scholarly journals Optimization of a High-Throughput 384-Well Plate-Based Screening Platform with Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 15442 Biofilms

2020 ◽  
Vol 21 (9) ◽  
pp. 3034 ◽  
Author(s):  
Shella Gilbert-Girard ◽  
Kirsi Savijoki ◽  
Jari Yli-Kauhaluoma ◽  
Adyary Fallarero
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
High Throughput ◽  
High Throughput Screening ◽  
Bacterial Infections ◽  
Rapid Screening ◽  
Bacterial Biofilms ◽  
Main Concern ◽  
Assay Optimization ◽  
Screening Platform

In recent years, bacterial infections have become a main concern following the spread of antimicrobial resistance. In addition, bacterial biofilms are known for their high tolerance to antimicrobials and they are regarded as a main cause of recalcitrant infections in humans. Many efforts have been deployed in order to find new antibacterial therapeutic options and the high-throughput screening (HTS) of large libraries of compounds is one of the utilized strategies. However, HTS efforts for anti-biofilm discovery remain uncommon. Here, we miniaturized a 96-well plate (96WP) screening platform, into a 384-well plate (384WP) format, based on a sequential viability and biomass measurements for the assessment of anti-biofilm activity. During the assay optimization process, different parameters were evaluated while using Staphylococcus aureus and Pseudomonas aeruginosa as the bacterial models. We compared the performance of the optimized 384WP platform to our previously established 96WP-based platform by carrying out a pilot screening of 100 compounds, followed by the screening of a library of 2000 compounds to identify new repurposed anti-biofilm agents. Our results show that the optimized 384WP platform is well-suited for screening purposes, allowing for the rapid screening of a higher number of compounds in a run in a reliable manner.

scholarly journals Development of a Miniaturized 384-Well High Throughput Screen for the Detection of Substrates of Cytochrome P450 2D6 and 3A4 Metabolism

2001 ◽  
Vol 6 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Ilona Kariv ◽  
Mark P. Fereshteh ◽  
Kevin R. Oldenburg
Keyword(s):  
Drug Metabolism ◽  
High Throughput ◽  
High Throughput Screening ◽  
Biologically Active ◽  
In Vitro Assays ◽  
Main Concern ◽  
Assay Sensitivity ◽  
Cyp Enzymes ◽  
Assay Optimization

The identification of a large number of biologically active chemical entities during high throughput screening (HTS) necessitates the incorporation of new strategies to identify compounds with druglike properties early during the lead prioritization and development process. One of the major steps in lead prioritization is the assessment of drug metabolism mediated by the cytochrome P450 (CYP) enzymes to evaluate the potential drug-drug interactions. CYP2D6 and CYP3A4 comprise the main human CYP enzymes involved in drug metabolism. The recent availability of specific CYP cDNA expression systems and the development of specific fluorescent probes have accelerated the ability to develop robust in vitro assays in HTS format. The aim of this study was to optimize conditions for the CYP2D6 and CYP3A4 HTS assays and subsequently adapt those assays to a miniaturized 384-well format. Assay conversion to a miniaturized format presents certain difficulties, such as robustness of the signal and of compound delivery. Thus the assay optimization involved the comparison of different substrates to identify those most suitable for use in a miniaturized format. Because of current technical limitations in liquid dispensing of nanoliter volumes, assay sensitivity to organic solvents also provides a main concern during assay miniaturization. Therefore, compound activity from redissolved dry films and from DMSO stocks directly delivered into assay buffer was compared. The data indicate that compound activity was comparable in both formats. The data support the conclusion that CYP2D6 and CYP3A4 in vitro metabolism assays can be successfully performed in 384-well plate format and the substrate potencies, as evaluated by the IC50 values, determined.

