microbial activities of some Thai crops  

Microsoft Academic Search

Thirteen Thai crops including banana, okra, jackfruit, germinated rice, rambutan, durian, jampadah, huasa potato, tamarind, coconut, mango, fan palm fruit and dioscorea tuber were tested for anti-allergic effect using RBL-2H3 cells and anti-microbial activity. These 13 crops, some of which included different parts, e.g. skin, flesh, and seed, were extracted with four solvents separately ((95% ethanol (EtOH), 50% EtOH, water

Supinya Tewtrakul; Arunporn Itharat; Piboon Thammaratwasik; Buncha Ooraikul

269

The production of antimicrobial compounds by British marine algae. IV. Variation of antimicrobial activity with algal generation  

Microsoft Academic Search

Using Staphylococcus aureus and Escherichia coli as test organisms, various life-cycle phases of 22 species of British marine algae were screened for antimicrobial activity. The species examined were members of the three major seaweed groups: Rhodophyta, Phaeophyta and Chlorophyta. The growth forms of the two species of Chlorophyta investigated exhibited no variation in activity and of the 10 species of

I. S. Hornsey; D. Hide

1985-01-01

270

In vitro antimicrobial activities of cinnamon bark oil, anethole, carvacrol, eugenol and guaiazulene against Mycoplasma hominis clinical isolates.  

PubMed

AIMS: The aim of this study was to evaluate the antimicrobial effects of five natural substances against 50 clinical isolates of Mycoplasma hominis. METHODS AND RESULTS: The in vitro activity of selected natural compounds, cinnamon bark oil, anethole, carvacrol, eugenol and guaiazulene, was investigated against 50 M. hominis isolates cultivated from cervical swabs by the broth dilution method. All showed valuable antimicrobial activity against the tested isolates. Oil from the bark of Cinnamomum zeylanicum (MBC(90) = 500 µg/mL) however was found to be the most effective. Carvacrol (MBC(90) = 600 µg/mL) and eugenol (MBC(90) = 1000 µg/mL) also possessed strong antimycoplasmal activity. CONCLUSIONS: The results indicate that cinnamon bark oil, carvacrol and eugenol have strong antimycoplasmal activity and the potential for use as antimicrobial agents in the treatment of mycoplasmal infections. PMID:23128812

Sleha, Radek; Mosio, Petra; Vydrzalova, Marketa; Jantovska, Alexandra; Bostikova, Vanda; Mazurova, Jaroslava

2012-10-30

271

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.

Olajuyigbe, Olufunmiso O.; Afolayan, Anthony J.

2012-01-01

272

Antimicrobial activity of essential oils from mediterranean aromatic plants against several foodborne and spoilage bacteria.  

PubMed

The antimicrobial activity of essential oils extracted from a variety of aromatic plants, often used in the Portuguese gastronomy was studied in vitro by the agar diffusion method. The essential oils of thyme, oregano, rosemary, verbena, basil, peppermint, pennyroyal and mint were tested against Gram-positive (Listeria monocytogenes, Clostridium perfringens, Bacillus cereus, Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, and Staphylococcus epidermidis) and Gram-negative strains (Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa). For most essential oils examined, S. aureus, was the most susceptible bacteria, while P. aeruginosa showed, in general, least susceptibility. Among the eight essential oils evaluated, thyme, oregano and pennyroyal oils showed the greatest antimicrobial activity, followed by rosemary, peppermint and verbena, while basil and mint showed the weakest antimicrobial activity. Most of the essential oils considered in this study exhibited a significant inhibitory effect. Thyme oil showed a promising inhibitory activity even at low concentration, thus revealing its potential as a natural preservative in food products against several causal agents of foodborne diseases and food spoilage. In general, the results demonstrate that, besides flavoring the food, the use of aromatic herbs in gastronomy can also contribute to a bacteriostatic effect against pathogens. PMID:23444311

Silva, Nuno; Alves, Sofia; Gonçalves, Alexandre; Amaral, Joana S; Poeta, Patricia

2013-02-26

273

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.

2012-01-01

274

Distinct antimicrobial activities in aphid galls on Pistacia atlantica  

PubMed Central

Gall-formers are parasitic organisms that manipulate plant traits for their own benefit. Galls have been shown to protect their inhabitants from natural enemies such as predators and parasitoids by various chemical and mechanical means. Much less attention, however, has been given to the possibility of defense against microbial pathogens in the humid and nutrient-rich gall environment. We found that the large, cauliflower-shaped, galls induced by the aphid Slavum wertheimae on buds of Pistacia atlantica trees express antibacterial and antifungal activities distinct from those found in leaves. Antibacterial activity was especially profound against Bacillus spp (a genus of many known insect pathogen) and against Pseudomonas aeruginosa (a known plant pathogen). Antifungal activity was also demonstrated against multiple filamentous fungi. Our results provide evidence for the protective antimicrobial role of galls. This remarkable antibacterial and antifungal activity in the galls of S. wertheimae may be of agricultural and pharmaceutical value.

Yoram, Gerchman; Inbar, Moseh

2011-01-01

275

Chemical constituents and antimicrobial activities of Canthium horridum.  

PubMed

Bioassay-guided isolation studies of the extract of Canthium horridum Bl. stem led to the isolation of ten compounds: (+)-syringaresinol (1), scoparone (2), scopoletin (3), 3'-methoxy-4'-hydroxy-trans-cinnamaldehyde (4), sinapic aldehyde (5), syringic acid (6), mannitol (7), vanillic acid 4-O-beta-D-glucopyranoside (8), beta-daucosterol (9), and beta-sitosterol (10). Compounds 1-10 were reported for the first time from this species, and compounds 1, 4, 5, 6, and 8 from the genus. The antimicrobial activities of the isolated compounds were studied; 6 had the highest activity against Bacillus subtilis, but 1 showed good activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Compounds 2, 4 and 6 also inhibited the growth of these three bacteria. None of the compounds demonstrated inhibitory activity against Aspergillus niger. PMID:20614823

Yang, Biao; Chen, Guangying; Song, Xiaoping; Chen, Zhong; Song, Xinming; Wang, Jing

2010-06-01

276

Distinct antimicrobial activities in aphid galls on Pistacia atlantica.  

PubMed

Gall-formers are parasitic organisms that manipulate plant traits for their own benefit. Galls have been shown to protect their inhabitants from natural enemies such as predators and parasitoids by various chemical and mechanical means. Much less attention, however, has been given to the possibility of defense against microbial pathogens in the humid and nutrient-rich gall environment. We found that the large, cauliflower-shaped, galls induced by the aphid Slavum wertheimae on buds of Pistacia atlantica trees express antibacterial and antifungal activities distinct from those found in leaves. Antibacterial activity was especially profound against Bacillus spp (a genus of many known insect pathogen) and against Pseudomonas aeruginosa (a known plant pathogen). Antifungal activity was also demonstrated against multiple filamentous fungi. Our results provide evidence for the protective antimicrobial role of galls. This remarkable antibacterial and antifungal activity in the galls of S. wertheimae may be of agricultural and pharmaceutical value. PMID:22105034

Gerchman, Yoram; Inbar, Moshe

2011-12-01

277

Antimicrobial activities of pomegranate rind extracts: enhancement by addition of metal salts and vitamin C  

Microsoft Academic Search

BACKGROUND: Punica granatum L. or pomegranates, have been reported to have antimicrobial activity against a range of Gram positive and negative bacteria. Pomegranate formulations containing ferrous salts have enhanced although short-term, antibacteriophage activities which are rapidly diminished owing to instability of the ferrous combination. The aim of this study was to determine the antimicrobial activities of combinations of pomegranate rind

Erin M McCarrell; Simon WJ Gould; Mark D Fielder; Alison F Kelly; Waffa El Sankary; Declan P Naughton

2008-01-01

278

Antimicrobial activity of aerial parts of Drosera peltata Smith on oral bacteria  

Microsoft Academic Search

The antimicrobial activity of extracts of aerial parts of Drosera peltata Smith against oral bacteria was investigated using agar diffusion and dilution micromethods. The chloroformic extract, active against all the bacteria tested, showed the most significant antimicrobial properties. Plumbagin, isolated from the extract, is the active principle. Results obtained suggest that Drosera peltata extract could be used in the treatment

Nicole Didry; Luc Dubreuil; Francis Trotin; Madeleine Pinkas

1998-01-01

279

Evaluation of the Antioxidant and Antimicrobial Activities of Clary Sage (Salvia sclarea L.)  

Microsoft Academic Search

The present work evaluates the antioxidant and antimicrobial activity of clary sage (CS) Salvia sclarea L. Antimicrobial, total antioxidant, DPPH radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities, reducing power, and total contents of phenolic compounds of dried herb samples extracted with chloroform and acetone were studied. The chloroform extract had stronger total antioxidant activity

Münir OKTAY

2004-01-01

280

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

2010-04-24

281

Antimicrobial activities of tea catechins and theaflavins and tea extracts against Bacillus cereus.  

PubMed

We evaluated the antimicrobial activities of seven green tea catechins and four black tea theaflavins, generally referred to as flavonoids, as well as the aqueous extracts (infusions) of 36 commercial black, green, oolong, white, and herbal teas against Bacillus cereus (strain RM3190) incubated at 21 degrees C for 3, 15, 30, and 60 min. The results obtained demonstrate that (i) (-)-gallocatechin-3-gallate, (-)-epigallocatechin-3-gallate, (-)-catechin-3-gallate, (-)-epicatechin-3-gallate, theaflavin-3, 3'-digallate, theaflavin-3'-gallate, and theaflavin-3-gallate showed antimicrobial activities at nanomolar levels; (ii) most compounds were more active than were medicinal antibiotics, such as tetracycline or vancomycin, at comparable concentrations; (iii) the bactericidal activities of the teas could be accounted for by the levels of catechins and theaflavins as determined by high-pressure liquid chromatography; (iv) freshly prepared tea infusions were more active than day-old teas; and (v) tea catechins without gallate side chains, gallic acid and the alkaloids caffeine and theobromine also present in teas, and herbal (chamomile and peppermint) teas that contain no flavonoids are all inactive. These studies extend our knowledge about the antimicrobial effects of food ingredients. PMID:16496576

Friedman, Mendel; Henika, Philip R; Levin, Carol E; Mandrell, Robert E; Kozukue, Nobuyuki

2006-02-01

282

Persistence of antimicrobial activity through sustained release of triclosan from pegylated silicone elastomers.  

PubMed

Microbial adhesion to silicone elastomer biomaterials is a major problem often resulting in infection and medical device failure. Several strategies have been employed to modulate eukaryotic cell adhesion and to hamper bacterial adherence to polymeric biomaterials. Chemical modification of the surface by grafting of polyethylene glycol (PEG) chains or the incorporation of non-antibiotic antimicrobial agents such as triclosan into the biomaterial matrix may reduce bacterial adhesion. Here, such strategies are simultaneously applied to the preparation of both condensation-cure and addition-cure silicone elastomer systems, seeking a sustained release antimicrobial device biomaterial. The influence of triclosan incorporation and degree of pegylation on antimicrobial release, surface microbial adherence and persistence (Escherichia coli and Staphylococcus epidermidis) were evaluated in vitro. Non-pegylated silicone elastomers provided an increased percentage release of triclosan extending over a relatively short duration (99% release by day 64) compared with their pegylated (4% w/w) counterparts (65% and 72% release by day 64, for condensation and addition-cure systems respectively). Viable E. coli adherence to a non-pegylated silicone elastomer containing 1% w/w triclosan was reduced by over 99% after 24 h compared to the non-pegylated silicone elastomer containing no triclosan. No viable S. epidermidis adhered to any of the triclosan-loaded (>0.1% w/w) formulations other than the control. Persistence of the antimicrobial activity of the triclosan-loaded pegylated silicone elastomers continued for at least 70 days compared to the triclosan-loaded non-pegylated elastomers (at least 49 days). Understanding how PEG affects the release of triclosan from silicone elastomers may prove useful in the development of a biomaterial providing prolonged, effective antimicrobial activity. PMID:19765822

McBride, Marcella C; Karl Malcolm, R; David Woolfson, A; Gorman, Sean P

2009-09-17

283

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

2012-10-12

284

Synthesis, characterization and antimicrobial activity of novel xanthene sulfonamide and carboxamide derivatives.  

PubMed

Xanthene intermediates 4a and 4b were obtained from the reduction of nitro xanthene derivatives 3a and 3b which were synthesized via condensation of dimedone with m-nitrobenzaldehyde and p-nitrobenzaldehyde, respectively. Then xanthene sulfonamide 6a-n, and xanthene carboxamide derivatives 8a-h were synthesized by reaction of amino xanthene 4a, 4b with sulfonyl chlorides 5a-g and acyl chlorides 7a-d. Structures of the novel amino xanthene compounds and xanthene sulfonamide/carboxamide derivatives were established by their spectral data and elemental analyses. Furthermore, all the synthesized compounds were tested in vitro for their antimicrobial activity. The results were compared with reference standard antibiotics, erythromycin and nystatin. 6c, 6f, 6m and 8b Compounds were found to display most effective antimicrobial activity against a series of bacteria and fungi. PMID:22803669

Kaya, Muharrem; Demir, Ersin; Bekci, Hatice

2012-07-18

285

Quinolone molecular structure-activity relationships: what we have learned about improving antimicrobial activity.  

PubMed

Recently, understanding of how molecular modifications of the core quinolone structure affect(s) antimicrobial agent activity has progressed rapidly. Three positions (2, 3, and 4) cannot be changed without a significant loss of biological activity. Furthermore, it appears that a cyclopropyl group is optimal at position 1. Substituents at positions 5 and 8 affect planar configuration, and either a methyl or methoxy appear optimal at these sites. Hydrogen and amino groups have been investigated as useful substituents at position 6, replacing the fluorine of the fluoroquinolones. Interestingly, in vitro activity enhancement observed with alterations at positions 5 and 6 is not always accompanied by improved in vivo action. For all these modifications, the substituents at positions 7 and 8 are critical for potent antimicrobial activity. Optimizing overall molecular configuration enhances the number of intracellular targets for antimicrobial action (R-8) and impedes the efficiency of efflux proteins (R-7) that diminish intracellular penetration. PMID:11524717

Peterson, L R

2001-09-15

286

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.

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

2013-01-01

287

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

2013-03-04

288

Alternative Hand Contamination Technique To Compare the Activities of Antimicrobial and Nonantimicrobial Soaps under Different Test Conditions?  

