Antibacterial Agent

Powdered grape seeds and bagasse were extracted with petroleum ether to remove fatty material and then re-extracted with different solvent mixtures to determine their total phenolics and antibacterial activities. In the grape seeds extracts the content of total phenolic compounds was found to be 627.98 mg gallic acid equivalent (GAE)/g with acetone:water:acetic acid (90:9.5:0.5) and 667.87 mg GAE/g with ethyl acetate:methanol:water (60:30:10). The bagasse extracts contained 45.44 mg GAE/g and 29.55 mg GAE/g with ethyl acetate:methanol:water (60:30:10) and ethanol:water (95:5), respectively. These extracts at 1%, 2%, 4% and 20% concentrations were tested for their antibacterial effects by using the paper disc diffusion method against some food spoilage and pathogenic bacteria including Aeromonas hydrophila ATCC 7965, Bacillus amyloliquefaciens ATCC 3842, Bacillus brevis FMC 3,

The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid pre-corneal elimination of the drug may be overcome by the use of in situ gel forming systems that are instilled as drops into the eye and then undergo a sol-gel transition in the cul-de-sac. The present work describes the formulation and evaluation of an ophthalmic delivery system of an antibacterial agent ofloxacin, based on the concept of ion-activated in situ gelation. Sodium alginate was used as the gelling agent in combination with HPC (Hydroxy Propyl Cellulose) that acted as a viscosity-enhancing agent. In vitro release studies indicated that the alginate/HPC solution retained the drug better than the alginate or HPC solutions alone. The formulations were therapeutically efficacious, sterile, stable and provided sustained release of the drug over a period of time. These results demonstrate that the developed system is an alternative to conventional ophthalmic drops, patient compliance, industrially oriented and economical.

Validation of antibiotic mode of action in whole bacterial cells is a key step for antibiotic drug discovery. In this study, one potential drug target, enoyl-acyl carrier protein reductase (FabI), an essential enzyme in the fatty acid biosynthesis pathway, was used to evaluate the feasibility of using a regulated antisense RNA interference approach to determine antibiotic mode of action. Antisense isogenic strains expressing antisense RNA to fabI were created using a tetracycline-regulated vector in Staphylococcus aureus. We demonstrated that down-regulation of FabI expression by induction of fabI antisense RNA induces a conditional lethal phenotype. In contrast, partial down-regulation gives a viable cell with a significant increase in sensitivity to FabI-specific inhibitors (i.e., a sensitized phenotype). More importantly, the mode of action for novel FabI inhibitors has been confirmed using this genetic approach in whole cell assay. These results indicate that controlled antisense technology provides a robust tool for defining and tracking the mode of action of novel antibacterial agents.

Slow-growing bacteria and biofilms are notoriously tolerant to antibiotics. Oritavancin is a lipoglycopeptide with multiple mechanisms of action that contribute to its bactericidal action against exponentially growing gram-positive pathogens, including the inhibition of cell wall synthesis and perturbation of membrane barrier function. We sought to determine whether oritavancin could eradicate cells known to be tolerant to many antimicrobial agents, that is, stationary-phase and biofilm cultures of Staphylococcus aureus in vitro. Oritavancin exhibited concentration-dependent bactericidal activity against stationaryphase inocula of methicillin-susceptible S. aureus (MSSA) ATCC 29213, methicillin-resistant S. aureus (MRSA) ATCC 33591, and vancomycin-resistant S. aureus (VRSA) VRS5 inoculated into nutrient-depleted cation-adjusted Mueller-Hinton broth. As has been described for exponential-phase cells, oritavancin induced membrane depolarization, increased membrane permeability, and caused ultrastructural defects including a loss of nascent septal cross walls in stationary-phase MSSA. Furthermore, oritavancin sterilized biofilms of MSSA, MRSA, and VRSA at minimal biofilm eradication concentrations (MBECs) of between 0.5 and 8 g/ml. Importantly, MBECs for oritavancin were within 1 doubling dilution of their respective planktonic broth MICs, highlighting the potency of oritavancin against biofilms. These results demonstrate a significant activity of oritavancin against S. aureus in phases of growth that exhibit tolerance to other antimicrobial agents.

