Displaying publications 81 - 100 of 2162 in total

Abstract:
Sort:
  1. Yang SK, Tan NP, Chong CW, Abushelaibi A, Lim SH, Lai KS
    Evol Bioinform Online, 2021;17:1176934320938391.
    PMID: 34017165 DOI: 10.1177/1176934320938391
    Antibiotic resistance is a major global health issue that has seen alarming rates of increase in all parts of the world over the past two decades. The surge in antibiotic resistance has resulted in longer hospital stays, higher medical costs, and elevated mortality rates. Constant attempts have been made to discover newer and more effective antimicrobials to reduce the severity of antibiotic resistance. Plant secondary metabolites, such as essential oils, have been the major focus due to their complexity and bioactive nature. However, the underlying mechanism of their antimicrobial effect remains largely unknown. Understanding the antimicrobial mode of action of essential oils is crucial in developing potential strategies for the use of essential oils in a clinical setting. Recent advances in genomics and proteomics have enhanced our understanding of the antimicrobial mode of action of essential oils. We might well be at the dawn of completing a mystery on how essential oils carry out their antimicrobial activities. Therefore, an overview of essential oils with regard to their antimicrobial activities and mode of action is discussed in this review. Recent approaches used in identifying the antimicrobial mode of action of essential oils, specifically from the perspective of genomics and proteomics, are also synthesized. Based on the information gathered from this review, we offer recommendations for future strategies and prospects for the study of essential oils and their function as antimicrobials.
    Matched MeSH terms: Anti-Bacterial Agents
  2. Yang F, Jin C, Wang S, Wang Y, Wei L, Zheng L, et al.
    Chemosphere, 2023 May;323:138245.
    PMID: 36841450 DOI: 10.1016/j.chemosphere.2023.138245
    Due to increasing antibiotic pollution in the water environment, green and efficient adsorbents are urgently needed to solve this problem. Here we prepare magnetic bamboo-based activated carbon (MDBAC) through delignification and carbonization using ZnCl2 as activator, resulting in production of an activated carbon with large specific surface area (1388.83 m2 g-1). The influencing factors, such as solution pH, initial sulfadiazine (SD) concentration, temperature, and contact time, were assessed in batch adsorption experiments. The Langmuir isotherm model demonstrated that MDBAC adsorption capacity on SD was 645.08 mg g-1 at its maximum, being higher than majority of previously reported adsorbents. In SD adsorption, the kinetic adsorption process closely followed the pseudo-second kinetic model, and the thermodynamic adsorption process was discovered to be exothermic and spontaneous in nature. The MDBAC exhibited excellent physicochemical stability, facile magnetic recovery and acceptable recyclability properties. Moreover, the synergistic interactions between MDBAC and SD mainly involved electrostatic forces, hydrogen bonding, π-π stacking, and chelation. Within the benefits of low cost, ease of production and excellent adsorption performance, the MDBAC biosorbent shows promising utilization in removing antibiotic contaminants from wastewater.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  3. Yan Q, Li X, Ma B, Zou Y, Wang Y, Liao X, et al.
    Front Microbiol, 2018;9:3129.
    PMID: 30619199 DOI: 10.3389/fmicb.2018.03129
    Antibiotic residues that enter the soil through swine manure could disturb the number, community structure and functions of microbiota which could also degrade antibiotics in soil. Five different concentrations of doxycycline (DOX) incorporated into swine manure were added to soil to explore the effects of DOX on microbiota in soil and degradation itself. The results showed that the soil microbiome evolved an adaptation to the soil containing DOX by generating resistance genes. Moreover, some of the organisms within the soil microbiome played crucial roles in the degradation of DOX. The average degradation half-life of DOX in non-sterile groups was 13.85 ± 0.45 days, which was significantly shorter than the 29.26 ± 0.98 days in the group with sterilized soil (P < 0.01), indicating that the soil microbiome promoted DOX degradation. DOX addition affected the number of tetracycline resistance genes, depending on the type of gene and the DOX concentration. Among these genes, tetA, tetM, tetW, and tetX had significantly higher copy numbers when the concentration of DOX was higher. In contrast, a lower concentration of DOX had an inhibitory effect on tetG. At the same time, the microbial compositions were affected by the initial concentration of DOX and the different experimental periods. The soil chemical indicators also affected the microbial diversity changes, mainly because some microorganisms could survive in adversity and become dominant bacterial groups, such as the genera Vagococcus and Enterococcus (which were associated with electrical conductivity) and Caldicoprobacter spp. (which were positively correlated with pH). Our study mainly revealed soil microbiota and DOX degradation answered differently under variable concentrations of DOX mixed with swine manure in soil.
