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1.
Magda Ferreira Maria Ogren Joana N. R. Dias Marta Silva Solange Gil Luís Tavares Frederico Aires-da-Silva Maria Manuela Gaspar Sandra Isabel Aguiar 《Molecules (Basel, Switzerland)》2021,26(7)
Antimicrobial drugs are key tools to prevent and treat bacterial infections. Despite the early success of antibiotics, the current treatment of bacterial infections faces serious challenges due to the emergence and spread of resistant bacteria. Moreover, the decline of research and private investment in new antibiotics further aggravates this antibiotic crisis era. Overcoming the complexity of antimicrobial resistance must go beyond the search of new classes of antibiotics and include the development of alternative solutions. The evolution of nanomedicine has allowed the design of new drug delivery systems with improved therapeutic index for the incorporated compounds. One of the most promising strategies is their association to lipid-based delivery (nano)systems. A drug’s encapsulation in liposomes has been demonstrated to increase its accumulation at the infection site, minimizing drug toxicity and protecting the antibiotic from peripheral degradation. In addition, liposomes may be designed to fuse with bacterial cells, holding the potential to overcome antimicrobial resistance and biofilm formation and constituting a promising solution for the treatment of potential fatal multidrug-resistant bacterial infections, such as methicillin resistant Staphylococcus aureus. In this review, we aim to address the applicability of antibiotic encapsulated liposomes as an effective therapeutic strategy for bacterial infections. 相似文献
2.
A new affinity adsorbent, using D-alanyl-D-alanine as ligand, has been prepared. The dipeptide immobilized on Activated CH-Sepharose
4B (D-Ala-D-Ala-AGA) bioselectively binds the glycopeptide antibiotics teicoplanin, vancomycin, ristocetin A (vancomycinlike
group of antibiotics) while it does not bind other antibiotics equally active on cell wall biosynthesis but with different
target sites, such as penicillin G, cephalosporin C, gardimycin, and bacitracin. Teicoplanin, vancomycin, and ristocetin A
have similar binding characteristics for the immobilized dipeptide, as indicated by equilibrium binding experiments. The affinity
constants of the three antibiotics for D-Ala-D-Ala-AGA is of the same order of magnitude (105 L mol-1) and the number of effective binding sites is similar for each antibiotic (6–7 μEq/mL of gel). The adsorption is biospecific
as no binding has been observed to immobilized L-alanyl-L -alanine.
D-Ala-D-Ala-AGA has been successfully used to purify teicoplanin from mixtures of different complexity and for concomitant
extraction and purification from fermentation liquors by both batch adsorption and column chromatography. The antibiotic can
be recovered from the resin in high yields by elution at pH 11. 相似文献
3.
超高效液相色谱-串联质谱联用法同步检测抗生素生产废水中螺旋霉素与新螺旋霉素残留 总被引:1,自引:0,他引:1
采用超高效液相色谱-串联质谱法同步测定了抗生素生产废水中残留的螺旋霉素(SPM-Ⅰ)和新螺旋霉素(NSPM-Ⅰ)。考察了萃取溶剂种类、水样pH值、萃取次数、水样与萃取溶剂的体积比等因素对目标物回收率的影响。以ACQUITY UPLC BEH C18(100 mm×2.1 mm i.d.,1.7 μm)为分析柱,0.1%甲酸水溶液和乙腈为流动相梯度淋洗,流速0.2 mL/min,电喷雾正离子多重反应监测模式检测。标准曲线在0.02~1.00 mg/L范围内线性关系良好,r2均大于0.999。方法回收率为70% ~ 88%,相对标准偏差小于10%,检出限(S/N=3)分别为0.03 μg/L(SPM-Ⅰ)和0.06 μg/L(NSPM-Ⅰ)。该方法应用于无锡市某制药厂抗生素生产废水中SPM-Ⅰ和NSPM-Ⅰ的检测,检出质量浓度分别为(115.6±2.7) mg/L和(5.3±0.4) mg/L。 相似文献
4.
The model binding of the glycopeptide antibiotic teicoplanin (Teic) from Actinoplanes teichomyceticus, immobilized on magnetic microspheres, to d-Ala-d-Ala terminus peptides was assessed using microchip capillary electrophoresis (MCE) with continuous frontal analysis (FA).
