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AbstractA new library of quinoline–natural product conjugates bearing 1,2,3-triazole moiety as a linker has been synthesized using the copper(I) catalyzed azide-alkyne [3 + 2] cycloaddition reaction (CuAAC) methodology. The structure characterization of the synthesized compounds was achieved using NMR and HRMS analysis. The compounds were subsequently screened for their antimicrobial efficacies against methicillin resistant Staphylococcus aureus (MRSA), MDR Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, and Cryptococcus neoformans. The studied compounds generally displayed stronger inhibition of microbial cell growth compared to their parent phenolic natural products. Eugenol, thymol, guaiacol, and o-vanillin based 1H-1,2,3-triazole compounds exhibited the best antimicrobial profiles while the pathogen, A. baumannii showed the highest susceptibility to the hybrids. Precisely, hybrids 19a, 20b, and 25b derived from eugenol, thymol, and o-vanillin, respectively, exhibited over 50% growth inhibition of the pathogen. K. pneumoniae was however strongly resistant to the compound series. In silico docking studies of the representative compounds further explored the characteristic binding orientations of these compounds in the active sites of the bacterial and fungal proteins. Overall, we perceive that rational scaffold hopping of these compounds holds promise to offer novel antimicrobial agents with enhanced potency. [ABSTRACT FROM AUTHOR]

The constantly accelerating occurrence of microbial infections and their antibiotic resistance has spurred advancement in the field of material sciences and has guided the development of novel materials with anti-bacterial properties. To address the clinical exigencies, the material of choice should be biodegradable, biocompatible, and able to offer prolonged antibacterial effects. As an attractive option, hydrogels have been explored globally as a potent biomaterial platform that can furnish essential antibacterial attributes owing to its three-dimensional (3D) hydrophilic polymeric network, adequate biocompatibility, and cellular adhesion. The current review focuses on the utilization of different antimicrobial hydrogels based on their sources (natural and synthetic). Further, the review also highlights the strategies for the generation of hydrogels with their advantages and disadvantages and their applications in different biomedical fields. Finally, the prospects in the development of hydrogels-based antimicrobial biomaterials are discussed along with some key challenges encountered during their development and clinical translation. [ABSTRACT FROM AUTHOR]

AbstractAs a promising probiotic strain, Escherichia coli Nissle 1917 (EcN) has been demonstrated to confer beneficial effects on intestinal health, immune function, and pathogen prevention. Additionally, EcN has also been widely studied due to its clear genomic information, tractable gene regulation, and simple growth conditions. This review summarizes the various applications potential of EcN in food science and nutrition, including inflammation prevention, tumor-targeting therapy, antibacterial agents for food, and nutrient production with a focus on specific case studies. Moreover, we highlight the major challenges of employing EcN in food science and nutrition, including regulatory approval, stability during food processing, and consumer acceptance. Finally, we conclude with a discussion on perspectives related to employing EcN in food science and nutrition. [ABSTRACT FROM AUTHOR]

AbstractThis study explores the utilization of natural compounds, including zinc oxide (ZnO) derived from aloe vera, chitosan, and pandan leaves (Pandanus amaryllifolius Roxb) extract, for the development of antimicrobial-coated fabric textiles. The objectives of this research are to optimize the formulation, structural properties, and antimicrobial effectiveness of these textiles through comprehensive characterization techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Particle Size Analysis (PSA), and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX). The addition of NaOH as a base at pH 13.0 played a crucial role in obtaining smaller particles with improved homogeneity. The XRD analysis confirmed the hexagonal crystalline structure of ZnO in the composite. The use of Chloroacetamide (CAA) binder and NaOH in different molar compositions influenced the coating of ZnO-Chitosan/Pandan leaf on cotton fibers. A molar ratio of 1:2 for CAA and NaOH resulted in the most substantial reduction in the intensity of the carbonyl absorption peak in the FT-IR spectrum, indicating a more complete and robust coating. [ABSTRACT FROM AUTHOR]

Peri-implantitis is the leading cause of dental implant loss and is initiated by a polymicrobial dysbiotic biofilm formation on the implant surface. The destruction of peri-implant tissue by the host immune response and the low effectiveness of surgical or non-surgical treatments highlight the need for new strategies to prevent, modulate and/or eliminate biofilm formation on the implant surface. Currently, several surface modifications have been proposed using biomolecules, ions, antimicrobial agents, and topography alterations. Initially, this review provides an overview of the etiopathogenesis and host- and material-dependent modulating factors of peri-implant disease. In addition, a critical discussion about the antimicrobial surface modification mechanisms and techniques employed to modify the titanium implant material is provided. Finally, we also considered the future perspectives on the development of antimicrobial surfaces to narrow the bridge between idea and product and favor the clinical application possibility. Antimicrobial surface modifications have demonstrated effective results; however, there is no consensus about the best modification strategy and in-depth information on the safety and longevity of the antimicrobial effect. Modified surfaces display recurring challenges such as short-term effectiveness, the burst release of drugs, cytotoxicity, and lack of reusability. Stimulus-responsive surfaces seem to be a promising strategy for a controlled and precise antimicrobial effect, and future research should focus on this technology and study it from models that better mimic clinical conditions. [ABSTRACT FROM AUTHOR]

In the food industry, packaging is used to protect food. However, traditional packaging has serious environmental impacts. Thus, studies have investigated packaging composed of biodegradable polymers. Accordingly, the present study aimed to obtain and characterize polymeric films of sodium alginate and polyethylene glycol crosslinked with tetraethoxysilane and doped with nano-zinc oxide or nano-silicon oxide and evaluate their cytotoxicity and bactericidal activity against coliforms and Escherichia coli. The nanoparticles and crosslinked materials were characterized using infrared and Raman spectroscopy. The cytotoxicity of the films was evaluated using a direct contact assay with a bovine fibroblast cell model. The bactericidal activity of the films was assessed by determining whether the contamination indicators were activated. The average sizes of the ZnO and SiO2 nanoparticles were 408.3 and 125.3 nm, respectively, and their zeta potentials were −31.6 and −31.1 mV, respectively. Cell growth inhibition zone tests indicated that 75 ALG/25 PEG/SiO2 was slightly toxic, while 25 ALG/75 PEG/ZnO exhibited mild toxicity. Cell area analysis showed that the addition of SiO2 decreased the cytotoxicity of the obtained films. Finally, it was possible to observe the inactivation of both contamination bioindicators. Therefore, films containing nanoparticles could be promising biomaterials for packaging in the food industry. [ABSTRACT FROM AUTHOR]