    Matched MeSH terms: Anti-Bacterial Agents
  4. Yan LP, Gopinath SCB, Anbu P, Kasim FH, Zulhaimi HI, Yaakub ARW
    Prep Biochem Biotechnol, 2020;50(10):1053-1062.
    PMID: 32597353 DOI: 10.1080/10826068.2020.1783678
    This research comprehends iron-oxide nanoparticle (IONP) production, the apparent metallic nanostructure with unique superparamagnetic properties. Durian-rind-extract was utilized to synthesize IONP and the color of reaction mixture becomes dark brown, indicated the formation of IONPs and the peak was observed at ∼330 nm under UV-visible spectroscopy. The morphological observation under high-resolution microscopies has revealed the spherical shape and the average size (∼10 nm) of IONP. The further support was rendered by EDX-analysis showing apparent iron and oxygen peaks. XRD results displayed the crystalline planes with (110) and (300) planes at 2θ of 35.73° and 63.53°, respectively. XPS-data has clearly demonstrated the presence of Fe2P and O1s peaks. The IONPs were successfully capped by the polyphenol compounds from durian-rind-extract as evidenced by the representative peaks between 1633 and 595 cm-1 from FTIR analysis. The antimicrobial potentials of IONPs were evidenced by the disk-diffusion assay. The obtained results have abundant attention and being actively explored owing to their beneficial applications.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology; Anti-Bacterial Agents/chemistry*
  5. Yan L, Chen W, Wang C, Liu S, Liu C, Yu L, et al.
    Chemosphere, 2022 Feb;288(Pt 2):132510.
    PMID: 34627823 DOI: 10.1016/j.chemosphere.2021.132510
    Tetracycline is a potentially hazardous residual antibiotic detected in various sewages. High concentration (mg/L) of tetracycline is found in pharmaceutical/hospital wastewater and wastewater derived from livestock and poultry. So far, only antibiotics in μg/L level have been reported in granulation of aerobic sludge during wastewater treatment, but its effects in high concentration are rarely reported. In this study, the influence of tetracycline in high concentration (∼2 mg/L) on the formation of granular sludge, structure, and metabolic function of the microbial community during the granulation of aerobic sludge was investigated to improve the understanding of the aerobic granular sludge formation under high-level of tetracycline. The role of extracellular polymers substances (EPSs) derived from granular sludge in the granulation and tetracycline removal process was also investigated, showing that tetracycline improved the relative hydrophobicity, flocculability and protein/polysaccharide ratio of EPSs, accelerating the granulation of sludge. Succession of microbial communities occurred during the domestication of functional bacteria present in the sludge and was accompanied with regulation of metabolic function. The addition of tetracycline lead to an increase of tetracycline-degrading bacteria or antibiotic resistance genus. Those findings provide new perspectives of the influence of tetracycline on aerobic sludge granulation and the removal mechanism of tetracycline.
    Matched MeSH terms: Anti-Bacterial Agents
  6. Yam WK, Wahab HA
    J Chem Inf Model, 2009 Jun;49(6):1558-67.