Teic is closely related to vancomycin (Van), historically, the drug of last resort used to treat many Gram-positive bacterial
infections. Glycopeptide antibiotics inhibit bacterial growth by binding to the d-Ala-d-Ala terminus on the cell wall of Gram-positive bacteria via hydrogen bonds, thereby preventing the enzyme-mediated cross-linking
of peptidoglycan and eventual cell death. In this work direct and competitive bead-based assays in a microfluidic chip are
demonstrated. The binding constants obtained using the technique are comparable with values reported in the literature. 相似文献
5.
Tobramycin and Nebramine as Pseudo‐oligosaccharide Scaffolds for the Development of Antimicrobial Cationic Amphiphiles 下载免费PDF全文
Yifat Berkov‐Zrihen Ido M. Herzog Raphael I. Benhamou Dr. Mark Feldman Kfir B. Steinbuch Pazit Shaul Dr. Shachar Lerer Dr. Avigdor Eldar Dr. Micha Fridman 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4340-4349
Antimicrobial cationic amphiphiles derived from aminoglycoside pseudo‐oligosaccharide antibiotics interfere with the structure and function of bacterial membranes and offer a promising direction for the development of novel antibiotics. Herein, we report the design and synthesis of cationic amphiphiles derived from the pseudo‐trisaccharide aminoglycoside tobramycin and its pseudo‐disaccharide segment nebramine. Antimicrobial activity, membrane selectivity, mode of action, and structure–activity relationships were studied. Several cationic amphiphiles showed marked antimicrobial activity, and one amphiphilic nebramine derivative proved effective against all of the tested strains of bacteria; furthermore, against several of the tested strains, this compound was well over an order of magnitude more potent than the parent antibiotic tobramycin, the membrane‐targeting antimicrobial peptide mixture gramicidin D, and the cationic lipopeptide polymyxin B, which are in clinical use. 相似文献
6.
蜂王浆产品中5种大环内酯类抗生素残留量的高效液相色谱-质谱/质谱检测方法 总被引:13,自引:0,他引:13
建立了高效液相色谱-质谱/质谱测定蜂王浆中5种大环内酯类抗生素(螺旋霉素、竹桃霉素、泰乐菌素、罗红霉素、交沙霉素)残留的方法。先用三氯乙酸沉淀蜂王浆中的蛋白质,上层清液再用乙腈提取、C18小柱净化。每种抗生素选择一个母离子和两个子离子进行监测。5种大环内酯类抗生素在0.002~0.05 mg/L 范围内与其峰面积具有良好的线性关系,检测低限均为20 μg/kg,3个加标水平(每种抗生素的添加水平均为20, 100 和 200 μg/kg)下的加标回收率为73.0%~90.2%,相对标准偏差为5.6%~10.5%。 相似文献
7.
Aaron T. Garrison Yasmeen Abouelhassan Dimitris Kallifidas Fang Bai Maria Ukhanova Volker Mai Shouguang Jin Hendrik Luesch Robert W. Huigens 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(49):15032-15036
Conventional antibiotics are ineffective against non‐replicating bacteria (for example, bacteria within biofilms). We report a series of halogenated phenazines (HP), inspired by marine antibiotic 1 , that targets persistent bacteria. HP 14 demonstrated the most potent biofilm eradication activities to date against MRSA, MRSE, and VRE biofilms (MBEC=0.2–12.5 μM), as well as the effective killing of MRSA persister cells in non‐biofilm cultures. Frontline MRSA treatments, vancomycin and daptomycin, were unable to eradicate MRSA biofilms or non‐biofilm persisters alongside 14 . HP 13 displayed potent antibacterial activity against slow‐growing M. tuberculosis (MIC=3.13 μM), the leading cause of death by bacterial infection around the world. HP analogues effectively target persistent bacteria through a mechanism that is non‐toxic to mammalian cells and could have a significant impact on treatments for chronic bacterial infections. 相似文献
8.