Abstract Antimicrobial agents are safe preservatives having the ability to protect foods from microbial spoilage and extend their shelf life. Many factors, including antimicrobials’ chemical features, storage environments, delivery methods, and diffusion in foods, can affect their antimicrobial activities. The physical-chemical characteristics of the food itself play an important role in determining the efficacy of antimicrobial agents in foods; however the mechanisms behind it have not been fully explored. This review provides new insights and comprehensive knowledge regarding the impacts of the food matrix, including the food components and food (micro)structures, on the activities of antimicrobial agents. Studies of the last 10 years regarding the influences of the food structure on the effects of antimicrobial agents against the microorganisms’ growth were summarized. The mechanisms underpinning the loss of the antimicrobial agents’ activity in foods are proposed. Finally, some strategies/technologies to improve the protection of antimicrobial agents in specific food categories are discussed. [ABSTRACT FROM AUTHOR]

Life-style changes, environmental pollution, and genetic factors have resulted in a large number of diseases to human beings. Though plant extracts have been widely used to counteract these diseases wherein the combined effect of the constituents was found to be responsible for the cure of a disease, activity of individual constituent was unknown. Further, naturally obtained heterocyclic compounds have been found to possess excellent pharmacological activity. In view of improvement of pharmacological activity, synthesis of derivatized heterocyclic compounds is considered as prime importance in drug-design. It is evident that azepine derivatives have been reported to possess a wide range of pharmacological activity. Recently, the critical reviews on pharmacology of azepines have not been reported. Here, the importance of azepine analogs and azepine-related scaffolds in drug design and discovery for various diseases such as antimicrobial, anticonvulsive, analgesic, etc. has been described. Particularly, the most remarkable azepine therapeutic molecules are emphasized via structure–activity relationship. The review specially focused on disorders of central nervous system (convulsions, pain, anxiety, Alzheimer's, and mood disorder). In this review, it is found that heterocycle-fused azepine derivatives bestowed the most promising activity. The review might be a real help to researchers in finding efficient azepine-based pharmacological agents in future. [ABSTRACT FROM AUTHOR]

The increase in environmental consciousness and the pollution issues raised by the textile industries take natural dyes from back to the front stage. The trend of the textile industry shows a gradual change from fashion to functional apparel and healthy lifestyles. Since cotton is the most preferred natural fiber for the apparel industry, most of the research attempts had been done to overcome the inherent drawbacks of poor bacterial and UV resistance. The natural dyes are loaded with an abundant amount of phytochemicals, which provide characteristic functional finishing to the textiles. This paper reviews the scientific efforts done in the field of natural dyes for obtaining antimicrobial activity. The principal phytochemicals responsible for color, antimicrobial and antifungal activity, their mode of action, method of application, and evaluation of bacterial resistance, challenges, and market potentials are also attempted to cover at the maximum possible extent. [ABSTRACT FROM AUTHOR]

We describe the synthesis of new series of thiazolo[4,5-d]thiopyrimidine derivatives 8 and 9 by reaction of 2-(phenylimino)-5-(thiophen-2-ylmethylene)thiazolidin-4-one 6 and 7 with thiourea in the presence of 5% KOH. We predict dipole moment, the geometry, bond angles and bond length by used DFT method and also used quantum chemical calculations to predict the reactivity and stability of new compounds through energy gap between HOMO and LUMO and DFT calculations give agree based on experimental elucidated of some newly compounds as IR, 1H-NMR, 13C-NMR. Compounds 8 and 9 were screened for in vitro antimicrobial activity Bacillus subtilis and Staphylococcus aureus as examples of bacterial strains and also antifungal activities. (Aspergillus flavus and Candida albicans). Compound 8 was showed higher activity than compound 9. [ABSTRACT FROM AUTHOR]

This study investigated the influence of N-chlorosuccinimide (NCS) pretreatment on the antimicrobial effect of benzalkonium chloride (BZC, representative of QACs) against biofilm bacteria and its mechanisms. Results show that 0.04 − 0.07 mmol/L NCS pretreatment significantly increased the antimicrobial efficacy of 0.03 mmol/L BZC on biofilm cells by 30% − 70%. The main mechanisms involved membrane permeability, oxidative damage, and metabolic disorder. More precisely, NCS pretreatment increased the permeability of bacteria and reduced the activity of the electron transport system (ETS) and dehydrogenase (DHA). At the same time, the oxidative damage of both endogenous and exogenous ROS and the disorder of the antioxidant enzymes (superoxide dismutase and catalase) further improved their combined antibacterial ability. Moreover, NCS pretreatment greatly reduced the resistance of biofilm Pseudomonas aeruginosa to BZC. The findings of the study provide a new method to effectively enhance the antimicrobial efficiency of quaternary ammonium cationic surfactants (e.g., BZC) and reduce bacterial resistance, as well as a scientific guidance for the development of new antimicrobial products. [ABSTRACT FROM AUTHOR]

Microbial contamination is an utmost cause of food spoilage. Antimicrobial agents are used to treat microbial diseases in food. They also serve food packaging industry, as they are used for the formation of antimicrobial packaging films which maintain the structure, texture, color, and nutrition value of food. Due to ever growing population, the demands of food are also rising. There is need to stop food wastage and to prevent spoilage. Most of the food is spoiled during harvesting, transportation, and distribution. This is a serious problem to overcome. Adding antibacterial agents is the most convenient way to reduce food spoilage and contamination. To support the characteristics and properties of antibacterial materials, different modifications are performed in the field of food packaging, which is one of the most demanding techniques for food preservation. This review will summarize the research about antimicrobial agents, with an emphasis on recent findings, to highlight the importance of new developments in this field. Concepts of antimicrobial packaging with a focus on antibiotics and antibacterial agents are discussed briefly in this review, along with the different types of food packaging and applications of antimicrobial packaging. Synthetic and natural antimicrobial materials are described. In summary, this article will explain the importance of antibacterial agents and their use in food packaging industry. Furthermore, readers will get good information about natural antibacterial polymers which were extensively used in past few decades. Subsequently, different innovations should be done to control food spoilage and wastage to ensure food safety. Food packaging is a sole element that helps to provide safe and secure food for all. [ABSTRACT FROM AUTHOR]

