Background:In view of the ever-increasing representation of Staphylococcus spp.strains resistant to various antibiotics,the development of in vivo models for evaluation of novel antimicrobials is of utmost importance....Background:In view of the ever-increasing representation of Staphylococcus spp.strains resistant to various antibiotics,the development of in vivo models for evaluation of novel antimicrobials is of utmost importance.Methods:In this article,we describe the development of a fully immunocompetent porcine model of extensive skin and soft tissue damage suitable for testing topical anti-microbial agents that matches the real clinical situation.The model was developed in three consecutive stages with protocols for each stage amended based on the results of the previous one.Results:In the final model,10 excisions of the skin and underlying soft tissue were created in each pig under general anesthesia,with additional incisions to the fascia performed at the base of the defects and immediately inoculated with Staphylococcus aureus suspension.One pig was not inoculated and used as the negative control.Subsequently,the bandages were changed on Days 4,8,11,and 15.At these time points,a filter paper imprint technique(FPIT)was made from each wound for semi-quantitative microbiological evaluation.Tissue samples from the base of the wound together with the adjacent intact tissue of three randomly selected defects of each pig were taken for microbiological,histopathological,and molecular-biological examination.The infection with the inoculated S.aureus strains was sufficient during the whole experiment as confirmed by both FPIT and from tissue samples.The dynamics of the inflammatory markers and clinical signs of infection are also described.Conclusions:A successfully developed porcine model is suitable for in vivo testing of novel short-acting topical antimicrobial agents.展开更多
In order to investigate the susceptibility of mixed infection of Ureaplasma Urealyticum (UU) and Mycoplasma Hominis (MH) to 7 kinds of antimicrobial agents and comparison with that of UU infection in NGU patients, the...In order to investigate the susceptibility of mixed infection of Ureaplasma Urealyticum (UU) and Mycoplasma Hominis (MH) to 7 kinds of antimicrobial agents and comparison with that of UU infection in NGU patients, the in vitro susceptibility was determined by using microdilution method. The positive results were analyzed. The results showed that the sequence of susceptibility to 7 kinds of antimicrobial agents for both UU infection group and UU-MH mixed infection group was almost the same from the highest susceptibility to the lowest accordingly: Josamycin, Doxycycline, Minocycline, Sparfloxacin, Roxithromycin, Ofloxacin and Azithromycin. The total drug resistance rate for UU-MH mixed infection group (97. 67 %) was significantly higher than that for UU infection group (44. 67 %, P<.0. 01). The highest drug resistance rate in UU group and UU-MH mixed infection group was 31. 33 % (Ofloxacin) and 90. 48 % (Azithromycin) respectively. UU-MH mixed infection showed an increased drug resistance and changes of drug resistance spectrum.展开更多
The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. ...The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.展开更多
We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly...We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly found in the human oral cavity and causes tooth decay. The objective was to improve the function of marine Arthrobacter oxydans KQll dextranase mouthwash （designed and developed by our laboratory）. The experiment was conducted in a three-level, four-variable central composite design to determine the best combination of ZnSO4, lysozyme, citric acid and chitosan. The optimized antibacterial agents were 2.16 g/L ZnSO4, 14 g/L lysozyme, 4.5 g/L citric acid and 5 g/L chitosan. The biofilm formation inhibition reached 84.49%. In addition, microscopic observation of the biofilm was performed using scanning electron microscopy and confocal laser scanning microscopy. The optimized formula was tested in marine dextranase Arthrobacter oxydans KQ11 mouthwash and enhanced the inhibition of S. mutans. This work may be promoted for the design and development of future marine dextranase oral care products.展开更多
AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METH...AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: FBGT should not be treated with metronidazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.展开更多
The present study sought to assess the rational use of antimicrobial agents in a Brazilian intensive care unit (ICU) and its association with antimicrobial resistance in elderly patients admitted to the unit. Results:...The present study sought to assess the rational use of antimicrobial agents in a Brazilian intensive care unit (ICU) and its association with antimicrobial resistance in elderly patients admitted to the unit. Results: Choice of empiric and sensitivity-guided therapy was inadequate in > 80% and 59% of cases respectively. Inadequate antimicrobial therapy, whether empiric or sensitivity-guided, was positively correlated with bacterial resistance (r = 0.316;p = 0.001). Sensitivity testing revealed a 46.5% resistance rate to eight out of the ten most commonly used antibiotics. Multiple drug-resistant organisms were found in 40.8% of patients. A significant increase was observed in the number of multidrug-resistant samples between 2006/2007 and 2008 (r = 0.41, p = 0.006), (r = 0.598, p = 0.001), (r = 0.688, p = 0.00). Conclusion: We found a high rate of antibiotic misuse in the study sample. Inadequate therapy was correlated with resistance to antimicrobial agents.展开更多
Biofilms at the tooth-restoration bonded interface can produce acids and cause recurrent caries. Recurrent caries is a primary reason for restoration failures. The objectives of this study were to synthesize a novel b...Biofilms at the tooth-restoration bonded interface can produce acids and cause recurrent caries. Recurrent caries is a primary reason for restoration failures. The objectives of this study were to synthesize a novel bioactive dental bonding agent containing dimethylaminohexadecyl methacrylate(DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine(MPC) to inhibit biofilm formation at the tooth-restoration margin and to investigate the effects of water-aging for 6 months on the dentin bond strength and protein-repellent and antibacterial durability. A protein-repellent agent(MPC) and antibacterial agent(DMAHDM) were added to a Scotchbond multi-purpose(SBMP) primer and adhesive. Specimens were stored in water at 37 °C for 1, 30, 90, or 180 days(d).At the end of each time period, the dentin bond strength and protein-repellent and antibacterial properties were evaluated. Protein attachment onto resin specimens was measured by the micro-bicinchoninic acid approach. A dental plaque microcosm biofilm model was used to test the biofilm response. The SBMP + MPC + DMAHDM group showed no decline in dentin bond strength after water-aging for 6 months, which was significantly higher than that of the control(P < 0.05). The SBMP + MPC + DMAHDM group had protein adhesion that was only 1/20 of that of the SBMP control(P < 0.05). Incorporation of MPC and DMAHDM into SBMP provided a synergistic effect on biofilm reduction. The antibacterial effect and resistance to protein adsorption exhibited no decrease from 1 to 180 d(P > 0.1). In conclusion, a bonding agent with MPC and DMAHDM achieved a durable dentin bond strength and long-term resistance to proteins and oral bacteria. The novel dental bonding agent is promising for applications in preventive and restorative dentistry to reduce biofilm formation at the tooth-restoration margin.展开更多
In this study,we used citric acid(CA)as a crosslinking agent,mixed with polyhexamethylene biguanide,to perform a pad-dry-cure treatment on wool fabrics to study its antimicrobial effects and physical properties.
