-
ChemMedChem Jul 2022Carbon dots are small carbon nanoparticles with intrinsic photoluminescence. Because of the advantages such as good biocompatibility and water dispersity, many... (Review)
Review
Carbon dots are small carbon nanoparticles with intrinsic photoluminescence. Because of the advantages such as good biocompatibility and water dispersity, many researchers have applied carbon dots as delivery platforms of antimicrobial agents. Compared with the free small-molecule antimicrobial agents alone, the carbon dot-based systems may exhibit enhanced antimicrobial activity, increased stability, improved cellular uptake, and reduced side effects. This review will mainly discuss the antimicrobial agent-loaded carbon dots for various antibacterial, antifungal, and antiviral applications. The current limitations and future research directions in the related field are also proposed. It is hoped that this review will have implications for the future development of functional carbon dots for various practical antimicrobial uses.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Carbon; Drug Delivery Systems
PubMed: 35429414
DOI: 10.1002/cmdc.202200003 -
Bioprocess and Biosystems Engineering Sep 2021Silver nanoparticles (Ag NP) were produced utilizing leaf extract of rice cultivar Taichung native-1. Various factors like leaf extract, silver nitrate concentrations,...
Silver nanoparticles (Ag NP) were produced utilizing leaf extract of rice cultivar Taichung native-1. Various factors like leaf extract, silver nitrate concentrations, and duration of autoclaving were standardized during synthesis. Nanoparticles were analyzed with UV-visible absorption spectroscopy (UV-vis), dynamic light scattering, zeta potential, X-ray diffraction and transmission electron microscopy techniques. The synthesis was noted at 0.4% extract, 0.6 mM silver nitrate, 30 min of autoclaving and NP formation was confirmed from 424 nm peak in UV-vis. NP showed zeta potential of - 27 mV, face-centered cubic (fcc) crystal nature and sized around 16.5 ± 5.9 nm. Biogenic NP synthesized from susceptible rice variety were used as an antibacterial agent against phytopathogen Xanthomonas oryzae pv. oryzae (Xoo), the causative agent of bacterial leaf blight (BLB) disease in rice. Antibacterial effect of Ag NP was evaluated using in vitro assays and in vivo efficacy under greenhouse conditions. Results confirmed effective inhibition of Xoo growth and colony formation by Ag NP and found to be the more powerful antibacterial agent. Besides, Ag NP treatment (10 µg/mL) caused an enhancement in seedling vigor index. Pots treated with Ag NP (15 μg/mL) in vivo in greenhouse showed disease severity of 26.6% and disease decrease over control of 49.2%, at a much lower NP concentration than earlier reported studies. Thus, the current report implies using the leaf extract synthesized Ag NP to control and BLB disease management in field conditions.
Topics: Anti-Bacterial Agents; Metal Nanoparticles; Oryza; Plant Diseases; Plant Leaves; Silver; Xanthomonas
PubMed: 33974135
DOI: 10.1007/s00449-021-02579-7 -
Diagnostic Microbiology and Infectious... 1989Many antimicrobial agents have been either found in nature or synthesized in the past 45 years. Antibacterial agents inhibit cell-wall formation, disrupt cytoplasmic... (Review)
Review
Many antimicrobial agents have been either found in nature or synthesized in the past 45 years. Antibacterial agents inhibit cell-wall formation, disrupt cytoplasmic membrane function, prevent DNA synthesis, interfere with protein synthesis, and halt folate synthesis. Resistance to antibiotics is a result of three major mechanisms: prevention of the antibacterial agent from reaching its receptor site, production of altered targets, and destruction or modification of the agents. Bacterial resistance has occurred due to chromosomal changes or the presence of plasmids and transposons. Resistance to beta-lactams is the result of beta-lactamases and the production of altered penicillin-binding proteins as well as altered cell-wall permeability. Important examples of these resistance forms occur in staphylococci and pneumococci which have altered penicillin-binding proteins. A new form of target change has been the production of proteins in enterococci that inhibit the activity of glycopeptides. Beta-lactamases are present in both Gram-positive and Gram-negative species; recently, new plasmid beta-lactamases have been isolated that destroy iminomethoxy and iminocarboxy cephalosporins. Resistance to aminoglycosides is due to enzymes that acetylate, adenylate, or phosphorylate aminoglycosides that inhibit binding to ribosomes and thus cause the poor uptake of drug. Tetracycline resistance is due to plasmids which cause efflux of the agent from the cytoplasm. Macrolide and lincinoid resistance is the result of an altered 23S ribosomal component of the 50S ribosomes. Sulfonamide and trimethoprim resistance is due to production of altered synthetase and reductase enzymes essential in the synthesis of folate.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Anti-Bacterial Agents; Bacteria; Bacterial Infections; Biological Transport, Active; Drug Resistance, Microbial; Humans; Permeability; Receptors, Drug