    PMID: 19469526 DOI: 10.1021/ci8003495
    Erythromycin A and roxithromycin are clinically important macrolide antibiotics that selectively act on the bacterial 50S large ribosomal subunit to inhibit bacteria's protein elongation process by blocking the exit tunnel for the nascent peptide away from ribosome. The detailed molecular mechanism of macrolide binding is yet to be elucidated as it is currently known to the most general idea only. In this study, molecular dynamics (MD) simulation was employed to study their interaction at the molecular level, and the binding free energies for both systems were calculated using the molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) method. The calculated binding free energies for both systems were slightly overestimated compared to the experimental values, but individual energy terms enabled better understanding in the binding for both systems. Decomposition of results into residue basis was able to show the contribution of each residue at the binding pocket toward the binding affinity of macrolides and hence identified several key interacting residues that were in agreement with previous experimental and computational data. Results also indicated the contributions from van der Waals are more important and significant than electrostatic contribution in the binding of macrolides to the binding pocket. The findings from this study are expected to contribute to the understanding of a detailed mechanism of action in a quantitative matter and thus assisting in the development of a safer macrolide antibiotic.
    Matched MeSH terms: Anti-Bacterial Agents/metabolism*; Anti-Bacterial Agents/chemistry*
  7. Yahya MFZR, Alias Z, Karsani SA
    Protein J, 2017 08;36(4):286-298.
    PMID: 28470375 DOI: 10.1007/s10930-017-9719-9
    Salmonella typhimurium is an important biofilm-forming bacteria. It is known to be resistant to a wide range of antimicrobials. The present study was carried out to evaluate the effects of dimethyl sulfoxide (DMSO) against S. typhimurium biofilm and investigate whole-cell protein expression by biofilm cells following treatment with DMSO. Antibiofilm activities were assessed using pellicle assay, crystal violet assay, colony-forming unit counting and extracellular polymeric substance (EPS) matrix assay whilst differential protein expression was investigated using a combination of one dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis, tandem mass spectrometry and bioinformatics. Treatment with 32% DMSO inhibited pellicle formation, biofilm viability, biofilm biomass and several important components of EPS matrix. Subtractive protein profiling identified two unique protein bands (25.4 and 51.2 kDa) which were present only in control biofilm and not in 32% DMSO-treated biofilm. In turn, 29 and 46 proteins were successfully identified from the protein bands of 25.4 and 51.2 kDa respectively. Protein interaction network analysis identified several biological pathways to be affected, including glycolysis, PhoP-PhoQ phosphorelay signalling and flagellar biosynthesis. The present study suggests that DMSO may inhibit multiple biological pathways to control biofilm formation.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  8. Yahya MFZR, Alias Z, Karsani SA
    Folia Microbiol (Praha), 2018 Jan;63(1):23-30.
    PMID: 28540585 DOI: 10.1007/s12223-017-0532-9
    Biofilms are complex microbial communities that tend to attach to either biotic or abiotic surface. Enclosed in a self-produced extracellular polymeric substance (EPS) matrix, the biofilms often cause persistent infections. The objective of this study was to investigate the antibiofilm activity of dimethyl sulfoxide (DMSO) and afatinib against Gram-negative pathogens. Test microorganisms used in this study were Escherichia coli ATCC 1299, Pseudomonas aeruginosa ATCC 10145, and Salmonella typhimurium ATCC 14028. Biofilms were developed in 96-well microplate at 37°C for 24 h. Following removal of non-adherent cells, analysis of biofilm viability, biofilm biomass, and extracellular polymeric substances (EPS) matrix were performed using resazurin assay, crystal violet assay, and attenuated total reflectance fourier transform infrared (ATR-FTIR) spectroscopy, respectively. Bradford protein assay was conducted to determine the total amount of EPS proteins. The results demonstrated that both 32% DMSO alone and its combination with 3.2 μg/mL afatinib were effective in killing biofilm cells and reducing biofilm biomass. IR spectral variations of EPS matrix of biofilms in the range between 1700 and 900 cm-1 were also observed. Reduction in EPS proteins verified the chemical modifications of EPS matrix. In conclusion, 32% DMSO alone and its combination with 3.2 μg/mL afatinib showed remarkable antibiofilm activities against Gram-negative pathogens. It was suggested that the biofilm inhibition was mediated by the chemical modification of EPS matrix.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  9. Yadav S, Arya DK, Pandey P, Anand S, Gautam AK, Ranjan S, et al.