Objective： Myanmar has a long history of using medicinal plants for treatment of various diseases. To the best of our knowledge there are no previous reports on antiglycation activities of medicinal plants from Myanm...Objective： Myanmar has a long history of using medicinal plants for treatment of various diseases. To the best of our knowledge there are no previous reports on antiglycation activities of medicinal plants from Myanmar. Therefore, this study was aimed to evaluate the antioxidant, antiglycation and antimicrobial properties of 20 ethanolic extracts from 17 medicinal plants indigenous to Myanmar. Methods： In vitro scavenging assays of 2,2-diphenyl-l-picrylhydrazyl （DPPH）, nitric oxide （NO）, superoxide （SO） radicals were used to determine the antioxidant activities. Folin-Ciocalteu＇s method was performed to determine the total phenolic content. Antiglycation and antimicrobial activities were detected by bovine serum albumin-fluorescent assay and agar well diffusion method. Results： Terminalia cbebula Retz. （Fruit）, containing the highest total phenolic content, showed high antioxidant activities with inhibition of 77.98% ± 0.92% 88.95% ± 2.42%, 88.56% ±1.87% and 70.74% ±2.57% for DPPH, NO, SO assays and antiglycation activity respectively. It also showed the antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Escherichia coil, Pseudomonas aeruginosa and Candida albicans with inhibition zone of 19, 18, 17, 25 and 15 ram, respectively. Garcinia mangostana Linn. showed the strongest activities for SO and antiglycation assays with inhibition of 93.68% ± 2.63% and 82.37%± 1.78%. Bark of Melia sp. was the best NO radical scavenger with inhibition rate of 89.39%± 0.60%. Conclusion： The results suggest that these plants are potential sources of antioxidants with free radical-scavenging and antiglycation activities and could be useful for decreasing the oxidative stress and glycation end-product formation in glycation-related diseases.展开更多
A convenient one-pot three-component method for the preparation of tetra-substituted thiophene derivatives has been developed. Reaction ofacetyl acetone 1, phenyl isothiocynate 2 and 2-chloromethyI derivatives 3a-3c i...A convenient one-pot three-component method for the preparation of tetra-substituted thiophene derivatives has been developed. Reaction ofacetyl acetone 1, phenyl isothiocynate 2 and 2-chloromethyI derivatives 3a-3c in the presence of potassium carbonate afforded the target compounds, namely ethyl 2-（4-acetyl-3-methyl-5-（phenylamino）thiophen-2-yl）-2-oxoacetate derivatives 4a-4e, ethyl 3-（4- acetyl-3-methyl-5-（phenylamino）thiophen-2-yl）-3-oxopropanoate derivatives 4f-4i, di（（4-acetyl-3- methyl-5-phenylamino）thiophen-2-yl）ketone derivatives 4j-4n in reasonable overall yields. The synthesized compounds were screened for antirnicrobial activity. The detailed synthesis, spectroscopic data and antimicrobial activities of synthesized compounds were reported.展开更多
In order to resolve the increasing resistance phenomena of the Gram-negative bacteria against single chain quaternary ammonium salts （QAS）, lysine with a pedant fluorinated bis-ammonium salts was synthesized and its...In order to resolve the increasing resistance phenomena of the Gram-negative bacteria against single chain quaternary ammonium salts （QAS）, lysine with a pedant fluorinated bis-ammonium salts was synthesized and its antimicrobial properties were evaluated in this work. The novel fluorinated bis-ammonium salts shows similar activity with conventional single chain quaternary ammonium salts against Gram-positive bacteria but stronger activity against Gram-negative bacteria and yeast compared with the single chained counterpart.展开更多
Anacardium occidentale L., Anacardiaceae, is frequently used to treat infections. We evaluated the antimicrobial and antioxidant activity of extracts obtained from aerial parts of the plant in comparison with the extr...Anacardium occidentale L., Anacardiaceae, is frequently used to treat infections. We evaluated the antimicrobial and antioxidant activity of extracts obtained from aerial parts of the plant in comparison with the extract prepared with the flowers. Ethanol extracts of the leaves (EEL), stem bark (EEB), and flowers (EEF) were prepared separately. The antimicrobial activity was evaluated by agar diffusion and broth dilution methods. The minimum bactericidal and fungicidal concentrations were determined against: Streptococcus mutans, Lactobacillus acidophilus, Staphylococcus aureus, MRSA, Enterococcus faecalis, Streptococcus pyogenes, Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Klebsiella pneumoniae, Helicobacter pylori, Salmonella choleraesuis, Candida albicans, and Candida tropicalis. The antioxidant activity of the extracts was evaluated based on their scavenger capacity of 2,2-diphenyl-1-picrylhydrazyle. The phytochemical profile was analyzed by colorimetric methods and by HPLC with UV detection. All extracts exhibited antioxidant and antimicrobial activity. Although, the EEF was the most effective since it inhibited the growth of all 14 microorganisms tested. Anacardic and galic acids were identified in all extracts as well phenolic compounds, triterpenes, flavones and xanthones. In conclusion, the extracts obtained from the aerial parts of A. occidentale, mainly the extract of flowers that was the most effective, are rich in bioactive metabolites that exert a potent antioxidant and antimicrobial effect. Taken together, the results indicate an important biotechnological potential of A. occidentale as a source of compounds with broad-spectrum antimicrobial and of antioxidant activity to be used in the food and cosmetics industry.展开更多
A biofilm contains a consortium of cohesive bacterial cells forming a complex structure that is a sedentary, but dynamic, community. Biofilms adhere on biotic and abiotic surfaces, including the surfaces of practicall...A biofilm contains a consortium of cohesive bacterial cells forming a complex structure that is a sedentary, but dynamic, community. Biofilms adhere on biotic and abiotic surfaces, including the surfaces of practically all medical devices. Biofilms are reported to be responsible for approximately 60% of nosocomial infections due to implanted medical devices, such as intravenous catheters, and they also cause other foreign-body infections and chronic infections. The presence of biofilm on a medical device may result in the infection of surrounding tissues and failure of the device, necessitating the removal and replacement ofthe device. Bacteria from biofilms formed on medical devices may be released and disperse, with the potential for the formation of new biofilms in other locations and the development of a systemic infection. Regardless of their location, bacteria in biofilms are tolerant of the activities of the immune system, antimicrobial agents, and antiseptics. Concentrations of antimicrobial agents sufficient to eradicate planktonic cells have no effect on the same microorganism in a biofilm. Depending on the microbial consortium or component of the biofilm that is involved, various combinations of factors have been suggested to explain the recalcitrant nature of biofilms toward killing by antibiotics. In this mini-review, some of the factors contributing to antimicrobial resistance in biofilms are discussed.展开更多
