scholarly journals Discovery of a Novel and Potent Class of FabI-Directed Antibacterial Agents

2002 ◽  
Vol 46 (10) ◽  
pp. 3118-3124 ◽  
Author(s):  
David J. Payne ◽  
William H. Miller ◽  
Valerie Berry ◽  
John Brosky ◽  
Walter J. Burgess ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
High Throughput ◽  
High Throughput Screening ◽  
Antibacterial Agents ◽  
Fatty Acid Biosynthesis ◽  
Acyl Carrier Protein ◽  
Multidrug Resistant ◽  
Infection Model ◽  
Enoyl Acp Reductase

ABSTRACT Bacterial enoyl-acyl carrier protein (ACP) reductase (FabI) catalyzes the final step in each elongation cycle of bacterial fatty acid biosynthesis and is an attractive target for the development of new antibacterial agents. High-throughput screening of the Staphylococcus aureus FabI enzyme identified a novel, weak inhibitor with no detectable antibacterial activity against S. aureus. Iterative medicinal chemistry and X-ray crystal structure-based design led to the identification of compound 4 [(E)-N-methyl-N-(2-methyl-1H-indol-3-ylmethyl)-3-(7-oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)acrylamide], which is 350-fold more potent than the original lead compound obtained by high-throughput screening in the FabI inhibition assay. Compound 4 has exquisite antistaphylococci activity, achieving MICs at which 90% of isolates are inhibited more than 500 times lower than those of nine currently available antibiotics against a panel of multidrug-resistant strains of S. aureus and Staphylococcus epidermidis. Furthermore, compound 4 exhibits excellent in vivo efficacy in an S. aureus infection model in rats. Biochemical and genetic approaches have confirmed that the mode of antibacterial action of compound 4 and related compounds is via inhibition of FabI. Compound 4 also exhibits weak FabK inhibitory activity, which may explain its antibacterial activity against Streptococcus pneumoniae and Enterococcus faecalis, which depend on FabK and both FabK and FabI, respectively, for their enoyl-ACP reductase function. These results show that compound 4 is representative of a new, totally synthetic series of antibacterial agents that has the potential to provide novel alternatives for the treatment of S. aureus infections that are resistant to our present armory of antibiotics.

Large-scale High-throughput Screening Revealed 5'-(carbonylamino)-2,3'- bithiophene-4'-carboxylate as Novel Template for Antibacterial Agents

2020 ◽  
Vol 17 (5) ◽  
pp. 716-724
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
High Throughput ◽  
High Throughput Screening ◽  
Large Scale ◽  
Antibacterial Agents ◽  
Sos Response ◽  
Luciferase Assay ◽  
Translational Machinery ◽  
E Coli ◽  
New Class

Background: The key issue in the development of novel antimicrobials is a rapid expansion of new bacterial strains resistant to current antibiotics. Indeed, World Health Organization has reported that bacteria commonly causing infections in hospitals and in the community, e.g. E. Coli, K. pneumoniae and S. aureus, have high resistance vs the last generations of cephalosporins, carbapenems and fluoroquinolones. During the past decades, only few successful efforts to develop and launch new antibacterial medications have been performed. This study aims to identify new class of antibacterial agents using novel high-throughput screening technique. Methods: We have designed library containing 125K compounds not similar in structure (Tanimoto coeff.< 0.7) to that published previously as antibiotics. The HTS platform based on double reporter system pDualrep2 was used to distinguish between molecules able to block translational machinery or induce SOS-response in a model E. coli system. MICs for most active chemicals in LB and M9 medium were determined using broth microdilution assay. Results: In an attempt to discover novel classes of antibacterials, we performed HTS of a large-scale small molecule library using our unique screening platform. This approach permitted us to quickly and robustly evaluate a lot of compounds as well as to determine the mechanism of action in the case of compounds being either translational machinery inhibitors or DNA-damaging agents/replication blockers. HTS has resulted in several new structural classes of molecules exhibiting an attractive antibacterial activity. Herein, we report as promising antibacterials. Two most active compounds from this series showed MIC value of 1.2 (5) and 1.8 μg/mL (6) and good selectivity index. Compound 6 caused RFP induction and low SOS response. In vitro luciferase assay has revealed that it is able to slightly inhibit protein biosynthesis. Compound 5 was tested on several archival strains and exhibited slight activity against gram-negative bacteria and outstanding activity against S. aureus. The key structural requirements for antibacterial potency were also explored. We found, that the unsubstituted carboxylic group is crucial for antibacterial activity as well as the presence of bulky hydrophobic substituents at phenyl fragment. Conclusion: The obtained results provide a solid background for further characterization of the 5'- (carbonylamino)-2,3'-bithiophene-4'-carboxylate derivatives discussed herein as new class of antibacterials and their optimization campaign.