Nine new metal complexes of the quinolone antibacterial agent N-propyl-norfloxacin, pr-norfloxacin, with VO 2+ , Mn 2+ , Fe 3+ , Co 2+ , Ni 2+ , Zn 2+ , MoO 2þ 2 , Cd 2+ and UO 2þ 2 have been prepared and characterized with physicochemical and spectroscopic techniques while molecular mechanics calculations for Fe 3+ , VO 2+ and MoO 2þ 2 complexes have been performed. In all complexes, pr-norfloxacin acts as a bidentate deprotonated ligand bound to the metal through the pyridone and one carboxylate oxygen atoms. All complexes are six-coordinate with slightly distorted octahedral geometry. For the complex VO(N-propyl-norfloxacinato) 2 (H 2 O) the axial position, trans to the vanadyl oxygen, is occupied by one pyridone oxygen atom. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with diverse spectroscopic techniques and has shown that the complexes can be bound to calf-thymus DNA resulting to a B ! A DNA transition. The antimicrobial activity of the complexes has been tested on three different microorganisms. The complexes show equal or decreased biological activity in comparison to the free pr-norfloxacin except UO 2 (pr-norf) 2 which shows better inhibition against S. aureus.

Steroidal [oxazolo(4,5-b)quinoxaline-2-yl-hydrazone] derivative (7a-9a) (7b-9b) were prepared by the multi-step reactions of steroid. It is prepared via the reaction of steroidal semicarbazones with 2,3-dichloroquinoxaline at 80°C in ethanol. The structures of the compounds were evident by IR, 1H NMR and mass spectrometry and their purities were confirmed by elemental analyses. The antibacterial activity of these compounds was evaluated by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria and then the minimum inhibitory concentration (MIC) of compounds was determined. The results showed that compounds (7a, 7b, 8a, 8b) are better antibacterial agent as compared with the standard drug amoxicillin.

Electrically conductive fabrics were produced by deposition of a thin film of doped polypyrrole on the surface of cotton fibres. In situ oxidative chemical polymerisation were carried out in aqueous solutions of pyrrole, oxidant and doping agents, at room temperature. Polypyrrole-coated fibres were characterized by Light Microscopy, SEM, EDX, FTIR and TGA. Moreover, fabric samples were also evaluated for moisture regain, electrical resistivity, heat generation and antibacterial activity. PPy alters the combustion process of cellulose fibres that maintain the fibrous shape after heating in air. Moreover, it seems that PPy is really an antibacterial agent, apart from the oxidant or dopant used. The results highlight potential applications as technical textiles with antistatic (low electrical resistance), heat generation, hygroscopy, antibacterial and high temperature resistance properties.

a b s t r a c t 2-Chloro-3-(4-methylpiperazin-1-yl)naphthalene-1,4-dione (3a), 2-chloro-3-(pyrrolidin-1-yl)naphthalene-1,4-dione (3b), 2-chloro-3-(piperidin-1-yl)naphthalene-1,4-dione (3c), 2-chloro-3-morpholinonaphthalene-1,4-dione (3d), 2-chloro-3-(2-phenylhydrazinyl)naphthalene-1,4-dione (3e), 2-(allylamino) ,4]thiazine-5,10-dione (3k) and compounds 3leq have been synthesized by a green methodology approach using water as solvent and evaluated for their antifungal and antibacterial activity. The antifungal profile of 3aen indicated that compounds 3aed, 3j, 3e and 3k have potent antifungal activity. Amongst the most promising antifungal compounds, 3aeg, 3j, 3k showed better antifungal activity than clinically prevalent antifungal drugs Fluconazole and Amphotericin-B against Trichophyton mentagraphytes and compounds 3j and 3k have been found to be lead antifungal bicyclic and tricyclic 1,4-naphthoquinones. Compound 3k also exhibited pronounced antibacterial activity.

A high-throughput mass spectrometry assay to measure the catalytic activity of UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase, LpxC, is described. This reaction is essential in the biosynthesis of lipopolysaccharide (LPS) of gram-negative bacteria and is an attractive target for the development of new antibacterial agents. The assay uses the RapidFire mass spectrometry platform to measure the native LpxC substrate and the reaction product and thereby generates a ratiometric readout with minimal artifacts due to detection interference. The assay was robust in a high-throughput screen of a library of more than 700,000 compounds arrayed as orthogonal mixtures, with a median Z' factor of 0.74. Selected novel inhibitors from the screening campaign were confirmed as binding to LpxC by biophysical measurements using a thermal stability shift assay. Some inhibitors showed whole-cell antimicrobial activity against a sensitive strain of Escherichia coli with reduced LpxC ...