Background The emergence of antibiotic resistant microorganisms associated with conventional swine production practices has increased interest in acid-based compounds having antimicrobial properties and other biologic...Background The emergence of antibiotic resistant microorganisms associated with conventional swine production practices has increased interest in acid-based compounds having antimicrobial properties and other biological functions as nutritional interventions.Despite the interest in organic acids and monoglycerides,few studies have examined the effects of the combination of these acid-based additives in weaned pigs under disease challenge conditions.Therefore,this study aimed to investigate the effects of dietary supplementation with blend of organic acids and/or medium-chain fatty acid monoglycerides on intestinal health and systemic immunity of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli(ETEC)F18 at 4-week of age.Results Dietary supplementation of organic acids,monoglycerides,or both organic acids and monoglycerides(combination)reduced(P<0.05)the diarrhea frequency of ETEC F18-infected pigs throughout the experimental period(d−7 to 21 post-inoculation).This is consistent with the reduced(P<0.05)proportion ofβ-hemolytic coliforms in feces observed for the organic acid and combination treatments on d 10 post-inoculation.Supplementation of organic acids,monoglycerides,or combination also reduced(P<0.05)bacterial translocation in mesenteric lymph nodes on d 21 post-inoculation.Pigs fed with monoglycerides or combination had lower(P<0.05)white blood cells on d 5 post-inoculation,and pigs fed the combination also had lower(P<0.05)lymphocytes than pigs in control group.Monoglyceride supplementation increased(P<0.05)white blood cells and neutrophils compared with control group on d 14 post-inoculation.However,supplementation with organic acid blend,monoglyceride blend,or combination did not affect growth performance in this experiment.Conclusions Supplementation with monoglycerides or organic acids alone or in combination improves the detrimental effects of ETEC F18 infection in weaned pigs,as indicated by reduced diarrhea,fecal shedding ofβ-hemolytic coliforms,and bacterial translocation,and thus enhancing disease resistance.Monoglycerides reduced the inflammatory response during peak infection,but their immunomodulatory and possible synergistic effects with organic acids need to be further investigated.展开更多
The treatment of Acinetobacter baumannii(A.baumannii)poses significant clinical challenges due to its multidrug/pan-drug resistance.In this study,we isolated a broad-spectrum lytic A.baumannii phage,named P425,from me...The treatment of Acinetobacter baumannii(A.baumannii)poses significant clinical challenges due to its multidrug/pan-drug resistance.In this study,we isolated a broad-spectrum lytic A.baumannii phage,named P425,from medical wastewater,targeting nine multidrug-resistant A.baumannii(MDRAB)with diverse capsular types.Biological characterization revealed that P425 maintains activity at pH range of 3–12 and temperature range of 4–50℃.It resists UV irradiation for 20 minutes,and had an optimal multiplicity of infection(OMOI)is 0.00001.The adsorption kinetics showed that P425 achieves>90%within 10 minutes of incubation,and the one-step growth curve indicated a 10-min latent period,with a burst size of 184 PFU/cell.The genome sequencing results indicated that it harbors a double-stranded DNA genome of 40,583 bp with a GC content of 39.39%.Intergenomic similarity analysis classified it as a novel species within the Friunavirus genus,while electron microscopy results showed that it belongs to the Podoviridae family.Notably,P425 exhibits potent 24-h in vitro inhibitory activity against MDRAB,and demonstrates synergistic effect at an MOI of 0.001 when combined with five classes of antibiotics targeting distinct antimicrobial mechanisms.Safety evaluations confirmed the absence of cytotoxicity,hemolytic activity,or systemic toxicity both in vitro and in vivo.In mouse infection models,P425 can significantly improve the survival rates of mice infected with Ab25(ST1791/KL101).When co-administered with levofloxacin,it achieved 100%protection against mortality and promoted immune recovery.Collectively,P425 is a prospective lytic phage that could offer novel strategies for combating MDRAB infections.展开更多
In this study,a novel Ce-based metal-organic framework(Ce-OFDC)was synthesized via the hydrothermal method.To enhance its photocatalytic antimicrobial properties,polymeric carbon nitride(PCN)was incorporated into the ...In this study,a novel Ce-based metal-organic framework(Ce-OFDC)was synthesized via the hydrothermal method.To enhance its photocatalytic antimicrobial properties,polymeric carbon nitride(PCN)was incorporated into the Ce-OFDC matrix,forming a CeOFDC/PCN composite material.Antibacterial assays demonstrated that Ce-OFDC/PCN had significant inhibitory effects on both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus),achieving inhibition rates of 99.5%and 94.3%,respectively.Notably,the antibacterial performance of Ce-OFDC/PCN was superior to that of Ce-OFDC or PCN alone.Furthermore,photocurrent and electrical impedance scanning measurements demonstrated that the Ce-OFDC/PCN composites showed improved photocurrent response and superior efficiency in separating photogenerated electrons and holes.The photocurrent density of Ce-OFDC/PCN reached 120μA cm^(-2),which was 1.5 times higher than that of PCN(80μA cm^(-2))and 12 times higher than that of Ce-OFDC(10μA cm^(-2)).Electron paramagnetic resonance analysis indicated that reactive oxygen species played a crucial role in the antimicrobial process,with super oxide radicals(·O_(2)^(-))and hydroxyl radical(·OH)showing the most prominent influence.We conducted reactive oxygen species(ROS)scavenging experiments to further confirm this view.After adding glutathione(GSH)to remove all ROS,the antibacterial efficiency of Ce-OFDC/PCN decreased by about 40%.Adding D-mannitol to remove·OH reduced the inhibition rate to 54.7%,and adding superoxide dismutase(SOD)to remove·O_(2)^(-)reduced the inhibition rate to 65.4%.The Ce-OFDC/PCN heterostructure increased the separation efficiency of photogenerated electrons and holes,producing increased reactive oxygen species.That,in turn,contributed to the observed superior photocatalytic antibacterial performance.This research significantly advanced the development of metal-organic framework(MOF)-based materials and provided valuable insights into the design of antimicrobial photocatalysts.展开更多
