The purpose of this investigation was to study the modulator and efflux pump inhibitor activity of coumarins isolated from Mesua ferrea against clinical strains as well as NorA-over expressed strain of Staphylococcus aureus 1199B. Seven coumarins were tested for modulator activity using ethidium bromide (EtBr) as a substrate. Compounds 1, 4-7 modulated the MIC of EtBr by ≥ 2 fold against wild type clinical strains of S. aureus 1199 and S. aureus 1199B, whereas compounds 4-7 modulated the MIC of EtBr by ≥ 16 fold against MRSA 831. Compounds 1, 4-7 also reduced the MIC of norfloxacin by ≥ 8 fold against S. aureus 1199B, and 4-6 reduced the MIC of norfloxacin by ≥ 8 fold against MRSA 831 at half of their MICs. Inhibition of EtBr efflux by NorA-overproducing S. aureus 1199B and MRSA 831 confirmed the role of compounds 4-6 as NorA efflux pump inhibitors (EPI). Dose-dependent activity at sub-inhibitory concentration (6.25 μg/mL) suggested that compounds 4 and 5 are promising EPI compared to verapamil against 1199B and MRSA 831 strains.
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http://dx.doi.org/10.1016/j.fitote.2013.07.015 | DOI Listing |
BMC Microbiol
December 2024
Department of Physics, College of Science, University of Halabja, Halabja, Kurdistan Region, Iraq.
Background: Antimicrobial resistance (AMR) presents a serious threat to health, highlighting the urgent need for more effective antimicrobial agents with innovative mechanisms of action. Nanotechnology offers promising solutions by enabling the creation of nanoparticles (NPs) with antibacterial properties. This study aimed to explore the antibacterial, anti-biofilm, and anti-virulence effects of eco-friendly synthesized α-Fe₂O₃ nanoparticles (α-Fe₂O₃-NPs) against pathogenic bacteria.
View Article and Find Full Text PDFBiochimie
December 2024
Department of Biological Chemistry, Universidade Regional Do Cariri, Crato, CE, Brazil. Electronic address:
Thiadiazines are heterocyclic compounds known for some pharmacological activities. However, the ability of these compounds and their derivatives to act as antibacterial agents and inhibitors of the efflux system in resistant bacteria remains unknown. This study aims to evaluate the antibacterial and NorA efflux pump inhibitory activities of thiadiazine-derived compounds (IJ14, IJ15, IJ16, IJ17, IJ18, IJ19, and IJ20) against the Staphylococcus aureus 1199B strain.
View Article and Find Full Text PDFPharmaceutics
November 2024
Laboratory of Pharmacology and Molecular Chemistry (LFQM), Department of Biological Chemistry, Regional University of Cariri, Rua Coronel Antônio Luis 1161, Pimenta, Crato 63105-000, CE, Brazil.
The work investigates the effect of the estragole complex encapsulated in beta-cyclodextrin (ES/β-CD) in modulating bacterial resistance, specifically in strains expressing NorA and MepA efflux pumps. Efflux pumps are mechanisms that bacteria use to resist antibiotics by expelling them from the cell. Methodology: Several compounds and antibiotics, such as ciprofloxacin and norfloxacin, were used to evaluate the antimicrobial activity and the ability of the ES/β-CD complex to reverse resistance.
View Article and Find Full Text PDFBiomed Pharmacother
November 2024
Department of Biological Chemistry, Regional University of Cariri (URCA), Crato, CE 63105-010, Brazil. Electronic address:
This study aimed to evaluate the effects of liposome-encapsulated eugenol-based thiazolic derivatives against efflux pump-carrying bacteria. The Minimum Inhibitory Concentration (MIC) was determined to evaluate the antibacterial activity and antibiotic potentiation against Pseudomonas aeruginosa and Staphylococcus aureus, as well as to analyze the inhibition of efflux pumps in S. aureus strains 1199B and K2068 in the ethidium bromide assay.
View Article and Find Full Text PDFAntimicrobials fight microorganisms, preventing and treating infectious diseases. However, antimicrobial resistance (AMR) is a growing concern due to the inappropriate and excessive use of these drugs. Several mechanisms can lead to resistance, including efflux pumps such as the NorA pump in Staphylococcus aureus, which reduces the effectiveness of fluoroquinolones.
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