    Int J Nanomedicine, 2022;17:6843-6859.
    PMID: 36605559 DOI: 10.2147/IJN.S388264
    INTRODUCTION: Foot ulceration is one of the most severe and debilitating complications of diabetes, which leads to the cause of non-traumatic lower-extremity amputation in 15-24% of affected individuals. The healing of diabetic foot (DF) is a significant therapeutic problem due to complications from the multifactorial healing process. Electrospun nanofibrous scaffold loaded with various wound dressing materials has excellent wound healing properties due to its multifunctional action.

    PURPOSE: This work aimed to develop and characterize chitosan (CS)-polyvinyl alcohol (PVA) blended electrospun multifunctional nanofiber loaded with curcumin (CUR) and zinc oxide (ZnO) to accelerate diabetic wound healing in STZ-induced diabetic rats.

    RESULTS: In-vitro characterization results revealed that nanofiber was fabricated successfully using the electrospinning technique. SEM results confirmed the smooth surface with web-like fiber nanostructure diameter ranging from 200 - 250 nm. An in-vitro release study confirmed the sustained release of CUR and ZnO for a prolonged time. In-vitro cell-line studies demonstrated significantly low cytotoxicity of nanofiber in HaCaT cells. Anti-bacterial studies demonstrated good anti-bacterial and anti-biofilm activities of nanofiber. In-vivo animal studies demonstrated an excellent wound-healing efficiency of the nanofibers in STZ-induced diabetic rats. Furthermore, the ELISA assay revealed that the optimized nanofiber membrane terminated the inflammatory phases successfully by downregulating the pro-inflammatory cytokines (TNF-α, MMP-2, and MMP-9) in wound healing. In-vitro and in-vivo studies conclude that the developed nanofiber loaded with bioactive material can promote diabetic wound healing efficiently via multifunction action such as the sustained release of bioactive molecules for a prolonged time of duration, proving anti-bacterial/anti-biofilm properties and acceleration of cell migration and proliferation process during the wound healing.

    DISCUSSION: CUR-ZnO electrospun nanofibers could be a promising drug delivery platform with the potential to be scaled up to treat diabetic foot ulcers effectively.

    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  10. Yaacob, M., Rajab N.F., Shahar, S., Sharif, R.
    Food Research, 2018;2(2):124-133.
    MyJurnal
    Modern science has found that most traditional practice of using stingless bee honey has
    great potential as an added value in modern medicine and considered to have a higher
    medicinal value than other bee species. However, due to the relatively low output of honey
    compared to other honey so, focus on this honey is limited. Hence, this systematic review
    provides the updated result on the potential value of stingless bee honey as an antioxidant,
    anti-inflammatory, cytotoxicity and antimicrobial. The search strategy was developed in
    four databases (Scopus, Medline and Ovid, EMBASE and PubMed) with the search terms
    "("honey" and "Kelulut", "honey" and "stingless bee", "honey" and "Trigona", "honey"
    and "pot honey", and "honey" and "Melipon")". The merged data was assessed using
    PRISMA guidelines and after the duplicates were removed, 1271 articles were segregated.
    Afterwards, 1232 articles were eliminated because they do not meet the inclusion criteria
    and 39 articles were reevaluated again for eligibility. Finally, after the evaluation process,
    only 26 of the articles were chosen for this review. The data of 26 articles of stingless bee
    honey were deliberated based on antioxidant properties, anti-inflammatory, cytotoxicity
    and analysis of antimicrobial activity. Three articles reported on antioxidant properties,
    one article on anti-inflammatory analysis, two articles on cytotoxicity analysis, and twenty
    articles on analysis of antimicrobial activity. Based on the feasible affirmation from the
    literature, stingless bee honey has an antioxidant capacity that able to decrease the ROS.