High-Throughput Screening Strategies for the Development of Anti-Virulence Inhibitors Against Staphylococcus aureus

2019 ◽  
Vol 26 (13) ◽  
pp. 2297-2312 ◽  
Author(s):  
Xiaodan Cai ◽  
Weihao Zheng ◽  
Zigang Li
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
High Throughput ◽  
High Throughput Screening ◽  
Bacterial Infections ◽  
Promising Alternative ◽  
Regulatory Pathways ◽  
Advantages And Disadvantages ◽  
Virulence Regulation ◽  
Conventional Antibiotics

Background:The increasing threats of antibiotic resistance urge the need for developing new approaches to combat bacterial infections including those caused by Staphylococcus aureus (S. aureus). Unlike conventional antibiotics that aim to kill bacteria or inhibit their growth, targeting bacterial virulence may be a promising alternative approach, which imposes less selective pressure for antibiotic resistance in future generations.Objective:Our goal is to provide a systematic review about developing high-throughput screening (HTS) strategies for the identification of inhibitors targeting virulence of S. aureus. We also describe an overview of virulence regulatory pathways for potential antivirulence targets.Methods:We focus on five potential targets or target families, including agr quorum sensing system, SarA/MgrA protein family, sortase A, Clp protease and eukaryotic-like Ser/Thr phosphatase (Stp1). For each target, we introduce its role in virulence regulation, summarize the HTS approaches that are used to identify novel anti-virulence inhibitors, and discuss the advantages and disadvantages of these strategies.Conclusion:The discovery of anti-virulence inhibitors via HTS underlines the promising potential of anti-virulence therapy for S. aureus. The development of HTS strategies can facilitate the identification of novel anti-virulence inhibitors for combating S. aureus infection, and may also advance our understanding on virulence regulation in S. aureus.

scholarly journals Pseudomonas aeruginosa PA14 Enhances the Efficacy of Norfloxacin against Staphylococcus aureus Newman Biofilms

2020 ◽  
Vol 202 (18) ◽  
Author(s):  
Giulia Orazi ◽  
Fabrice Jean-Pierre ◽  
George A. O’Toole
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
Respiratory Infections ◽  
Multiple Infection ◽  
Bacterial Biofilms ◽  
Interspecies Interactions ◽  
Chronic Infections ◽  
Content Type

ABSTRACT The thick mucus within the airways of individuals with cystic fibrosis (CF) promotes frequent respiratory infections that are often polymicrobial. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most prevalent pathogens that cause CF pulmonary infections, and both are among the most common etiologic agents of chronic wound infections. Furthermore, the ability of P. aeruginosa and S. aureus to form biofilms promotes the establishment of chronic infections that are often difficult to eradicate using antimicrobial agents. In this study, we found that multiple LasR-regulated exoproducts of P. aeruginosa, including 2-heptyl-4-hydroxyquinoline N-oxide (HQNO), siderophores, phenazines, and rhamnolipids, likely contribute to the ability of P. aeruginosa PA14 to shift S. aureus Newman norfloxacin susceptibility profiles. Here, we observe that exposure to P. aeruginosa exoproducts leads to an increase in intracellular norfloxacin accumulation by S. aureus. We previously showed that P. aeruginosa supernatant dissipates the S. aureus membrane potential, and furthermore, depletion of the S. aureus proton motive force recapitulates the effect of the P. aeruginosa PA14 supernatant on shifting norfloxacin sensitivity profiles of biofilm-grown S. aureus Newman. From these results, we hypothesize that exposure to P. aeruginosa PA14 exoproducts leads to increased uptake of the drug and/or an impaired ability of S. aureus Newman to efflux norfloxacin. Surprisingly, the effect observed here of P. aeruginosa PA14 exoproducts on S. aureus Newman susceptibility to norfloxacin seemed to be specific to these strains and this antibiotic. Our results illustrate that microbially derived products can alter the ability of antimicrobial agents to kill bacterial biofilms. IMPORTANCE Pseudomonas aeruginosa and Staphylococcus aureus are frequently coisolated from multiple infection sites, including the lungs of individuals with cystic fibrosis (CF) and nonhealing diabetic foot ulcers. Coinfection with P. aeruginosa and S. aureus has been shown to produce worse outcomes compared to infection with either organism alone. Furthermore, the ability of these pathogens to form biofilms enables them to cause persistent infection and withstand antimicrobial therapy. In this study, we found that P. aeruginosa-secreted products dramatically increase the ability of the antibiotic norfloxacin to kill S. aureus biofilms. Understanding how interspecies interactions alter the antibiotic susceptibility of bacterial biofilms may inform treatment decisions and inspire the development of new therapeutic strategies.