The problem of drug resistance of food borne pathogens is becoming more and more serious. Although traditional antimicrobial agents have good therapeutic effects on a variety of food borne pathogens, more effective antimicrobial agents are still needed to combat the development of drug-resistant food borne pathogens. Plant-based natural essential oils (EOs) are widely used because of their remarkable antimicrobial activity. A potential strategy to address food borne pathogens drug resistance is to use a combination of EOs and antimicrobial agents. Because EOs have multi-target inhibitory effects on microorganisms, combining them with drugs can enhance the activity of the drugs and avoid the emergence of food borne pathogens drug resistance. This paper introduces the main factors affecting the antibacterial activity of EOs and describes methods for evaluating their synergistic antibacterial effects. The possible mechanisms of action of EOs and the synergistic inhibitory effects on pathogens of EOs in combination with antimicrobial agents is described. In summary, the combined use of EOs and existing antimicrobial agents is a promising potential new antibacterial therapy. [ABSTRACT FROM AUTHOR]

Infectious diseases are one of the leading cause of mortality and morbidity worldwide. Metal-Organic Frameworks (MOFs), which are porous coordination materials composed of bridging organic ligands and metallic ions or clusters, exhibits great potential to be used against several pathogens, such as bacteria, viruses, fungi and protozoa. MOFs can show sustained release capability, high surface area, adjustable pore size and structural flexibility, which makes them good candidates for new therapeutic systems. This review provides a detailed summary of the biological application of MOFs, focussing on diagnosis and treatment of infectious diseases. MOFs have been reported for usage as antimicrobial agents, drug delivery systems, therapeutic composites, nanozymes and phototherapies. Furthermore, different MOF-based biosensors have also been developed to detect specific pathogens by electrochemical, fluorometric and colorimetric assays. Finally, we present limitations and perspectives in this field. [ABSTRACT FROM AUTHOR]

In this study, we reviewed the biogenic route for the synthesis of iron nanomaterials (Fe-NMs) with special emphasis on recent progress. Natural products or its derivatives including extract of plants part, microorganisms, and various biomolecules have been used as stabilizing and reducing agents during synthesis. The greener methodology is quite simple, eco-friendly and generally followed single step process. This review summarized recent literature regarding the greener synthetic assemblies and environmental remediation, biomedical, and antimicrobial applications. [ABSTRACT FROM AUTHOR]

Electrospinning refers to a technique for producing nano- and micrometric-scale fibers using high voltage. It is a novel and useful technique applied over the last few years in the areas of food processing and medicine due to its versatility and low cost in the development of ultra-thin structures from natural and synthetic biopolymers, facilitating the incorporation, transport, and release of preservation agents, in particular antimicrobial compounds. These membranes find application in food and medical areas where antimicrobials inhibit cellular processes of harmful biological agents. In that sense, this study provides a comprehensive review of some recent developments and technological aspects of antimicrobial ultra-thin electrospun membranes for potential use in the food and pharmaceutical industry, with a particular approach based on biopolymers. [ABSTRACT FROM AUTHOR]

The global number of bees has recently declined. One reason is pathogenic microorganisms including Paenibacillus larvae, which causes American foulbrood disease, and Melissococcus plutonius, which causes European foulbrood disease. The aim of this study was to identify new antimicrobial agents against foulbrood disease. Broth-microdilution assays with 20 natural compounds were used to detect the in vitro antimicrobial activity against foulbrood disease, and MTT assays were performed to determine cytotoxicity against a human cell line. 4-Hydroxydericin, sophoraflavanone G, acetylshikonin, and kurarinone were found to have antimicrobial activity against P. larvae and M. plutonius, with less cytotoxicity against HaCaT cells. In addition, these compounds have a synergic effect with tetracycline or macelignan, which could potentially be effective to control foulbrood disease of honey bees. [ABSTRACT FROM AUTHOR]

A library of new sulfonyl decahydroacridine-1,8-diones has been efficiently synthesized by the one-pot three-component reactions of 4-(p-tolyl sulfonoxy) benzaldehyde, dimedone, and amines in choline chloride-based deep eutectic mixture. Pure target compounds are obtained in very good to excellent yields over short reaction times using straightforward work-up procedure. The synthesized heterocyclic decahydroacridine-1,8-diones were investigated for their in vitro antimicrobial activity. The minimum inhibitory concentration was determined for the test compounds as well as for reference standards. Compounds 4f, 4m, 4n, and 4o have shown good antibacterial activity whereas compounds 4a, 4c, 4g, 4j, and 4r have displayed better antifungal activity. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the physico-chemical and antimicrobial properties of a dual polymerization experimental endodontic sealer (E) and experimental sealers containing dibutyltin methacrylate (Sn2+) (ETs) or calcium methacrylate (Ca2+) (ECs). The pH and ion release levels of the sealers were measured. The dimensional stability was evaluated in accordance with ISO 6876. Biofilm growth inhibition was evaluated using confocal laser scanning microscopy (CLSM). Biofilm viability analysis was performed using the SYTO 9 technique. The shelf life was evaluated through the degree of conversion and film thickness tests after the sealers had been stored for different periods of time. For statistical analysis, ANOVA and Tukey's post hoc test were used, with a significance level of 5%. ETs revealed better anti-biofilm potential after 15 days than that of the controls. The degree of conversion was reduced after the shelf-life period. The addition of calcium and dibutyltin methacrylate improved the anti-biofilm properties of the experimental endodontic sealer without impairing their physico-chemical properties. [ABSTRACT FROM AUTHOR]