    ROS able to lead a variety of health problems thus stingless bee honey can be a dietary
    supplement to overcome this problem.
    Matched MeSH terms: Anti-Bacterial Agents
  11. Yaacob I, Ariffin Z
    Singapore Med J, 1991 Feb;32(1):63-6.
    PMID: 2017709
    The case histories of 22 patients with lung abscess and empyema presenting to Hospital University Sains Malaysia (HUSM) between 1984 and 1989 are reviewed. The presenting features of both lung abscess and empyema were similar. The commonest predisposing factor was pneumonia, and the commonest organism isolated was Staphylococcus aureus but in the majority of cases, no causal organisms were identified. All the patients were treated with antibiotics and in addition, closed chest tube drainage was performed initially in all patients with empyema. Three patients with empyema required additional surgical drainage procedures. Death occurred in one patient with empyema and in one patient with lung abscess. The features, aetiology, treatment and outcome of thoracic empyema and lung abscess are discussed.
    Matched MeSH terms: Anti-Bacterial Agents/therapeutic use
  12. Xu T, Tang X, Qiu M, Lv X, Shi Y, Zhou Y, et al.
    J Environ Manage, 2023 Oct 15;344:118718.
    PMID: 37541001 DOI: 10.1016/j.jenvman.2023.118718
    Antibiotic-containing wastewater is a typical biochemical refractory organic wastewater and general treatment methods cannot effectively and quickly degrade the antibiotic molecules. In this study, a novel boron-doped diamond (BDD) pulse electrochemical oxidation (PEO) technology was proposed for the efficient removal of levofloxacin (LFXN) from wastewater. The effects of current density (j), initial pH (pH0), frequency (f), electrolyte types and initial concentration (c0(LFXN)) on the degradation of LFXN were systematically investigated. The degradation kinetics under four different processes have also been studied. The possible degradation mechanism of LFXN was proposed by Density functional theory calculation and analysis of degradation intermediates. The results showed that under the optimal parameters, the COD removal efficiency (η(COD)) was 94.4% and the energy consumption (EEC) was 81.43 kWh·m-3 at t = 120 min. The degradation of LFXN at pH = 2.8/c(H2O2) followed pseudo-first-order kinetics. The apparent rate constant was 1.33 × 10-2 min-1, which was much higher than other processes. The degradation rate of LFXN was as follows: pH = 2.8/c(H2O2) > pH = 2.8 > pH = 7/c(H2O2) > pH = 7. Ten aromatic intermediates were formed during the degradation of LFXN, which were further degraded to F-, NH4+, NO3-, CO2 and H2O. This study provides a promising approach for efficiently treating LFXN antibiotic wastewater by pulsed electrochemical oxidation with a BDD electrode without adding H2O2.
    Matched MeSH terms: Anti-Bacterial Agents
  13. Xu FX, Ooi CW, Liu BL, Song CP, Chiu CY, Wang CY, et al.
    Int J Biol Macromol, 2021 Jun 30;181:508-520.
    PMID: 33775766 DOI: 10.1016/j.ijbiomac.2021.03.151
    This study aimed to develop a novel electrospun polyacrylonitrile (PAN) nanofiber membrane with the enhanced antibacterial property. The PAN nanofiber membrane was first subjected to alkaline hydrolysis treatment, and the treated membrane was subsequently grafted with chitosan (CS) to obtain a CS-modified nanofiber membrane (P-COOH-CS). The modified membrane was then coupled with different dye molecules to form P-COOH-CS-Dye membranes. Lastly, poly(hexamethylene biguanide) hydrochloride (PHMB) was immobilized on the modified membrane to produce P-COOH-CS-Dye-PHMB. Physical characterization studies were conducted on all the synthesized nanofiber membranes. The antibacterial efficacies of nanofiber membranes prepared under different synthesis conditions were evaluated systematically. Under the optimum synthesis conditions, P-COOH-CS-Dye-PHMB was highly effective in disinfecting a high concentration of Escherichia coli, with an antibacterial efficacy of approximately 100%. Additionally, the P-COOH-CS-Dye-PHMB exhibited an outstanding wash durability as its antibacterial efficacy was only reduced in the range of 5%-7% even after 5 repeated cycles of treatment. Overall, the experimental results of this study suggested that the P-COOH-CS-Dye-PHMB is a promising antibacterial nanofiber membrane that can be adopted in the food, pharmaceutical, and textile industries.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis; Anti-Bacterial Agents/pharmacology*; Anti-Bacterial Agents/chemistry
  14. Xie S, Hamid N, Zhang T, Zhang Z, Peng L
    J Hazard Mater, 2024 Jun 05;471:134324.