Cell population density-dependent regulation of gene expression is an important determinant of bacterial pathogenesis. Staphylococci have two quorum-sensing (QS) systems. The accessory gene regulator (agr) is genus specific and uses a post-translationally modified peptide as an autoinducing signal. In the pathogens Staphylococcus aureus and Staphylococcus epidermidis, agr controls the expression of a series of toxins and virulence factors and the interaction with the innate immune system. However, the role of agr during infection is controversial. A possible second QS system of staphylococci, luxS, is found in a variety of Gram-positive and Gram-negative bacteria. Importantly, unlike many QS systems described in Gram-negative bacteria, agr and luxS of staphylococci reduce rather than induce biofilm formation and virulence during biofilm-associated infection. agr enhances biofilm detachment by up-regulation of the expression of detergent-like peptides, whereas luxS reduces cell-to-cell adhesion by down-regulating expression of biofilm exopolysaccharide. Significant QS activity in staphylococci is observed for actively growing cells at a high cell density, such as during the initial stages of an infection and under optimal environmental conditions. In contrast, the metabolically quiescent biofilm mode of growth appears to be characterized by an overall low activity of the staphylococcal QS systems. It remains to be shown whether QS control in staphylococci represents a promising target for the development of novel antibacterial agents.

The purpose of the present study was to investigate the antibacterial activity of seven ethanolic extracts and three aqueous extracts from various parts (leaves, stems and flowers) of A. aroma against 163 strains of antibiotic multi-resistant bacteria. The disc diffusion assay was performed to evaluate antibacterial activity of the A. aroma crude extracts, against several Gram-positive bacteria (E.

The study of nanoparticles has become a target of major interest in science. Metallic silver nanoparticles (Ag 0) and ionic silver (Ag +) are the future of the post-antibiotic era, with the latter playing perhaps the central role in this fight. Traditional chemical synthesis methods for colloidal silver (CS) may lead to the presence of toxic chemical species or chemical residues, which may inhibit the effective authentication of CS as an antibacterial agent. To counter these problems a good alternative method-electric spark discharge system (ESDS) was used to fabricate a silver nanoparticles suspension in deionized water with no added chemical additives. Most related research in this field is confined to exploring the composition of nanoparticle, ignoring ions. However, we aim to identify and quantify the proportion of ionic silver in ESDS-CS. The results reveal that ESDS-CS contains both metallic silver nanoparticles and ionic silver. Furthermore, the antimicrobial affect of ESDS-CS on Staphylococcus aureus was also studied. The experimental data suggest that CS solutions with an ionic silver concentration of 30 ppm or higher are strong enough to eliminate S. aureus. In addition, it was found that a solution's antimicrobial potency is directly related to its level of silver ion concentration.

The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid pre-corneal elimination of the drug may be overcome by the use of in situ gel forming systems that are instilled as drops into the eye and then undergo a sol-gel transition in the cul-de-sac. The present work describes the formulation and evaluation of an ophthalmic delivery system of an antibacterial agent ofloxacin, based on the concept of ion-activated in situ gelation. Sodium alginate was used as the gelling agent in combination with HPC (Hydroxy Propyl Cellulose) that acted as a viscosity-enhancing agent. In vitro release studies indicated that the alginate/HPC solution retained the drug better than the alginate or HPC solutions alone. The formulations were therapeutically efficacious, sterile, stable and provided sustained release of the drug over a period of time. These results demonstrate that the developed system is an alternative to conventional ophthalmic drops, patient compliance, industrially oriented and economical.

A series of 3-aminoquinazolinediones was synthesized and evaluated for its antibacterial and DNA gyrase activity. The SAR around the quinazolinedione core was explored and the optimal substitutions were combined to give two compounds, 2r and 2s, with exceptional enzyme potency (IC 50 = 0.2 lM) and activity against Gram-positive organisms (MIC's = 0.015-0.06 l g/mL).

Dulcisxanthones C-F (1-4) and dulcinone (5) together with 22 known compounds were isolated from the flowers of Garcinia dulcis. Their structures were determined by spectroscopic methods. The abilities of some of these compounds to act as radical scavengers and antibacterial agents were investigated.