Following antimicrobial administrations in oral environments, bacteria become exposed to a sub-minimum inhibitory concentration (sub-MIC), which can induce in vitro single-species biofilms. This study explored the effects of chlorhexidine gluconate (CHG) at a sub-MIC on in vitro multi-species biofilms comprising Streptococcus mutans, Streptococcus oralis and Actinomyces naeslundii. CHG at a sub-MIC was found to induce in vitro biofilm growth, although the bacterial growth was not significantly different from that in the control. The gene transcription related to S. mutans multi-species biofilm formation with CHG at a sub-MIC was significantly higher than that of the control, but this was not found in S. mutans single-species biofilms. The bio-volume of extracellular polysaccharides with CHG at a sub-MIC was significantly higher than that of the control. This suggests that CHG at a sub-MIC may promote the development of multi-species biofilms by affecting the gene transcription related to S. mutans biofilm formation. [ABSTRACT FROM AUTHOR]

Background:Targeting Streptococcus mutans, the principle cariogenic bacterium, could prove to be an effective means of preventing dental caries. A de novo designed antimicrobial peptide, GH12, has shown bactericidal effects on S. mutans and inhibitory effects on virulence and regulatory systems of S. mutans. However, the effects of GH12 on caries remain to be elucidated.Objectives: The objectives of this study were to evaluate the direct effects of GH12 on caries and numbers of S. mutansin vivo.Design: The Keyes score was evaluated in a rodent model and in vivo S. mutans was quantified by qPCR. To further interpret the in vivo anticaries efficacy, an in vitro biofilm model using short-term treatments with GH12 mimicked treatments in vivo was adopted. Results: In vivo data showed that GH12 at 8 mg/L reduced the incidence and severity of caries. Furthermore, GH12-treated animals had less S. mutans infection. In vitro data revealed that GH12 reduced the number of S. mutans within the biofilm, as well as reducing lactic acid and water-insoluble EPS synthesis of S. mutans biofilms. Afterwards, all rats showed no significant difference in weight gain, and no sign of harm to the mucosa, indicating that GH12 possessed good biocompatibility in vivo.Conclusion: Due to the combined inhibitory effects of GH12 on the biomass and cariogenic properties of S. mutans biofilms, the population of S. mutans in vivo was reduced, residual S. mutans biofilms were less acidic and compact, and thereby the onset and development of caries were arrested. Such findings collectively certified the clinical prospects for GH12. [ABSTRACT FROM AUTHOR]

Nanotechnology has attracted increasing interest in different aspects of biotechnology. The fabrication of electrospun nanofibers (NFs) containing antibacterial agents for antimicrobial applications has been significantly enhanced in recent years. In the current review, various electrospun NFs with antimicrobial properties were introduced and evaluated. The main focus was on the recent developments and applications of antimicrobial electrospun NFs incorporated with different antimicrobial agents, including metal nanoparticles (NPs), antibiotics, quaternized ammonium compounds, triclosan, herbal extracts, carbon nanomaterials, and antimicrobial biopolymers with inherent antimicrobial properties. The search results revealed that antimicrobial containing electrospun NFs had enhanced antimicrobial performance with various biomedical applications compared to the traditional antimicrobial materials. According to the reported results, most of the studies were of an investigative nature and were mostly based on in vitro tests. Hence, further examination on in vivo clinical performance of these antimicrobial NFs seems necessary. However, these antimicrobial NFs appear to have the potential to achieve clinical usefulness and commercial production in the near future. [ABSTRACT FROM AUTHOR]

Introduction: The rise of antibiotic resistance, the limited efficacy and the adverse events associated with antibiotics have urged the development of alternative measures to treat bacterial infections. Novel therapies which are pathogen specific and are safer to the healthy microbiome are being developed. Areas covered: This manuscript provides a compact overview of the feasibility and clinical impact of the latest novel therapies, with a focus on monoclonal antibodies (mAbs), vaccines, stem cells, bacteriophages, and liposomes. This is a follow-up of a previous manuscript (doi: 10.1080/17512433.2016.1241141); a database search (PubMed, EMBASE, Cochrane) was used to identify recently published literature (from January 2016) which was not covered in the previous publication. Expert opinion: Among non-traditional agents, monoclonal antibodies have not been as successful as in other therapeutic areas. In particular many are developed to prevent hospital-acquired infections caused by S. aureus or P. aeruginosa and, so far, results have been overall disappointing. Stem cells and bacteriophages still have a long way to go. Vaccines are always desirable to prevent infections but again there is a lack of confirmatory results. Broad spectrum liposomes have shown promising results in treating severely infected patients and could be game changers in patient management. [ABSTRACT FROM AUTHOR]