scholarly journals In Vitro Inhibition of the Mycobacterium tuberculosis β-Ketoacyl-Acyl Carrier Protein Reductase MabA by Isoniazid

2004 ◽  
Vol 48 (1) ◽  
pp. 242-249 ◽  
Author(s):  
Stéphanie Ducasse-Cabanot ◽  
Martin Cohen-Gonsaud ◽  
Hedia Marrakchi ◽  
Michel Nguyen ◽  
Didier Zerbib ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
Dynamic Equilibrium ◽  
Acyl Carrier Protein ◽  
Multidrug Resistant ◽  
Carrier Protein ◽  
Ligand Complex ◽  
Fas Ii

ABSTRACT The first-line specific antituberculous drug isoniazid inhibits the fatty acid elongation system (FAS) FAS-II involved in the biosynthesis of mycolic acids, which are major lipids of the mycobacterial envelope. The MabA protein that catalyzes the second step of the FAS-II elongation cycle is structurally and functionally related to the in vivo target of isoniazid, InhA, an NADH-dependent enoyl-acyl carrier protein reductase. The present work shows that the NADPH-dependent β-ketoacyl reduction activity of MabA is efficiently inhibited by isoniazid in vitro by a mechanism similar to that by which isoniazid inhibits InhA activity. It involves the formation of a covalent adduct between MnIII-activated isoniazid and the MabA cofactor. Liquid chromatography-mass spectrometry analyses revealed that the isonicotinoyl-NADP adduct has multiple chemical forms in dynamic equilibrium. Both kinetic experiments with isolated forms and purification of the enzyme-ligand complex strongly suggested that the molecules active against MabA activity are the oxidized derivative and a major cyclic form. Spectrofluorimetry showed that the adduct binds to the MabA active site. Modeling of the MabA-adduct complex predicted an interaction between the isonicotinoyl moiety of the inhibitor and Tyr185. This hypothesis was supported by the fact that a higher 50% inhibitory concentration of the adduct was measured for MabA Y185L than for the wild-type enzyme, while both proteins presented similar affinities for NADP+. The crystal structure of MabA Y185L that was solved showed that the substitution of Tyr185 induced no significant conformational change. The description of the first inhibitor of the β-ketoacyl reduction step of fatty acid biosynthesis should help in the design of new antituberculous drugs efficient against multidrug-resistant tubercle bacilli.

scholarly journals The Burkholderia pseudomallei Enoyl-Acyl Carrier Protein Reductase FabI1 Is Essential forIn VivoGrowth and Is the Target of a Novel Chemotherapeutic with Efficacy

2013 ◽  
Vol 58 (2) ◽  
pp. 931-935 ◽  
Author(s):  
Jason E. Cummings ◽  
Luke C. Kingry ◽  
Drew A. Rholl ◽  
Herbert P. Schweizer ◽  
Peter J. Tonge ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Fatty Acid Biosynthesis ◽  
Acyl Carrier Protein ◽  
Specific Inhibitor ◽  
Carrier Protein ◽  
Wild Type ◽  
Content Type ◽  
Fatty Acid Biosynthesis Pathway ◽  
Enoyl Acp Reductase

ABSTRACTThe bacterial fatty acid biosynthesis pathway is a validated target for the development of novel chemotherapeutics. However, sinceBurkholderia pseudomalleicarries genes that encode both FabI and FabV enoyl-acyl carrier protein (ACP) reductase homologues, the enoyl-ACP reductase that is essential forin vivogrowth needs to be defined so that the correct drug target can be chosen for development. Accordingly, ΔfabI1, ΔfabI2, and ΔfabVknockout strains were constructed and tested in a mouse model of infection. Mice infected with a ΔfabI1strain did not show signs of morbidity, mortality, or dissemination after 30 days of infection compared to the wild-type and ΔfabI2and ΔfabVmutant strains that had times to mortality of 60 to 84 h. Although signs of morbidity and mortality of ΔfabI2and ΔfabVstrains were not significantly different from those of the wild-type strain, a slight delay was observed. A FabI1-specific inhibitor was used to confirm that inhibition of FabI1 results in reduced bacterial burden and efficacy in an acuteB. pseudomalleimurine model of infection. This work establishes that FabI1 is required for growth ofBurkholderia pseudomalleiin vivoand is a potential molecular target for drug development.