The photocatalytic degradation of fenitrothion under UV and near visible light in the presence of polyoxometallate (POM) photocatalyst PW 12 O 40 3− , in aqueous solutions has been studied and compared with the photodegradation by TiO 2 suspensions. Fenitrothion is effectively degraded in the presence of both photocatalysts following pseudo first order kinetics. Complete mineralization of fenitrothion is achieved using both photocatalysts, leading to the formation of CO 2 and inorganic ions (PO 4 3− , SO 4 2− , NO 2 − , and NO 3 − ) as final products. Various inermediates, identical in the presence of both photocatalysts, have been detected and identified using HPLC and GC-MS techniques. The similarity of the intermediates by these two methods, i.e. PW 12 O 40 3− and TiO 2 tends to suggest, that the photodegradation mechanism of fenitrothion as other cases as well, takes place mainly via a common reagent, i.e. OH radicals. A photodegradation mechanism is proposed.

The discovery and initial optimization of a novel anthranilic acid derived class of antibacterial agents which suffered from extensive protein binding has been previously reported. The structure-activity relationships around the carboxylic acid substituent are described herein. This acid was replaced by several alternative functional groups in attempts to retain bioactivity while reducing protein binding. Only groups with an acidic proton retained activity, and analogs containing those groups maintained the protein binding inherent to this class of antibacterial agents.

The pyrrolamides are a new class of antibacterial agents targeting DNA gyrase, an essential enzyme across bacterial species and inhibition results in the disruption of DNA synthesis and subsequently, cell death. The optimization of biochemical activity and other drug-like properties through substitutions to the pyrrole, piperidine, and heterocycle portions of the molecule resulted in pyrrolamides with improved cellular activity and in vivo efficacy.

Terminalia arjuna Wight & Arn. (Combretaceae) is a tree having an extensive medicinal potential. The plant is used traditionally in the treatment of various aliments. T. arjuna is a very good hypocholsteremic, hypolipidemic, anticoagulant, antihypertensive, antithrombotic, antiviral, antifungal and antibacterial agent Various parts of plant have been investigated for the presence of phytoconstituents and pharmacological activities. Many useful phytoconstituents have been isolated from T. arjuna. Triterpenoids are mainly responsible for cardiovascular properties. Tannins and flavonoids are responsible for its anticancer properties. The present review summarizes the ethnic use, pharmacological activities of the extracts and phytoconstituents of T. arjuna for last 90 years.

Titanium dioxide represents an effective photocatalyst for water and air purification and for self-cleaning surfaces. Additionally, it can be used as antibacterial agent because of strong oxidation activity and superhydrophilicity. TiO 2 shows relatively high reactivity and chemical stability under ultraviolet light ( <387nm), whose energy exceeds the band gap of 3.3 eV in the anatase crystalline phase. The development of photocatalysts exhibiting high reactivity under visible light ( > 400 nm) should allow the main part of the solar spectrum, even under poor illumination of interior lighting, to be used. Visible light-activated TiO 2 could be prepared by metal-ion implantation, reducing of TiO 2 , nonmetal doping or sensitizing of TiO 2 with dyes. This paper reviews preparation methods of doped-TiO 2 with metallic and nonmetallic species, including various types of dopants and doping methods currently available. The mechanism of heterogeneous photocatalysis in the presence of TiO 2 is also discussed. . Mechanism of TiO 2 photocatalysis: hv 1 : pure TiO 2 ; hv 2 : metal-doped TiO 2 and hv 3 : nonmetal-doped TiO 2 .

Lavender essential oil is popular as a complementary medicine in its own right and as an additive to many over the counter complementary medicine and cosmetic products ' \ Indeed, products derived from the popular garden herb Lavender (Lavandula spp.) have been used for centuries as a therapeutic agent, with the more 'recent ' addition, the essential oils derived from these plants, being widely used as an antibacterial in World War I],! The oil is traditionally believed to have sedative, carminative, anti-depressive and antiinflammatory properties, in addition to its recognised antimicrobial effects.

This study aims to check the antibacterial activity of various branded soaps against bacteria that are normally present in the environment. The proposed study includes selection of most common bacterial strains from the environment. Identification of bacterial strains was done by ...