The aim of this trial was to establish the clinical efficacy of essential oils (EO) and chlorhexidine digluconate (CHX) when used as a cooling agent with ultrasonic instrumentation, on periodontal parameters and halitosis. Ninety patients with periodontal disease were divided into the control and test group on a non- bias selection method. All patients completed a questionnaire and standard periodontal outcome variables were assessed. For both groups, the plaque index (PI), gingival index (GI), pocket depth (PD), bleeding on probing (BOP) and clinical attachment level (CAL) scores were assessed at the beginning and at the end of the treatment period. Volatile sulphur compound (VSC) levels were evaluated by a Halimeter (Interscan Corp., Chatsworth, CA, USA) prior to treatment, immediately after treatment, and 7, 14 and 30 days post-treatment. In all the groups periodontal parameter scores decreased throughout the study. Only on the 30th day the difference of PD and CAL scores were statistically significant between the control and the EO treated group. When groups were compared in relation to the VSC values a significant reduction was identified in both EO and CHX groups at the baseline and 30th day. However, the intergroup comparisons of the VSC values showed no significant differences at any time point. Within the limits of this study, ultrasonic mechanical instrumentation is effective for the management of periodontal disease and halitosis. However, using EOs as a cooling agent with ultrasonic devices has little beneficial effects on periodontal parameters when compared control and CHX groups. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii have evolved as an exceedingly troublesome pathogenic microorganisms and prevention and controlling this pathogen is considered to be a public health problem. Nanoemulsions (NE) are a distinctive type of decontaminator produced by integration of immiscible oil phase with aqueous phase under extreme shear forces. The effectiveness of NEs and their components was determined against four stains of A. baumannii by MBC, adherence assay, biofilm assay and SEM studies. NE dilutions ranging from 125 to 225 reduced adhesion by from 61.8 to 99.9% in NE-treated groups (p<.05) as determined by MBC. Four-day-old A. baumannii biofilms were treated with NE; LIVE/DEAD staining showed dead cell intensity of 56.2-92.0% in NE-treated groups. After NE treatment and observation by SEM, cell surfaces appeared to be remarkably disintegrated. Irregular boundaries were observed and margins of cell walls were unclear. The anti-adherence, anti-biofilm and morphological disruption effects of NE suggest that this material could be useful for the development of promising antimicrobial agents. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the antimicrobial (anti-biofilm) and anti-caries (enamel demineralization prevention) effects of Malva sylvestris (Malvatricin® Plus) compared with known antimicrobial mouthrinses. Microcosm biofilm was produced on enamel, using inoculum from pooled human saliva mixed with McBain saliva (0.2% sucrose) for 14 days. The biofilm was treated with mouthrinses for 1 min day−1. Oral-B® Complete, Listerine® Zero and Malvatricin® Plus had the greatest effect on the reduction of biofilm viability (p < 0.0001). On the other hand, lactic acid production was reduced significantly with PerioGard®, Noplak® Max and Listerine® Zero compared with the control (p < 0.0001). No significant differences were found among the mouthrinses with respect to the colony-forming unit counting (total microorganisms, total streptococci, mutans streptococci and lactobacilli) and extracellular polysaccharide production. Enamel demineralization was reduced significantly with PerioGard®, Noplak® Max and Malvatricin® Plus compared with the control (p < 0.0001). Malva sylvestris has a comparable anti-caries effect to chlorhexidine mouthrinses. [ABSTRACT FROM AUTHOR]

Introduction: Bacterial resistance to antibiotics is increasing worldwide, due to the emergence of multidrug-resistant strains. With this panorama, there is a serious danger that we may be entering the ‘post-antibiotic era’. Areas covered: We assess why so few new classes of antibiotics have been developed in the past years and discuss a variety of treatments that may be able to replace antimicrobials: monoclonal antibodies, bacteriophages, stem cells and anti-virulence agents such as liposomes. Expert commentary: There are a series of economic, scientific-research and regulatory reasons for the scarcity of new antimicrobials. New approaches are needed to combat infections. Innovative strategies like Eco-Evo drugs and innovative delivery methods such as aerosol or nanoparticle administration require a new management paradigm, in combination with rapid molecular diagnostic tests. Biopharma, clinical researchers, regulatory agencies, governments and investors must work together in the attempts to achieve effective treatment for infections caused by MDR organisms. [ABSTRACT FROM AUTHOR]

Background:Tetracyclines are used as acne treatment in adolescents worldwide. A large increase in the consumption of antimicrobial agents in Danish primary health care was recently linked to high levels of tetracycline use in adolescents. Methods:Here we closely examine how demographic factors influenced tetracycline use from 2005 to 2014 using consumption data from primary health care expressed as defined daily doses (DDDs) per 1000 inhabitants per day (DID) and number of persons treated per 1000 inhabitants. Results:From 2005 to 2013, tetracycline consumption increased by 54% followed by a decrease of 14% in 2014. Increases were especially pronounced in persons aged 15–39 years where nearly 9000 additional persons were treated with tetracyclines. Conclusions:This study shows a long-lasting high consumption of tetracyclines in young Danes with a notable recent decrease breaking the otherwise worrying trend. To obtain a further decrease, focus on public awareness and suitable acne treatment guidelines are highly important. [ABSTRACT FROM AUTHOR]

ContextThe increasing problem of drug-resistant strains has led to the failure of current treatment regimens ofHelicobacter pylori(HP) infection. Recently, a new treatment strategy has been developed to overcome the problem by using natural products in combination with antibiotics to enhance the treatment efficacy. ObjectiveThe antimicrobial combinatory effect of the aqueous extract ofHibiscus sabdariffaL. (Malvaceae) (AEHS) with antibiotics (clarithromycin, CLA; amoxicillin, AMX; metronidazole, MTZ) has been evaluatedin vitroagainst HP strains. Materials and methodsHibiscuscalyces (35 g) were brewed in 250 mL of boiled water for 30 min, and minimum inhibitory concentrations (MICs) were determined by agar dilution method. The checkerboard assay was used to evaluate the antimicrobial combinatory effect according to the sum of fractional inhibitory concentration (∑FIC) indices. ResultsIn this study, AEHS exerted remarkable bacteriostatic effect against all HP strains tested with MICs values ranging from 9.18 to 16.68 μg/mL. Synergy effect of AEHS with CLA or MTZ was obtained against four of seven HP strains tested with ∑FIC ranging from 0.21 to 0.39. The additive effect of AEHS with AMX was obtained against five of seven HP strains tested with ∑FIC ranging from 0.61 to 0.91. ConclusionThis study presents AEHS as a potent therapeutic candidate alone, or in combination with antibiotics for the treatment of HP infection. [ABSTRACT FROM PUBLISHER]

This article describes an efficient and facile synthesis of 11 2,4,6-trisubstituted 5-cyanopyrimidines starting frommeta-andpara-substituted 2-cyanocinnamonitriles and arylamidines. The synthesized heterocycles,3a–k,were characterized by infrared (IR),1H NMR,13C NMR, and mass spectral data. The probable mechanism of formation of the title compounds employing 2-cyanocinnamonitriles and arylamidines in the presence of a base was clarified. A preliminary screening of the antibacterial tests clearly showed that 4 out of 11 pyrimidines,3a, 3e, 3f,and3k,were effective against bacteriaStaphyloccus aureus, Bacillus subtillis,andPseudomonas aeruginosa.Further, the minimum inhibitory concentration (MIC) against the bacteria has been determined. [ABSTRACT FROM PUBLISHER]