To improve the antimicrobial performance of cinnamon essential oil,lauric arginate was selected as a surfactant and a synergistic antimicrobial agent,and hydroxypropyl-β-cyclodextrin was used to further enhance the s...To improve the antimicrobial performance of cinnamon essential oil,lauric arginate was selected as a surfactant and a synergistic antimicrobial agent,and hydroxypropyl-β-cyclodextrin was used to further enhance the stability and antimicrobial activity of lauric arginate-stabilized cinnamon essential oil emulsions.The results showed that hydroxypropyl-β-cyclodextrin reduced droplet size and increased storage stability of the cinnamon essential oil emulsions stabilized by lauric arginate.The emulsification and inclusion effect of hydroxypropyl-β-cyclodextrin increased the degree of dispersion of cinnamon essential oil and lauric arginate,and protected lauric arginate and cinnamon essential oil from environmental conditions.Minimum inhibitory concentration and minimum bactericidal concentration values demonstrated that the addition of hydroxypropyl-β-cyclodextrin caused the synergistic inhibitory effects between lauric arginate and cinnamon essential oil against Escherichia coli and lauric arginate-stabilized cinnamon essential oil emulsions displayed the synergistic inhibitory effects against Staphylococcus aureus whether the hydroxypropyl-β-cyclodextrin existed or not.This work indicated that the cinnamon essential oil nanoemulsions co-stabilized by hydroxypropyl-β-cyclodextrin and lauric arginate could be used as high effective antimicrobial agents for food preservation.展开更多
Helicobacter pylori(H.pylori)infection is highly associated with the occurrence of gastrointestinal diseases,including gastric inflammation,peptic ulcer,gastric cancer,and gastric mucosa-associated lymphoid-tissue lym...Helicobacter pylori(H.pylori)infection is highly associated with the occurrence of gastrointestinal diseases,including gastric inflammation,peptic ulcer,gastric cancer,and gastric mucosa-associated lymphoid-tissue lymphoma.Although alternative therapies,including phytomedicines and probiotics,have been used to improve eradication,current treatment still relies on a combination of antimicrobial agents,such as amoxicillin,clarithromycin,metronidazole,and levofloxacin,and antisecretory agents,such as proton pump inhibitors(PPIs).A standard triple therapy consisting of a PPI and two antibiotics(clarithromycin and amoxicillin/metronidazole)is widely used as the first-line regimen for treatment of infection,but the increased resistance of H.pylori to clarithromycin and metronidazole has significantly reduced the eradication rate using this therapy and bismuth-containing therapy or 10-d sequential therapy has therefore been proposed to replace standard triple therapy.Alternatively,levofloxacin-based triple therapy can be used as rescue therapy for H.pylori infection after failure of first-line therapy.The increase in resistance to antibiotics,including levofloxacin,may limit the applicability of such regimens.However,since resistance of H.pylori to amoxicillin is generally low,an optimized high dose dual therapy consisting of a PPI and amoxicillin can be an effective first-line or rescue therapy.In addition,the concomitant use of alternative medicine has the potential to provide additive or synergistic effects against H.pylori infection,though its efficacy needs to be verified in clinical studies.展开更多
Microorganisms provide both beneficial and harmful effects to human beings. Beneficial effects come from the symbiotic relationship that exists between humans and microbiota, but then several human illnesses have turn...Microorganisms provide both beneficial and harmful effects to human beings. Beneficial effects come from the symbiotic relationship that exists between humans and microbiota, but then several human illnesses have turned some friendly microbes into opportunistic pathogens, causing several microbial-related diseases. Various efforts have been made to create and utilize antimicrobial agents in the treatment and prevention of these infections, but such efforts have been hampered by the emergence of antimicrobial resistance. Despite extensive studies on drug dis- covery to alleviate this problem, issues with the toxicity and tolerance of certain compounds and continuous microbial evolution have forced researchers to focus on screening various phytochemical dietary compounds for antimicrobial activity. Linolenic acid and its derivatives （eicosapentaenoic acid and docosahexaenoic acid） are omega-3 fatty acids that have been studied due to their role in human health, being important for the brain, the eye, the cardiovascular system, and general human growth. However, their utilization as antimicrobial agents has not been widely appreciated, perhaps due to a lack of understanding of antimicrobial mechanisms, toxicity, and route of administration. Therefore, this review focuses on the efficacy, mechanism, and toxicity of omega-3 fatty acids as alternative therapeutic agents for treating and preventing diseases associated with pathogenic microorganisms.展开更多
In this work,we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers(BCF)as a template.Silver(Ag)nanoparticles with an average diameter of 1...In this work,we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers(BCF)as a template.Silver(Ag)nanoparticles with an average diameter of 1.5 nm were well dispersed on BCF via a simple in situ chemical-reduction between AgNO3and NaBH4at a relatively low temperature.A growth mechanism is proposed that Ag nanoparticles are uniformly anchored onto BCF by coordination with BC-containing hydroxyl groups.The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by several techniques including transmission electron microscopy,X-ray diffraction,thermogravimetric analyses,and ultraviolet-visible(UV-Vis)absorption spectra.The antibacterial properties of Ag/BCF hybrid nanofibers against Escherichia coli(E.coli,Gram-negative)and Staphylococcu saureus(S.saureus,Gram-positive)bacteria were evaluated by using modified Kirby Bauer method and colony forming count method.The results show that Ag nanoparticles are well dispersed on BCF surface via in situ chemical-reduction.The Ag/BCF hybrid nanofiber presents strong antibacterial property and thus offers its candidature for use as functional antimicrobial agents.展开更多
基金Supported by the Ministry of Health of the Czech Republic,Grant/Award Number:NU22-05-00475 and NV19-05-00214。
文摘Background:In view of the ever-increasing representation of Staphylococcus spp.strains resistant to various antibiotics,the development of in vivo models for evaluation of novel antimicrobials is of utmost importance.Methods:In this article,we describe the development of a fully immunocompetent porcine model of extensive skin and soft tissue damage suitable for testing topical anti-microbial agents that matches the real clinical situation.The model was developed in three consecutive stages with protocols for each stage amended based on the results of the previous one.Results:In the final model,10 excisions of the skin and underlying soft tissue were created in each pig under general anesthesia,with additional incisions to the fascia performed at the base of the defects and immediately inoculated with Staphylococcus aureus suspension.One pig was not inoculated and used as the negative control.Subsequently,the bandages were changed on Days 4,8,11,and 15.At these time points,a filter paper imprint technique(FPIT)was made from each wound for semi-quantitative microbiological evaluation.Tissue samples from the base of the wound together with the adjacent intact tissue of three randomly selected defects of each pig were taken for microbiological,histopathological,and molecular-biological examination.The infection with the inoculated S.aureus strains was sufficient during the whole experiment as confirmed by both FPIT and from tissue samples.The dynamics of the inflammatory markers and clinical signs of infection are also described.Conclusions:A successfully developed porcine model is suitable for in vivo testing of novel short-acting topical antimicrobial agents.