Hydrogen peroxide (H 2 O 2 ) is widely regarded as a cytotoxic agent whose levels must be minimized by the action of antioxidant defence enzymes. In fact, H 2 O 2 is poorly reactive in the absence of transition metal ions. Exposure of certain human tissues to H 2 O 2 may be greater than is commonly supposed: substantial amounts of H 2 O 2 can be present in beverages commonly drunk (especially instant coffee), in freshly voided human urine, and in exhaled air. Levels of H 2 O 2 in the human body may be controlled not only by catabolism but also by excretion, and H 2 O 2 could play a role in the regulation of renal function and as an antibacterial agent in the urine. Urinary H 2 O 2 levels are influenced by diet, but under certain conditions might be a valuable biomarker of`oxidative stress'. ß

Melissa officinalis (Lemon balm) is a herbal medicine that has traditionally been attributed with memory-enhancing properties, but which is currently more widely used as a mild sedative and sleep aid. In a previous study it was demonstrated that a commercial Melissa extract led to dose-specific increases in calmness, and dose-dependent decrements in timed memory task performance. However, the extract utilized in that study did not exhibit in vitro cholinergic receptor-binding properties. The current study involved an initial screening of samples of M. officinalis for human acetylcholinesterase inhibition and cholinergic receptor-binding properties. The cognitive and mood effects of single doses of the most cholinergically active dried leaf were then assessed in a randomized, placebo-controlled, double-blind, balanced crossover study. Following the in vitro analysis, 20 healthy, young participants received single doses of 600, 1000, and 1600 mg of encapsulated dried leaf, or a matching placebo, at 7-day intervals. Cognitive performance and mood were assessed predose and at 1, 3, and 6 h postdose using the Cognitive Drug Research computerized assessment battery and Bond-Lader visual analog scales, respectively. In vitro analysis of the chosen extract established IC 50 concentrations of 0.18 and 3.47 mg ml À1 , respectively, for the displacement of [ 3 H]-(N)-nicotine and [ 3 H]-(N)-scopolamine from nicotinic and muscarinic receptors in human cerebral cortex tissue. However, no cholinesterase inhibitory properties were detected. The most notable cognitive and mood effects were improved memory performance and increased 'calmness' at all postdose time points for the highest (1600 mg) dose. However, while the profile of results was overwhelmingly favorable for the highest dose, decrements in the speed of timed memory task performance and on a rapid visual information-processing task increased with decreasing dose. These results suggest that doses of Melissa officinalis at or above the maximum employed here can improve cognitive performance and mood and may therefore be a valuable adjunct in the treatment of Alzheimer's disease. The results also suggest that different preparations derived from the same plant species may exhibit different properties depending on the process used for the sample preparation.

2-Chloro-6-ethoxy-4-phenylpyridine-3,5dicarbonitrile was taken as versatile building block that allows the synthesis of 1H-pyrrolo[2,3-b]pyridine, thieno[2,3-b]pyridine and pyrido[2 0 ,3 0 :5,4]pyrrolo[2,3-b]pyrimidine systems. Some of the synthesized compounds were screened as antibacterial agents.

A series of isoxazole-3-hydroxamic acid derivatives has been identified as a new class of small, nonpeptidic inhibitors of peptide deformylase (PDF). The synthesis, enzyme inhibition and preliminary investigation of the binding mode of this potential antibacterial compounds are reported.

Drug-eluting medical implants are actually active implants that induce healing effects, in addition to their regular task of support. This effect is achieved by controlled release of active pharmaceutical ingredients (API) into the surrounding tissue. In this chapter we focus on three types of drug-eluting devices: drug-eluting vascular stents, drug-eluting wound dressings and protein-eluting scaffolds for tissue regeneration, thus describing both internal and external implants. Each of these drug-eluting devices also presents an approach for solving the drug release issue. Most drug-eluting vascular stents are loaded with water-insoluble antiproliferative agents, and their diffusion from the device to the surrounding tissue is relatively slow. In contrast, most drug-eluting wound dressings are loaded with highly water-soluble antibacterial agents and the issue of fast release must therefore be addressed. Growth factor release from scaffolds for tissue regeneration offers a new approach of incorporating high-molecular-weight bioactive agents which are very sensitive to process conditions and preserve their activity during the preparation stage. The drug-eluting medical implants are described here in terms of matrix formats and polymers, incorporated drugs and their release profiles from the implants, and implant functioning. Basic elements, such as new composite core/shell fibers and structured films, can be used to build new antibiotic-eluting devices. As presented in this chapter, the effect of the processing parameters on the microstructure and the resulting drug release profiles, mechanical and physical properties, and other relevant properties, must be elucidated in order to achieve the desired properties. Newly developed implants and novel modifications of previously developed approaches have enhanced the tools available for creating clinically important biomedical applications.