In recent years autologous platelet concentrates (APCs) have become popular in several medicine fields, representing a valuable adjunct to regenerative surgical procedures. Beneficial effects in the control of postsurgical discomfort and infection have also been frequently reported, suggesting that APC may possess anti-inflammatory and antimicrobial properties. The aim of the present review was to summarize the current evidence regarding the antimicrobial effects of platelet concentrates, investigated byin vitroand animal studies. This review was conducted following a systematic approach. An electronic search was performed on MEDLINE, EMBASE and Scopus databases using appropriate search terms, without language or time restrictions. Preclinical studies assessing the antimicrobial activity of APC were included and divided according to the experimental design. Twentyin vitrostudies and four animal studies, investigating APC effects on a broad range of microorganisms, were included. Inin vitrostudies APC reduced the growth of microorganisms during the first hours of incubation, while they could not completely break down the microbial load. In fact, over time a recovery of bacterial growth was always observed, suggesting that APCs display a bacteriostatic rather than a microbicidal activity. All animal studies showed that APC administered by local injections were able to reduce the infection caused by different microorganisms, although to a lesser extent compared to antibiotics. In conclusion, although the exact action mechanisms of interaction with microbial pathogens need further investigation, platelet concentrates proved to have antimicrobial properties, and therefore could represent a useful natural substance for controlling postoperative infections at surgical sites. [ABSTRACT FROM AUTHOR]

Microbial resistance to the available drugs poses a serious threat in modern medicine. We report the design, synthesis andin vitroantimicrobial evaluation of new functionalized 2,3-dihydrothiazoles and 4-thiazolidinones tagged with sulfisoxazole moiety. Compound8dwas most active againstBacillis subtilis(MIC, 0.007 µg/mL). Moreover, compounds7c–dand8cdisplayed significant activities againstB. subtilisandStreptococcus pneumoniae(MIC, 0.03–0.06 µg/mL and 0.06–0.12 µg/mL versus ampicillin 0.24 µg/mL and 0.12 µg/mL; respectively). Compounds7aand7c–dwere highly potent againstEscherichia coli(MIC, 0.49–0.98 µg/mL versus gentamycin 1.95 µg/mL). On the other hand, compounds7eand9cwere fourfolds more active than amphotericin B againstSyncephalastrum racemosum. Molecular docking studies showed that the synthesized compounds could act as inhibitors for the dihydropteroate synthase enzyme (DHPS). This study is a platform for the future design of more potent antimicrobial agents. [ABSTRACT FROM AUTHOR]

Given their broad spectrum, cephalosporins are used for combating mastitis in dairy species. Many cephalosporins, such as cephalexin, have not been authorized for use in lactating sheep and because veterinary drugs for use in small species are lacking, the regulations of several countries allow extra-label use. Incorrect use of extra-label tools may cause residues in milk, and could negatively affect public health by provoking technological failures in the dairy fermenting processes. The effects of cephalexin, at concentrations close to its European Maximal Residue Limit (MRL), have been studied in set-type yogurts made from sheep’s milk. Milk was fortified at different cephalexin concentrations and stored yogurts were evaluated in acidification, textural parameters and microbial evolution terms. The results showed that cephalexin concentrations equal to or below its MRL could mainly inhibit normalStreptococcus thermophilusgrowth and provoke some alterations to acidity parameters, which were more marked in the L(+)-lactic acid isomer. [ABSTRACT FROM PUBLISHER]

Although most bacterial infectious diseases can be treated successfully with the remarkable array of antibiotics, the microbial pathogens continue to be one of the most critical health challenges worldwide. One of the common efforts in addressing this issue lies in improving the existing antibacterial delivery systems since inefficient delivery can lead to poor therapeutic outcome of the administered drug. Recently, nanoliposomal systems have been widely used as promising strategies to overcome these challenges due to their unique set of properties. This article tries to briefly summarize the current studies that have taken advantage of liposomal nanoparticles as carriers to deliver antibacterial agents. The reviewed investigations demonstrate the immense potential of liposomal nanoparticles as carriers for antibiotic delivery and highlight the latent promise in this class of vehicles for treatment of bacterial infections. The future of these promising approaches lies in the development of more efficient techniques for preparing liposomal nanoparticles with great potential in effective and selective targeting of antibiotics to bacterial cells for eradication as well as the highest safety for human host. [ABSTRACT FROM AUTHOR]

New 2-amino-N-hydroxybenzamide derivatives(3a–j)have been synthesized in good to excellent yields from the reaction of isatoic anhydride with different hydroxamic acids. All the compounds of the series were screened against both Gram-positive and Gram-negative bacteria and fungi, and some of them have antibacterial and antifungal activities compared to the standard drugs. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of a series of new 2-amino-3-cyano-8-methyl-4-substituted-5,6,7,8-tetrahydroquinolines along with some derived fused-ring systems. Ten compounds have shown remarkable cytotoxic activity against human colon carcinoma HT29, hepatocellular carcinoma HepG2 and Caucasian breast adenocarcinoma MCF7 cell lines. Six compounds showed considerable broad-spectrum cytotoxic activity among which two proved to be the most active derivatives. Likewise, seven compounds from the series were found to exhibit significant antimicrobial activity and three of them proved to be the most active candidates. Two alkylthio-pyrimido quinolines are suggested as possible antimicrobial and anticancer candidates in the present series. [ABSTRACT FROM AUTHOR]

We report the synthesis and structural studies of oligo(3-hydroxybutyrate) conjugates with sorbic acid and benzoic acid, designed for food active packaging systems. The preservative–oligomer conjugates were obtained via the anionic ring-opening oligomerization of racemicβ-butyrolactone initiated by sodium sorbate and sodium benzoate, respectively. The structures of the resulting conjugates have been established at the molecular level by electrospray ionization multistage mass spectrometry in positive-ion mode supported by proton nuclear magnetic resonance. The fragmentation of the selected ions of the resulting conjugates confirmed that preservatives molecules, with unchanged structure, are covalently bonded to oligo(3-hydroxybutyrate). [ABSTRACT FROM PUBLISHER]