文摘In order to investigate the susceptibility of mixed infection of Ureaplasma Urealyticum (UU) and Mycoplasma Hominis (MH) to 7 kinds of antimicrobial agents and comparison with that of UU infection in NGU patients, the in vitro susceptibility was determined by using microdilution method. The positive results were analyzed. The results showed that the sequence of susceptibility to 7 kinds of antimicrobial agents for both UU infection group and UU-MH mixed infection group was almost the same from the highest susceptibility to the lowest accordingly: Josamycin, Doxycycline, Minocycline, Sparfloxacin, Roxithromycin, Ofloxacin and Azithromycin. The total drug resistance rate for UU-MH mixed infection group (97. 67 %) was significantly higher than that for UU infection group (44. 67 %, P<.0. 01). The highest drug resistance rate in UU group and UU-MH mixed infection group was 31. 33 % (Ofloxacin) and 90. 48 % (Azithromycin) respectively. UU-MH mixed infection showed an increased drug resistance and changes of drug resistance spectrum.
文摘The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.
基金Supported by the National Natural Science Foundation of China(Nos.3147171931271929)+2 种基金the Jiangsu Province and Technology Support Program(No.BE2013662)the Lianyungang Fifth“521 High-Level Talent Training Project”the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly found in the human oral cavity and causes tooth decay. The objective was to improve the function of marine Arthrobacter oxydans KQll dextranase mouthwash （designed and developed by our laboratory）. The experiment was conducted in a three-level, four-variable central composite design to determine the best combination of ZnSO4, lysozyme, citric acid and chitosan. The optimized antibacterial agents were 2.16 g/L ZnSO4, 14 g/L lysozyme, 4.5 g/L citric acid and 5 g/L chitosan. The biofilm formation inhibition reached 84.49%. In addition, microscopic observation of the biofilm was performed using scanning electron microscopy and confocal laser scanning microscopy. The optimized formula was tested in marine dextranase Arthrobacter oxydans KQ11 mouthwash and enhanced the inhibition of S. mutans. This work may be promoted for the design and development of future marine dextranase oral care products.
文摘AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: FBGT should not be treated with metronidazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.
文摘The present study sought to assess the rational use of antimicrobial agents in a Brazilian intensive care unit (ICU) and its association with antimicrobial resistance in elderly patients admitted to the unit. Results: Choice of empiric and sensitivity-guided therapy was inadequate in > 80% and 59% of cases respectively. Inadequate antimicrobial therapy, whether empiric or sensitivity-guided, was positively correlated with bacterial resistance (r = 0.316;p = 0.001). Sensitivity testing revealed a 46.5% resistance rate to eight out of the ten most commonly used antibiotics. Multiple drug-resistant organisms were found in 40.8% of patients. A significant increase was observed in the number of multidrug-resistant samples between 2006/2007 and 2008 (r = 0.41, p = 0.006), (r = 0.598, p = 0.001), (r = 0.688, p = 0.00). Conclusion: We found a high rate of antibiotic misuse in the study sample. Inadequate therapy was correlated with resistance to antimicrobial agents.
基金the Natural Science Foundation of China NSFC 81500879(N.Z.),81400540(K.Z.)the Beijing Municipal Science and Technology Commission Z151100003915137(N.Z.)+2 种基金the Beijing Municipal Administration of Hospitals’YouthProgram QML20161501(N.Z.),QML20151401(K.Z.)the Beijing Municipal Hospitals’Program ZYLX201703(Y.B.),NIH R01 DE17974(H.X.)a Seed Grant(H.X.)from the University of Maryland School of Dentistry
文摘Biofilms at the tooth-restoration bonded interface can produce acids and cause recurrent caries. Recurrent caries is a primary reason for restoration failures. The objectives of this study were to synthesize a novel bioactive dental bonding agent containing dimethylaminohexadecyl methacrylate(DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine(MPC) to inhibit biofilm formation at the tooth-restoration margin and to investigate the effects of water-aging for 6 months on the dentin bond strength and protein-repellent and antibacterial durability. A protein-repellent agent(MPC) and antibacterial agent(DMAHDM) were added to a Scotchbond multi-purpose(SBMP) primer and adhesive. Specimens were stored in water at 37 °C for 1, 30, 90, or 180 days(d).At the end of each time period, the dentin bond strength and protein-repellent and antibacterial properties were evaluated. Protein attachment onto resin specimens was measured by the micro-bicinchoninic acid approach. A dental plaque microcosm biofilm model was used to test the biofilm response. The SBMP + MPC + DMAHDM group showed no decline in dentin bond strength after water-aging for 6 months, which was significantly higher than that of the control(P < 0.05). The SBMP + MPC + DMAHDM group had protein adhesion that was only 1/20 of that of the SBMP control(P < 0.05). Incorporation of MPC and DMAHDM into SBMP provided a synergistic effect on biofilm reduction. The antibacterial effect and resistance to protein adsorption exhibited no decrease from 1 to 180 d(P > 0.1). In conclusion, a bonding agent with MPC and DMAHDM achieved a durable dentin bond strength and long-term resistance to proteins and oral bacteria. The novel dental bonding agent is promising for applications in preventive and restorative dentistry to reduce biofilm formation at the tooth-restoration margin.