Halogenated Phenazines that Potently Eradicate Biofilms,MRSA Persister Cells in Non‐Biofilm Cultures,and Mycobacterium tuberculosis 下载免费PDF全文
Aaron T. Garrison Yasmeen Abouelhassan Dr. Dimitris Kallifidas Dr. Fang Bai Dr. Maria Ukhanova Prof. Dr. Volker Mai Prof. Dr. Shouguang Jin Prof. Dr. Hendrik Luesch Prof. Dr. Robert W. Huigens III 《Angewandte Chemie (International ed. in English)》2015,54(49):14819-14823
Conventional antibiotics are ineffective against non‐replicating bacteria (for example, bacteria within biofilms). We report a series of halogenated phenazines (HP), inspired by marine antibiotic 1 , that targets persistent bacteria. HP 14 demonstrated the most potent biofilm eradication activities to date against MRSA, MRSE, and VRE biofilms (MBEC=0.2–12.5 μM), as well as the effective killing of MRSA persister cells in non‐biofilm cultures. Frontline MRSA treatments, vancomycin and daptomycin, were unable to eradicate MRSA biofilms or non‐biofilm persisters alongside 14 . HP 13 displayed potent antibacterial activity against slow‐growing M. tuberculosis (MIC=3.13 μM), the leading cause of death by bacterial infection around the world. HP analogues effectively target persistent bacteria through a mechanism that is non‐toxic to mammalian cells and could have a significant impact on treatments for chronic bacterial infections. 相似文献
9.
Antibiotic resistance of biofilms is a growing public health concern due to overuse and improper use of antibiotics. Thus, determining an effective minimal concentration of antibiotics to eradicate bacterial biofilms is crucial. Here we present a simple, novel one-pot assay for the analysis of antibiotic susceptibility of bacterial biofilms using a microfluidics system where continuous concentration gradients of antibiotics are generated. The results of minimal biofilm eradication concentration (MBEC) clearly confirm that the concentration required to eradicate biofilm-grown Pseudomonas aeruginosa is higher than the minimal inhibitory concentration (MIC) that has been widely used to determine the lowest concentration of antibiotics against planktonically grown bacteria. 相似文献
10.
The influence of Elbe river bacteria isolated from suspended particulate matter (SPM) on dynamic species transformation of mercury was investigated. Experiments were carried out in the presence of bacteria (batch cultures) and in sterile tapwater as a control. For the methylation of inorganic mercury ions by bacteria several cofactors are under discussion. In this work, methylcobalamin, methyl iodide and S-adenosylmethionine were tested as biogenic methyl donors and trimethyl-lead chloride, trimethyltin chloride and dimethylarsenic acid as abiotic methyl donors. Transmethylation reactions as examples of abiotic methyl transfers have higher effectiveness in the formation of methylmercury (CH3Hg+) than methylation with biogenic compounds. This result was observed in batch cultures as well as in sterile water. SPM-bacteria inhibit methyl transfer to mercury(II) ions. This is not only due to passive adsorption processes of mercury(II) to bacterial cell walls; methylmercury is also decomposed very rapidly by SPM-bacteria and is immobilized as mercury(II) by the cells. 相似文献
11.
The effect of frequency and power density on the ultrasonically-enhanced killing of biofilm-sequestered Escherichia coli 总被引:2,自引:0,他引:2
Infection on implanted medical devices is a critical concern because the bacteria are recalcitrant to antibiotic therapy; currently the only way to eliminate the infection is to remove the device. We have found that low-frequency ultrasound renders bacteria more susceptible to antibiotics. The effect of low-intensity ultrasound on the enhancement of antibiotic action against biofilm bacteria was measured by subjecting thick E. coli biofilms for 2 h at 37°C to one of four conditions: (1) incubation in nutrient broth; (2) incubation in nutrient broth with antibiotic; (3) ultrasonication in nutrient broth without antibiotic; and (4) ultrasonication in nutrient broth with antibiotic. Two frequencies (70 and 500 kHz) and several ultrasonic intensities were examined, ranging from 2 to 200 mW/cm2. It was determined that low-intensity ultrasound significantly enhanced killing of biofilm E. coli by gentamicin. This enhancement increased with increasing ultrasonic intensity and decreased with increasing frequency. A mathematical model of ultrasonically-enhanced transport in cylindrical pores and channels shows that gentamicin transport increases with ultrasonic intensity and decreases with increasing frequency. However, the magnitude of increased transport is so small that it is difficult to attribute enhanced killing of bacteria to enhanced antibiotic transport through the pores and channels of the biofilm; therefore, other mechanisms must play a role. The use of low-intensity ultrasound in conjunction with antibiotic treatment may prove to be a viable clinical method of eliminating biofilm infections from the surfaces of implanted medical devices. 相似文献
12.