Staphylococcus epidermidisis nowadays regarded as the most frequent cause of nosocomial infections and indwelling medical device-associated infections. One of the features that contributes to the success of this microorganism and which is elemental to the onset of pathogenesis is its ability to form biofilms. Cells in this mode of growth are inherently more resistant to antimicrobials. Seeking to treat staphylococcal-related infections and to prevent their side effects, such as the significant morbidity and health care costs, many efforts are being made to develop of new and effective antistaphylococcal drugs. Indeed, due to its frequency and extreme resistance to treatment, staphylococcal-associated infections represent a serious burden for the public health system. This review will provide an overview of some conventional and emerging anti-biofilm approaches in the management of medical device-associated infections related to this important nosocomial pathogen. [ABSTRACT FROM AUTHOR]

New furanone derivatives incorporating the indolin-2-one moiety 3 were prepared via the Perkin reaction of isatins 1 with aroylpropionic acids 2 under conventional conditions or microwave irradiation. A series of functionally heterocyclic derivatives (e.g., pyridazines, pyrroles, and sulfonamides) incorporating the indolin-2-one moiety was achieved via reaction of 3 with different reagents under microwave irradiation conditions. The newly synthesized compounds were characterized on the basis of FTIR, 1H, 13C NMR and mass spectral studies. Some of the new synthesized compounds were screened for antibacterial activity against Gram-positive bacteria ( Staphylococcus aureus and Bacillus cereus), Gram-negative bacteria ( Escherichia coli and Shigilla flexneri) and antifungal activity against Aspergillus flavus and Candida albicans. Compound 8 j was equipotent to chloramphenicol in inhibiting the growth of E. coli minimum inhibitory concentration (MIC 2.5 μg/mL). Compound 8j may possibly be used as a lead compound for developing a new antibacterial agents. The antibacterial activity is expressed as the corresponding MIC (μg/mL) values. [ABSTRACT FROM AUTHOR]

Context: Lawsonia inermis Linn. (Lythraceae) or henna has been used since the earliest times as a medicine, preservative, and cosmetic. It has long been recommended in traditional medicine as an astringent, purgative, and abortifacient. Objective: Lawsone and six extracts of L. inermis plant, used by Algerian traditional healers to treat infectious diseases, were screened for their antifungal activity against filamentous fungi. Materials and methods: Water and five organic extracts - DMSO, ethanol, chloroform, ethyl acetate, and di-ethyl ether - of L. inermis leaves, collected in the area of Adrar (Algeria), were prepared by soaking 25 g of powdered plant in 100 mL of solvent. The extracts were screened for antifungal activity using the poisoned food technique against five filamentous fungi. Results: Results demonstrated that the best yield (8.03%) was obtained with the ethanol extract. The commercial lawsone showed potentially interesting MICs against the strains Fusarium oxysporum (12 µg/mL) and Aspergillus flavus (50 µg/mL). The ethanol extract showed the only interesting MIC (230 µg/mL of crude extract) against the strain F. oxysporum compared with other extracts. Discussion and conclusion: These results suggest that the Algerian L. inermis plant has antifungal activity that can be related to the presence of lawsone in the leaves plant. The results can be exploited largely in research of new antifungal drugs. [ABSTRACT FROM AUTHOR]

This study describes a simple, rapid, and green method for the reliable quantification of antibacterial compounds in personal care products in aqueous samples. Water samples were extracted by solid phase micro-extraction (SPME), and the chemicals of interest were detected and quantified using a high performance liquid chromatography/diode array detector (HPLC-DAD) coupled using a homemade interface. Parameters that affect extraction efficiencies of SPME were optimized, including the salt concentration, the sample pH, the extraction and desorption times, and the sample volume. The optimized method provided a simple and rapid (<1 hr) sample pretreatment that gave satisfactory sensitivities, accuracies, and precisions. The method detection limit (MDL) of target compounds in 5 mL sample volumes spiked with analytes was as low as 0.06−0.21 ng/mL for deionized water samples, and 0.12−0.73 ng/mL for river water samples. Recoveries for spiked samples ranged from 84.62 to 100.80% and 81.54 to 102.32% for the deionized water and river water samples, respectively. This is the first description of an analytical procedure that enables reliable and simultaneous detection and quantification of up to six antibacterial compounds and their derivatives in water, despite the complexity present in the samples. [ABSTRACT FROM PUBLISHER]

This study evaluated the antimicrobial activity of three different ethanol extracts of Agaricus brasiliensis S. Wasser et al. (Agaricaceae) on the growth and cell adherence of mutans streptococci. Crude ethanol extracts (100% EtOH, 75% EtOH, and 50% EtOH, v/v) obtained from dried basidiomes of A. brasiliensis were assessed against Streptococcus mutans UA159 and Streptococcus sobrinus 6715 by the agar diffusion method, determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), and inhibition of cell adherence to a glass surface. In the agar diffusion method, only the 100% ethanol extract revealed inhibition of bacterial growth. Yet, in MIC and MBC tests, the three extracts presented antimicrobial properties and MIC and MBC values between 87.4 and 444.5 μg mL−1. The MBC was predominantly similar to MIC against S. mutans, but only the 75% ethanol extract was bactericidal against S. sobrinus. Among the ethanol extracts tested, the 100% ethanol extract was the most active (MIC 87.4 μg mL−1). The cellular adherence also was inhibited at concentrations from 100 to 400 μg mL−1 of 50% and 75% ethanol extracts. These results provide promising baseline formation for the potential use of A. brasiliensis against mutans streptococci. These findings warrant more in-depth studies of the active principles of this mushroom ethanol extract. [ABSTRACT FROM AUTHOR]

Despite the application of various preservation methods, many problems are still encountered as a result of food spoilage and food poisoning. There is increasing demand for foods produced with milder treatments, and the movement towards more natural and even certified organic foods has been the fastest growing sector of the food industry over the last decade. The interest in bio-preservation of food systems has necessitated the development of new natural antimicrobial compounds from different origins, and in response to modern consumer trends and food legislation, the food industry is faced with serious challenges. Both conventional and organic modes of production are at risk of contamination, but it is possible that organic food might present a bigger problem. Organic acids have been of considerable value as food preservatives since they are also food ingredients and often naturally produced by microorganisms. However, limited data on their effects in commercial practice are available, and despite regulatory approval, organic acids are not widely accepted in commercial practice, and in particular in meat decontamination. Susceptibility of microorganisms to the most currently used preservatives has been decreasing, and there is concern that decontamination with organic acids could result in the emergence of acid-tolerant food-borne pathogens, evolving to overcome the protective barrier of the human gastric stomach. In the evaluation and integration of new processing/preservation treatments, research objectives would have to include the identification of specific targets of organic acids - understanding the molecular mechanisms that confer high level resistance and analysing pathogen response to antimicrobials. This article provides an overview of various studies done on organic acids as preservatives and highlights aspects such as application, antimicrobial action, and future prospects. Other important issues, such as the application of functional genomics in developing new preservation methods, resistance development, and conventional laboratory procedures are also discussed. [ABSTRACT FROM AUTHOR]