文摘In this study,we used citric acid(CA)as a crosslinking agent,mixed with polyhexamethylene biguanide,to perform a pad-dry-cure treatment on wool fabrics to study its antimicrobial effects and physical properties.
基金financially supported by Biotechnology Research Department, Ministry of Education, Myanmar (Project Grant No. Bio/NPT/20/2013/034)
文摘Objective： Myanmar has a long history of using medicinal plants for treatment of various diseases. To the best of our knowledge there are no previous reports on antiglycation activities of medicinal plants from Myanmar. Therefore, this study was aimed to evaluate the antioxidant, antiglycation and antimicrobial properties of 20 ethanolic extracts from 17 medicinal plants indigenous to Myanmar. Methods： In vitro scavenging assays of 2,2-diphenyl-l-picrylhydrazyl （DPPH）, nitric oxide （NO）, superoxide （SO） radicals were used to determine the antioxidant activities. Folin-Ciocalteu＇s method was performed to determine the total phenolic content. Antiglycation and antimicrobial activities were detected by bovine serum albumin-fluorescent assay and agar well diffusion method. Results： Terminalia cbebula Retz. （Fruit）, containing the highest total phenolic content, showed high antioxidant activities with inhibition of 77.98% ± 0.92% 88.95% ± 2.42%, 88.56% ±1.87% and 70.74% ±2.57% for DPPH, NO, SO assays and antiglycation activity respectively. It also showed the antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Escherichia coil, Pseudomonas aeruginosa and Candida albicans with inhibition zone of 19, 18, 17, 25 and 15 ram, respectively. Garcinia mangostana Linn. showed the strongest activities for SO and antiglycation assays with inhibition of 93.68% ± 2.63% and 82.37%± 1.78%. Bark of Melia sp. was the best NO radical scavenger with inhibition rate of 89.39%± 0.60%. Conclusion： The results suggest that these plants are potential sources of antioxidants with free radical-scavenging and antiglycation activities and could be useful for decreasing the oxidative stress and glycation end-product formation in glycation-related diseases.
文摘A convenient one-pot three-component method for the preparation of tetra-substituted thiophene derivatives has been developed. Reaction ofacetyl acetone 1, phenyl isothiocynate 2 and 2-chloromethyI derivatives 3a-3c in the presence of potassium carbonate afforded the target compounds, namely ethyl 2-（4-acetyl-3-methyl-5-（phenylamino）thiophen-2-yl）-2-oxoacetate derivatives 4a-4e, ethyl 3-（4- acetyl-3-methyl-5-（phenylamino）thiophen-2-yl）-3-oxopropanoate derivatives 4f-4i, di（（4-acetyl-3- methyl-5-phenylamino）thiophen-2-yl）ketone derivatives 4j-4n in reasonable overall yields. The synthesized compounds were screened for antirnicrobial activity. The detailed synthesis, spectroscopic data and antimicrobial activities of synthesized compounds were reported.
文摘In order to resolve the increasing resistance phenomena of the Gram-negative bacteria against single chain quaternary ammonium salts （QAS）, lysine with a pedant fluorinated bis-ammonium salts was synthesized and its antimicrobial properties were evaluated in this work. The novel fluorinated bis-ammonium salts shows similar activity with conventional single chain quaternary ammonium salts against Gram-positive bacteria but stronger activity against Gram-negative bacteria and yeast compared with the single chained counterpart.
文摘Anacardium occidentale L., Anacardiaceae, is frequently used to treat infections. We evaluated the antimicrobial and antioxidant activity of extracts obtained from aerial parts of the plant in comparison with the extract prepared with the flowers. Ethanol extracts of the leaves (EEL), stem bark (EEB), and flowers (EEF) were prepared separately. The antimicrobial activity was evaluated by agar diffusion and broth dilution methods. The minimum bactericidal and fungicidal concentrations were determined against: Streptococcus mutans, Lactobacillus acidophilus, Staphylococcus aureus, MRSA, Enterococcus faecalis, Streptococcus pyogenes, Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Klebsiella pneumoniae, Helicobacter pylori, Salmonella choleraesuis, Candida albicans, and Candida tropicalis. The antioxidant activity of the extracts was evaluated based on their scavenger capacity of 2,2-diphenyl-1-picrylhydrazyle. The phytochemical profile was analyzed by colorimetric methods and by HPLC with UV detection. All extracts exhibited antioxidant and antimicrobial activity. Although, the EEF was the most effective since it inhibited the growth of all 14 microorganisms tested. Anacardic and galic acids were identified in all extracts as well phenolic compounds, triterpenes, flavones and xanthones. In conclusion, the extracts obtained from the aerial parts of A. occidentale, mainly the extract of flowers that was the most effective, are rich in bioactive metabolites that exert a potent antioxidant and antimicrobial effect. Taken together, the results indicate an important biotechnological potential of A. occidentale as a source of compounds with broad-spectrum antimicrobial and of antioxidant activity to be used in the food and cosmetics industry.