scholarly journals Efficacy of Humanized Exposures of Cefiderocol (S-649266) against a Diverse Population of Gram-Negative Bacteria in a Murine Thigh Infection Model

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Marguerite L. Monogue ◽  
Masakatsu Tsuji ◽  
Yoshinori Yamano ◽  
Roger Echols ◽  
David P. Nicolau
Keyword(s):  
Antibacterial Activity ◽  
Multidrug Resistant ◽  
Infection Model ◽  
Gram Negative Bacteria ◽  
Diverse Population ◽  
Gram Negative ◽  
Content Type ◽  
Log Reduction

ABSTRACT Cefiderocol (S-649266) is a novel siderophore cephalosporin with potent in vitro activity against clinically encountered multidrug-resistant (MDR) Gram-negative isolates; however, its spectrum of antibacterial activity against these difficult-to-treat isolates remains to be fully explored in vivo. Here, we evaluated the efficacy of cefiderocol humanized exposures in a neutropenic murine thigh model to support a suitable MIC breakpoint. Furthermore, we compared cefiderocol's efficacy with humanized exposures of meropenem and cefepime against a subset of these phenotypically diverse isolates. Ninety-five Gram-negative isolates were studied. Efficacy was determined as the change in log10 CFU at 24 h compared with 0-h controls. Bacterial stasis or ≥1 log reduction in 67 isolates with MICs of ≤4 μg/ml was noted in 77, 88, and 85% of Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa, respectively. For isolates with MICs of ≥8 μg/ml, bacterial stasis or ≥1 log10 reduction was observed in only 2 of 28 (8 Enterobacteriaceae, 19 A. baumannii, and 1 P. aeruginosa) strains. Against highly resistant meropenem and cefepime organisms, cefiderocol maintained its in vivo efficacy. Overall, humanized exposures of cefiderocol produced similar reductions in bacterial density for organisms with MICs of ≤4 μg/ml, whereas isolates with MICs of ≥8 μg/ml generally displayed bacterial growth in the presence of the compound. Data derived in the current study will assist with the delineation of MIC susceptibility breakpoints for cefiderocol against these important nosocomial Gram-negative pathogens; however, additional clinical data are required to substantiate these observations.

scholarly journals AG205, a Novel Agent Directed against FabK of Streptococcus pneumoniae

2006 ◽  
Vol 50 (8) ◽  
pp. 2869-2871 ◽  
Author(s):  
Sho Takahata ◽  
Maiko Iida ◽  
Yumi Osaki ◽  
Jun Saito ◽  
Hideo Kitagawa ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Pneumoniae ◽  
High Throughput ◽  
High Throughput Screening ◽  
Potent Inhibitor ◽  
Lipid Biosynthesis ◽  
Specific Inhibition ◽  
Enoyl Acp Reductase ◽  
Resistant Mutants ◽  
Novel Agent

ABSTRACT AG205 was identified from high-throughput screening as a potent inhibitor of FabK, the enoyl-ACP reductase in Streptococcus pneumoniae. Specific inhibition of lipid biosynthesis in a macromolecular biosynthesis assay and identification of an Ala141Ser substitution in FabK from spontaneous AG205-resistant mutants indicated that AG205 exerts antibacterial activity against S. pneumoniae through the specific inhibition of FabK.

scholarly journals High-throughput screening and rational design of biofunctionalized surfaces with optimized biocompatibility and antimicrobial activity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhou Fang ◽  
Junjian Chen ◽  
Ye Zhu ◽  
Guansong Hu ◽  
Haoqian Xin ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
High Throughput ◽  
High Throughput Screening ◽  
Rational Design ◽  
Click Reaction ◽  
Reaction Times ◽  
Great Promise ◽  
Biomaterial Surfaces