    PMID: 38640666 DOI: 10.1016/j.jhazmat.2024.134324
    In recent years, aquaculture has expanded rapidly to address food scarcity and provides high-quality aquatic products. However, this growth has led to the release of significant effluents, containing emerging contaminants like antibiotics, microplastics (MPs), and antibiotic resistance genes (ARGs). This study investigated the occurrence and interactions of these pollutants in aquaculture environment. Combined pollutants, such as MPs and coexisting adsorbents, were widespread and could include antibiotics, heavy metals, resistance genes, and pathogens. Elevated levels of chemical pollutants on MPs could lead to the emergence of resistance genes under selective pressure, facilitated by bacterial communities and horizontal gene transfer (HGT). MPs acted as vectors, transferring pollutants into the food web. Various technologies, including membrane technology, coagulation, and advanced oxidation, have been trialed for pollutants removal, each with its benefits and drawbacks. Future research should focus on ecologically friendly treatment technologies for emerging contaminants in aquaculture wastewater. This review provided insights into understanding and addressing newly developing toxins, aiming to develop integrated systems for effective aquaculture wastewater treatment.
    Matched MeSH terms: Anti-Bacterial Agents*
  15. Xiao G, Chen J, Show PL, Yang Q, Ke J, Zhao Q, et al.
    Chemosphere, 2021 Nov;282:130966.
    PMID: 34082314 DOI: 10.1016/j.chemosphere.2021.130966
    Biological methods are promising treatment methods to remove pollutants from wastewater. Recently, microalgae have been proved to be of strong application potential in wastewater treatment. In this study, a microalga - antibiotic treatment system was built to evaluate the treatment capacity of microalgae in antibiotic wastewater. In the group with Chlorella pyrenoidosa, the removal rate of cefradine was 41.47 ± 0.62% after 24 h of treatment, which was 3.4 times higher than that without microalgae (12.37 ± 2.30%). Algal decomposition was the main removal mechanism. Meanwhile, the effect of multiple microalgae species on antibiotic treatment was studied. The removal rates of cefradine by C. pyrenoidosa cultivated in the filtered fluid of Microcystis aeruginosa were 75.48 ± 0.29%, which was significantly higher than those by C. pyrenoidosa only. Those indicated that multiple microalgae species strategy was a potential enhancement strategy for algae-based antibiotic treatment. Finally, amoxicillin and norfloxacin were used to study the treatment potential of this technology for more different kinds antibiotics and the integration of microalgae with activated sludge was also investigated. Amoxicillin can be quickly removed by microalgae, but the removal effect of norfloxacin by microalgae is poor. The refractory antibiotic norfloxacin can be treated by co-culturing microalgae and activated sludge. Those showed the good expansibility of microalgae-based technology. The findings indicated that with microalgae-based antibiotic removal method has good application potential, and combined with other technologies, it can effectively remove the refractory antibiotics.
    Matched MeSH terms: Anti-Bacterial Agents
  16. Wu Y, Wang K, Liu Q, Liu X, Mou B, Lai OM, et al.
    Food Chem, 2022 Jan 15;367:130700.