PubMed Central

Antimicrobial hand soaps provide a greater bacterial reduction than nonantimicrobial soaps. However, the link between greater bacterial reduction and a reduction of disease has not been definitively demonstrated. Confounding factors, such as compliance, soap volume, and wash time, may all influence the outcomes of studies. The aim of this work was to examine the effects of wash time and soap volume on the relative activities and the subsequent transfer of bacteria to inanimate objects for antimicrobial and nonantimicrobial soaps. Increasing the wash time from 15 to 30 seconds increased reduction of Shigella flexneri from 2.90 to 3.33 log10 counts (P = 0.086) for the antimicrobial soap, while nonantimicrobial soap achieved reductions of 1.72 and 1.67 log10 counts (P > 0.6). Increasing soap volume increased bacterial reductions for both the antimicrobial and the nonantimicrobial soaps. When the soap volume was normalized based on weight (?3 g), nonantimicrobial soap reduced Serratia marcescens by 1.08 log10 counts, compared to the 3.83-log10 reduction caused by the antimicrobial soap (P < 0.001). The transfer of Escherichia coli to plastic balls following a 15-second hand wash with antimicrobial soap resulted in a bacterial recovery of 2.49 log10 counts, compared to the 4.22-log10 (P < 0.001) bacterial recovery on balls handled by hands washed with nonantimicrobial soap. This indicates that nonantimicrobial soap was less active and that the effectiveness of antimicrobial soaps can be improved with longer wash time and greater soap volume. The transfer of bacteria to objects was significantly reduced due to greater reduction in bacteria following the use of antimicrobial soap.

Fuls, Janice L.; Rodgers, Nancy D.; Fischler, George E.; Howard, Jeanne M.; Patel, Monica; Weidner, Patrick L.; Duran, Melani H.

2008-01-01

289

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.

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

2011-01-01

290

Uptake, transport, delivery, and intracellular activity of antimicrobial agents.  

PubMed

Antibiotic interactions with cells, including polymorphonuclear neutrophils, may influence therapeutic outcomes. Selected microbes (e.g., Legionella pneumophila) may survive ingestion by polymorphonuclear neutrophils and are thus protected from the action of antimicrobial agents that remain extracellular. Antibiotics that penetrate the cell can kill these microbes. Certain antibiotics are concentrated inside phagocytes, and when the phagocyte migrates toward the site of infection, the antibiotic-loaded cell carries the active agent to the infecting microbes. Active antibiotic may be released when the short-lived phagocyte dies. Even microbes considered to be extracellular pathogens, such as pneumococci, may survive high concentrations of antibiotic by entering cells. Antibiotics that penetrate and are active in cells may aid in enhancing therapeutic outcomes and in eliminating the carrier state for some pathogens. PMID:16305282

Mandell, Gerald L

2005-12-01

291

Novel, UV-curable coatings containing a tethered biocide: Synthesis, characterization, and antimicrobial activity.  

PubMed

Cationic, UV -curable coatings containing the tethered biocide, triclosan, were produced and their antimicrobial activity toward Staphylococcus epidermidis and Escherichia coli determined. Two polysiloxanes functionalized with both cycloaliphatic epoxy and triclosan were synthesized using hydrosilylation. The functionalized polysiloxanes, with varied concentration of pendant triclosan, were used to produce UV-curable coatings with reasonably good coating properties. Fourier transform (FT)-Raman spectroscopy showed that the tethered triclosan moieties self-concentrate on the coating surface. Using biological assays, it was determined that the coatings possessed nearly 100% antimicrobial activity toward the Gram-positive bacterium, S. epidermidis, without leaching toxic components. For the Gram-negative bacterium, E. coli, 60-80% reduction in biofilm retention was observed for all the coatings. Interestingly, the coatings were lesser effective in reducing E. coli cell viability suggesting that the tethered triclosan were able to substantially reduce the production of the biofilm extracellular matrix with minimal adverse affect on the bacterial cells attached to the coating surfaces. The high specificity of the coatings toward S. epidermidis indicates that a novel mode of contact-active antimicrobial activity was achieved through the disruption of processes unique to the Gram-positive cell wall. These novel UV-curable coatings have potential applications in inhibiting implantable biomedical device associated infections. PMID:20665625

Chen, Zhigang; Chisholm, Bret J; Stafslien, Shane; He, Jie; Patel, Sandeep

2010-11-01

292

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

293

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.

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

2008-01-01

294

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

295

Silanols, a New Class of Antimicrobial Agent.  

National Technical Information Service (NTIS)

Alkyldimethylsilanols, R(CH3)2SiOH, were recently reported to exhibit unexpectedly strong antimicrobial effects. The antimicrobial activities of alkyldimethylsilanols were significantly higher than their analogous alcohols. A study of structural dependenc...

R. H. Baney S. Farrah Y. Kim

2006-01-01

296

Antimicrobial activities and usage in folkloric medicine of some Lamiaceae species growing in Mugla, Turkey  

Microsoft Academic Search

In this study; 23 selected plant species belonging to the Lamiaceae family, used in traditional treatments, were collected from different localities of Mugla, dried and extracted with ethanol using the soxhlet extraction apparatus. The antimicrobial activities of the plant extracts on the various test microorganisms, including multiple antibiotic resistant bacteria, were investigated. Antimicrobial activities of the extracts were determined by

Nurdan Sarac; Aysel Ugur

2007-01-01

297

Polarity Based Solvents Extraction of Opuntia Dillenii and Zingiber Officinale for In-vitro Antimicrobial Activities  

Microsoft Academic Search

Extracts from dried stem of Opuntia dillenii and rhizome of Zingiber officinale were evaluated for antimicrobial activities by extraction in non-polar (petroleum ether and chloroform) and polar solvents (methanol and water). Bacillus subtilis and Staphylococcus aureus showed considerable susceptibility to all extracts of Opuntia dillenii and Zingiber officinale. Ether and chloroform extracts of Opuntia dillenii showed improved antimicrobial activity against

Muhammad Ihtisham Umar; Aqeel Javeed; Muhammad Ashraf; Amjad Riaz; Muhammad Mahmood Mukhtar; Sheryar Afzal; Rabia Altaf

2011-01-01

298

In Vitro Antimicrobial Activity of Extracts of Passiflora edulis (Passifloraceae) and Sphaeranthus indicus (Asteraceae)  

Microsoft Academic Search

The organic extracts of Passiflora edulis and Sphaeranthus indicus were evaluated for antimicrobial activity against clinically important bacteria, viz., Escherichia coli MTCC 443, Salmonella typhi MTCC 734, Staphylococus aureus MTCC 737, Bacillus subtilis, Streptococcus pyogens, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, Aspergillus flavus, Pencillium restrictum, and Trichoderma viride. The in vitro antimicrobial activity was performed by agar disc diffusion method.

Asirvatham Doss; Pichai Anthoni Doss; Rangasamy Dhanabalan

2008-01-01

299

Antimicrobial Activity of Bacillus amyloliquefaciens LBM 5006 is Enhanced in the Presence of Escherichia coli  

Microsoft Academic Search

Increased antimicrobial activity was observed when Bacillus amyloliquefaciens LBM 5006 strain was cultivated in the presence of thermally inactivated cells of Escherichia coli, but not with Staphylococcus aureus, Listeria monocytogenes, or Bacillus cereus. E. coli also enhanced the antimicrobial activity when it was added to the medium in the form of living cells or as cell debris after\\u000a cellular fractionation.

Lisianne Benitez; AnaPaula Correa; Daniel Daroit; Adriano Brandelli

2011-01-01

300

In vitro evaluation of antimicrobial activity of Kutajghan vati - an Ayurvedic formulation.  

PubMed

The present investigation focuses to determine the antimicrobial potential of an Ayurvedic formulation Kutajghan vati. In this study the activity of this formulation was compared with the standard antibiotics like Amikacin and Norfloxacin. Ethanol, methanol and acetone extract of Kutajghan vati demonstrated good antimicrobial activity and thus can form the basis for the development of a novel antibacterial formulation. PMID:22713963

Lather, Amit; Gupta, Vikas; Chaudhary, Amrendra Kumar; Singh, Ranjit; Bansal, Parveen; Ghaiye, Pankaj; Bansal, Renu

2012-07-01

301

Phytochemical analysis of Gymnema sylvestre and evaluation of its antimicrobial activity  

Microsoft Academic Search

Gymnema sylvestre (CS 149), known to be a rich source of saponins and other valuable phytochemicals, has been analysed for antimicrobial activity. The chloroform extracts of aerial and root parts of G. sylvestre exhibited higher antimicrobial activity as compared to diethyl ether and acetone. The root extracts of chloroform have shown competitive minimum inhibitory concentration and minimum bactericidal concentration values

Bhuvaneswari Chodisetti; Kiranmayee Rao; Archana Giri

2012-01-01

302

Antimicrobial susceptibilities of multidrug-resistant Campylobacter jejuni and C. coli strains: in vitro activities of 20 antimicrobial agents.  

PubMed

There is a paucity of information regarding antimicrobial agents that are suitable to treat severe infections caused by multidrug-resistant Campylobacter spp. Our aim was to identify agents that are potentially effective against multiresistant Campylobacter strains. The in vitro activities of 20 antimicrobial agents against 238 Campylobacter strains were analyzed by determining MICs by the agar plate dilution method or the Etest. These strains were selected from 1,808 Campylobacter isolates collected from Finnish patients between 2003 and 2005 and screened for macrolide susceptibility by using the disk diffusion test. The 238 strains consisted of 183 strains with erythromycin inhibition zone diameters of < or =23 mm and 55 strains with inhibition zone diameters of >23 mm. Of the 238 Campylobacter strains, 19 were resistant to erythromycin by MIC determinations (MIC > or = 16 microg/ml). Given that the resistant strains were identified among the collection of 1,808 isolates, the frequency of erythromycin resistance was 1.1%. All erythromycin-resistant strains were multidrug resistant, with 18 (94.7%) of them being resistant to ciprofloxacin (MIC > or = 4 microg/ml). The percentages of resistance to tetracycline and amoxicillin-clavulanic acid (co-amoxiclav) were 73.7% and 31.6%, respectively. All macrolide-resistant strains were susceptible to imipenem, meropenem, and tigecycline. Ten (52.6%) multiresistant strains were identified as being Campylobacter jejuni strains, and 9 (47.4%) were identified as being C. coli strains. These data demonstrate that the incidence of macrolide resistance was low but that the macrolide-resistant Campylobacter strains were uniformly multidrug resistant. In addition to the carbapenems, tigecycline was also highly effective against these multidrug-resistant Campylobacter strains in vitro. Its efficacy for the treatment of human campylobacteriosis should be evaluated in clinical trials. PMID:20038624

Lehtopolku, Mirva; Nakari, Ulla-Maija; Kotilainen, Pirkko; Huovinen, Pentti; Siitonen, Anja; Hakanen, Antti J

2009-12-28

303

Antimicrobial Susceptibilities of Multidrug-Resistant Campylobacter jejuni and C. coli Strains: In Vitro Activities of 20 Antimicrobial Agents ?  

PubMed Central

There is a paucity of information regarding antimicrobial agents that are suitable to treat severe infections caused by multidrug-resistant Campylobacter spp. Our aim was to identify agents that are potentially effective against multiresistant Campylobacter strains. The in vitro activities of 20 antimicrobial agents against 238 Campylobacter strains were analyzed by determining MICs by the agar plate dilution method or the Etest. These strains were selected from 1,808 Campylobacter isolates collected from Finnish patients between 2003 and 2005 and screened for macrolide susceptibility by using the disk diffusion test. The 238 strains consisted of 183 strains with erythromycin inhibition zone diameters of ?23 mm and 55 strains with inhibition zone diameters of >23 mm. Of the 238 Campylobacter strains, 19 were resistant to erythromycin by MIC determinations (MIC ? 16 ?g/ml). Given that the resistant strains were identified among the collection of 1,808 isolates, the frequency of erythromycin resistance was 1.1%. All erythromycin-resistant strains were multidrug resistant, with 18 (94.7%) of them being resistant to ciprofloxacin (MIC ? 4 ?g/ml). The percentages of resistance to tetracycline and amoxicillin-clavulanic acid (co-amoxiclav) were 73.7% and 31.6%, respectively. All macrolide-resistant strains were susceptible to imipenem, meropenem, and tigecycline. Ten (52.6%) multiresistant strains were identified as being Campylobacter jejuni strains, and 9 (47.4%) were identified as being C. coli strains. These data demonstrate that the incidence of macrolide resistance was low but that the macrolide-resistant Campylobacter strains were uniformly multidrug resistant. In addition to the carbapenems, tigecycline was also highly effective against these multidrug-resistant Campylobacter strains in vitro. Its efficacy for the treatment of human campylobacteriosis should be evaluated in clinical trials.

Lehtopolku, Mirva; Nakari, Ulla-Maija; Kotilainen, Pirkko; Huovinen, Pentti; Siitonen, Anja; Hakanen, Antti J.

2010-01-01

304

An amino acid composition criterion for membrane active antimicrobials  

NASA Astrophysics Data System (ADS)

Membrane active antimicrobials (AMPs) are short amphipathic peptides with broad spectrum anti microbial activity. While it is believed that their hydrophobic and cationic moieties are responsible for membrane-based mechanisms of action, membrane disruption by AMPs is manifested in a diversity of outcomes, such as pore formation, blebbing, and budding. This complication, along with others, have made a detailed, molecular understanding of AMPs difficult. We use synchrotron small angle xray scattering to investigate the interaction of model bacterial and eukaryotic cell membranes with archetypes from beta-sheet AMPs (e.g. defensins) and alpha-helical AMPs (e.g. magainins). The relationship between membrane composition and peptide induced changes in membrane curvature and topology is examined. By comparing the membrane rearrangement and phase behavior induced by these different peptides we will discuss the importance of amino acid composition on AMP design.

Schmidt, Nathan; Hwee Lai, Ghee; Mishra, Abhijit; Bong, Dennis; McCray, Paul, Jr.; Selsted, Michael; Ouellette, Andre; Wong, Gerard

2011-03-01

305

Characterization of antimicrobial peptide activity by electrochemical impedance spectroscopy  

PubMed Central

Summary Electrochemical impedance spectroscopy performed on surface-supported bilayer membranes allows for the monitoring of changes in membrane properties, such as thickness, ion permeability, and homogeneity, after exposure to antimicrobial peptides (AMPs). We show that two model cationic peptides, very similar in sequence but different in activity, induce dramatically different changes in membrane properties as probed by impedance spectroscopy. Moreover, the impedance results excluded the “barrel-stave” and the “toroidal pore” models of AMP mode of action, and are more consistent with the “carpet” and the “detergent” models. The impedance data provide important new insights about the kinetics and the scale of the peptide action which currently are not addressed by the “carpet” and the “detergent” models. The method presented not only provides additional information about the mode of action of a particular AMP, but offers a means of characterizing AMP activity in reproducible, well-defined quantitative terms.

Chang, William K.; Wimley, William C.; Searson, Peter C.; Hristova, Kalina; Merzlyakov, Mikhail

2008-01-01

306

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

307

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

308

Effect of antimicrobial agents on livestock waste emissions.  