AbstractPeptides are widely used for surface modification to develop improved implants, such as cell adhesion RGD peptide and antimicrobial peptide (AMP). However, it is a daunting challenge to identify an optimized condition with the two peptides showing their intended activities and the parameters for reaching such a condition. Herein, we develop a high-throughput strategy, preparing titanium (Ti) surfaces with a gradient in peptide density by click reaction as a platform, to screen the positions with desired functions. Such positions are corresponding to optimized molecular parameters (peptide densities/ratios) and associated preparation parameters (reaction times/reactant concentrations). These parameters are then extracted to prepare nongradient mono- and dual-peptide functionalized Ti surfaces with desired biocompatibility or/and antimicrobial activity in vitro and in vivo. We also demonstrate this strategy could be extended to other materials. Here, we show that the high-throughput versatile strategy holds great promise for rational design and preparation of functional biomaterial surfaces.

scholarly journals Silver Nanoparticles and Their Antibacterial Applications

2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Secondary Effects ◽  
Cytotoxic Effects ◽  
Factors Affecting ◽  
Gram Positive Bacteria ◽  
Resistant Strains

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.

scholarly journals A Microfluidic Spheroid Culture Device with a Concentration Gradient Generator for High-Throughput Screening of Drug Efficacy

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3355 ◽  
Author(s):  
Wanyoung Lim ◽  
Sungsu Park
Keyword(s):  
High Throughput ◽  
Concentration Gradient ◽  
High Throughput Screening ◽  
3D Cell Culture ◽  
Drug Efficacy ◽  
Cancer Drug ◽  
Spheroid Culture ◽  
Gradient Generator ◽  
Micro Channels

Three-dimensional (3D) cell culture is considered more clinically relevant in mimicking the structural and physiological conditions of tumors in vivo compared to two-dimensional cell cultures. In recent years, high-throughput screening (HTS) in 3D cell arrays has been extensively used for drug discovery because of its usability and applicability. Herein, we developed a microfluidic spheroid culture device (μFSCD) with a concentration gradient generator (CGG) that enabled cells to form spheroids and grow in the presence of cancer drug gradients. The device is composed of concave microwells with several serpentine micro-channels which generate a concentration gradient. Once the colon cancer cells (HCT116) formed a single spheroid (approximately 120 μm in diameter) in each microwell, spheroids were perfused in the presence of the cancer drug gradient irinotecan for three days. The number of spheroids, roundness, and cell viability, were inversely proportional to the drug concentration. These results suggest that the μFSCD with a CGG has the potential to become an HTS platform for screening the efficacy of cancer drugs.

scholarly journals Evaluation of the electron transfer flavoprotein as an antibacterial target in Burkholderia cenocepacia

2017 ◽  
Vol 63 (10) ◽  
pp. 857-863 ◽  
Author(s):  
Maria S. Stietz ◽  
Christina Lopez ◽  
Osasumwen Osifo ◽  
Marcelo E. Tolmasky ◽  
Silvia T. Cardona
Keyword(s):  
Electron Transfer ◽  
Burkholderia Cepacia ◽  
Multidrug Resistant ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Infection Model ◽  
Electron Transfer Flavoprotein ◽  
C Elegans

There are hundreds of essential genes in multidrug-resistant bacterial genomes, but only a few of their products are exploited as antibacterial targets. An example is the electron transfer flavoprotein (ETF), which is required for growth and viability in Burkholderia cenocepacia. Here, we evaluated ETF as an antibiotic target for Burkholderia cepacia complex (Bcc). Depletion of the bacterial ETF during infection of Caenorhabditis elegans significantly extended survival of the nematodes, proving that ETF is essential for survival of B. cenocepacia in this host model. In spite of the arrest in respiration in ETF mutants, the inhibition of etf expression did not increase the formation of persister cells, when treated with high doses of ciprofloxacin or meropenem. To test if etf translation could be inhibited by RNA interference, antisense oligonucleotides that target the etfBA operon were synthesized. One antisense oligonucleotide was effective in inhibiting etfB translation in vitro but not in vivo, highlighting the challenge of reduced membrane permeability for the design of drugs against B. cenocepacia. This work contributes to the validation of ETF of B. cenocepacia as a target for antibacterial therapy and demonstrates the utility of a C. elegans liquid killing assay to validate gene essentiality in an in vivo infection model.

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