文摘A biofilm contains a consortium of cohesive bacterial cells forming a complex structure that is a sedentary, but dynamic, community. Biofilms adhere on biotic and abiotic surfaces, including the surfaces of practically all medical devices. Biofilms are reported to be responsible for approximately 60% of nosocomial infections due to implanted medical devices, such as intravenous catheters, and they also cause other foreign-body infections and chronic infections. The presence of biofilm on a medical device may result in the infection of surrounding tissues and failure of the device, necessitating the removal and replacement ofthe device. Bacteria from biofilms formed on medical devices may be released and disperse, with the potential for the formation of new biofilms in other locations and the development of a systemic infection. Regardless of their location, bacteria in biofilms are tolerant of the activities of the immune system, antimicrobial agents, and antiseptics. Concentrations of antimicrobial agents sufficient to eradicate planktonic cells have no effect on the same microorganism in a biofilm. Depending on the microbial consortium or component of the biofilm that is involved, various combinations of factors have been suggested to explain the recalcitrant nature of biofilms toward killing by antibiotics. In this mini-review, some of the factors contributing to antimicrobial resistance in biofilms are discussed.
基金supported by Animal Nutrition,Eastman Chemical Company,Kingsport,TN,USA.
文摘Background The emergence of antibiotic resistant microorganisms associated with conventional swine production practices has increased interest in acid-based compounds having antimicrobial properties and other biological functions as nutritional interventions.Despite the interest in organic acids and monoglycerides,few studies have examined the effects of the combination of these acid-based additives in weaned pigs under disease challenge conditions.Therefore,this study aimed to investigate the effects of dietary supplementation with blend of organic acids and/or medium-chain fatty acid monoglycerides on intestinal health and systemic immunity of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli(ETEC)F18 at 4-week of age.Results Dietary supplementation of organic acids,monoglycerides,or both organic acids and monoglycerides(combination)reduced(P<0.05)the diarrhea frequency of ETEC F18-infected pigs throughout the experimental period(d−7 to 21 post-inoculation).This is consistent with the reduced(P<0.05)proportion ofβ-hemolytic coliforms in feces observed for the organic acid and combination treatments on d 10 post-inoculation.Supplementation of organic acids,monoglycerides,or combination also reduced(P<0.05)bacterial translocation in mesenteric lymph nodes on d 21 post-inoculation.Pigs fed with monoglycerides or combination had lower(P<0.05)white blood cells on d 5 post-inoculation,and pigs fed the combination also had lower(P<0.05)lymphocytes than pigs in control group.Monoglyceride supplementation increased(P<0.05)white blood cells and neutrophils compared with control group on d 14 post-inoculation.However,supplementation with organic acid blend,monoglyceride blend,or combination did not affect growth performance in this experiment.Conclusions Supplementation with monoglycerides or organic acids alone or in combination improves the detrimental effects of ETEC F18 infection in weaned pigs,as indicated by reduced diarrhea,fecal shedding ofβ-hemolytic coliforms,and bacterial translocation,and thus enhancing disease resistance.Monoglycerides reduced the inflammatory response during peak infection,but their immunomodulatory and possible synergistic effects with organic acids need to be further investigated.
基金supported by the Nanjing Infectious Disease Clinical Medical Center,Innovation center for infectious disease of Jiangsu Province(NO.CXZX202232)the Leading Talent Project of Jiangsu Province Traditional Chinese Medicine(NO.SLJ0216)+4 种基金the Nanjing Health science and Technology Development Special fund Project(NO.YKK20102)the General Program of Jiangsu Commission of Health(NO.M2021088)the Nanjing Health science and Technology Development General Project(NO.YKK21121)the 2023 Nanjing Second Hospital Talent Support Project Grant(RCZD23003)the Jiangsu Province Postgraduate Research and Practice Innovation Program(KYCX24_2176).
文摘The treatment of Acinetobacter baumannii(A.baumannii)poses significant clinical challenges due to its multidrug/pan-drug resistance.In this study,we isolated a broad-spectrum lytic A.baumannii phage,named P425,from medical wastewater,targeting nine multidrug-resistant A.baumannii(MDRAB)with diverse capsular types.Biological characterization revealed that P425 maintains activity at pH range of 3–12 and temperature range of 4–50℃.It resists UV irradiation for 20 minutes,and had an optimal multiplicity of infection(OMOI)is 0.00001.The adsorption kinetics showed that P425 achieves>90%within 10 minutes of incubation,and the one-step growth curve indicated a 10-min latent period,with a burst size of 184 PFU/cell.The genome sequencing results indicated that it harbors a double-stranded DNA genome of 40,583 bp with a GC content of 39.39%.Intergenomic similarity analysis classified it as a novel species within the Friunavirus genus,while electron microscopy results showed that it belongs to the Podoviridae family.Notably,P425 exhibits potent 24-h in vitro inhibitory activity against MDRAB,and demonstrates synergistic effect at an MOI of 0.001 when combined with five classes of antibiotics targeting distinct antimicrobial mechanisms.Safety evaluations confirmed the absence of cytotoxicity,hemolytic activity,or systemic toxicity both in vitro and in vivo.In mouse infection models,P425 can significantly improve the survival rates of mice infected with Ab25(ST1791/KL101).When co-administered with levofloxacin,it achieved 100%protection against mortality and promoted immune recovery.Collectively,P425 is a prospective lytic phage that could offer novel strategies for combating MDRAB infections.
基金financially supported by the Youth Fund of the National Natural Science Foundation of China(No.22406161)“Lvyang Jinfeng Project”Funded by Yangzhou City(No.137013435)+2 种基金the Innovative Science and Technology Platform Project of Cooperation between Yangzhou City and Yangzhou Universitythe Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_1910)JST ACT-C program of Japan
文摘In this study,a novel Ce-based metal-organic framework(Ce-OFDC)was synthesized via the hydrothermal method.To enhance its photocatalytic antimicrobial properties,polymeric carbon nitride(PCN)was incorporated into the Ce-OFDC matrix,forming a CeOFDC/PCN composite material.Antibacterial assays demonstrated that Ce-OFDC/PCN had significant inhibitory effects on both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus),achieving inhibition rates of 99.5%and 94.3%,respectively.Notably,the antibacterial performance of Ce-OFDC/PCN was superior to that of Ce-OFDC or PCN alone.Furthermore,photocurrent and electrical impedance scanning measurements demonstrated that the Ce-OFDC/PCN composites showed improved photocurrent response and superior efficiency in separating photogenerated electrons and holes.The photocurrent density of Ce-OFDC/PCN reached 120μA cm^(-2),which was 1.5 times higher than that of PCN(80μA cm^(-2))and 12 times higher than that of Ce-OFDC(10μA cm^(-2)).Electron paramagnetic resonance analysis indicated that reactive oxygen species played a crucial role in the antimicrobial process,with super oxide radicals(·O_(2)^(-))and hydroxyl radical(·OH)showing the most prominent influence.We conducted reactive oxygen species(ROS)scavenging experiments to further confirm this view.After adding glutathione(GSH)to remove all ROS,the antibacterial efficiency of Ce-OFDC/PCN decreased by about 40%.Adding D-mannitol to remove·OH reduced the inhibition rate to 54.7%,and adding superoxide dismutase(SOD)to remove·O_(2)^(-)reduced the inhibition rate to 65.4%.The Ce-OFDC/PCN heterostructure increased the separation efficiency of photogenerated electrons and holes,producing increased reactive oxygen species.That,in turn,contributed to the observed superior photocatalytic antibacterial performance.This research significantly advanced the development of metal-organic framework(MOF)-based materials and provided valuable insights into the design of antimicrobial photocatalysts.