PubMed

Various antimicrobial agents were evaluated with the purpose of reducing the microbial fermentation in stored cattle waste and the resulting odor emissions. Duplicate sealed 2-L flasks with 500 ml waste slurry, with and without antimicrobial inhibitors, were used to measure the production of short-chain volatile fatty acids, lactate, and total fermentation gas over 27-30 days. A combination of chlorhexidine diacetate (2 mM), iodoacetate (2 mM), and alpha-pinene (3.8 mM) reduced gas production 80% (1000 ml to 200 ml) and total volatile fatty acid production 50% (145 mM to 72 mM). Pinene had little antimicrobial effect; rather, it served as an effective masking agent, giving the waste a less offensive odor. A combination of chlorhexidine diacetate and the deaminase inhibitor, diphenyliodonium chloride (1.3 mM) had a similar effect in reducing short-chain volatile fatty acid production (145 mM to 80 mM). It is concluded that a combination of antimicrobial agents may be useful in controlling odor emissions and conserving organic matter in livestock wastes, therefore providing a potentially more useful byproduct waste when used as plant fertilizer. PMID:10827282

Varel, V H; Miller, D N

2000-06-01

309

[In vitro activity of antimicrobial agents against clinical isolates of Pseudomonas aeruginosa].  

PubMed

Two hundred and seven clinical isolates of Pseudomonas aeruginosa were collected at Tenri Hospital between April 2003 and March 2004. We determined the minimum inhibitory concentration (MIC) of 16 antimicrobial agents, including prulifloxacin, pazufloxacin and biapenem which were recently published in Japan, against these isolates according to the guidelines of the Clinical and Laboratory Standards Institute. For the fluoroquinolones, the rank order of activity was prulifloxacin (MIC50, 0.5 microg/ml)>ciprofloxacin (1 microg/ml)> pazufloxacin (2 microg/ml)=levofloxacin (2 microg/ml)>gatifloxacin (4 microg/ml). For the carbapenems, the rank order of activity was meropenem (MIC50, 1 microg/ml)=biapenem (1 microg/ml)>imipenem (2 microg/m)>panipenem (8 microg/ml). For the cephalosporins and monobactam, the overall rank order of activity was cefozopran (MIC50, 4 microg/ml)= ceftazidime (4 microg/ml)>cefepime (8 microg/ml)=piperacillin/tazobactam (8 microg/ml)>aztreonam (16 microg/ml)= cefoperazone/sulbactam (16 microg/ml)=cefpirome (16 microg/ml). The rates of susceptibility to antimicrobial agents as per the criteria of the Japanese Society of Antimicrobial Chemotherapy were especially high for cefozopran (63%), biapenem and meropenem (61%), and pazufloxacin (53%) and ciprofloxacin (53%). These findings suggest that prulifloxacin, pazufloxacin and biapenem, which are newly introduced, are clinically effective in the treatment of infection caused with P. aeruginosa. PMID:16379156

Abe, Noriyuki; Komatsu, Masaru; Iwasaki, Mizuho; Nagasaka, Yoko; Fukuda, Saori; Matsuo, Shuji; Shimakawa, Koichi

2005-10-01

310

Chemical composition, and antioxidant and antimicrobial activities of three hazelnut (Corylus avellana L.) cultivars.  

PubMed

Hazelnut (Corylus avellana L.) is a very popular dry fruit in the world being consumed in different form and presentations. In the present work, three hazelnut cultivars (cv. Daviana, Fertille de Coutard and M. Bollwiller) produced in Portugal, were characterized in respect to their chemical composition, antioxidant potential and antimicrobial activity. The samples were analysed for proximate constituents (moisture, fat, crude protein, ash), nutritional value and fatty acids profile by GC/FID. Antioxidant potential was accessed by the reducing power assay, the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and beta-carotene linoleate model system. Their antimicrobial capacity was also checked against Gram positive (Bacillus cereus, B. subtilis, Staphylococcus aureus) and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae) and fungi (Candida albicans, Cryptococcus neoformans). Results showed that the main constituent of fruits was fat ranging from 56% to 61%, being the nutritional value around 650 kcal per 100 g of fruits. Oleic was the major fatty acid varying between 80.67% in cv. F. Coutard and 82.63% in cv. Daviana, followed by linoleic, palmitic, and stearic acids. Aqueous hazelnut extract presented antioxidant activity in a concentration-dependent way, in general with similar behaviour for all cultivars. Hazelnut extracts revealed a high antimicrobial activity against Gram positive bacteria (MIC 0.1 mg/mL) showing a good bioactivity of these fruits. PMID:18316150

Oliveira, Ivo; Sousa, Anabela; Morais, Jorge Sá; Ferreira, Isabel C F R; Bento, Albino; Estevinho, Letícia; Pereira, José Alberto

2008-01-26

311

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

312

Evaluation of the antimicrobial activity and materials compatibility of orthophthalaldehyde as a high-level disinfectant.  

PubMed

We tested the antimicrobial activity of orthophthalaldehyde (OPA) against 21 strains (16 species) of pathogenic microorganisms that cause hospital-associated infections. Changes in hepatitis B surface antigen (HBs-Ag) resulting from the addition of OPA to HBs-Ag-positive serum were measured using a radioimmunoassay. We also examined the effect of immersing medical instruments in OPA (0.55%) for 168 h at room temperature. OPA (0.5%, 0.37% and 0.25%) killed 11 strains of vegetative bacteria within 15 s, and it killed the test micro-organisms faster than 3.0% glutaraldehyde (GTA). Incubation with OPA or GTA caused levels of HBs-Ag to fall below a cut-off value within 30 s. OPA did not adversely affect instruments made from various materials. OPA demonstrated more effective antimicrobial activity than GTA against a range of microorganisms. We conclude that OPA should replace GTA as the first-choice high-level disinfectant for endoscopes, considering its antimicrobial efficacy and low inhalation toxicity. PMID:15790129

Akamatsu, T; Minemoto, M; Uyeda, M

313

Zinc ascorbate has superoxide dismutase-like activity and in vitro antimicrobial activity against Staphylococcus aureus and Escherichia coli  

PubMed Central

Background: Acne vulgaris is a common dermatological disease, and its pathogenesis is multifactorial. Objective: We examined whether the ascorbic acid derivative zinc ascorbate has superoxide dismutase (SOD)-like activity. SOD is an enzyme that controls reactive oxygen species production. In addition, the in vitro antimicrobial activity of zinc ascorbate against the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacterium Escherichia coli was tested either alone or in combination with a variety of antimicrobial agents; their fractional inhibitory concentration index was determined using checkerboard tests. Methods: The SOD-like activity was measured in comparison with other ascorbic acid derivatives (ascorbic acid, magnesium ascorbyl phosphate, and sodium ascorbyl phosphate) and zinc. The antimicrobial susceptibility of twelve strains each of S. aureus and E. coli isolated from patients with dermatological infections was tested, in comparison to a type strain of S. aureus and E. coli. Results: Zinc ascorbate had significant (P < 0.001) SOD-like activity compared with other ascorbic acid derivatives and zinc. Moreover, it showed antimicrobial activity against a type strain of S. aureus and E. coli, and its concentration (0.064% and 0.128% for S. aureus and E. coli, respectively) was sufficiently lower than the normal dose (5%) of other ascorbic acid derivatives. Furthermore, combinations of zinc ascorbate with clindamycin, erythromycin, and imipenem against S. aureus (average fractional inhibitory concentration, 0.59–0.90), and with imipenem against E. coli (average fractional inhibitory concentration, 0.64) isolated from patients with dermatological infections showed an additive effect. Conclusions: Our results provide novel evidence that zinc ascorbate may be effective for acne treatment.

Iinuma, Katsuhiro; Tsuboi, Isami

2012-01-01

314

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

2013-03-28

315

Sulfonyl-polyol N,N-dichloroamines with rapid, broad-spectrum antimicrobial activity.  

PubMed

The discovery and development of antimicrobial agents that do not give rise to resistance remains an ongoing challenge. Our efforts in this regard continue to reveal new potential therapeutic agents with differing physicochemical properties while retaining the effective N,N-dichloroamine pharmacophore as the key antimicrobial warhead. In this Letter, we disclose agents containing polyol units as a water solubilizing group. These sulfonyl-polyol agents show broad spectrum bactericidal and virucidal activity. These compounds show 1h MBC's of 16-512?g/mL against Escherichia coli and 4-256?g/mL against Staphylococcus aureus at neutral pH, and 1-h IC50's of 4.5-32?M against Adenovirus 5 and 0.7-3.0?M against Herpes simplex virus 1. The lead compounds were tested in a tissue culture irritancy assay and showed only minimal irritation at the highest concentrations tested. PMID:23999044

Shiau, Timothy P; Low, Eddy; Kim, Bum; Turtle, Eric D; Francavilla, Charles; O'Mahony, Donogh J R; Friedman, Lisa; D'Lima, Louisa; Jekle, Andreas; Debabov, Dmitri; Zuck, Meghan; Alvarez, Nichole J; Anderson, Mark; Najafi, Ramin Ron; Jain, Rakesh K

2013-08-17

316

The effect of substrate material on silver nanoparticle antimicrobial efficacy.  

PubMed

With the advent of nanotechnology, silver nanoparticles increasingly are being used in coatings, especially in medical device applications, to capitalize on their antimicrobial properties. The attractiveness of nanoparticulate silver systems is the expected increased antimicrobial efficacy relative to their bulk counterparts, which may be attributed to an increased silver ion (Ag+) solubility, and hence availability, that arises from capillarity effects in small, nanometer-sized particles. However, a change of the material upon which the antimicrobial nanoparticulate silver is deposited (herein called "substrate") may affect the availability of Ag+ ions and the intended efficacy of the device. We utilize both theory and experiment to determine the effect of substrate on ion release from silver particles in electrochemical environments and find that substrate surface charge, chemical reactivity or affinity of the surface for Ag+ ions, and wettability of the surface all affect availability of Ag+ ions, and hence antimicrobial efficacy. It is also observed that with time of exposure to deionized water, Ag+ ion release increases to a maximum value at 5 min before decreasing to undetectable levels, which is attributed to coarsening of the nanoparticles, and which subsequently reduces the solubility and availability of Ag+ ions. This coarsening phenomenon is also predicted by the theoretical considerations and has been confirmed experimentally by transmission electron microscopy. PMID:21121354

Dair, Benita J; Saylor, David M; Cargal, T Eric; French, Grace R; Kennedy, Kristen M; Casas, Rachel S; Guyer, Jonathan E; Warren, James A; Kim, Chang-Soo; Pollack, Steven K

2010-12-01

317

In vitro antimicrobial effects of commercially available mouth-wetting agents.  

PubMed

Products have been developed to provide palliation for persons with dry mouth. In addition to mouth-wetting agents, some products incorporate antimicrobial constituents with the goal of improving oral microbial defenses. The aim of this in vitro study was to investigate the potential antimicrobial and antifungal effects of two commercially available saliva substitutes on Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans by using the agar-well diffusion method. Antimicrobial activity as measured by the size of the inhibition zone growth for S. mutans and L. acidophilus was observed only with Biotene Dry Mouth Oral Rinse® and BioXtra® gel. The zone of inhibition of Biotene Dry Mouth Oral Rinse was larger than that of BioXtra gel (p= 0.00, p < 0.01). No anticandidal effect was seen with any of the test products. The pH of the preparations, the variations between the amount of active ingredients within the products, and the potential antimicrobial effects of inactive ingredients should be investigated to determine the factors that impacted microbial inhibition. PMID:21729120

Güneri, Pelin; Alpöz, Esin; Epstein, Joel B; Çankaya, Hülya; Ate?, Mustafa

318

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.

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

2012-01-01

319

Prokaryotic selectivity and LPS-neutralizing activity of short antimicrobial peptides designed from the human antimicrobial peptide LL-37.  

PubMed

To develop novel antimicrobial peptides (AMPs) with shorter lengths, improved prokaryotic selectivity and retained lipolysaccharide (LPS)-neutralizing activity compared to human cathelicidin AMP, LL-37, a series of amino acid-substituted analogs based on IG-19 (residues 13-31 of LL-37) were synthesized. Among the IG-19 analogs, the analog a4 showed the highest prokaryotic selectivity, but much lower LPS-neutralizing activity compared to parental LL-37. The analogs, a5, a6, a7 and a8 with higher hydrophobicity displayed LPS-neutralizing activity comparable to that of LL-37, but much lesser prokaryotic selectivity. These results indicate that the proper hydrophobicity of the peptides is crucial to exert the amalgamated property of LPS-neutralizing activity and prokaryotic selectivity. Furthermore, to increase LPS-neutralizing activity of the analog a4 without a remarkable decrease in prokaryotic selectivity, we synthesized Trp-substituted analogs (a4-W1 and a4-W2), in which Phe(5) or Phe(15) of a4 is replaced by Trp. Despite their same prokaryotic selectivity, a4-W2 displayed much higher LPS-neutralizing activity compared to a4-W1. When compared with parental LL-37, a4-W2 showed retained LPS-neutralizing activity and 2.8-fold enhanced prokaryotic selectivity. These results suggest that the effective site for Trp-substitution when designing novel AMPs with higher LPS-neutralizing activity, without a remarkable reduction in prokaryotic selectivity, is the amphipathic interface between the end of the hydrophilic side and the start of the hydrophobic side rather than the central position of the hydrophobic side in their ?-helical wheel projection. Taken together, the analog a4-W2 can serve as a promising template for the development of therapeutic agents for the treatment of endotoxic shock and bacterial infection. PMID:22521196

Nan, Yong Hai; Bang, Jeong-Kyu; Jacob, Binu; Park, Il-Seon; Shin, Song Yub

2012-04-10

320

An efficient growth of silver and copper nanoparticles on multiwalled carbon nanotube with enhanced antimicrobial activity.  

