In vitro e in silico evaluation of the inhibition of Staphylococcus aureus efflux pumps by caffeic and gallic acid

2018 ◽  
Vol 57 ◽  
pp. 22-28 ◽  
Author(s):  
Joycy F.S. dos Santos ◽  
Saulo R. Tintino ◽  
Thiago S. de Freitas ◽  
Fábia F. Campina ◽  
Irwin R. de A. Menezes ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gallic Acid ◽  
In Silico ◽  
Efflux Pumps

scholarly journals Antifungal Azoles as Tetracycline Resistance-Modifiers in Staphylococcus aureus

2021 ◽  
Author(s):  
Nisha Mahey ◽  
Rushikesh Tambat ◽  
Dipesh Kumar Verma ◽  
Nishtha Chandal ◽  
Krishan Gopal Thakur ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
In Silico ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Major Facilitator Superfamily ◽  
Efflux Pump Inhibitors ◽  
Approved Drugs ◽  
Major Facilitator

Staphylococcus aureus has developed resistance to antimicrobials since its first use. The S. aureus major facilitator superfamily (MFS) efflux pump Tet(K) contributes to resistance to tetracyclines. The efflux pump diminishes antibiotic accumulation, and biofilm hampers the diffusion of antibiotics. None of the currently known compounds have been approved as efflux pump inhibitors (EPIs) for clinical use. In the current study, we screened clinically approved drugs for possible Tet(K) efflux pump inhibition. In silico docking followed by in vitro checkerboard assays, we identified five azoles (the fungal ergosterol synthesis inhibitors) showing the putative EPI-like potential with a fractional inhibitory concentration index of ≤0.5, indicating synergism. The functionality of the azoles was confirmed using ethidium bromide (EtBr) accumulation and efflux inhibition assays. In time-kill kinetics, the combination treatment with butoconazole engendered a marked increase in the bactericidal capacity of tetracycline. When assessing the off-target effects of the azoles, we observed no disruption of bacterial membrane permeability and polarization. Finally, the combination of azoles with tetracycline led to a significant eradication of preformed mature biofilms. This study is the primary representation of azoles that can be repurposed as putative Tet(K) EPIs and to reduce biofilm formation at clinically relevant concentrations. IMPORTANCE Staphylococcus aureus use efflux pumps to transport antibiotics out of the cell and thus increase the dosage at which they endure antibiotics. Also, efflux pumps play a role in biofilm formation by the excretion of extracellular matrix molecules. One way to combat these pathogens may be to reduce the activity of efflux pumps and thereby increase pathogen sensitivity to existing antibiotics. We describe the in silico-based screen of clinically approved drugs that identified antifungal azoles inhibiting Tet(K); a pump belongs to the Major Facilitator Superfamily and shows that these compounds bind to and block the activity of the Tet(K) pump. Azoles enhanced the susceptibility of tetracycline against S. aureus and its methicillin-resistant strains. The combination of azoles with tetracycline led to a significant reduction in preformed biofilms. Repurposing of approved drugs may help solve the classical toxicity issues related to efflux pump inhibitors.

In vitro and in silico studies of chalcones derived from natural acetophenone inhibitors of NorA and MepA multidrug efflux pumps in Staphylococcus aureus

2021 ◽  
pp. 105286
Author(s):  
Thiago S. Freitas ◽  
Jayze C. Xavier ◽  
Raimundo L.S. Pereira ◽  
Janaína E. Rocha ◽  
Fábia F. Campina ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
In Silico ◽  
Efflux Pumps ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pumps ◽  
In Silico Studies

In silico and in vitro evaluation of efflux pumps inhibition of α,β-amyrin

2021 ◽  
pp. 1-15
Author(s):  
Raissa C. Oliveira ◽  
Paulo N. Bandeira ◽  
Telma L. G. Lemos ◽  
Hélcio S. dos Santos ◽  
Jackelyne R. Scherf ◽  
...  
Keyword(s):  
In Silico ◽  
Efflux Pumps ◽  
In Vitro Evaluation

In Vitro and In Silico Inhibition of Staphylococcus aureus Efflux Pump NorA by α-Pinene and Limonene

2021 ◽  
Author(s):  
Ana Carolina Justino de Araújo ◽  
Priscilla Ramos Freitas ◽  
Cristina Rodrigues dos Santos Barbosa ◽  
Débora Feitosa Muniz ◽  
Ray Silva de Almeida ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
In Silico ◽  
Efflux Pump

scholarly journals IN VITRO AND IN SILICO ANTIBACTERIAL ACTIVITY OF 1.5-BIS (3’-ETHOXY-4’-HYDROXYPHENYL)-1-4-PENTADIENE-3-ONE