Magorzata Szultka-Myska Daria Janiszewska Pawe Pomastowski Micha Zoch Wojciech Kupczyk Bogusaw Buszewski 《Molecules (Basel, Switzerland)》2021,26(16)
The bacterial infection of post-operative wounds is a common health problem. Therefore, it is important to investigate fast and accurate methods of identifying bacteria in clinical samples. The aim of the study was to analyse the use of the MALDI-TOF MS technique to identify microorganism wounds that are difficult to heal. The most common bacteria are Escherichia coli, Staphylococcus spp., and Enterococcus spp. We also demonstrate the effect of culture conditions, such as the used growth medium (solid: Brain Heart Infusion Agar, Mueller Hilton Agar, Glucose Bromocresol Purple Agar, and Vancomycin Resistance Enterococci Agar Base and liquid: Tryptic Soy Broth and BACTEC Lytic/10 Anaerobic/F), the incubation time (4, 6, and 24h), and the method of the preparation of bacterial protein extracts (the standard method based on the Bruker guideline, the Sepsityper method) to identify factors and the quality of the obtained mass spectra. By comparing the protein profiles of bacteria from patients not treated with antibiotics to those treated with antibiotics based on the presence/absence of specific signals and using the UniProt platform, it was possible to predict the probable mechanism of the action of the antibiotic used and the mechanism of drug resistance. 相似文献
13.
Struss AK Pasini P Flomenhoft D Shashidhar H Daunert S 《Analytical and bioanalytical chemistry》2012,402(10):3227-3236
Quorum sensing (QS) allows bacteria to communicate with one another by means of QS signaling molecules and control certain
behaviors in a group-based manner, including pathogenicity and biofilm formation. Bacterial gut microflora may play a role
in inflammatory bowel disease pathogenesis, and antibiotics are one of the available therapeutic options for Crohn’s disease.
In the present study, we employed genetically engineered bioluminescent bacterial whole-cell sensing systems as a tool to
evaluate the ability of antibiotics commonly employed in the treatment of chronic inflammatory conditions to interfere with
QS. We investigated the effect of ciprofloxacin, metronidazole, and tinidazole on quorum sensing. Several concentrations of
individual antibiotics were allowed to interact with two different types of bacterial sensing cells, in both the presence
and absence of a fixed concentration of N-acylhomoserine lactone (AHL) QS molecules. The antibiotic effect was then determined by monitoring the biosensor’s bioluminescence
response. Ciprofloxacin, metronidazole, and tinidazole exhibited a dose-dependent augmentation in the response of both bacterial
sensing systems, thus showing an AHL-like effect. Additionally, such an augmentation was observed, in both the presence and
absence of AHL. The data obtained indicate that ciprofloxacin, metronidazole, and tinidazole may interfere with bacterial
communication systems. The results suggest that these antibiotics, at the concentrations tested, may themselves act as bacterial
signaling molecules. The beneficial effect of these antibiotics in the treatment of intestinal inflammation may be due, at
least in part, to their effect on QS-related bacterial behavior in the gut. 相似文献
14.