    PMID: 34352694 DOI: 10.1016/j.foodchem.2021.130700
    Present study prepared curcumin-loaded nanoliposomes using bovine milk, krill phospholipids and cholesterol; and investigated the effects of cholesterol on membrane characteristics, storage stability and antibacterial properties of the curcumin nanoliposomes. Bovine milk phospholipids which have higher saturation than krill phospholipids resulted in formation of curcumin-loaded nanoliposomes with higher encapsulation efficiency (84.78%), larger absolute value of zeta potential and vesicle size (size: 159.15 ± 5.27 nm, zeta potential: -28.3 ± 0.62 mV). Cholesterol helps to formation of a more hydrophobic, compact and tighter bilayer membrane structure which improved the storage stability of nanoliposomes under alkaline (66.25 ± 0.46%), heat (43.25 ± 0.69%) and sunlight (49.44 ± 1.78%) conditions. In addition, curcumin-loaded nanoliposomes can effectively target infectious bacteria which secrete pore-forming toxins such as Staphylococcus aureus by causing the bacterial cell wall to lysis. Findings from present work can guide future development of novel antibacterial agents for use in food preservation.
    Matched MeSH terms: Anti-Bacterial Agents
  17. Wu XY, Zhao ZY, Osman EEA, Wang XJ, Choo YM, Benjamin MM, et al.
    Bioorg Chem, 2024 Feb;143:107103.
    PMID: 38211549 DOI: 10.1016/j.bioorg.2024.107103
    Three undescribed (1-3) and nine known (4-12) platanosides were isolated and characterized from a bioactive extract of the May leaves of Platanus × acerifolia that initially showed inhibition against Staphylococcus aureus. Targeted compound mining was guided by an LC-MS/MS-based molecular ion networking (MoIN) strategy combined with conventional isolation procedures from a unique geographic location. The novel structures were mainly determined by 2D NMR and computational (NMR/ECD calculations) methods. Compound 1 is a rare acylated kaempferol rhamnoside possessing a truxinate unit. 6 (Z,E-platanoside) and 7 (E,E-platanoside) were confirmed to have remarkable inhibitory effects against both methicillin-resistant S. aureus (MIC: ≤ 16 μg/mL) and glycopeptide-resistant Enterococcus faecium (MIC: ≤ 1 μg/mL). These platanosides were subjected to docking analyses against FabI (enoyl-ACP reductase) and PBP1/2 (penicillin binding protein), both of which are pivotal enzymes governing bacterial growth but not found in the human host. The results showed that 6 and 7 displayed superior binding affinities towards FabI and PBP2. Moreover, surface plasmon resonance studies on the interaction of 1/7 and FabI revealed that 7 has a higher affinity (KD = 1.72 μM), which further supports the above in vitro data and is thus expected to be a novel anti-antibacterial drug lead.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  18. Wu JY, Ooi CW, Song CP, Wang CY, Liu BL, Lin GY, et al.
    Carbohydr Polym, 2021 Jun 15;262:117910.
    PMID: 33838797 DOI: 10.1016/j.carbpol.2021.117910
    N-[(2-hydroxyl-3-trimethylammonium) propyl] chitosan chloride (HTCC), which is a type of chitosan derivative with quaternary ammonium groups, possesses a higher antibacterial activity as compared to the pristine chitosan. The nanofiber membranes made of HTCC are attractive for applications demanding for antibacterial function. However, the hydrophilic nature of HTCC makes it unsuitable for electrospinning of nanofibers. Hence, biodegradable polyvinyl alcohol (PVA) was proposed as an additive to improve the electrospinnability of HTCC. In this work, PVA/HTCC nanofiber membrane was crosslinked with the blocked diisocyanate (BI) to enhance the stability of nanofiber membrane in water. Microbiological assessments showed that the PVA/HTCC/BI nanofiber membranes possessed a good antibacterial efficacy (∼100 %) against E. coli. Moreover, the biocompatibility of PVA/HTCC/BI nanofiber membrane was proven by the cytotoxicity test on mouse fibroblasts. These promising results indicated that the PVA/HTCC/BI nanofiber membrane can be a promising material for food packaging and as a potential wound dressing for skin regeneration.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*; Anti-Bacterial Agents/chemistry
  19. Wright H, Harris PNA, Chatfield MD, Lye D, Henderson A, Harris-Brown T, et al.
    Trials, 2021 Dec 07;22(1):889.