PubMed

Transition metal nanoparticles (NPs) such as silver (Ag) and copper (Cu) have been grafted onto carbon nanotube surface through wet chemical approach leading to the development of densely packed NP decorated carbon nanotubes. Chemically active surface and high-temperature stability are the basic attributes to use carbon nanotubes as the template for the growth of NPs. Ag NP-grafted carbon nanotubes (Ag-MWCNT) are prepared by complexing Ag ion with acid functionalized carbon nanotubes followed by the reduction method. Alternatively, Cu-grafted carbon nanotubes (Cu-MWCNT) are prepared by simple chemical reduction method. X-ray diffraction results reveal that the Ag or Cu NPs formed on the surface of carbon nanotubes are determined to be face centered cubic crystals. The morphology and chemical structure of NP-grafted carbon nanotubes are investigated using transmission electron spectroscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The antimicrobial properties of acid-treated MWCNT (MWCNT-COOH), Ag-MWCNT, and Cu-MWCNT are investigated against gram negative Escherichia coli bacteria. Ag-MWCNT and Cu-MWCNT (97% kill vs. 75% kill), whereas MWCNT-COOH only killed 20% of this bacteria. Possible mechanisms are proposed to explain the higher antimicrobial activity by NP-coated MWCNT. These findings suggest that Ag-MWCNT and Cu-MWCNT may be used as effective antimicrobial materials that find applications in biomedical devices and antibacterial controlling system. PMID:21061363

Mohan, Raja; Shanmugharaj, A M; Sung Hun, Ryu

2011-01-01

321

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

PubMed

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. PMID:23537644

Wada, Akihiro; Wong, Pooi-Fong; Hojo, Hironobu; Hasegawa, Makoto; Ichinose, Akitoyo; Llanes, Rafael; Kubo, Yoshinao; Senba, Masachika; Ichinose, Yoshio

2013-03-26

322

Antimicrobial activities of silver used as a polymerization catalyst for a wound-healing matrix  

PubMed Central

Wound healing is a complex and orchestrated process that re-establishes the barrier and other functions of the skin. While wound healing proceeds apace in healthy individual, bacterial overgrowth and infection disrupts this process with significant morbidity and mortality. As such, any artificial matrix to promote wound healing must also control infecting microbes. We had earlier developed a two-part space-conforming gel backbone based on polyethyleneglycol (PEG) or lactose, which used ionic silver as the catalyst for gelation. As silver is widely used as an in vitro antimicrobial, use of silver as a catalyst for gelation provided the opportunity to assess its function as an anti-microbial agent in the gels. We found that these gels show bacteriostatic and bactericidal activity for a range of Gram-negative and Gram-positive organisms, including aerobic as well as anaerobic bacteria. This activity lasted for days, as silver leached out of the formed gels over a day in the manner of second-order decay. Importantly the gels did not limit either cell growth or viability, though cell migration was affected. Adding collagen I fragments to the gels corrected this effect on cell migration. We also found that the PEG gel did not interfere with hemostasis. These observations provide the basis for use of the gel backbones for incorporation of anesthetic agents and factors that promote wound repair. In conclusion, silver ions can serve dual functions of catalyzing gelation and providing anti-microbial properties to a biocompatible polymer.

Babu, Ranjith; Zhang, Jianying; Beckman, Eric J.; Virji, Mohammed; Pasculle, William A.; Wells, Alan

2007-01-01

323

[The antimicrobial activity and cytotoxicity of anti-infective preparations in a human cell-culture model].  

PubMed

The complex evaluation of Polysept, a new antiseptic, by its antimicrobial activity with the determination of the minimal inhibiting concentration, its antiadhesive effect and its cytotoxic action with the determination of the minimal toxic dose is presented after preclinical trial, carried out on the culture of skin and lung fibroblasts of human embryo used as an experimental model. The presence of 50% human blood serum enhances the antimicrobial and antiadhesive effects and decreases the cytotoxic action of the antiseptic with respect to fibroblasts, which makes it a promising preparation not only for the treatment, but also for prophylaxis of wound infection. PMID:9082724

Afinogenov, G E; Eropkina, E M; Bondarenko, V M; Eropkin, M Iu

324

Comparison of Compendial Antimicrobial Effectiveness Tests: A Review  

Microsoft Academic Search

The antimicrobial effectiveness or preservative effectiveness test is described in the tripartite compendia for sterile parenteral\\u000a multi-dose formulated products. The execution of the test is essentially harmonized with respect to inoculum preparation and\\u000a test execution but not the acceptance criteria. This article describes how a single test can be performed that procedurally\\u000a satisfies all of the compendia and their acceptance

Cheryl L. Moser; Brian K. Meyer

2011-01-01

325

Comparison of compendial antimicrobial effectiveness tests: a review.  

PubMed

The antimicrobial effectiveness or preservative effectiveness test is described in the tripartite compendia for sterile parenteral multi-dose formulated products. The execution of the test is essentially harmonized with respect to inoculum preparation and test execution but not the acceptance criteria. This article describes how a single test can be performed that procedurally satisfies all of the compendia and their acceptance criteria. PMID:21221871

Moser, Cheryl L; Meyer, Brian K

2011-01-08

326

In vitro antimicrobial effect of the tissue conditioner containing silver nanoparticles  

PubMed Central

PURPOSE The aim of this study was to identify in vitro antimicrobial activity of the tissue conditioner containing silver nanoparticles on microbial strains, Staphylococcus aureus, Streptococcus mutans and Candida albicans. MATERIALS AND METHODS Experimental disc samples (20.0×3.0 mm) of tissue conditioner (GC Soft-Liner, GC cooperation, Tokyo, Japan) containing 0.1 - 3.0% silver nanoparticles (0%: control) were fabricated. Samples were placed on separate culture plate dish and microbial suspensions (100 µL) of tested strains were inoculated then incubated at 37?. Microbial growth was verified at 24 hrs and 72 hrs and the antimicrobial effects of samples were evaluated as a percentage of viable cells in withdrawn suspension (100 µL). Data were recorded as the mean of three colony forming unit (CFU) numerations and the borderline of the antimicrobial effect was determined at 0.1% viable cells. RESULTS A 0.1% silver nanoparticles combined to tissue conditioner displayed minimal bactericidal effect against Staphylococcus aureus and Streptococcus mutans strains, a 0.5% for fungal strain. Control group did not show any microbial inhibitory effect and there were no statistical difference between 24 hrs and extended 72 hrs incubation time (P > .05). CONCLUSION Within the limitation of this in vitro study, the results suggest that the tissue conditioner containing silver nanoparticles could be an antimicrobial dental material in denture plaque control. Further mechanical stability and toxicity studies are still required.

2011-01-01

327

Antioxidant and antimicrobial activity of Cissus quadrangularis L.  

PubMed

Extracts of Cissus quadrangularis L. were tested for antioxidant activity by beta-carotene linoleic acid model and also by 1,1-diphenyl-2-picrylhydrazyl model. The ethyl acetate fraction of both fresh and dry stem extracts at a concentration of 100 ppm showed 64.8% antioxidant activity in the beta-carotene linoleic acid system and 61.6% in the 1,1-diphenyl-2-picrylhydrazyl system. This fraction showed the presence of sterols, vitamin C, and tannins as phytoconstituents. The antioxidant activity of methanol extract and aqueous extract were comparatively less significant than that of ethyl acetate extract, and n-hexane extract showed the least activity. The ethyl acetate extract and methanol extract of both fresh and dry stems further exhibited antimicrobial activity against Gram-positive bacteria, including Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, and Streptococcus species. The results of the study have implications in the use of C. quadrangularis as an antibacterial agent and more so as an antioxidant in several applications requiring these properties. PMID:12935320

Chidambara Murthy, K N; Vanitha, A; Mahadeva Swamy, M; Ravishankar, G A

2003-01-01

328

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

2011-10-19

329

Contribution of animal models of infection for the evaluation of the activity of antimicrobial agents  

Microsoft Academic Search

Animal models of infection should be considered as tools that may be used for many different purposes: investigation of the physiopathology and natural history of infection on one hand, evaluation of the toxicity, pharmacokinetics and activity of antimicrobials on the other hand. Many review articles on the use of animal models of infection for the evaluation of antimicrobial agents have

Nadia Belmatoug; Bruno Fantin

1997-01-01

330

Spectrum of antimicrobial activity and user acceptability of the hand disinfectant agent Sterillium® Gel  

Microsoft Academic Search

The antimicrobial efficacy of alcohol-based hand gels has been shown to be significantly less than liquid hand rubs probably because of a lower concentration of alcohol. Sterillium Gel is the first hand gel with 85% ethanol. Its antimicrobial efficacy and user acceptability was studied. Bactericidal activity was tested according to prEN 12054 against Staphylococcus aureus, Enterococcus hirae, Pseudomonas aeruginosa and

G Kampf; M Rudolf; J.-C Labadie; S. P Barrett

2002-01-01

331

Staphylococcus aureus Evades the Extracellular Antimicrobial Activity of Mast Cells by Promoting Its Own Uptake  

Microsoft Academic Search

In this study, we investigated the interactions of Staphylococcus aureus with mast cells, which are multifunctional sentinels lining the surfaces of the body. We found that bone marrow-derived murine mast cells (BMMC) exerted a powerful phagocytosis-independent antimicrobial activity against S. aureus. Both the release of extracellular traps as well as discharge of antimicrobial compounds were the mechanisms used by the

Jens Abel; Oliver Goldmann; Christina Ziegler; Claudia Höltje; Mark S. Smeltzer; Ambrose L. Cheung; Daniela Bruhn; Manfred Rohde; Eva Medina

2011-01-01

332

Antimicrobial Activity of Lactic Acid Bacteria from Sour Milk Products Narine, Karine, and Matsun  

Microsoft Academic Search

We studied antimicrobial properties of lactic acid bacteria from sour milk products Narine, Karine, and Matsun. The whey of the sour milk products included two major fractions, of sugars and L-lactic acid and its sodium and calcium salts. Antimicrobial activity of Narine, Karine, and Matsun was related to the presence of L-lactic acid and its sodium and calcium salts.

A. O. Martirosyan; Sh. L. Mndzhoyan; L. M. Charyan; L. G. Akopyan; M. N. Nikishchenko

2004-01-01

333

Retention of Antimicrobial Activity in Plaque and Saliva following Mouthrinse Use in vivo  

Microsoft Academic Search

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

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

2010-01-01

334

Comparative in vitro activities of twelve antimicrobial agents against Campylobacter species.  

PubMed Central

The in vitro susceptibility of 27 Campylobacter jejuni, 31 Campylobacter coli, and 30 Campylobacter fetus subsp. fetus strains to 12 antimicrobial agents was determined. Ciprofloxacin, a new quinoline derivative, was the most active agent tested. Antimicrobial susceptibility differed among the three species tested.

Fliegelman, R M; Petrak, R M; Goodman, L J; Segreti, J; Trenholme, G M; Kaplan, R L

1985-01-01

335

Antimicrobial activity of a new vaginal contraceptive NIM76 from neem oil (Azadirachta indica)  

Microsoft Academic Search

Efficacy of NIM-76, a spermicidal fraction from neem oil, was investigated for its antimicrobial action against certain bacteria, fungi and Polio virus as compared to whole neem oil. The NIM-76 preparation showed stronger anti-microbial activity than the whole neem oil. It inhibited growth of various pathogens tested including Escherichia coli and Kleibsiella pneumoniae which were not affected by the whole

M SaiRam; G Ilavazhagan; S. K Sharma; S. A Dhanraj; B Suresh; M. M Parida; A. M Jana; Kumar Devendra; W Selvamurthy

2000-01-01

336

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

2007-10-11

337

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

Microsoft Academic Search

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

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

2008-01-01

338

Antimicrobial activity of allyl isothiocyanate used to coat biodegradable composite films as affected by storage and handling conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

We evaluated the effects of storage and handling conditions on the antimicrobial activity of biodegradable composite films (polylactic acid and sugar beet pulp) coated with allyl isothiocyanate (AIT). Polylactic acid (PLA) and chitosan were incorporated with AIT and coated on one side of the film. T...

339

Do Aloe vera and Ageratum conyzoides enhance the anti-microbial activity of traditional medicinal soft soaps (Osedudu)?  

PubMed

The Nigerian traditional soft soaps prepared using varied locally sourced raw materials such as cocoa pod ash (Theobroma cacao) palm kernel shaft ash (Elaies guineensis) have been evaluated for their physico-chemical properties and anti-microbial activities using standard pharmacopoeia protocols and an in-vitro agar diffusion bioassay method. The anti-microbial evaluation was done with and without incorporation of Aloe vera and Ageratum conyzoides extractives into the soap samples. Results showed that the physico-chemical properties of the soaps are dependent on the raw materials utilised. The incorporated medicinal plants used in this study, however, did not show any significant effect on the anti-microbial activities exhibited by the various soaps against the bacterial and fungal test organisms. PMID:15099848

Moody, J O; Adebiyi, O A; Adeniyi, B A

2004-05-01

340

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

2010-09-13

341

Chemical composition of three Parmelia lichens and antioxidant, antimicrobial and cytotoxic activities of some their major metabolites.  

PubMed

The aim of this study is to investigate chemical composition of acetone extracts of the lichens Parmelia caperata, P. saxatilis and P. sulcata and antioxidant, antimicrobial and anticancer activities of some their major metabolites. The phytochemical analysis of acetone extracts of three Parmelia lichens were determined by HPLC-UV method. The predominant phenolic compounds in these extracts were protocetraric and usnic acids (P. caperata) and depsidone salazinic acid (other two species). Besides these compounds, atranorin and chloroatranorin, were also detected in some of these extracts. Antioxidant activity of their isolated metabolites was evaluated by free radical scavenging, superoxide anion radical scavenging and reducing power. As a result of the study salazinic acid had stronger antioxidant activity than protocetraric acid. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. Both compounds were highly active with minimum inhibitory concentration values ranging from 0.015 to 1mg/ml. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. Salazinic acid and protocetraric acid were found to be strong anticancer activity toward both cell lines with IC(50) values ranging from 35.67 to 60.18?g/ml. The present study shows that tested lichen compounds demonstrated a strong antioxidant, antimicrobial, and anticancer effects. That suggest that these lichens can be used as new sources of the natural antimicrobial agents, antioxidants and anticancer compounds. PMID:22921748

Manojlovi?, Nedeljko; Rankovi?, Branislav; Kosani?, Marijana; Vasiljevi?, Perica; Stanojkovi?, Tatjana

2012-08-22

342

Effects of the antimicrobial sulfamethoxazole on groundwater bacterial enrichment  

USGS Publications Warehouse

The effects of "trace" (environmentally relevant) concentrations of the antimicrobial agent sulfamethoxazole (SMX) on the growth, nitrate reduction activity, and bacterial composition of an enrichment culture prepared with groundwater from a pristine zone of a sandy drinking-water aquifer on Cape Cod, MA, were assessed by laboratory incubations. When the enrichments were grown under heterotrophic denitrifying conditions and exposed to SMX, noticeable differences from the control (no SMX) were observed. Exposure to SMX in concentrations as low as 0.005 ??M delayed the initiation of cell growth by up to 1 day and decreased nitrate reduction potential (total amount of nitrate reduced after 19 days) by 47% (p = 0.02). Exposure to 1 ??M SMX, a concentration below those prescribed for clinical applications but higher than concentrations typically detected in aqueous environments, resulted in additional inhibitions: reduced growth rates (p = 5 ?? 10-6), lower nitrate reduction rate potentials (p = 0.01), and decreased overall representation of 16S rRNA gene sequences belonging to the genus Pseudomonas. The reduced abundance of Pseudomonas sequences in the libraries was replaced by sequences representing the genus Variovorax. Results of these growth and nitrate reduction experiments collectively suggest that subtherapeutic concentrations of SMX altered the composition of the enriched nitrate-reducing microcosms and inhibited nitrate reduction capabilities. ?? 2011 American Chemical Society.

Underwood, J. C.; Harvey, R. W.; Metge, D. W.; Repert, D. A.; Baumgartner, L. K.; Smith, R. L.; Roane, T. M.; Barber, L. B.