2018 ◽  
Vol 10 (5) ◽  
pp. 70
Author(s):  
Agus Purwanggana ◽  
Esti Mumpuni ◽  
Esti Mulatsari
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Staphylococcus Epidermidis ◽  
In Silico ◽  
Inhibitory Concentration ◽  
Inhibition Zone ◽  
Antibacterial Study

Objective: The main objective of this research were screened in vitro and in silico of 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one as potential antibacterial agents.Methods: The in vitro antibacterial study was carried against Staphylococcus aureus, Staphylococcus epidermidis (gram positive) and Escherichia coli, Salmonella thypi (gram negative) using broth dilution method to determine Minimum Inhibitory Concentration (MIC), disc diffusion method to determine the diameter of inhibition zone. In silico antibacterial study was carried using computational software Protein-Ligand ANT System (PLANTS), computational docking was carried using receptor with Protein Data Bank (PDB) file 3MZD. The structures were optimized prior docking using YASARA, and MarvinSketch. The results of antibacterial testing were compared to two positive control drugs i. e amoxicillin and cefadroxil.Results: In vitro evaluation showed that 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one has a better antibacterial activity than amoxicillin and cefadroxil with a Minimum Inhibitory Concentration (MIC) of 0.15 ppm and diameter of inhibition zone of 11.27±0.31, 11.35±0.39, 11.25±0.33, and 11.05±0.45 mm in Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Salmonella thypi, respectively. These results in line with in silico evaluation that showed 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one has more negative docking score than amoxicillin, cefadroxil, and cloxacillin acyl as a native ligand on the 3MZD receptor.Conclusion: This results obtained in this research work were 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one compound potential as an antibacterial agent. 

scholarly journals In vitro and in silico anti-dengue activity of compounds obtained from Psidium guajava through bioprospecting

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Andrea Isabel Trujillo-Correa ◽  
Diana Carolina Quintero-Gil ◽  
Fredyc Diaz-Castillo ◽  
Winston Quiñones ◽  
Sara M. Robledo ◽  
...  
Keyword(s):  
Gallic Acid ◽  
Treatment Strategy ◽  
In Silico ◽  
Antiviral Effect ◽  
Psidium Guajava ◽  
Caribbean Coast ◽  
Ethanolic Extracts ◽  
Pharmacological Potential ◽  
Experimental Strategies

Abstract Background For decades, bioprospecting has proven to be useful for the identification of compounds with pharmacological potential. Considering the great diversity of Colombian plants and the serious worldwide public health problem of dengue—a disease caused by the dengue virus (DENV)—in the present study, we evaluated the anti-DENV effects of 12 ethanolic extracts derived from plants collected in the Colombian Caribbean coast, and 5 fractions and 5 compounds derived from Psidium guajava. Methods The cytotoxicity and antiviral effect of 12 ethanolic extracts derived from plants collected in the Colombian Caribbean coast was evaluated in epithelial VERO cells. Five fractions were obtained by open column chromatography from the ethanolic extract with the highest selectivity index (SI) (derived from P. guajava, SI: 128.2). From the fraction with the highest selectivity (Pg-YP-I-22C, SI: 35.5), five compounds were identified by one- and two-dimensional nuclear magnetic resonance spectroscopy. The antiviral effect in vitro of the fractions and compounds was evaluated by different experimental strategies (Pre- and post-treatment) using non-toxic concentrations calculated by MTT method. The DENV inhibition was evaluated by plate focus assay. The results were analyzed by means of statistical analysis using Student’s t-test. Finally the antiviral effect in Silico was evaluated by molecular docking. Results In vitro evaluation of these compounds showed that three of them (gallic acid, quercetin, and catechin) were promising antivirals as they inhibit the production of infectious viral particles via different experimental strategies, with the best antiviral being catechin (100% inhibition with a pre-treatment strategy and 91.8% with a post-treatment strategy). When testing the interactions of these compounds with the viral envelope protein in silico by docking, only naringin and hesperidin had better scores than the theoretical threshold of − 7.0 kcal/mol (− 8.0 kcal/mol and − 8.2 kcal/mol, respectively). All ligands tested except gallic acid showed higher affinity to the NS5 protein than the theoretical threshold. Conclusion Even though bioprospecting has recently been replaced by more targeted tools for identifying compounds with pharmacological potential, our results show it is still useful for this purpose. Additionally, combining in vitro and in silico evaluations allowed us to identify promising antivirals as well as their possible mechanisms of action.