High-Throughput Screening Platform for Nanoparticle-Mediated Alterations of DNA Repair Capacity

ACS Nano ◽  
2021 ◽  
Author(s):  
Sneh M. Toprani ◽  
Dimitrios Bitounis ◽  
Qiansheng Huang ◽  
Nathalia Oliveira ◽  
Kee Woei Ng ◽  
...  
Keyword(s):  
Dna Repair ◽  
High Throughput ◽  
High Throughput Screening ◽  
Repair Capacity ◽  
Dna Repair Capacity ◽  
Screening Platform

Time-Resolved Luminescent High-Throughput Screening Platform for Lysosomotropic Compounds in Living Cells

ACS Sensors ◽  
2020 ◽  
Author(s):  
Ke-Jia Wu ◽  
Chun Wu ◽  
Feng Chen ◽  
Sha-Sha Cheng ◽  
Dik-Lung Ma ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Living Cells ◽  
Time Resolved ◽  
Screening Platform

scholarly journals A High-Throughput Approach To Identify Compounds That Impair Envelope Integrity in Escherichia coli

2016 ◽  
Vol 60 (10) ◽  
pp. 5995-6002 ◽  
Author(s):  
Kristin R. Baker ◽  
Bimal Jana ◽  
Henrik Franzyk ◽  
Luca Guardabassi
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
High Throughput Screening ◽  
Gram Negative Bacteria ◽  
Chromogenic Substrate ◽  
Intrinsic Resistance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Screening Platform

ABSTRACTThe envelope of Gram-negative bacteria constitutes an impenetrable barrier to numerous classes of antimicrobials. This intrinsic resistance, coupled with acquired multidrug resistance, has drastically limited the treatment options against Gram-negative pathogens. The aim of the present study was to develop and validate an assay for identifying compounds that increase envelope permeability, thereby conferring antimicrobial susceptibility by weakening of the cell envelope barrier in Gram-negative bacteria. A high-throughput whole-cell screening platform was developed to measureEscherichia colienvelope permeability to a β-galactosidase chromogenic substrate. The signal produced by cytoplasmic β-galactosidase-dependent cleavage of the chromogenic substrate was used to determine the degree of envelope permeabilization. The assay was optimized by using known envelope-permeabilizing compounds andE. coligene deletion mutants with impaired envelope integrity. As a proof of concept, a compound library comprising 36 peptides and 45 peptidomimetics was screened, leading to identification of two peptides that substantially increased envelope permeability. Compound 79 reduced significantly (from 8- to 125-fold) the MICs of erythromycin, fusidic acid, novobiocin and rifampin and displayed synergy (fractional inhibitory concentration index, <0.2) with these antibiotics by checkerboard assays in two genetically distinctE. colistrains, including the high-risk multidrug-resistant, CTX-M-15-producing sequence type 131 clone. Notably, in the presence of 0.25 μM of this peptide, both strains were susceptible to rifampin according to the resistance breakpoints (R> 0.5 μg/ml) for Gram-positive bacterial pathogens. The high-throughput screening platform developed in this study can be applied to accelerate the discovery of antimicrobial helper drug candidates and targets that enhance the delivery of existing antibiotics by impairing envelope integrity in Gram-negative bacteria.