The occurrence of trace organic contaminants in wastewaters, their behaviour during wastewater treatment and drinking water production are the key issues in relation to the reuse of water resources. Elimination of different classes of emerging contaminants, such as surfactant degradates, pharmaceuticals and polar pesticides in wastewater treatment plants (WWTP) was found to be rather low and consequently sewage effluents are one of the main sources of these compounds and their recalcitrant metabolites. This paper reviews the state-of-the-art in the analysis of several groups of emerging contaminants (acidic pharmaceuticals, antibacterial agents, acidic pesticides and surfactant metabolites) in wastewaters. Their elimination in WWTP applying conventional activated sludge treatment and advanced treatment processes, such as membrane bioreactors (MBR) and advanced oxidation (AOP), as well as the elimination during drinking water production are discussed.

Ethnopharmacological relevance: Artemisia princeps Pampanini (family Asteraceae) is an herbal medicine widely used as a hepatoprotective, antioxidative, anti-inflammatory, and antibacterial agent in Korea, China, and Japan. Aim of the study: This study aimed to elucidate the anti-inflammatory effect of the main constituents, eupatilin and jaceosidin, isolated from Artemisia princeps. Materials and methods: We used carrageenan-induced inflammation in an air pouch on the back of mice and carrageenan-induced hind paw edema in rats to determine the anti-inflammatory effects of eupatilin and jaceosidin. Inflammatory makers, such as expression of pro-inflammatory cytokines and cyclooxygenase (COX)-2, and activation of nuclear factor-kappa B (NF-B), were measured by enzyme-linked immunosorbent assays and immunoblot analyses. Results: Eupatilin and jaceosidin blocked carrageenan-induced increase in leukocyte number and protein levels in air pouch exudates. Eupatilin and jaceosidin inhibited COX-2 expression and NF-B activation, and markedly reduced TNF-␣, IL-1␤, and prostaglandin E2 (PGE 2 ) levels. They also inhibited hind paw edema induced by carrageenan. Eupatilin and jaceosidin had similar activity. Conclusions: These findings suggest that eupatilin and jaceosidin may reduce inflammation by inhibiting NF-B activation, and that Artemisia princeps inhibits inflammation because of these constituents.

Fluoroquinolones (FQs) are among the most important antibacterial agents used in human and veterinary medicine. Because of the growing practice of adding manure and sewage sludge to agricultural fields these drugs end up in soils, where they can accumulate and have adverse effects on organisms. This paper presents an overview of recent developments in the determination of FQs in solid environmental matrices and describes the risks and challenges (persistence, fate, effects, and remediation) which result from their presence in soil.

Aim of the study: To evaluate the antibacterial activity of eugenol and its mechanism of bactericidal action against Salmonella typhi. Materials and methods: The antibacterial activity was checked by disc-diffusion method, MIC, MBC, time course assay and pH sensitivity assay. The chemo-attractant property of eugenol was verified by chemotaxis assay. The mode of action of eugenol was determined by crystal violet assay, measurement of release of 260 nm absorbing material, SDS-PAGE, FT-IR spectroscopy, AFM and SEM. Results: Treatment with eugenol at their MIC (0.0125%) and MBC (0.025%) reduced the viability and resulted in complete inhibition of the organism. Eugenol inactivated Salmonella typhi within 60 min exposure. The chemo-attractant property of eugenol combined with the observed high antibacterial activity at alkaline pH favors the fact that the compound can work more efficiently when given in vivo. Eugenol increased the permeability of the membrane, as evidenced by crystal violet assay. The measurement of release of 260 nm absorbing intracellular materials, SDS-PAGE, SEM and AFM analysis confirmed the disruptive action of eugenol on cytoplasmic membrane. The deformation of macromolecules in the membrane, upon treatment with eugenol was verified by FT-IR spectroscopy. Conclusion: The results suggest that the antibacterial activity of eugenol against Salmonella typhi is due to the interaction of eugenol on bacterial cell membrane.

2-Chloro-6-ethoxy-4-phenylpyridine-3,5dicarbonitrile was taken as versatile building block that allows the synthesis of 1H-pyrrolo[2,3-b]pyridine, thieno[2,3-b]pyridine and pyrido[2 0 ,3 0 :5,4]pyrrolo[2,3-b]pyrimidine systems. Some of the synthesized compounds were screened as antibacterial agents.