scholarly journals NorB, an Efflux Pump in Staphylococcus aureus Strain MW2, Contributes to Bacterial Fitness in Abscesses

2008 ◽  
Vol 190 (21) ◽  
pp. 7123-7129 ◽  
Author(s):  
Yanpeng Ding ◽  
Yoshikuni Onodera ◽  
Jean C. Lee ◽  
David C. Hooper
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Single Copy ◽  
Aureus Strain ◽  
Bacterial Survival ◽  
Bacterial Fitness

ABSTRACT While remaining a major problem in hospitals, Staphylococcus aureus is now spreading in communities. Strain MW2 (USA400 lineage) and other community methicillin-resistant S. aureus strains most commonly cause skin infections with abscess formation. Multidrug resistance (MDR) efflux pumps contribute to antimicrobial resistance but may also contribute to bacterial survival by removal of environmental toxins. In S. aureus, NorA, NorB, NorC, and Tet38 are chromosomally encoded efflux pumps whose overexpression can confer MDR to quinolones and other compounds (Nor pumps) or tetracyclines alone (Tet38), but the natural substrates of these pumps are not known. To determine the role of these efflux pumps in a natural environment in the absence of antibiotics, we used strain MW2 in a mouse subcutaneous abscess model and compared pump gene expression as determined by reverse transcription-PCR in the abscesses and in vitro. norB and tet38 were selectively upregulated in vivo more than 171- and 24-fold, respectively, whereas norA and norC were downregulated. These changes were associated with an increase in expression of mgrA, which encodes a transcriptional regulator known to affect pump gene expression. In competition experiments using equal inocula of a norB or tet38 mutant and parent strain MW2, each mutant exhibited growth defects of about two- to threefold in vivo. In complementation experiments, a single-copy insertion of norB (but not a single-copy insertion of tet38) in the attB site within geh restored the growth fitness of the norB mutant in vivo. Our findings indicate that some MDR pumps, like NorB, can facilitate bacterial survival when they are overexpressed in a staphylococcal abscess and may contribute to the relative resistance of abscesses to antimicrobial therapy, thus linking bacterial fitness and resistance in vivo.

scholarly journals Diseño, síntesis, caracterización y evaluación in vitro de la actividad de los péptidos antimicrobianos contra bacterias patógenas resistentes a antibióticos

2019 ◽  
Vol 43 (169) ◽  
pp. 614-627
Author(s):  
Claudia Ortiz López
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
In Silico ◽  
Escherichia Coli O157

Los péptidos antimicrobianos han atraído mucha atención como nuevos agentes terapéuticos contra enfermedades infecciosas. En este estudio se hizo el diseño racional in silico de 18 péptidos catiónicos con actividad antimicrobiana contra bacterias patógenas resistentes utilizando el programa DEPRAMP desarrollado en el Grupo de Investigación en Bioquímica y Microbiología de la Universidad Industrial de Santander. Posteriormente, los péptidos diseñados se sintetizaron en fase sólida con el método de 9-fluorenilmetoxicarbonilo en medio ácido. Se obtuvieron secuencias cortas de 17 aminoácidos con un grado de pureza entre 95 y 98 %, estructura secundaria de hélice alfa, carga neta catiónica (entre +3 y +6), punto isoeléctrico entre 10,04 y 12,03 e índice de hidropatía entre -0,62 y 1,14. Todos los péptidos antimicrobianos mostraron actividad antibacteriana y bactericida in vitro frente al menos una de las cepas patógenas estudiadas: Escherichia coli O157: H7, Pseudomonas aeruginosa y Staphylococcus aureus resistente a la meticilina. Los péptidos antimicrobianos GIBIM-P5S9K y GIBIM-P5F8W registraron la mejor actividad antibacteriana, alcanzando una concentración mínima inhibitoria (CMI 99) en rangos de 0,5 a 25 μM frente a las tres cepas evaluadas, de las cuales Escherichia coli O157: H7 fue la más sensible frente al péptido antimicrobiano GIBIMP5F8W, con una CMI 99 de 0,5 μM y una concentración mínima bactericida de 10 μM, en tanto que la cepa de Pseudomonas aeruginosa fue la más resistente, con una CMI de más de 100 μM frente a más de cinco péptidos antimicrobianos. La toxicidad de los péptidos sobre los eritrocitos produjo un porcentaje de hemólisis menor al 40 % en concentraciones de 50 μM. Por su parte, en las líneas celulares de carcinoma de pulmón A549 y HepG2, el único compuesto que presentó toxicidad fue GIBIM-P5F8W, presentando un 36% de células viables en concentraciones de 100 μM del péptido en la línea celular A549.

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