PubMed: 2686913
DOI: 10.1016/0732-8893(89)90122-3 -
DICP : the Annals of Pharmacotherapy 1989Protein binding can enhance or detract from a drug's performance. As a general rule, agents that are minimally protein bound penetrate tissue better than those that are... (Review)
Review
Protein binding can enhance or detract from a drug's performance. As a general rule, agents that are minimally protein bound penetrate tissue better than those that are highly bound, but they are excreted much faster. Among drugs that are less than 80-85 percent protein bound, differences appear to be of slight clinical importance. Agents that are highly protein bound may, however, differ markedly from those that are minimally bound in terms of tissue penetration and half-life. Drugs may bind to a wide variety of plasma proteins, including albumin. If the percentage of protein-bound drug is greater when measured in human blood than in a simple albumin solution, the clinician should suspect that the agent may be bound in vivo to one of these "minority" plasma proteins. The concentration of several plasma proteins can be altered by many factors, including stress, surgery, liver or kidney dysfunction, and pregnancy. In such circumstances, free drug concentrations are a more accurate index of clinical effect than are total concentrations. Formulary committees must grasp the clinical significance of qualitative and quantitative differences in protein binding when evaluating competing agents.
Topics: Anti-Bacterial Agents; Blood Proteins; Humans; Pharmaceutical Preparations; Pharmacokinetics; Protein Binding
PubMed: 2669380
DOI: 10.1177/106002808902300706 -
Biofouling Jan 2021Orthopedic device related infections (ODRI's) represent a difficult to treat situation owing to their biofilm based nature. Biofilm infections once established are... (Review)
Review
Orthopedic device related infections (ODRI's) represent a difficult to treat situation owing to their biofilm based nature. Biofilm infections once established are difficult to eradicate even with an aggressive treatment regimen due to their recalcitrance towards antibiotics and immune attack. The involvement of antibiotic resistant pathogens as the etiological agent further worsens the overall clinical picture, pressing on the need to look into alternative treatment strategies. The present review highlightes the microbiological challenges associated with treatment of ODRI's due to biofilm formation on the implant surface. Further, it details the newer anti-infective modalities that work either by preventing biofilm formation and/or through effective disruption of the mature biofilms formed on the medical implant. The study, therefore aims to provide a comprehensive insight into the newer anti-biofilm interventions (non-antibiotic approaches) and a better understanding of their mechanism of action essential for improved management of orthopedic implant infections.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Biofilms; Humans; Prostheses and Implants; Prosthesis-Related Infections
PubMed: 33618584
DOI: 10.1080/08927014.2020.1869725 -
Journal of Biomolecular Structure &... Feb 2021Drug resistance is an unsolved and major concern in the bacterial infection. Continuous development of drug-resistance to the antibiotics exponentially rises the danger...
Drug resistance is an unsolved and major concern in the bacterial infection. Continuous development of drug-resistance to the antibiotics exponentially rises the danger of bacterial infections. Chemical components from the plants are becoming a major resource of potentially effective therapeutic chemical agents for the wide range of diseases including bacterial infections. In the current study, pharmacoinformatics methodologies were implemented on more than two hundred known phytochemicals to find promising beta-lactamase inhibitors for therapeutically effective anti-bacterial agents. Initially, the molecular docking-based score was used to reduce the chemical space of the selected dataset. Fourteen molecules were found to have more affinity towards the beta-lactamase in compared to the well-known anti-bacterial agent, Avibactam. Binding interactions analysis revealed the strong binding interactions between phytochemicals and catalytic amino residues. For further analysis, molecular dynamics (MD) simulations, density functional theory (DFT) and pharmacokinetics studies were performed. Parameters from MD simulations studies suggested that selected molecules are strong enough to retain in the active site in different orientations of the beta-lactamase. The orbital energies obtained from the DFT study was undoubtedly explained the potentiality of the selected compounds for being effective beta-lactamase inhibitors. The drug-likeness and acceptable pharmacokinetics parameters were observed using ADME analysis. Therefore, observations from the multiple pharmacoinformatics approach explained without any doubt that selected molecules are potential enough being promising anti-bacterial compounds. [Formula: see text] Communicated by Ramaswamy H. Sarma.