High-Throughput Screening Platform in Postnatal Heart Cells and Chemical Probe Toolbox to Assess Cardiomyocyte Proliferation

2021 ◽  
Author(s):  
Carmen Carrillo García ◽  
Cora Becker ◽  
Michael Forster ◽  
Stefan Lohmann ◽  
Patricia Freitag ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Heart Cells ◽  
Cardiomyocyte Proliferation ◽  
Chemical Probe ◽  
Screening Platform

scholarly journals Pseudomonas aeruginosa and Staphylococcus aureus virulence factors as biomarkers of infection

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Artur J. Sabat ◽  
Daniele Pantano ◽  
Viktoria Akkerboom ◽  
Erik Bathoorn ◽  
Alexander W. Friedrich
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Clinical Status ◽  
Clinical Samples ◽  
Pathogenic Microorganisms ◽  
Bacterial Identification ◽  
Accurate Identification ◽  
Culture Independent ◽  
And Staphylococcus Aureus

Abstract The gold standard for the diagnosis of bacterial infections in clinical samples is based on culture tests that are time-consuming and labor-intense. For these reasons, an extraordinary effort has been made to identify biomarkers as the tools for sensitive, rapid and accurate identification of pathogenic microorganisms. Moreover, biomarkers have been tested to distinguish colonization from infection, monitor disease progression, determine the clinical status of patients or predict clinical outcomes. This mini-review describes Pseudomonas aeruginosa and Staphylococcus aureus biomarkers, which contribute to pathogenesis and have been used in culture-independent bacterial identification directly from patient samples.

scholarly journals Identification of Thyroid Hormone Receptor Active Compounds Using a Quantitative High-Throughput Screening Platform

2014 ◽  
Vol 8 (1) ◽  
pp. 36-46 ◽  
Author(s):  
Jaime Freitas ◽  
Nicole Miller ◽  
Brenda J. Mengeling ◽  
Menghang Xia ◽  
Ruili Huang ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
High Throughput ◽  
Hormone Receptor ◽  
High Throughput Screening ◽  
Thyroid Hormone Receptor ◽  
Active Compounds ◽  
Screening Platform

scholarly journals A Staphylococcus aureus clpX Mutant Used as a Unique Screening Tool to Identify Cell Wall Synthesis Inhibitors that Reverse β-Lactam Resistance in MRSA

2021 ◽  
Vol 8 ◽  
Author(s):  
Kristoffer T. Bæk ◽  
Camilla Jensen ◽  
Maya A. Farha ◽  
Tobias K. Nielsen ◽  
Ervin Paknejadi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
High Throughput Screening ◽  
Bacterial Infections ◽  
Screening Tool ◽  
Acquired Resistance ◽  
Teichoic Acid ◽  
Acid Synthesis ◽  
Biologically Active ◽  
Cell Wall Synthesis

Staphylococcus aureus is a leading cause of bacterial infections world-wide. Staphylococcal infections are preferentially treated with β-lactam antibiotics, however, methicillin-resistant S. aureus (MRSA) strains have acquired resistance to this superior class of antibiotics. We have developed a growth-based, high-throughput screening approach that directly identifies cell wall synthesis inhibitors capable of reversing β-lactam resistance in MRSA. The screen is based on the finding that S. aureus mutants lacking the ClpX chaperone grow very poorly at 30°C unless specific steps in teichoic acid synthesis or penicillin binding protein (PBP) activity are inhibited. This property allowed us to exploit the S. aureus clpX mutant as a unique screening tool to rapidly identify biologically active compounds that target cell wall synthesis. We tested a library of ∼50,000 small chemical compounds and searched for compounds that inhibited growth of the wild type while stimulating growth of the clpX mutant. Fifty-eight compounds met these screening criteria, and preliminary tests of 10 compounds identified seven compounds that reverse β-lactam resistance of MRSA as expected for inhibitors of teichoic acid synthesis. The hit compounds are therefore promising candidates for further development as novel combination agents to restore β-lactam efficacy against MRSA.

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