J. Lerchner D. Mueller-Hagen H. Roehr A. Wolf F. Mertens R. Mueller W. Witte I. Klare 《Journal of Thermal Analysis and Calorimetry》2011,104(1):31-36
Rapid detection of antibiotic resistances of clinical bacterial strains would allow an early selective antibiotic therapy
and a faster intervention and implementation of infection control measurements. In clinical practice, however, conventional
antibiotic susceptibility tests of bacteria often need 24 h until the results are obtained. The metabolic heat production
of bacteria is an excellent possibility to record their physiological activities and could therefore be used for a rapid discrimination
of bacterial strains which are resistant or non-resistant to antibiotics and also to lytic bacteriophages, respectively. Unfortunately,
conventional calorimeters suffer from need of comparably large volumes of bacterial suspensions are characterised by slow
operation and high costs which restrict their application in clinical laboratories. The present paper demonstrates that a
new type of calorimeters developed on silicon-chip technology enables the detection of antibiotic resistances on a minute-timescale.
For this reasons, a prototype chip calorimeter was used which sensitivity is 20 nW related to the heat production of about
104 bacteria. For a clear discrimination of antibiotic resistance about 105 bacteria are required. The antibiotic resistances and susceptibilities of different strains of Staphylococcus aureus to cefoxitin and the sensitivities of S. aureus DSM 18421 and E. coli DSM 498 to a mixture of two bacteriophages were studied. Comparing the heat productions of cultures incubated with antibiotics
or bacteriophages to those without these antibacterial preparations enabled a clear discrimination of resistant and non-resistant
strains already after totally 2 h. 相似文献
15.
Chetsumon Aparat Umeda Fusako Maeda Isamu Yagi Kiyohito Mizoguchi Tadashi Miura Yoshiharu 《Applied biochemistry and biotechnology》1998,(1):249-256
A photobioreactor was constructed using anchored polyurethane foam strips (1 x 1 x 40 cm) fixed onto a stainless-steel ring
to prevent flotation, as a biomass support material (BSM). This type of reactor was named a seaweed-type bioreactor. A filamentous
cyanobacterium, Scytonema sp. TISTR 8208, which produces a novel cyclic dodecapeptide antibiotic, was immobilized in seaweed-type
photobioreactor and cultivated with air containing 5% CO2 sparged at a gas flow rate of 250 mL/min under illumination at a light intensity of 200 μmol photon m-2s-1. The antibiotic produced in the seaweed-type photobioreactor was purified by HPLC and examined regarding its spectrum and
mode of action. The antibiotic effectively inhibited the growth of Gram-positive bacteria, pathogenic yeasts, and filamentous
fungi, but it had only a weak effect on Gram-negative bacteria. Scanning electron micrograph analysis showed that the most
characteristic change was swelling of the cells after exposure to the antibiotic. The antibiotic seems to alter the conformation
of the microbial cell membrane, thereby changing its permeability, leading to osmotic shock. 相似文献
16.
Enzyme‐Responsive Polymeric Vesicles for Bacterial‐Strain‐Selective Delivery of Antimicrobial Agents 下载免费PDF全文
Yamin Li Dr. Guhuan Liu Xiaorui Wang Dr. Jinming Hu Prof. Dr. Shiyong Liu 《Angewandte Chemie (International ed. in English)》2016,55(5):1760-1764
Antimicrobial resistance poses serious public health concerns and antibiotic misuse/abuse further complicates the situation; thus, it remains a considerable challenge to optimize/improve the usage of currently available drugs. We report a general strategy to construct a bacterial strain‐selective delivery system for antibiotics based on responsive polymeric vesicles. In response to enzymes including penicillin G amidase (PGA) and β‐lactamase (Bla), which are closely associated with drug‐resistant bacterial strains, antibiotic‐loaded polymeric vesicles undergo self‐immolative structural rearrangement and morphological transitions, leading to sustained release of antibiotics. Enhanced stability, reduced side effects, and bacterial strain‐selective drug release were achieved. Considering that Bla is the main cause of bacterial resistance to β‐lactam antibiotic drugs, as a further validation, we demonstrate methicillin‐resistant S. aureus (MRSA)‐triggered release of antibiotics from Bla‐degradable polymeric vesicles, in vitro inhibition of MRSA growth, and enhanced wound healing in an in vivo murine model. 相似文献
17.