2011-01-01

343

Comparing bacterial membrane interactions and antimicrobial activity of porcine lactoferricin-derived peptides.  

PubMed

Antibiotic treatment for microbial infections is under scrutiny due to increasing resistance to conventional antibiotics, warranting discovery of new classes of antibiotic agents. Antimicrobial peptides are part of the innate defense system found in nearly all organisms and possess bactericidal mechanisms that make it more difficult for bacteria to develop resistance. Porcine lactoferricin (LFP-20) is an antimicrobial peptide located in the N terminus of lactoferrin (LF). To develop novel cell-selective antimicrobial peptides with improved antimicrobial specificity compared with LFP-20, analogs LF2A LF-2, LF-4, and LF-6 were substituted with Ala, Ser, or Trp residues at different positions in the molecule. Analogs displayed a 2- to 16-fold higher antimicrobial activity than LFP-20, but were hemolytic at 64 ?g/mL. Additionally, LFP-20, LF2A, LF-2, and LF-4 exhibited lower cytotoxicity against human peripheral blood mononuclear cells than LF-6 at concentrations of 25 to 100 ?g/mL. To better understand the antibacterial mechanisms of LFP-20 and its analogs we examined their effect on the cytoplasmic membrane of Escherichia coli. The LFP-20 was not effective in depolarizing cytoplasmic membranes, whereas the other 3 analogs gradually dissipated the membrane potential of E. coli. Membrane potential increased with minimal inhibitory concentrations changes, demonstrating a correlation between bactericidal activity and membrane depolarization. Analogs were more efficient than LFP-20 in displacing lipopolysaccharide-bound dansyl-polymyxin B, which also rapidly increased 1-N-phenyl-naphthylamine uptake and release of cytoplasmic ?-galactosidase by increasing the permeability of the outer and inner membranes of E. coli. The 3 analogs caused an increased potential for calcein leakage from negatively charged lipid vesicles at high concentrations. Collectively, these results suggest that the first targets of LF-2, LF-4, and LF-6 in E. coli are cytoplasmic membranes. The 3 analogs exhibited lethal effects based on their abilities to disrupt membranes and permit transit of large intracellular components, such as calcein. PMID:23567049

Han, F F; Gao, Y H; Luan, C; Xie, Y G; Liu, Y F; Wang, Y Z

2013-04-05

344

Synergistic antimicrobial activities of phytoestrogens in crude extracts of two sesame species against some common pathogenic microorganisms.  

PubMed

Intensive studies on extracts and biologically active compounds isolated from medicinal plants have doubled in the last decade worldwide. However, as a result of paucity of knowledge and folkloric claim on the effectiveness of sesame leaves in infectious disease treatments, we aimed to determine the synergistic antimicrobial activity of essential oils and lignans present in the crude leaves extracts of Sesame radiatum and Sesame indicum. Ethanolic, methanolic and aqueous extracts of both leaves were studied for their in-vitro synergistic antimicrobial activity against both gram positive and gram negative micro-organisms, and Yeast using Agar diffusion method. The GC-MS phytochemical screening of methanolic extract showed that the major compounds in essential oils are of carboxylic acids and phenolic groups especially, the most potent antioxidants known to man like sesamol, sesamolin and sesamin among others. Methanolic and ethanolic extracts have broad spectrum antimicrobial effect against all the tested pathogenic micro-organisms except Streptococcus pneumoniae and Staphylococcus aureus respectively, while the aqueous extract exhibited inhibitory activity on Staphylococcus aureus, Streptococcus pneumoniae and Candida albicans. The result confirmed the folkloric claims of the antimicrobial effectiveness of locally consumed sesame leaves extracts especially against bacterial and common skin infection in many areas of Nigeria. PMID:20161911

Bankole, Munir A; Shittu, Lukeman A J; Ahmed, Titilade A; Bankole, Marian N; Shittu, Remilekun K; Kpela, Terkula; Ashiru, Oladapo A

2007-06-10

345

Synthesis, characterization and antimicrobial activity of water soluble dendritic macromolecules.  

PubMed

Several families of water soluble dendrimers were synthesized based on poly(propyleneoxide) amines (Jeffamines) (P(1)). P(1)-core and branched units were constructed from both methylacrylate and ethylenediamine (P(2)-P(9), and generations 0-3 with -NH(2), -COOH functionalities). They were characterized by elemental analysis (EA), gel permeation chromatography (GPC), FT-IR, (1)H, and (13)C NMR. The antimicrobial activities of only water soluble compounds (P(1), P(3), P(4), P(6), P(7) and P(9)) were evaluated using disk diffusion method in water as well as the minimal inhibitory concentration (MIC) dilution method against 9 bacteria. The obtained results from disk diffusion method are assessed in side-by-side comparison with those of Penicillin-g, Ampicillin, Cefotaxime, Vancomycin, Oflaxacin, and Tetracycline, well-known antibacterial agents. The results from dilution procedure are compared with Gentamycin as antibacterial and Nystatin as antifungal. The antifungal activities are reported on five yeast cultures namely, Candida albicans, Kluyveromyces fragilis, Rhodotorula rubra, Debaryomyces hansenii, and Hanseniaspora guilliermondii, and the results are referenced with Nystatin, Ketaconazole, and Clotrimazole, commercial antifungal agents. In most cases, the compounds show broad-spectrum (gram-positive and gram-negative bacteria) activities that are comparatively higher or equipotent to the antibiotic and antifungal agents in the comparison tests. PMID:18657884

Tulu, Metin; Aghatabay, Naz M; Senel, Mehmet; Dizman, Cemil; Parali, Tezcan; Dulger, Basaran

2008-06-26

346

Antimicrobial and Antioxidant Activities of Plants from Northeast of Mexico  

PubMed Central

Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalis and two Staphylococcus aureus strains), and seven clinically isolated yeasts (Candida albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 1000??g?ml?1. We report here for the first time activity of Ceanothus coeruleus against S. aureus (flowers, minimal inhibitory concentration (MIC) 125??g?ml?1), C. glabrata (MICs 31.25??g?ml?1) and C. parapsilosis (MICs between 31.25 and 125??g?ml?1); Chrysanctinia mexicana against C. glabrata (MICs 31.25 ?g ml?1); Colubrina greggii against E. faecalis (MICs 250??g?ml?1) and Cordia boissieri against C. glabrata (MIC 125 ?g ml?1). Furthermore, this is the first report about antioxidant activity of extracts from Ceanothus coeruleus, Chrysanctinia mexicana, Colubrina greggii and Cyperus alternifolius. Some correlation could exist between antioxidant activity and antiyeast activity against yeasts in the species Ceanothus coeruleus, Schinus molle, Colubrina greggii and Cordia boissieri.

Salazar-Aranda, Ricardo; Perez-Lopez, Luis Alejandro; Lopez-Arroyo, Joel; Alanis-Garza, Blanca Alicia; Waksman de Torres, Noemi

2011-01-01

347

In Vitro Antimicrobial, Antioxidant Activities and Phytochemical Analysis of Canarium patentinervium Miq. from Malaysia  

PubMed Central

Six different extracts of Canarium patentinervium Miq. (Burseraceae) leaves and barks were screened for their phytochemical composition, and antimicrobial and free radical scavenging activities. Among the different extracts tested, the ethanol extract of leaves showed significant antimicrobial and radical scavenging activities. The most susceptible micro-organisms were found to be Gram-positive bacteria (Staphylococcus aureus, methicillin-resistant Staphylococcus aureus or MRSA) and Gram-negative bacteria (Pseudomonas aeruginosa). Phytochemical analysis of the extracts revealed that the antimicrobial and the radical scavenging activities are mainly due to the presence of tannins and flavonoids. The results obtained suggest that Canarium patentinervium Miq. could be exploited in the management of various infectious diseases.

Mogana, R.; Teng-Jin, Khoo; Wiart, C.

2011-01-01

348

Prolonged antimicrobial effect of tissue conditioners containing silver-zeolite  

Microsoft Academic Search

Objectives: The purpose of this study was to elucidate the in vitro antimicrobial effect of tissue conditioners containing silver-zeolite on Candida albicans and nosocomial respiratory infection-causing bacteria, Staphylococcus aureus and Pseudomonas aeruginosa.Methods: Five commercially available tissue conditioners were selected: Visco-gel (VG), GC Soft-Liner (SL), Fitt (FT), SR-Ivoseal (IV) and Shofu Tissue Conditioner (TC). Samples, 10 × 10 × 2.5 mm

T. Matsuura; Y. Abe; Y. Sato; K. Okamoto; M. Ueshige; Y. Akagawa

1997-01-01

349

Screening of plant extracts for antimicrobial activity against bacteria and yeasts with dermatological relevance  

Microsoft Academic Search

There is cumulative resistance against antibiotics of many bacteria. Therefore, the development of new antiseptics and antimicrobial agents for the treatment of skin infections is of increasing interest. We have screened six plant extracts and isolated compounds for antimicrobial effects on bacteria and yeasts with dermatological relevance. The following plant extracts have been tested: Gentiana lutea, Harpagophytum procumbens, Boswellia serrata

S. Weckesser; K. Engel; B. Simon-Haarhaus; A. Wittmer; K. Pelz; C. M. Schempp

2007-01-01

350

New approach to study the mechanism of antimicrobial protection of an active packaging.  

PubMed

This article reports on the antimicrobial efficiency of a new active packaging concept based on the use of two essential oils (cinnamon and oregano) and their chemical descriptors (cinnamaldehyde, thymol, and carvacrol) against the Gram-positive bacterium Listeria monocytogenes, the Gram-negative bacterium Salmonella choleraesuis, the yeast Candida albicans, and the mold Aspergillus flavus. Complete inhibition of these microorganisms with either bactericidal or bacteriostatic effect has been demonstrated. It has been proven that the inhibition provided by these solutions is related not to the total amount of the active chemical released but to the amount of active compounds that reach the agar surface at a critical time. This critical time is notably related with the duration of the lag phase, as demonstrated for the bacteria, and shows that kinetic behavior has a critical role in the antimicrobial properties of the active packaging. Two different active films, polypropylene and the complex polyethylene-ethylenvynil alcohol, have been studied and a higher efficiency was found for polypropylene, mainly because of the mentioned kinetic reasons. These results can be used to understand the mechanism of action of the chemicals and provide valuable data for the development of the active packaging concept. PMID:20575672

Gutiérrez, Laura; Batlle, Ramón; Sánchez, Cristina; Nerín, Cristina

2010-09-01

351

In vitro antioxidant and antimicrobial activities of Merremia emarginata using thio glycolic acid-capped cadmium telluride quantum dots.  

PubMed

This study was undertaken to evaluate the antioxidant potential of an aqueous extract from Merremia emarginata leaves because this plant has a very high flavonoid and phenol content. The in vitro antioxidant activity was measured by diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid (ABTS), superoxide anion scavenging assay and lipid peroxidation activity; the total reducing capability of the plant extract indicates that this plant is a source for natural antioxidants. Furthermore, we investigated thio glycolic acid-capped cadmium telluride quantum dots (TGA-CdTe QDs) as fluorescent probes to study the antioxidant activity of the M. emarginata extract through fluorescence quenching. The antimicrobial activity was also investigated using a disc diffusion method and fluorescence microscopy. The TGA-CdTe QDs and M. emarginata complex could provide antimicrobial activity through a reactive oxygen species pathway and/or microbial endocytosis through an electrostatic attraction. Based on our findings, we suggest that the QDs act as potential probes for the in vitro antioxidant and antimicrobial activities. In addition, their cooperative effect with the plant extract indicates that QDs could be used as nanocarriers to enhance the antimicrobial capability. Further in vivo studies on the photolabelling of antioxidants with QDs will provide insights into the mechanistic pathways of secondary metabolites against various degenerative diseases. PMID:22796774

Rameshkumar, A; Sivasudha, T; Jeyadevi, R; Sangeetha, B; Ananth, D Arul; Aseervatham, G Smilin Bell; Nagarajan, N; Renganathan, R; Kathiravan, A

2012-06-07

352

Toxicity of essential oil of Satureja khuzistanica: In vitro cytotoxicity and anti-microbial activity.  

PubMed

Abstract In nature, essential oils play an important role in the protection of the plants by exerting anti-bacterial, -viral, -fungal, -oxidative, -genotoxic, and free radical scavenging properties, as well as in some cases acting as insecticides. Several Satureja species are used in traditional medicine due to recognized therapeutic properties, namely anti-microbial and cytotoxic activities. The purpose of the present work was to determine the biologic activity of the essential oil of S. khuzistanica Jamzad (Lamiaceae) against four human cancer cell lines, as well as its inhibitory effects against a wide array (i.e. n?=?11) of pathogenic bacteria and fungi. The essential oil was isolated by hydro-distillation and analyzed by GC-FID and GC-MS. Carvacrol (92.87%) and limonene (1.2%) were found to be the main components of the isolated oil. Anti-microbial activity of the essential oil was assessed using a disc diffusion method; an MTT cytotoxicity assay was employed to test effects of the oil on each cancer cell line. The oil exhibited considerable anti-microbial activity against the majority of the tested bacteria and fungi. The test oil also significantly reduced cell viability of Vero, SW480, MCF7, and JET 3 cells in a dose-dependent manner, with the IC50 values calculated for each cell type being, respectively, 31.2, 62.5, 125, and 125??g/ml. Based on the findings, it is concluded that the essential oil of S. khuzistanica and its major constituents have a potential for further use in anti-bacterial and anti-cancer applications, pending far more extensive testing of toxicities in normal (i.e. primary) cells. PMID:23662744

Yousefzadi, Morteza; Riahi-Madvar, Ali; Hadian, Javad; Rezaee, Fatemeh; Rafiee, Roya; Biniaz, Mehdi

2013-05-10

353

Synthesis and antimicrobial activity of amido linked pyrrolyl and pyrazolyl-oxazoles, thiazoles and imidazoles.  

PubMed

A new class of amido linked bis heterocycles viz., pyrrolyl/pyrazolyl-oxazoles, thiazoles and imidazoles were prepared by 1,3-dipolar cycloaddition of TosMIC and diazomethane to the respective cinnamamide derivatives and screened for antimicrobial activity. The chlorosubstituted imidazolyl cinnamamide (6c) is the most potential antimicrobial agent as it displayed strong antibacterial activity against Bacillus subtilis and antifungal activity against Penicillium chrysogenum. PMID:21906854

Padmavathi, V; Prema Kumari, C; Venkatesh, B C; Padmaja, A

2011-08-29

354

Antimicrobial activity of aerial parts of Drosera peltata Smith on oral bacteria.  

PubMed

The antimicrobial activity of extracts of aerial parts of Drosera peltata Smith against oral bacteria was investigated using agar diffusion and dilution micromethods. The chloroformic extract, active against all the bacteria tested, showed the most significant antimicrobial properties. Plumbagin, isolated from the extract, is the active principle. Results obtained suggest that Drosera peltata extract could be used in the treatment of oral infectious diseases like dental caries and periodontitis. PMID:9533437

Didry, N; Dubreuil, L; Trotin, F; Pinkas, M

1998-02-01

355

Comparative antimicrobial activity and mechanism of action of bovine lactoferricin-derived synthetic peptides.  