    PMID: 34876196 DOI: 10.1186/s13063-021-05870-w
    BACKGROUND: Increasing rates of antibiotic resistance in Gram-negative organisms due to the presence of extended-spectrum beta-lactamases (ESBL), hyperproduction of AmpC enzymes, carbapenemases and other mechanisms of resistance are identified in common hospital- and healthcare-associated pathogens including Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii. Cefiderocol is a novel siderophore cephalosporin antibiotic with a catechol moiety on the 3-position side chain. Cefiderocol has been shown to be potent in vitro against a broad range of Gram-negative organisms, including carbapenem-resistant Enterobacteriaceae (CRE) and multi-drug-resistant (MDR) P. aeruginosa and A. baumannii. Recent clinical data has shown cefiderocol to be effective in the setting of complicated urinary tract infections and nosocomial pneumonia, but it has not yet been studied as treatment of bloodstream infection.

    METHODS: This study will use a multicentre, open-label non-inferiority trial design comparing cefiderocol and standard of care antibiotics. Eligible participants will be adult inpatients who are diagnosed with a bloodstream infection with a Gram-negative organism on the basis of a positive blood culture result where the acquisition meets the definition for healthcare-associated or hospital-acquired. It will compare cefiderocol with the current standard of care (SOC) antibiotic regimen according to the patient's treating clinician. Eligible participants will be randomised 1:1 to cefiderocol or SOC and receive 5-14 days of antibiotic therapy. Trial recruitment will occur in at least 20 sites in ten countries (Australia, Malaysia, Singapore, Thailand, Turkey and Greece). The sample size has been derived from an estimated 14 day, all-cause mortality rate of 10% in the control group, and a non-inferiority margin of 10% difference in the two groups. A minimum of 284 patients are required in total to achieve 80% power with a two-sided alpha level of 0.05. Data describing demographic information, risk factors, concomitant antibiotics, illness scores, microbiology, multidrug-resistant organism screening, discharge and mortality will be collected.

    DISCUSSION: With increasing antimicrobial resistance, there is a need for the development of new antibiotics with broad activity against Gram-negative pathogens such as cefiderocol. By selecting a population at risk for multi-drug-resistant pathogens and commencing study treatment early in the clinical illness (within 48 h of index blood culture) the trial hopes to provide guidance to clinicians of the efficacy of this novel agent.

    TRIAL REGISTRATION: The GAME CHANGER trial is registered under the US National Institute of Health ClinicalTrials.gov register, reference number NCT03869437 . Registered on March 11, 2019.

    Matched MeSH terms: Anti-Bacterial Agents/therapeutic use
  20. Wong, Y.W.E., Abdullah, N.
    Malaysian Family Physician, 2018;13(2):42-44.
    MyJurnal
    Purple urine bag syndrome (PUBs) is a rare and startling phenomenon of purple discolouration
    in the urine or urinary catheter and bag. It is reported in chronically debilitated elderly patients,
    mostly in women on long-term urinary catheters. Its prevalence is strikingly more common in
    nursing home residents. Several factors contribute to the formation of indigo (blue) and indirubin
    (red) pigments from a breakdown of dietary tryptophan, which stains the urine purple. These
    factors include constipation, dysmotility of the bowel, bowel bacterial overgrowth, dehydration, and
    urinary tract infection. The presence of purple urine may cause undue alarm to both the patient and
    the doctor. Thus, we present this case report on an 86-year-old woman, a nursing home resident
    on a long-term urinary catheter, who presented to the primary care clinic. Her urine cleared
    after antibiotic therapy, replacement of her urinary catheter, and supportive management, which
    included hydration and nutrition. In addition to these measures, reducing the time between urinary
    catheter changes was recommended to prevent recurrence of this condition.
    Matched MeSH terms: Anti-Bacterial Agents
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links