Topics: Anti-Bacterial Agents; Molecular Docking Simulation; Molecular Dynamics Simulation; beta-Lactamase Inhibitors; beta-Lactamases
PubMed: 31984863
DOI: 10.1080/07391102.2020.1720819 -
Trends in Pharmacological Sciences Jun 1991The resistance of bacteria to beta-lactam antibiotics is usually associated with production of the enzyme, beta-lactamase, which inactivates the beta-lactam molecule. In... (Review)
Review
The resistance of bacteria to beta-lactam antibiotics is usually associated with production of the enzyme, beta-lactamase, which inactivates the beta-lactam molecule. In the long search for inhibitors of bacterial beta-lactamase the first clinically useful agent, clavulanic acid, was isolated as a metabolite of Streptomyces clavuligerus. Robert Sutherland describes the background to the demonstration of clinical efficacy of combinations of clavulanic acid and other agents with penicillins which has confirmed beta-lactamase inhibitors as one solution to the problems posed by beta-lactamase-producing bacteria.
Topics: Anti-Bacterial Agents; Drug Resistance, Microbial; beta-Lactamase Inhibitors; beta-Lactams
PubMed: 2048218
DOI: 10.1016/0165-6147(91)90557-9 -
Journal of Medicinal Chemistry Jul 2016The clinical management of prosthetic joint infections and other persistent bacterial infections represents a major unmet medical need. The rifamycins are one of the...
The clinical management of prosthetic joint infections and other persistent bacterial infections represents a major unmet medical need. The rifamycins are one of the most potent antibiotic classes against persistent bacterial infections, but bacteria can develop resistance to rifamycins rapidly and the clinical utility of the rifamycin class is typically limited to antibiotic combinations to minimize the development of resistance. To develop a better therapy against persistent bacterial infections, a series of rifamycin based bifunctional molecules were designed, synthesized, and evaluated with the goal to identify a dual-acting drug that maintains the potent activity of rifamycins against persistent pathogens and at the same time minimize the development of rifamycin resistance. TNP-2092 was identified as a drug candidate and is currently in an early stage of clinical development for the treatment of prosthetic joint infections.
Topics: Anti-Bacterial Agents; Bacterial Infections; Dose-Response Relationship, Drug; Microbial Sensitivity Tests; Molecular Structure; Rifamycins; Staphylococcus aureus; Structure-Activity Relationship
PubMed: 27336583
DOI: 10.1021/acs.jmedchem.6b00485 -
Survey of Ophthalmology 1995Preoperative, intraoperative, and postoperative antibiotic agents have been used by ophthalmic surgeons routinely as prophylaxis for postoperative endophthalmitis. The... (Review)
Review
Preoperative, intraoperative, and postoperative antibiotic agents have been used by ophthalmic surgeons routinely as prophylaxis for postoperative endophthalmitis. The rationale for such prophylaxis and the evidence which supports its efficacy are well founded. The optimal choice of antibiotic agent--from the standpoint of efficacy, route of delivery, adverse reactions, and cost--is far less established. This review considers these issues, as well as the role of topical disinfectants, including povidone-iodine, in preoperative prophylaxis.
Topics: Administration, Topical; Anti-Bacterial Agents; Disinfectants; Drug Administration Routes; Endophthalmitis; Humans; Ophthalmologic Surgical Procedures; Premedication
PubMed: 7660302
DOI: 10.1016/s0039-6257(05)80056-6 -
Angewandte Chemie (International Ed. in... May 2003The development of bacterial resistance to currently available antibacterial agents is a growing global health problem. Of particular concern are infections caused by... (Review)
Review
The development of bacterial resistance to currently available antibacterial agents is a growing global health problem. Of particular concern are infections caused by multidrug-resistant Gram-positive pathogens which are responsible for significant morbidity and mortality in both the hospital and community settings. A number of solutions to the problem of bacterial resistance are possible. The most common approach is to continue modifying existing classes of antibacterial agents to provide new analogues with improved attributes. Other successful strategies are to combine existing antibacterial agents with other drugs as well as the development of improved diagnostic procedures that may lead to rapid identification of the causative pathogen and permit the use of antibacterial agents with a narrow spectrum of activity. Finally, and most importantly, the discovery of novel classes of antibacterial agents employing new mechanisms of action has considerable promise. Such agents would exhibit a lack of cross-resistance with existing antimicrobial drugs. This review describes the work leading to the discovery of linezolid, the first clinically useful oxazolidinone antibacterial agent.
Topics: Acetamides; Animals; Anti-Bacterial Agents; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Linezolid; Molecular Structure; Oxazolidinones; Structure-Activity Relationship
PubMed: 12746812
DOI: 10.1002/anie.200200528