PubMed

Lactoferricin B (LfcinB), a 25 residue peptide derived from the N-terminal of bovine lactoferrin (bLF), causes depolarization of the cytoplasmic membrane in susceptible bacteria. Its mechanism of action, however, still needs to be elucidated. In the present study, synthetic LfcinB (without a disulfide bridge) and LfcinB (C-C; with a disulfide bridge) as well as three derivatives with 15-, 11- and 9-residue peptides were prepared to investigate their antimicrobial nature and mechanisms. The antimicrobial properties were measured via minimum inhibitory concentration (MIC) determinations, killing kinetics assays and synergy testing, and hemolytic activities were assessed by hemoglobin release. Finally, the morphology of peptide-treated bacteria was determined by atomic force microscopy (AFM). We found that there was no difference in MICs between LfcinB and LfcinB (C-C). Among the derivatives, only LfcinB15 maintained nearly the same level as LfcinB, in the MIC range of 16-128 ?g/ml, and the MICs of LfcinB11 (64-256 ?g/ml) were 4 times more than LfcinB, while LfcinB9 exhibited the lowest antimicrobial activity. When treated at MIC for 1 h, many blebs were formed and holes of various sizes appeared on the cell surface, but the cell still maintained its integrity. This suggested that LfcinB had a major permeability effect on the cytoplasmic membrane of both Gram-positive and Gram-negative bacteria, which also indicated it may be a possible intracellular target. Among the tested antibiotics, aureomycin increased the bactericidal activity of LfcinB against E. coli, S. aureus and P. aeruginosa, but neomycin did not have such an effect. We also found that the combination of cecropin A and LfcinB had synergistic effects against E. coli. PMID:21607695

Liu, Yifan; Han, Feifei; Xie, Yonggang; Wang, Yizhen

2011-05-24

356

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.

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

2011-01-01

357

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

PubMed Central

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.

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

2011-01-01

358

Cytotoxicity, blood compatibility and antimicrobial activity of two cyanoacrylate glues for surgical use.  

PubMed

The biocompatibility of two cyanoacrylate surgical glues (Glubran and Glubran 2), supplied by General Enterprise Marketing, Viareggio, Lucca, Italy, was tested through cytotoxicity and blood compatibility tests and the evaluation of antimicrobial activity. Cytotoxicity and blood compatibility tests were performed on the polymerized glues. Using the neutral red uptake test, the extracts from Glubran and Glubran 2 after polymerization were non-toxic to L929 cells only when diluted 1: 10 with culture medium. Glubran and Glubran 2 induced a significant decrease of activated partial thromboplastin time (APTT), which is favourable with regard to the desired haemostasis. The APTT shortening determines a haemostatic effect and therefore contribute to the tissue adhesion induced by the glues. Otherwise, no significant variation of prothrombin activity, fibrinogen, platelet number, total and differential leukocyte count was induced by the glues, which, in addition, did not show haemolytic effect. There was no difference between Glubran and Glubran 2 regarding haemocompatibility. The antimicrobial ability of the unpolymerized glues was tested onto Bacillus subtilis var. niger for 3 weeks: neither Glubran nor Glubran 2 were found effective in this respect. In conclusion, we can assume that cytotoxicity was severe with the undiluted glues, but was acceptable when glues were diluted. On the contrary, blood compatibility was acceptable for the intended use of the glues. No difference was found between Glubran and Glubran 2 after polymerization. PMID:11085384

Montanaro, L; Arciola, C R; Cenni, E; Ciapetti, G; Savioli, F; Filippini, F; Barsanti, L A

2001-01-01

359

Antimicrobial activity of Monascus pilosus IFO 4520 against contaminant of Koji.  

PubMed

Antimicrobial activity of Monascus pilosus IFO 4520 was examined to prevent contamination during beni-koji making in the open air. The antibacterial effect of the beni-koji prepared with this strain occured with 30 mg/ml of beni-koji extract in combination with 0.5% lactic acid against two contaminants of koji, Micrococcus varians and Bacillus subtilis. There were two compounds, antibacterial and antiyeast substances, in the beni-koji extract. These results suggest a possibility of inhibiting the growths of contaminants during beni-koji making using beni-koji extract and lactic acid. PMID:10501009

Kono, I; Himeno, K

1999-08-01

360

Membrane activities of colicin nuclease domains: analogies with antimicrobial peptides.  

PubMed

Nuclease colicins, such as colicin E9, are a class of Escherichia coli bacteriocins that kill E. coli and closely related Gram-negative bacteria through nucleolytic action in the cytoplasm. In order to accomplish this, their cytotoxic domains require transportation across two sets of membranes and the periplasmic space. Currently, little information is available concerning how the membrane translocation processes are achieved, and the present review summarizes our recent results on the in vitro membrane activities of the colicin nuclease domains. Using model membranes, we have analysed the cytotoxic domains of a number of DNase-type colicins and one rRNase colicin for their bilayer insertion depth and for their ability to induce vesicle aggregation, lipid mixing and increased bilayer permeability. We found that, by analogy with AMPs (antimicrobial peptides), the interplay between charge and hydrophobic character of the nuclease domains governs their pleiotropic membrane activities and these results form the basis of ongoing work to unravel the molecular mechanisms underlying their membrane translocation. PMID:23176509

Vankemmelbeke, Mireille; James, Richard; Penfold, Christopher N

2012-12-01

361

Antimicrobial activity of Bauhinia tomentosa and Bauhinia vahlii roots.  

PubMed

The hexane, ethylacetate and methanol extracts from Bauhinia tomentosa and Bauhinia vahlii roots were tested for their antimicrobial activity against Gram-positive bacteria (four strains), Gram-negative bacteria (three strains) and three fungi strains using microdilution methods, for the determination of minimal inhibition concentration (MIC) and the minimal microbicidal concentration (MMC). The MIC values of hexane extracts of B. tomentosa and B. vahlii roots were more than 250 µg/ml. The MIC values of ethylacetate and methanol extracts of B. tomentosa roots varied from 7.81 to 31.25 µg/ml and 31.25 to 62.50 µg/ml, respectively. The MIC values of ethylacetate and methanol extracts of B. vahlii roots varied from 15.63 to 62.5 µg/ml and 62.5 to 250 µg/ml, respectively. MMC values obtained are two times greater than the corresponding MIC values. The activities of ethylacetate extracts are attributed to the presence of flavonoids and that of methanol extracts are attributed to the presence of tannins. PMID:20931080

Dugasani, Swarnalatha; Balijepalli, Madhu Katyayani; Tandra, Satyanarayana; Pichika, Mallikarjuna Rao

2010-07-01

362

Antimicrobial activity of Bauhinia tomentosa and Bauhinia vahlii roots  

PubMed Central

The hexane, ethylacetate and methanol extracts from Bauhinia tomentosa and Bauhinia vahlii roots were tested for their antimicrobial activity against Gram-positive bacteria (four strains), Gram-negative bacteria (three strains) and three fungi strains using microdilution methods, for the determination of minimal inhibition concentration (MIC) and the minimal microbicidal concentration (MMC). The MIC values of hexane extracts of B. tomentosa and B. vahlii roots were more than 250 µg/ml. The MIC values of ethylacetate and methanol extracts of B. tomentosa roots varied from 7.81 to 31.25 µg/ml and 31.25 to 62.50 µg/ml, respectively. The MIC values of ethylacetate and methanol extracts of B. vahlii roots varied from 15.63 to 62.5 µg/ml and 62.5 to 250 µg/ml, respectively. MMC values obtained are two times greater than the corresponding MIC values. The activities of ethylacetate extracts are attributed to the presence of flavonoids and that of methanol extracts are attributed to the presence of tannins.

Dugasani, Swarnalatha; Balijepalli, Madhu Katyayani; Tandra, Satyanarayana; Pichika, Mallikarjuna Rao

2010-01-01

363

In vitro cytotoxic, antiprotozoal and antimicrobial activities of medicinal plants from Vanuatu.  

PubMed

Sixty-three extracts obtained from 18 plants traditionally used in the South Pacific archipelago Vanuatu for the treatment of infectious diseases were screened for antimicrobial and antiprotozoal activities. In addition, the extracts were subjected to a detailed analysis on cytotoxic effects toward a panel of human cancer cell lines, designed as a smaller version of the NCI60 screen. Intriguingly, 15 plant extracts exhibited strong cytotoxic effects specific for only one cancer cell line. Extracts of the leaves of Acalypha grandis Benth. significantly affected Plasmodium falciparum without showing obvious effects against the other protozoa tested. The leaves of Gyrocarpus americanus Jacq. displayed significant activity against Trypanosoma b. brucei and the leaves of Tabernaemontana pandacaqui Lam. I as well as the stems of Macropiper latifolium (L.f.) against Trypanosoma cruzi. In contrast none of the extracts showed relevant antibacterial or antifungal activity. PMID:20014163

Bradacs, Gesine; Maes, Louis; Heilmann, Jörg

2010-06-01

364

Chemical composition and antioxidant/antimicrobial activities in supercritical carbon dioxide fluid extract of Gloiopeltis tenax.  

PubMed

Gloiopeltis tenax (G. tenax) is widely distributed along the Chinese coastal areas and is commonly used in the treatment of diarrhea and colitis. This study aimed at investigating the bioactivities of the volatile constituents in G. tenax. We extracted the essential constituents of G. tenax by supercritical carbon dioxide extraction (CO?-SFE), then identified and analyzed the constituents by gas chromatography-mass spectrometry (GC-MS). In total, 30 components were identified in the G. tenax extract. The components showed remarkable antioxidant activity (radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH)), lipid peroxidation inhibition capacity (in a ?-carotene/linoleic acid-coupled oxidation reaction), and hydroxyl radical-scavenging activity (by deoxyribose degradation by iron-dependent hydroxyl radical), compared to butylated hydroxytoluene. In microdilution assays, G. tenax extracts showed a moderate inhibitory effects on Staphyloccocus aureus (minimum inhibitory concentration (MIC) = 3.9 mg/mL), Enterococcus faecalis (7.8 mg/mL), Pseudomonas aeruginosa (15.6 mg/mL), and Escherichia coli (3.9 mg/mL). Antioxidant and antimicrobial activities of G. tenax were related to the active chemical composition. These results suggest that the CO?-SFE extract from G. tenax has potential to be used as a natural antioxidant and antimicrobial agent in food processing. PMID:23342386

Zheng, Jiaojiao; Chen, Yicun; Yao, Fen; Chen, Weizhou; Shi, Ganggang

2012-12-01

365

Chemical Composition and Antioxidant/Antimicrobial Activities in Supercritical Carbon Dioxide Fluid Extract of Gloiopeltis tenax  

PubMed Central

Gloiopeltis tenax (G. tenax) is widely distributed along the Chinese coastal areas and is commonly used in the treatment of diarrhea and colitis. This study aimed at investigating the bioactivities of the volatile constituents in G. tenax. We extracted the essential constituents of G. tenax by supercritical carbon dioxide extraction (CO2-SFE), then identified and analyzed the constituents by gas chromatography-mass spectrometry (GC-MS). In total, 30 components were identified in the G. tenax extract. The components showed remarkable antioxidant activity (radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH)), lipid peroxidation inhibition capacity (in a ?-carotene/linoleic acid-coupled oxidation reaction), and hydroxyl radical-scavenging activity (by deoxyribose degradation by iron-dependent hydroxyl radical), compared to butylated hydroxytoluene. In microdilution assays, G. tenax extracts showed a moderate inhibitory effects on Staphyloccocus aureus (minimum inhibitory concentration (MIC) = 3.9 mg/mL), Enterococcus faecalis (7.8 mg/mL), Pseudomonas aeruginosa (15.6 mg/mL), and Escherichia coli (3.9 mg/mL). Antioxidant and antimicrobial activities of G. tenax were related to the active chemical composition. These results suggest that the CO2-SFE extract from G. tenax has potential to be used as a natural antioxidant and antimicrobial agent in food processing.

Zheng, Jiaojiao; Chen, Yicun; Yao, Fen; Chen, Weizhou; Shi, Ganggang

2012-01-01

366

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

367

Antimicrobial and Chemoattractant Activity, Lipopolysaccharide Neutralization, Cytotoxicity, and Inhibition by Serum of Analogs of Human Cathelicidin LL-37  

PubMed Central

Antimicrobial peptides have been evaluated in vitro and in vivo as alternatives to conventional antibiotics. Apart from being antimicrobial, the native human cathelicidin-derived peptide LL-37 (amino acids [aa] 104 to 140 of the human cathelicidin antimicrobial peptide) also binds and neutralizes bacterial lipopolysaccharide (LPS) and might therefore have beneficial effects in the treatment of septic shock. However, clinical trials have been hampered by indications of toxic effects of LL-37 on mammalian cells and evidence that its antimicrobial effects are inhibited by serum. For the present study, LL-37 was compared to two less hydrophobic fragments obtained by N-terminal truncation, named 106 (aa 106 to 140) and 110 (aa 110 to 140), and to a previously described more hydrophobic variant, the 18-mer LLKKK, concerning antimicrobial properties, lipopolysaccharide neutralization, toxicity against human erythrocytes and cultured vascular smooth muscle cells, chemotactic activity, and inhibition by serum. LL-37, fragments 106 and 110, and the 18-mer LLKKK inhibited the growth of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans in a radial diffusion assay, inhibited lipopolysaccharide-induced vascular nitric oxide production, and attracted neutrophil granulocytes similarly. While fragments 106 and 110 caused less hemolysis and DNA fragmentation in cultured cells than did LL-37, the 18-mer LLKKK induced severe hemolysis. The antibacterial effect of fragments 106 and 110 was not affected by serum, while the effect of LL-37 was reduced. We concluded that the removal of N-terminal hydrophobic amino acids from LL-37 decreases its cytotoxicity as well as its inhibition by serum without negatively affecting its antimicrobial or LPS-neutralizing action. Such LL-37-derived peptides may thus be beneficial for the treatment of patients with sepsis.

Ciornei, Cristina D.; Sigurdardottir, Thorgerdur; Schmidtchen, Artur; Bodelsson, Mikael

2005-01-01

368

Functional divergence among silkworm antimicrobial peptide paralogs by the activities of recombinant proteins and the induced expression profiles.  