Background: Microbial antibiotic resistance is a challenging medical problem nowadays. Two scorpion peptides displaying antibiotic activity: hadrurin and vejovine were taken as models for the design of novel shorter peptides with similar activity. Methods: Using the standard Fmoc-based solid phase synthesis technique of Merrifield twelve peptides (18 to 29 amino acids long) were synthesized, purified and assayed against a variety of multi-drug resistant Gram-negative bacteria from clinical isolates. Hemolytic and antiparasitic activities of the peptides and their possible interactions with eukaryotic cells were verified. Release of the fluorophore calcein from liposomes treated with these peptides was measured. Results: A peptide with sequence GILKTIKSIASKVANTVQKLKRKAKNAVA), and three analogs: Δ(Α29), Δ(K12-Q18; Ν26−Α29), and K4N Δ(K12-Q18; Ν26−Α29) were shown to inhibit the growth of Gram-negative (E. coli ATCC25922) and Gram-positive bacteria (S. aureus), as well as multi-drug resistant (MDR) clinical isolated. The antibacterial and antiparasitic activities were found with peptides at 0.78 to 25 μM and 5 to 25 μM concentration, respectively. These peptides have low cytotoxic and hemolytic activities at concentrations significantly exceeding their minimum inhibitory concentrations (MICs), showing values between 40 and 900 μM for their EC 50 , compared to the parent peptides vejovine and hadrurin that at the same concentration of their MICs lysed more than 50% of human erythrocytes cells. Conclusions: These peptides promise to be good candidates to combat infections caused by Gram-negative bacteria from nosocomial infections. General significance: Our results confirm that well designed synthetic peptides can be an alternative for solving the lack of effective antibiotics to control bacterial infections.

It has been demonstrated that patients showing symptoms of chronic bacterial prostatitis but culturenegative prostate-specific specimens can benefit from administration of antibacterial agents. This suggests that organisms that are not isolated in the routine practice may be responsible for prostate infection in an undefined fraction of subjects. Anaerobic bacteria have been proposed to play a pathogenic role in CBP, on the basis of studies describing clinical remission after eradication of pathogens like Peptostreptococcus spp or Bacterioides spp from prostatic secretions of symptomatic patients, or the significant association between prostatic infection by anaerobes and the presence of inflammation markers in prostatic secretions. In this paper, we report in detail a case of severely symptomatic chronic prostatitis in a patient with evidence of infection by Peptostreptococcus. We also report for the first time that treatment with the 3rd generation fluoroquinolone moxifloxacin was successful in eradicating the pathogen and in causing dramatic resolution of signs and symptoms of chronic bacterial prostatitis. The strict association between eradication of Peptostreptococcus and the rapid disappearance of clinical signs/symptoms points to a causative role of this anaerobe in the chronic bacterial prostatitis case described in this report.

Natural clays have been used to heal skin infections since the earliest recorded history. Recently our attention was drawn to a clinical use of French green clay (rich in Fe-smectite) for healing Buruli ulcer, a necrotizing fasciitis ('flesh-eating' infection) caused by Mycobacterium ulcerans. These clays and others like them are interesting as they may reveal an antibacterial mechanism that could provide an inexpensive treatment for this and other skin infections, especially in global areas with limited hospitals and medical resources. Microbiological testing of two French green clays, and other clays used traditionally for healing, identified three samples that were effective at killing a broad-spectrum of human pathogens. A clear distinction must be made between 'healing clays' and those we have identified as antibacterial clays. The highly adsorptive properties of many clays may contribute to healing a variety of ailments, although they are not antibacterial. The antibacterial process displayed by the three identified clays is unknown. Therefore, we have investigated the mineralogical and chemical compositions of the antibacterial clays for comparison with non-antibacterial clays in an attempt to elucidate differences that may lead to identification of the antibacterial mechanism(s). The two French green clays used to treat Buruli ulcer, while similar in mineralogy, crystal size, and major element chemistry, have opposite effects on the bacterial populations tested. One clay deposit promoted bacterial growth whereas another killed the bacteria. The reasons for the difference in antibacterial properties thus far show that the bactericidal mechanism is not physical (e.g., an attraction between clay and bacteria), but by a chemical transfer or reaction. The chemical variables are still under investigation. Cation exchange experiments showed that the antibacterial component of the clay can be removed, implicating exchangeable cations in the antibacterial process. Furthermore, aqueous leachates of the antibacterial clays effectively kill the bacteria. Progressively heating the clay leads first to dehydration (200°C), then dehydroxylation (550°C or more), and finally to destruction of the clay mineral structure by (~900°C). By identifying the elements lost after each heating step, and testing the bactericidal effect of the heated product, we eliminated many toxins from consideration (e.g., microbes, organic compounds, volatile elements) and identified several redox-sensitive refractory metals that are common among antibacterial clays. We conclude that the pH and oxidation state buffered by the clay mineral surfaces is key to controlling the solution chemistry and redox related reactions occurring at the bacterial cell wall.