The thiazole and imidazole nucleus, as well as carbohydrates are important classes of compounds found in many natural and synthetic products with a wide range of biological activities. Due to the importance of these classes of compounds as antimicrobial agents, the present article reports the synthesis of a new series of nine compounds based on the coupling of 2-mercaptobenzothiazole and 2-mercaptobenzimidazole with different carbohydrates. [ABSTRACT FROM AUTHOR]

Objective . To assess the relationship between the presence of mixed infection of Helicobacter pylori and both antimicrobial susceptibility and virulence markers. Material and methods . Thirty-six patients with H. pylori infection were included in the study. Three colonies were selected from each positive biopsy sample collected from each host for a total of 108 H. pylori strains. The genetic variability was evaluated through the amplified fragment length polymorphism (AFLP) analysis; the antibiotic susceptibility to amoxicillin, clarithromycin, moxifloxacin, rifabutin and tinidazole was determined using the minimum inhibitory concentrations (MICs) with the agar dilution method. Moreover, the vac A, cag A, ice A and bab A2 statuse were detected by polymerase chain reaction (PCR). Results . There was a strong connection between mixed H. pylori infection and antimicrobial resistance. In particular, H. pylori strains with genetic variability, in the same host, expressed more resistance to clarithromycin, moxifloxacin and tinidazole than that expressed in strains with a unique genetic host pattern. Vac A s1m1/s1m2 genotypes were found in 70% of strains isolated in mixed infection, whereas the same allelic combinations were found in 42% of strains, isolated in single infection. The cag A + status prevailed both in patients with mixed (97%) and in those with single infection (85%) without significant differences. The ice A1 status was more commonly found in patients with mixed infection, whereas the bab A2 status was significantly prevalent in single H. pylori infection. Conclusions . Mixed H. pylori infection harbouring in one patient is significantly related to strains that are more resistant to antibiotics and with a more virulent genotype ( vac A s1m1/s1m2, cag A, ice A1) than strains responsible for single infection. [ABSTRACT FROM AUTHOR]

Abstract: We have developed an efficient construction of spiro derivatives by anodic oxidation of the corresponding phenols, which enabled synthesis of spiroisoxazoline natural products as well as heliannuols, carrying chroman and benzooxepin structures. In addition to nucleophilic attack of hydroxyl or amino groups to the cation generated electrochemerically, it might be of interest to use a carbonyl oxygen as a nucleophilic center, which would provide hemiacetal-type spiro compounds. Gymnastatin A 1 was isolated from the strain of Gymnescella dankaliensis separated from the sponge Halichondria japonica, together with other gymnastatins. This marine natural product consists of the spiro structure between the dienone part including two chlorine atoms, and the tetrahydrofuran ring with a hemiacetal moiety, along with the fatty acid part having an asymmetric carbon center attached with the amino group. As part of our extensive electrochemical investigation of halogenated tyrosine derivatives, synthesis of the acetal-spiro derivatives and its application to gymnastatin A 1 was undertaken to develop further efficient and green sustainable methodology. In these investigations, construction of spiro compounds having hemiacetal moiety, and synthesis of gymnastatin A 1 was achieved successfully. In addition to the synthesis, biological assessment of synthetic samples was examined. Among them, 3, 5, 14, and 15 showed a wide range of inhibitory activity against Gram-positive, -negative bacteria, fungus, and Mycobacterium. [Copyright &y& Elsevier]

Reaction of an ethanolic solution of N -salicylidene- l -glutamatodiaquacopper(II) monohydrate with pyridine, 2-methylpyridine, 4-methylpyridine, 2-aminopyridine, 2,6-diaminopyridine, quinoline, 2-methylquinoline, 4-methylquinoline or 3-methylisoquinoline resulted in solid products containing complexes of the type Cu(sal- l -glu)L with distorted square-pyramidal coordination geometry. The products were characterized by elemental analysis, electronic spectroscopy and magnetic susceptibility measurements. Antimicrobial effects were tested on various strains of bacteria, yeasts and filamentous fungi. To compare the influence of individual ligands (neutral as well as anionic) on their biological activity, copper(II) complexes containing water and a Schiff base derived from salicyldehyde and methyl- and ethyl-esters of l -glutamic acid [Cu(sal-5-Me- l -glu)(H 2 O) 2 and Cu(sal-5-Et- l -glu)(H 2 O) 2 ] were also prepared and studied. Bioactivities of complexes tested were found to decrease in the sequence bacteria > filamentous fungi > yeasts. [ABSTRACT FROM AUTHOR]

The EU-funded PROPATH project addresses the important health issue of prevention of gastrointestinal disorders through probiotics and prebiotics. Seven European laboratories are co-operating in this project, which aims to isolate and characterize the relevant antimicrobial agents to combat Gram-negative bacteria including Helicobacter pylori and Salmonella enterica serovar Typhimurium. In this paper, the first results on the screening for probiotic or potentially probiotic lactobacilli that exhibit antimicrobial activity towards these Gram-negative pathogenic bacteria are presented. Spot-on-lawn assays, well-diffusion assays and time-kill studies were performed among the lactic acid bacteria strains that were either collected from fermented foods and faeces (breast-fed babies, infants and animals) or isolated from commercial products to investigate whether any of the collected strains were inhibiting growth of or were killing certain indicator bacteria. Strains inhibiting the gastrointestinal pathogens mentioned above were found. Evidence has been obtained that compounds different from organic acids are produced. [ABSTRACT FROM AUTHOR]