PubMed

Antimicrobial peptides are small-molecule proteins that are usually encoded by multiple-gene families. They play crucial roles in the innate immune response, but reports on the functional divergence of antimicrobial peptide gene families are rare. In this study, 14 paralogs of antimicrobial peptides belonging to cecropin, moricin and gloverin families were recombinantly expressed in pET expression systems. By antimicrobial activity tests, peptides representing paralogs in the same family of cecropin and moricin families, displayed remarkable differences against 10 tested bacteria. The evolutionary rates were relatively fast in the two families, which presented obvious functional divergence among paralogs of each family. Four peptides of gloverin family had similar antimicrobial spectrum and activity against tested bacteria. The gloverin family showed similar antimicrobial function and slow evolutionary rates. By induced transcriptional activity, genes encoding active antimicrobial peptides were upregulated at obviously different levels when silkworm pupae were infected by three types of microbes. Association analysis of antimicrobial activities and induced transcriptional activities indicated that the antimicrobial activities might be positively correlated with induced transcriptional activities in the cecropin and moricin families. These results suggest that representative BmcecB6, BmcecD and Bmmor as the major effector genes have broad antimicrobial spectrum, strong antimicrobial activity and high microbe-induced expression among each family and maybe play crucial roles in eliminating microbial infection. PMID:21479226

Yang, Wanying; Cheng, Tingcai; Ye, Mingqiang; Deng, Xiaojuan; Yi, Huiyu; Huang, Yadong; Tan, Xiang; Han, Dong; Wang, Bo; Xiang, Zhonghuai; Cao, Yang; Xia, Qingyou

2011-03-29

369

Functional Divergence among Silkworm Antimicrobial Peptide Paralogs by the Activities of Recombinant Proteins and the Induced Expression Profiles  

PubMed Central

Antimicrobial peptides are small-molecule proteins that are usually encoded by multiple-gene families. They play crucial roles in the innate immune response, but reports on the functional divergence of antimicrobial peptide gene families are rare. In this study, 14 paralogs of antimicrobial peptides belonging to cecropin, moricin and gloverin families were recombinantly expressed in pET expression systems. By antimicrobial activity tests, peptides representing paralogs in the same family of cecropin and moricin families, displayed remarkable differences against 10 tested bacteria. The evolutionary rates were relatively fast in the two families, which presented obvious functional divergence among paralogs of each family. Four peptides of gloverin family had similar antimicrobial spectrum and activity against tested bacteria. The gloverin family showed similar antimicrobial function and slow evolutionary rates. By induced transcriptional activity, genes encoding active antimicrobial peptides were upregulated at obviously different levels when silkworm pupae were infected by three types of microbes. Association analysis of antimicrobial activities and induced transcriptional activities indicated that the antimicrobial activities might be positively correlated with induced transcriptional activities in the cecropin and moricin families. These results suggest that representative BmcecB6, BmcecD and Bmmor as the major effector genes have broad antimicrobial spectrum, strong antimicrobial activity and high microbe-induced expression among each family and maybe play crucial roles in eliminating microbial infection.

Ye, Mingqiang; Deng, Xiaojuan; Yi, Huiyu; Huang, Yadong; Tan, Xiang; Han, Dong; Wang, Bo; Xiang, Zhonghuai; Cao, Yang; Xia, Qingyou

2011-01-01

370

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

371

PLASMOSE - antimicrobial effects of modular atmospheric plasma sources.  

PubMed

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

2008-11-03

372

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.

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

2008-01-01

373

Antimicrobial activity of six pomegranate (Punica granatum L.) varieties and their relation to some of their pomological and phytonutrient characteristics.  

PubMed

Arils from six pomegranate (Punica granatum L.) varieties grown in the Mediterranean region of Turkey were tested for their antimicrobial properties by the agar diffusion and minimum inhibitory concentration (MIC) methods against seven bacteria: (Bacillus megaterium DSM 32, Pseudomonas aeruginosa DSM 9027, Staphylococcus aureus Cowan 1, Corynebacterium xerosis UC 9165, Escherichia coli DM, Enterococcus faecalis A10, Micrococcus luteus LA 2971), and threefungi (Kluvyeromyces marxianus A230, Rhodotorula rubra MC12, Candida albicans ATCC 1023). It has been observed that the pomegranate aril extracts had antimicrobial effect on all microorganisms, giving inhibition zones ranging in size from 13 to 26 mm. The MIC values for active pomegranate extracts ranged between 30 and >90 microg/mL. The results obtained appeared to confirm the antimicrobial potential of the Punica granatum varieties. PMID:19471201

Duman, Ahmet D; Ozgen, Mustafa; Dayisoylu, Kenan S; Erbil, Nurcan; Durgac, Coskun

2009-05-13

374

Electrospun mats from styrene/maleic anhydride copolymers: modification with amines and assessment of antimicrobial activity.  

PubMed

New antimicrobial microfibrous electrospun mats from styrene/maleic anhydride copolymers were prepared. Two approaches were applied: (i) grafting of poly(propylene glycol) monoamine (Jeffamine® M-600) on the mats followed by formation of complex with iodine; (ii) modification of the mats with amines of 8-hydroxyquinoline or biguanide type with antimicrobial activity. Microbiological screening against S. aureus, E. coli and C. albicans revealed that both the formation of complex with iodine and the covalent attachment of 5-amino-8-hydroxyquinoline or of chlorhexidine impart high antimicrobial activity to the mats. In addition, S. aureus bacteria did not adhere to modified mats. PMID:20480508

Ignatova, Milena; Stoilova, Olya; Manolova, Nevena; Markova, Nadya; Rashkov, Iliya

2010-08-11

375

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

PubMed

The objective of this study was to determine the in vitro minimum inhibitory concentration (MIC) of antimicrobials against 10 isolates of Lawsonia intracellularis, the etiological agent of proliferative enteropathy (PE). Antimicrobials tested included carbadox, chlortetracycline, lincomycin, tiamulin, tylosin and valnemulin. The MIC of each antimicrobial against L. intracellularis was determined using a tissue culture system and was identified as the lowest concentration that inhibited 99% of L. intracellularis growth, as compared to the antimicrobial-free control. Each antimicrobial concentration was evaluated for both intracellular and extracellular activity against L. intracellularis, an obligately intracellular bacterium. When tested for intracellular activity, carbadox, tiamulin, and valnemulin were the most active antimicrobials with MICs of < or =0.5microg/ml. Tylosin (MICs ranging from 0.25 to 32microg/ml) and chlortetracycline (MICs ranging from 0.125 to 64microg/ml) showed intermediate activities and lincomycin (MICs ranging from 8 to >128mIcog/ml) showed the least activity. When tested for extracellular activity, valnemulin (MICs ranging from 0.125 to 4microg/ml) was the most active against most L. intracellularis isolates. Chlortetracycline (MICs ranging from 16 to 64microg/ml), tylosin (MICs ranging from 1 to >128microg/ml), and tiamulin (MICs ranging from 1 to 32microg/ml) showed intermediate activities. Lincomycin (MICs ranging from 32 to >128microg/ml) showed the least activity. Our in vitro results showed that each L. intracellularis isolate had a different antimicrobial sensitivity pattern and these data can be utilized as an in vitro guideline for the further antimicrobial evaluation of field L. intracellularis isolates. PMID:18823723

Wattanaphansak, Suphot; Singer, Randall S; Gebhart, Connie J

2008-08-22

376

Antimicrobial Activity of Ultra-fine Fiber Nonwoven Fabrics Produced by Electrospinning  

NASA Astrophysics Data System (ADS)

Electrospinning is based on an electrohydrodynamic process, and it is a straightforward and versatile method for forming continuous thin fibers from several nanometers to several tens of micrometers in diameter. One major advantage of electrospinning is the one-step forming of nonwoven fibrous fabrics. In the present study, we prepared ultra-fine fiber nonwoven fabrics from 13 kinds of commercial polymers (e.g., PLA, PA, PU, Cellulose, PVDC, and PS) by electrospinning and tested their antimicrobial activity. Most of ultra-fine fiber nonwoven fabrics showed excellent antimicrobial activity. Our experimental results showed that there is close correlation between fiber diameter of nonwoven fabrics and their antimicrobial activity: the nonwoven fabrics with average fiber diameter of smaller than 800 nm showed better antimicrobial activity.

Ogushi, Yukiko; Sasaki, Naokazu; Imashiro, Yasuo; Minagawa, Mie; Matsumoto, Hidetoshi; Tanioka, Akihiko

377

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

378

Endophytic fungi isolated from wheat (Triticum durum Desf.): evaluation of their antimicrobial activity, antioxidant activity and host growth promotion.  

PubMed

The emergence of antibiotic-resistant micro-organisms calls for inventive research and development strategies. The screening for antimicrobial compounds from endophytes is a promising way to meet the increasing threat of drug-resistant strains of human and plant pathogens. Endophytes may be defined as "microbes that colonize living, internal tissues of plants without causing any immediate, overt negative effects". Endophytes are relatively unstudied as potential sources of novel natural products for exploitation in medicine, agriculture, and industry. The purpose of this study was to evaluate several isolated fungi from wheat (Triticum durum Desf.) Mohamed Ben Bachir variety and to select endophytic fungi for further evaluation of its antimicrobial, antioxidant activities and host growth promotion. A total of 20 endophytic fungi have been isolated. Antimicrobial activity was evaluated for crude ethyl acetate extracts using an agar diffusion assay. All extracts showed inhibitory activity on at least one or more pathogenic microorganism, with an average zone of inhibition varied between 7 mm to 25 mm, a large zone of 23 and 25mm against candida albicans and Escherichia coli respectively. The antioxidant capacity of the extracts was evaluated by beta-carotene/linoleic acid assay. Results showed that 70% of these extracts have antioxidant activity, exhibiting 50, 57% to 78, 96% inhibitions. While 30% from them, their inhibitory activity for oxidation of linoleic acid Were less than 50%. Growth promotion ability of these endophytes was tested on seed germination among ten isolates tested, two isolates showed significant growth promotion effects on wheat seeds. From the present work we can conclude that these microorganisms could be promising source of bioactive compounds, growth promotion and warrant further study. PMID:23878980

Harzallah, Daoud; Sadrati, Nouari; Zerroug, Amina; Dahamna, Saliha; Bouharati, Saddek

2012-01-01

379

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

PubMed

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

2012-03-12

380

The effects of postexercise feeding on saliva antimicrobial proteins.  

PubMed

The purpose of this study was to determine the effects of a carbohydrate (CHO) and protein (PRO) drink consumed immediately after endurance exercise on saliva antimicrobial proteins known to be important for host defense. Eleven male runners ran for 2 hr at 75% VO2max on 2 occasions and immediately postexercise were provided, in randomized order, either a placebo solution (CON) or a CHO-PRO solution containing 1.2 g CHO/kg body mass (BM) and 0.4 g PRO/kg BM (CHO-PRO). The solutions were flavor and volume equivalent (12 ml/kg BM). Saliva flow rate, lysozyme, ?-amylase, and secretory (S) IgA concentrations were determined from unstimulated saliva samples collected preexercise, immediately postexercise, and every 30 min until 180 min postexercise. CHO-PRO ingestion immediately postexercise resulted in a lower saliva flow rate than with CON at 30 and 60 min postexercise. Saliva lysozyme concentration increased immediately postexercise in both trials compared with preexercise (p< .05), and CHO-PRO ingestion immediately postexercise resulted in a higher saliva lysozyme concentration in the first hour of recovery than with CON (125% greater at 30 min, 94% greater at 60 min; p< .01). Saliva SIgA concentration decreased below preexercise concentrations 90-150 min postexercise (p< .001), with no effect of CHO-PRO. Saliva ?-amylase activity was unaffected by exercise or CHO-PRO refeeding. CHO-PRO refeeding did not alter the secretion rates of any saliva variables during recovery. In conclusion, immediate refeeding with CHO-PRO evoked a greater saliva lysozyme concentration during the first hour of recovery after prolonged exercise than ingestion of placebo but had minimal impact on saliva ?-amylase and SIgA responses. PMID:22693239

Costa, Ricardo J S; Fortes, Matthew B; Richardson, Katharine; Bilzon, James L J; Walsh, Neil P

2012-06-01

381

Antimicrobial activity of flavonoids in medicinal plants from Tafí del Valle (Tucumán, Argentina).  

PubMed

Preliminary studies of flavonoids have been realised in five native species from Tafí del Valle (Tucumán, Argentina) used in popular medicine. Most of compounds detected were flavonoids mono and dihydroxylated in B ring. Screening for antimicrobial activity against Gram positive and Gram negative microorganisms has been realised with Lippia turbinata, Satureja parvifolia, Sambucus peruviana, Verbena officinalis and Chenopodium graveolens. The total extracts of flavonoids of each plant were tested and four species studied showed antimicrobial activity. PMID:11025172

Hernández, N E; Tereschuk, M L; Abdala, L R

2000-11-01

382

Synthesis of distinctly different sets of antimicrobial activities by elicited plant cell suspension cultures  

Microsoft Academic Search

The aim of this study was to evaluate the potential of plant suspension cultures for the production of antimicrobial activities.\\u000a The extracellular, intracellular and cell wall bound fractions of 16 heterotrophic, photoautotrophic and photomixotrophic\\u000a plant cell suspension cultures each treated with nine different elicitors were tested for the elicitor dependent production\\u000a of antimicrobial activities. Distinctly different patterns of bioactivities directed

Usama Ramadan Abdelmohsen; Walid Ali; Seung Hee Eom; Ute Hentschel; Thomas Roitsch

2011-01-01

383

Recent developments in the bioactivity of mono- and diterpenes: anticancer and antimicrobial activity  

Microsoft Academic Search

Secondary plant metabolites, and in particular monoterpenes, have been recognised as potential medicinal agents for centuries.\\u000a As such, terpenes have been the focus of a plethora of scientific studies examining various aspects of their bioactivity.\\u000a In particular, antimicrobial activity and anticancer potential have been studied extensively. Whilst the antimicrobial and\\u000a anticancer activity of terpenes has been demonstrated in vitro, fewer

Sara J. Greay; Katherine A. Hammer

384

An antimicrobial modified silicone peritoneal catheter with activity against both Gram positive and Gram negative bacteria  

Microsoft Academic Search

Peritonitis, exit site and tunnel infections are serious complications of peritoneal dialysis (CAPD), which may lead to catheter loss, despite measures taken to reduce the infection rate. Catheters coated with antimicrobials have shown only short-term activity. We have developed a process for conferring broad-spectrum, long-duration antimicrobial activity on CAPD catheters while reducing the risk of resistance. Catheters were processed using

Roger Bayston; Leanne E. Fisher; Klaus Weber

2009-01-01

385

The molecular design of a recombinant antimicrobial peptide CP and its in vitro activity  

Microsoft Academic Search

Antibacterial peptides from various sources express different antibacterial activity. In order to obtain a high activity antibacterial peptide, the sequences of four antimicrobial peptides—Protegrin-1, 4kDa Scorpion Defensin, Metalnikowin-2A and Sheep Myeloid Antibacterial Peptide SMAP-29—were exploited to generate a synthetic antimicrobial peptide cp gene, which was then cloned into the expression vector pPICZ?-A. The constructed recombinant expression vector pPICZ?-cp was transformed

Mingfu Niu; Xiang Li; Jianchao Wei; Ruibing Cao; Bin Zhou; Puyan Chen

2008-01-01

386

Antimicrobial activity of Enterococcus Faecium Fair-E 198 against gram-positive pathogens  

PubMed Central

ABSTRACT This study investigated the antimicrobial activity of Enterococcus faecium FAIR-E 198 against Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus. Using the critical-dilution method, the bacteriocin produced by E. faecium FAIR-E 198 inhibited all L. monocytogenes strains evaluated (1,600 to 19,200 AU mL-1). However, none of the B. cereus and S. aureus strains investigated were inhibited. The maximum activity of this bacteriocin (800 AU mL-1) was observed in MRS broth, while the activity in milk was 100 AU mL-1. In the co-cultivation test in milk, B. cereus K1-B041 was reduced to below the detection limit (1.00 log CFU mL-1) after 48 h. E. faecium reduced the initial L. monocytogenes Scott A population by 1 log CFU mL-1 after 3 h at 35°C, However, the pathogen regained growth, reaching 3.68 log CFU mL-1 after 48 h. E. faecium did not influence the growth of S. aureus ATCC 27154 during the 48 h of co-cultivation, Therefore, it can be concluded that the effectiveness of the antimicrobial activity of E. faecium FAIR-E 198 is strictly related to the species and strain of the target microorganism and to the culture medium,

do Nascimento, Maristela da Silva; Moreno, Izildinha; Kuaye, Arnaldo Yoshiteru

2010-01-01

387

Paenibacillus elgii sp. nov., with broad antimicrobial activity.  