Berry fruits are rich sources of bioactive compounds, such as phenolics and organic acids, which have antimicrobial activities against human pathogens. Among different berries and berry phenolics, cranberry, cloudberry, raspberry, strawberry and bilberry especially possess clear antimicrobial effects against, e.g. Salmonella and Staphylococcus. Complex phenolic polymers, like ellagitannins, are strong antibacterial agents present in cloudberry and raspberry. Several mechanisms of action in the growth inhibition of bacteria are involved, such as destabilisation of cytoplasmic membrane, permeabilisation of plasma membrane, inhibition of extracellular microbial enzymes, direct actions on microbial metabolism and deprivation of the substrates required for microbial growth. Antimicrobial activity of berries may also be related to antiadherence of bacteria to epithelial cells, which is a prerequisite for colonisation and infection of many pathogens. Antimicrobial berry compounds may have important applications in the future as natural antimicrobial agents for food industry as well as for medicine. Some of the novel approaches are discussed.

a b s t r a c t Dual inhibitors of bacterial gyrB and parE based on a 5-(2-pyrimidinyl)-imidazo[1,2-a]pyridine template exhibited MICs (lg/mL) of 0.06-64 (Sau), 0.25-64 (MRSA), 0.06-64 (Spy), 0.06-64 (Spn), and 0.03-64 (FQR Spn). Selected examples were efficacious in mouse sepsis and lung infection models at <50 mg/kg (PO dosing).

Background: Blechnum orientale Linn. (Blechnaceae) is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of Blechnum orientale Linn.

Volatile oil composition of hydro-distilled (HD) and supercritical carbon dioxide (SC-CO2) essential oil of freshly collected aerial parts of Heracleum thomsonii (Umbeliferae) from the western Himalayas was studied by GC-FID and GC-MS. Results revealed qualitative and quantitative dissimilarity in the composition of hydro-distilled and SC-CO2 extracted oils. Nineteen constituents, which accounted for 89.32% of total constituents in HD oil, represented

"The clinical bacteria of multi-drug resistant to some antibiotics are
considered a common problem in the world wide. Alternative
antibacterial strategies are urgently needed, and thus this situation
has led to a re-evaluation of the therapeutic use of ancient
remedies, such as plants and plant-based products, including
Nigella sativa (N. sativa). This study aimed to evaluate the
antibacterial activity of Yemeni N. sativa oil against some Clinical
Bacterial Isolates (CBI) and Control Strains of Bacteria (CSB) in
comparison with Augmentin® (Amoxicillin and Clavulanic Acid).
This study was carried out in Sana’a city during the period of one
year from May 2012 to April 2013. The antibacterial activity of oil
with different concentrations was determined by using disc agar
diffusion technique against CBI (Staphylococcus aureus and
Pseudomonas aeruginosa) and CSB (Staphylococcus aureus
ATCC25619, Pseudomonas aeruginosa ATCC29737), also the
Minimum Inhibition Concentration (MIC) of oil extract was
determined. The results indicated that, the highest significant
antibacterial activity was at the maximum concentration of the oil
against Staphylococcus aureus and Pseudomonas aeruginosa in
comparison with Augmentin ® discs (p < 0.05) respectively. This
study observed that, there was strong positive correlation between
the diameter zone (DZ-mm) and oil concentrations (%). In
addition, the DZ (mm) of the oil for CSB was higher than CBI.
Also the oil activity was found to be more effective against
Staphylococcus aureus than Pseudomonas aeruginosa. On the
other hand, the MIC of the oil against CBI were ranged between ≥
0.5% and 4%. Whereas, the CSB particularly Staphylococcus
aureus were sensitive to low concentrations of oil. It could be
concluded that, the oil had high antibacterial effect against CSB
and CBI with high concentration and more effective than
Augmentin® discs."