The rough-form lipopolysaccharide (LPS) interacted with cationic antibiotic polymyxin B and gramicidin S in solution, and
showed altered thermotropic phase behavior and viscoelasticity. The phase behavior was measured by differential scanning calorimetry
and quartz crystal microbalance (QCM). Addition of polymyxin B of up to 0.5 mg/mL to the 5.0 mg/mL LPS solution increased
gel-to-liquid crystalline phase transition enthalpy (ΔH) and raised the transition temperature (tmax). The further addition of polymyxin B reduced the ΔH value. Gramicidin S produced a different effect, whereby a minor addition
reduced tmax and ΔH value of the LPS. The LPS film on the platinum electrode of the QCM indicated a downward shift of resonant frequency
and an upward shift of resonant resistance when in contact with the antibiotic solution. An interpretation of these variations
is that the LPS on the QCM electrode changed not only film weight, but also viscoelasticity owing to contact with the antibiotic
solution. The different effects between the antibiotics between polymyxin B and gramicidin S on the LPS are induced by the
difference of the governing effect. Polymyxin B interacts with the LPS electrostatically, whereas gramicidin S interacts by
hydrophobic moieties. 相似文献
18.
M. P. Evstigneev A. O. Rozvadovskaya A. S. Chubarov A. A. Hernandez Santiago D. B. Davies A. N. Veselkov 《Journal of Structural Chemistry》2005,46(1):67-74
Heteroassociation of the antitumor antibiotic daunomycin (DAU) with flavin mononucleotide (FMN) has been investigated by one-and two-dimensional 1H NMR spectroscopy (500 MHz) in a water solution to determine the molecular mechanism of the combined action of the antibiotic and vitamin in the FMN-DAU system. The equilibrium constants of the reactions, induced proton chemical shifts, and thermodynamic parameters (ΔH, ΔS) of heteroassociation were determined from the concentration and temperature dependences of the proton chemical shifts in the interacting aromatic molecules. Analysis of the results indicate that heterocomplexes of riboflavin mononucleotide and daunomycin are formed due to stacking interactions between aromatic chromophores. The most probable spatial structure of the 1:1 DAU-FMN heterocomplex was determined by the molecular dynamics method using the X-PLOR program and the results of the analysis of the induced proton chemical shifts in molecules. Calculation of the relative content of self-and hetero-complexes of daunomycin for different values of the ratio (r) between the concentrations of flavin mononucleotide and daunomycin demonstrated that for r > 3, the contribution of DAU-FMN heterocomplexes to the equilibrium distribution of associates in aqueous solution is dominant. It is concluded that the aromatic molecules of vitamins, in particular, riboflavin, can form energetically strong heteroassociates with antitumor antibiotics in water solution and can thereby affect their medical and biological activity. 相似文献
19.
Dr. Mathieu F. Chellat Luka Raguž Prof. Dr. Rainer Riedl 《Angewandte Chemie (International ed. in English)》2016,55(23):6600-6626
Finding strategies against the development of antibiotic resistance is a major global challenge for the life sciences community and for public health. The past decades have seen a dramatic worldwide increase in human‐pathogenic bacteria that are resistant to one or multiple antibiotics. More and more infections caused by resistant microorganisms fail to respond to conventional treatment, and in some cases, even last‐resort antibiotics have lost their power. In addition, industry pipelines for the development of novel antibiotics have run dry over the past decades. A recent world health day by the World Health Organization titled “Combat drug resistance: no action today means no cure tomorrow” triggered an increase in research activity, and several promising strategies have been developed to restore treatment options against infections by resistant bacterial pathogens. 相似文献
20.
Maria F. B. Morais-Braga Teógenes M. Souza Karla K. A. Santos Gláucia M. M. Guedes Jacqueline C. Andrade Saulo R. Tintino 《Natural product research》2016,30(16):1851-1853
The aim of this work was to evaluate the interactions between gentamicin and the ethanol extract of the fern Lygodium venustum SW (EELV). The ethanol extract of L. venustum was obtained, the phytocompounds were identified and the EELV was assayed by the checkerboard method with gentamicin against two bacterial strains multiresistant to antibiotics. The antibiotic activity of gentamicin, when associated with the extract, was enhanced in an additive manner against both strains. The results indicated that L. venustum can be a source of secondary metabolites to be used in association with antibiotics as aminoglycosides in the antibiotic chemotherapy against resistant bacteria. 相似文献