基金the support from the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘To improve the antimicrobial performance of cinnamon essential oil,lauric arginate was selected as a surfactant and a synergistic antimicrobial agent,and hydroxypropyl-β-cyclodextrin was used to further enhance the stability and antimicrobial activity of lauric arginate-stabilized cinnamon essential oil emulsions.The results showed that hydroxypropyl-β-cyclodextrin reduced droplet size and increased storage stability of the cinnamon essential oil emulsions stabilized by lauric arginate.The emulsification and inclusion effect of hydroxypropyl-β-cyclodextrin increased the degree of dispersion of cinnamon essential oil and lauric arginate,and protected lauric arginate and cinnamon essential oil from environmental conditions.Minimum inhibitory concentration and minimum bactericidal concentration values demonstrated that the addition of hydroxypropyl-β-cyclodextrin caused the synergistic inhibitory effects between lauric arginate and cinnamon essential oil against Escherichia coli and lauric arginate-stabilized cinnamon essential oil emulsions displayed the synergistic inhibitory effects against Staphylococcus aureus whether the hydroxypropyl-β-cyclodextrin existed or not.This work indicated that the cinnamon essential oil nanoemulsions co-stabilized by hydroxypropyl-β-cyclodextrin and lauric arginate could be used as high effective antimicrobial agents for food preservation.
文摘Helicobacter pylori(H.pylori)infection is highly associated with the occurrence of gastrointestinal diseases,including gastric inflammation,peptic ulcer,gastric cancer,and gastric mucosa-associated lymphoid-tissue lymphoma.Although alternative therapies,including phytomedicines and probiotics,have been used to improve eradication,current treatment still relies on a combination of antimicrobial agents,such as amoxicillin,clarithromycin,metronidazole,and levofloxacin,and antisecretory agents,such as proton pump inhibitors(PPIs).A standard triple therapy consisting of a PPI and two antibiotics(clarithromycin and amoxicillin/metronidazole)is widely used as the first-line regimen for treatment of infection,but the increased resistance of H.pylori to clarithromycin and metronidazole has significantly reduced the eradication rate using this therapy and bismuth-containing therapy or 10-d sequential therapy has therefore been proposed to replace standard triple therapy.Alternatively,levofloxacin-based triple therapy can be used as rescue therapy for H.pylori infection after failure of first-line therapy.The increase in resistance to antibiotics,including levofloxacin,may limit the applicability of such regimens.However,since resistance of H.pylori to amoxicillin is generally low,an optimized high dose dual therapy consisting of a PPI and amoxicillin can be an effective first-line or rescue therapy.In addition,the concomitant use of alternative medicine has the potential to provide additive or synergistic effects against H.pylori infection,though its efficacy needs to be verified in clinical studies.
文摘Microorganisms provide both beneficial and harmful effects to human beings. Beneficial effects come from the symbiotic relationship that exists between humans and microbiota, but then several human illnesses have turned some friendly microbes into opportunistic pathogens, causing several microbial-related diseases. Various efforts have been made to create and utilize antimicrobial agents in the treatment and prevention of these infections, but such efforts have been hampered by the emergence of antimicrobial resistance. Despite extensive studies on drug dis- covery to alleviate this problem, issues with the toxicity and tolerance of certain compounds and continuous microbial evolution have forced researchers to focus on screening various phytochemical dietary compounds for antimicrobial activity. Linolenic acid and its derivatives （eicosapentaenoic acid and docosahexaenoic acid） are omega-3 fatty acids that have been studied due to their role in human health, being important for the brain, the eye, the cardiovascular system, and general human growth. However, their utilization as antimicrobial agents has not been widely appreciated, perhaps due to a lack of understanding of antimicrobial mechanisms, toxicity, and route of administration. Therefore, this review focuses on the efficacy, mechanism, and toxicity of omega-3 fatty acids as alternative therapeutic agents for treating and preventing diseases associated with pathogenic microorganisms.
基金Supported by the National Natural Science Foundation of China（21206076） the Natural Science Foundation of Jiangsu Province（BK2012401 and BK2011715） National High Technology Research and Development Program of China（2011AA050701）
文摘In this work,we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers(BCF)as a template.Silver(Ag)nanoparticles with an average diameter of 1.5 nm were well dispersed on BCF via a simple in situ chemical-reduction between AgNO3and NaBH4at a relatively low temperature.A growth mechanism is proposed that Ag nanoparticles are uniformly anchored onto BCF by coordination with BC-containing hydroxyl groups.The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by several techniques including transmission electron microscopy,X-ray diffraction,thermogravimetric analyses,and ultraviolet-visible(UV-Vis)absorption spectra.The antibacterial properties of Ag/BCF hybrid nanofibers against Escherichia coli(E.coli,Gram-negative)and Staphylococcu saureus(S.saureus,Gram-positive)bacteria were evaluated by using modified Kirby Bauer method and colony forming count method.The results show that Ag nanoparticles are well dispersed on BCF surface via in situ chemical-reduction.The Ag/BCF hybrid nanofiber presents strong antibacterial property and thus offers its candidature for use as functional antimicrobial agents.