PubMed

Two novel spore-forming bacteria with broad antimicrobial activity were isolated from roots of Perilla frutescens. The isolates, SD17(T) and SD18, were facultatively anaerobic and showed variable Gram reaction. Growth was observed between 20 and 45 degrees C. DNA G+C content of SD17(T) was 51.7 mol%, and the major fatty acid was anteiso-C(15 : 0) (54.1 %). 16S rRNA gene sequence similarity of SD17(T) ranged from 98.6 to 91.3 % with other Paenibacillus species. The phylogenetic tree showed that isolate SD17(T) formed a significant monophyletic clade with Paenibacillus koreensis KCTC 2393(T) and Paenibacillus ehimensis IFO 15659(T). DNA-DNA relatedness values for strain SD17(T) with Paenibacillus koreensis KCTC 2393(T) and Paenibacillus ehimensis IFO 15659(T) were 17.4 and 19.8 %, respectively. These isolates thus merit species status within Paenibacillus, for which the name Paenibacillus elgii sp. nov. is proposed. The type strain is SD17(T) (=KCTC 10016BP(T)=NBRC 100335(T)). PMID:15545429

Kim, Dal-Soo; Bae, Cheol-Yong; Jeon, Jae-Jin; Chun, Sam-Jae; Oh, Hyun Woo; Hong, Soon Gyu; Baek, Keun-Sik; Moon, Eun Young; Bae, Kyung Sook

2004-11-01

388

Antimicrobial activity of polymers coated with iodine-complexed polyvinylpyrrolidone.  

PubMed

Polymer-associated infection is a problem of increasing importance in modern medicine. In a new approach to prevent such infections we have modified polyvinylfluoride (TEDLAR) films by graft copolymerization with N-vinylpyrrolidone to which iodine can be complexed. Grafting reaction was performed by the preirradiation technique using an electron accelerator. Grafted films were then treated in Lugol's solution for at least 24 h. Release of free iodine from the films was determined either by titration or using the agar disc diffusion test, showing an iodine release for up to 4-5 days. The antimicrobial activity of the films was tested in bacterial adhesion measurements. Bacterial and fungal cells in the range of 10(3) to 10(6) cfu/cm2 polymer were found on control samples without iodine, whereas on iodine-complexed films no viable cells could be detected at least for 5 days or even longer. Thus, microbial adhesion and growth can be inhibited by iodine-containing polymers. PMID:2013834

Kristinsson, K G; Jansen, B; Treitz, U; Schumacher-Perdreau, F; Peters, G; Pulverer, G

1991-01-01

389

Chemical composition and antimicrobial activity of Cymbopogon citratus and Cymbopogon giganteus essential oils alone and in combination.  

PubMed

As part of ongoing research on the chemical composition and the antimicrobial properties of Burkinabe plants essential oils alone and in combination, essential oils (EOs) from leaves of Cymbopogon citratus and Cymbopogon giganteus from Burkina Faso were analyzed by GC-FID and GC-MS. Five constituents, which accounted for 96.3% of the oil, were identified in the EO of C. citratus. Geranial (48.1%), neral (34.6%) and myrcene (11.0%) were the major constituents. For C. giganteus a total of eight compounds were identified which represented 86.0% of the oils extracted. The dominant compounds were limonene (42%) and a set of monoterpene alcohols: trans-p-mentha-1(7),8-dien-2-ol (14.2%), cis-p-mentha-1(7),8-dien-2-ol (12%), trans-p-mentha-2,8-dien-1-ol (5.6%) and cis-p-mentha-2,8-dien-1-ol (5.2%). The EOs were tested against nine bacteria by using disc diffusion and microdilution methods. C. giganteus EO showed antimicrobial effects against all microorganisms tested whereas C. citratus EO failed to inhibit Pseudomonas aeruginosa. The antimicrobial activity of combinations of the two EOs was quantified by the checkerboard method. Combinations of the two EOs exerted synergistic, additive and indifferent antimicrobial effects. Results of the present investigation provide evidence that the combinations of plant EOs could be assessed for synergistic activity in order to reduce their minimum effective dose. PMID:21665450

Bassolé, I H N; Lamien-Meda, A; Bayala, B; Obame, L C; Ilboudo, A J; Franz, C; Novak, J; Nebié, R C; Dicko, M H

2011-06-12

390

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

PubMed Central

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

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

2012-01-01

391

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

2012-09-10

392

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.

2012-01-01

393

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

PubMed

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 superoxide 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; Skapin, Sre?o D; Uskokovi?, Dragan

2013-09-09

394

Essential oil constituents and in vitro antimicrobial activity of Decalepis hamiltonii roots against foodborne pathogens.  

PubMed

Hydrodistillation of Decalepis hamiltonii roots yielded an essential oil (0.33% v/w) that contained 2-hydroxy-4-methoxybenzaldehyde (37.45%), 2-hydroxybenzaldehyde (31.01%), 4-O-methylresorcylaldehyde (9.12%), benzyl alcohol (3.16%), and alpha-atlantone (2.06%) as major constituents, with aromatic aldehydes constituting the main fraction of this root's essential oil. The oil was tested for its antimicrobial activity against foodborne pathogens responsible for food spoilage and human pathologies using standard antimicrobial assays. It exhibited strong antimicrobial activity against Bacillus cereus, Bacillus megaterium, Candida albicans, Escherichia coli, Micrococcus luteus, Micrococcus roseus, and Staphylococcus aureus at a concentration range of 1:0 with inhibitory activities of 27, 23, 16, 19, 22, 19, and 23 mm, respectively, which are comparable to those of the standards. The roots of D. hamiltonii, therefore, may be considered as an inexpensive source of an essential oil rich in antimicrobial compounds against foodborne pathogens. PMID:12009977

Thangadurai, Devarajan; Anitha, Sreeyapureddy; Pullaiah, Thammineni; Reddy, Ponnathota Narasimha; Ramachandraiah, Oleti Siva

2002-05-22

395

Antimicrobial efficacy and irrigating potential of irrigation solutions using different activation methods.  

PubMed

The objective of this in vitro study was to establish the antimicrobial efficacy and the effect of different activation methods on the smear layer at the coronal level of straight root canals of four different root canal irrigation solutions. The four irrigation solutions were 3.5% sodium hypochlorite liquid (NaOCl), 2% sodium hypochlorite gel, chlorhexidine gluconate liquid and a mixture of 100 mg doxycycline capsules with 2 ml sterile water. ANTIMICROBIAL EFFECTS: The surfaces of four agar plates were inoculated with Enterococcus faecalis and divided into four equal quadrants. Ten microlitres of each test solution was dispensed onto the four filter paper disks on each agar plate. The antibacterial activity of materials was apparent from circular clear inhibition zones forming around the filtration paper. The diameters of these inhibition zones were measured using a micrometer gauge. EFFECT ON SMEAR LAYER: Access cavities were prepared on fifty, extracted, single rooted, human teeth and the root canals prepared with rotary files. The teeth were randomly divided into five groups (n = 10) and each group irrigated with a different irrigation solution. Different activation methods were used in the coronal portion of each root canal. The solutions were activated in the canals using one of the following methods: a 30 gauge needle (Control), a sonic scaler tip, and a rotary brush. After sampling, the roots of the treated teeth were fractured and prepared for Scanning Electron Microscopy (SEM) according to standard methods. The one-way ANOVA test was used to determine whether there were any statistical significant differences between the different groups. The average zones of inhibition for 3.5% NaOCl, 2% NaOCl, 2.5% chlorhexidine and doxycycline were 2.7mm, 2.0 mm, 11.2 mm and 12.4 mm respectively. Sterile water, 3.5% NaOCl and 2% NaOCl had no significant effect on the smear layer. However, when chlorhexidine and doxycycline solutions were activated with a rotary brush, 90 and 80 per cent of the observed surfaces were free of smear layer respectively. Doxycyline and 2.5% chlorhexidine demonstrated the highest antimicrobial activity against Enterococcus faecalis and removed most of the smear layer when the solutions were activated with a rotary brush. PMID:19517856

van der Vyver, P J; Botha, F S; Herbst, D; Ismail, M

2009-03-01

396

Antimicrobial effect of chitooligosaccharides produced by bioreactor  

Microsoft Academic Search

The antibacterial effect of three kinds of chitooligosaccharides with relatively higher molecular weights (HMWCOS), medium molecular weight (MMWCOS), and lower molecular weight (LMWCOS), respectively, was evaluated against various microorganisms. The oligosaccharides were prepared from chitosan and fractionated using ultrafiltration (UF) membrane in conjunction with an enzymatic bioreactor. The growth of most bacteria tested was inhibited by chitooligosaccharide treatments, in particular

You-Jin Jeon; Pyo-Jam Park; Se-Kwon Kim

2001-01-01

397

Inhibition of verocytotoxigenic Escherichia coli by antimicrobial peptides caseicin A and B and the factors affecting their antimicrobial activities.  

PubMed

The antimic robial activities of caseicin A and B antimicrobial peptides (AMPs) were assessed against a selection of verocytotoxigenic Escherichia coli (VTEC) strains (n=11), other bacterial pathogenic and spoilage bacteria (n=7), using a model broth system. The ability of the AMPs to retain their antimicrobial activities against a strain of E. coli O157:H7 380-94 under various test conditions (pH, temperature, water activity, sodium chloride concentrations, inoculum size and the presence of competitive microflora) was assessed and the minimum inhibitory concentrations (MIC) and number of surviving E. coli O157:H7 calculated. The mean number of VTEC surviving after exposure to 2 mg/ml caseicin A and B was reduced by 4.96 and 4.19 log(10) cfu/ml compared to the respective controls. The susceptibility of E. coli O157:H7 to the caseicin AMPs decreased as temperature, pH, water activity and inoculum size were reduced. The presence of sodium chloride (0.5-2.5%) did not affect the activity of caseicin A (p>0.05), however it did inhibit the activity of caseicin B. The presence of a competitive microflora cocktail did not significantly (p>0.05) affect the activities of the AMPs for the majority of the concentrations tested. Using a quantitative PCR assay, the levels of verotoxins (vt1 and vt2) expressed by E. coli O157:H7 following exposure to a sub-inhibitory concentration (0.5 mg/ml) of caseicin A showed that the verotoxin levels did not differ from the levels produced by the control cultures. The antimicrobial activity of caseicin A against E. coli O157:H7 was also tested in a model rumen system, however concentrations of ?2 mg/ml did not significantly (p>0.05) reduce E. coli O157:H7 numbers in the model system over a 24 h period. The application of caseicin AMPs in food and/or animal production may be valuable in combination with other antimicrobials although further research is required. PMID:22177226

McDonnell, Mary J; Rivas, Lucia; Burgess, Catherine M; Fanning, Séamus; Duffy, Geraldine

2011-10-08

398

Immune-modifying and antimicrobial effects of Eucalyptus oil and simple inhalation devices.  

PubMed

Eucalyptus oil (EO) and its major component, 1,8-cineole, have antimicrobial effects against many bacteria, including Mycobacterium tuberculosis and methicillin-resistant Staphylococcus aureus (MRSA), viruses, and fungi (including Candida). Surprisingly for an antimicrobial substance, there are also immune-stimulatory, anti-inflammatory, antioxidant, analgesic, and spasmolytic effects. Of the white blood cells, monocytes and macrophages are most affected, especially with increased phagocytic activity. Application by either vapor inhalation or oral route provides benefit for both purulent and non-purulent respiratory problems, such as bronchitis, asthma, and chronic obstructive pulmonary disease (COPD). There is a long history of folk usage with a good safety record. More recently, the biochemical details behind these effects have been clarified. Although other plant oils may be more microbiologically active, the safety of moderate doses of EO and its broad-spectrum antimicrobial action make it an attractive alternative to pharmaceuticals. EO has also been shown to offset the myelotoxicity of one chemotherapy agent. Whether this is a general attribute that does not decrease the benefit of chemotherapy remains to be determined. This article also provides instruction on how to assemble inexpensive devices for vapor inhalation. PMID:20359267

Sadlon, Angela E; Lamson, Davis W

2010-04-01

399

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.

Enzler, Mark J.; Berbari, Elie; Osmon, Douglas R.

2011-01-01

400

Antimicrobial, antioxidant, and anti-inflammatory activities of essential oils from five selected herbs.  

PubMed

Eucalyptus bridgesiana, Cymbopogon martinii, Thymus vulgaris, Lindernia anagallis, and Pelargonium fragrans are five species of herbs used in Asia. Their essential oils were analyzed by GC-MS, and a total of 36 components were detected. The results of our study indicated that, except for the essential oil of P. fragrans, all of the essential oils demonstrated obvious antimicrobial activity against a broad range of microorganisms. The C. martinii essential oil, which is rich in geraniol, was the most effective antimicrobial additive. All of the essential oils demonstrated antioxidant activities on 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, ?-carotene/linoleic acid assay, and nitric oxide radical scavenging assay. Furthermore, the T. vulgaris essential oil, which possesses plentiful thymol, exhibited the highest antioxidant activity. For P. acnes-induced secretion of pro-inflammatory cytokines, the essential oils of P. aeruginosa, C. martinii, and T. vulgaris reduced the TNF-?, IL-1?, and IL-8 secretion levels of THP-1 cells. PMID:21979069

Tsai, Mei-Lin; Lin, Chih-Chien; Lin, Wei-Chao; Yang, Chao-Hsun

2011-10-07