Biofilm development in Pseudomonas aeruginosa is regulated by its quorum sensing (QS) systems. It has three major QS systems: LasI/R, RhlI/R and PQS/MvfR. Previous studies showed that phenyllactic acid (PLA) binds to RhlR and PqsR and inhibits the Rhl and PQS QS; and eugenol at sublethal concentration inhibits Las and PQS QS systems. Here, we have demonstrated that a combination of sublethal doses of eugenol and PLA enhanced the inhibition of the QS mediated production of the virulence factors and biofilm development of this pathogen. A combination of 50 μmol l eugenol and 0·3 mmol l PLA significantly inhibited the pyocyanin production, protease activity, swarming motility and cytotoxic activities of P. aeruginosa strain PAO1, whereas eugenol and PLA when added individually to PAO1 cultures were less effective in inhibiting its virulence factor expression. Biofilm formation of PAO1 was reduced by 32, 19 and 87% on glass surfaces; and 54, 49 and 93% on catheter surfaces when treated using 50 μmol l eugenol or 0·3 mmol l PLA and their combinations, respectively. The in vitro finding in the reduction of biofilm development was further validated in vivo using a catheter associated medaka fish biofilm model. Our results indicate that a combination of QS inhibitors targeting different QS pathways should be selected while designing therapeutic molecules to achieve maximum QS mediated biofilm inhibition and clinical outcome against P. aeruginosa.
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http://dx.doi.org/10.1111/lam.13803 | DOI Listing |
BMC Microbiol
January 2025
Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
Carbapenem resistant Acinetobacter baumannii has evolved as the most troublesome microorganism with multiple virulence factors. Biofilm formation, porins, micronutrient capturing mechanism and quorum sensing, provide protection against desiccation, host-pathogen killing and enhance its persistence. The conservation of these factors between colonizing and pathogenic carbapenem resistant A.
View Article and Find Full Text PDFWater Res
December 2024
Department of Civil and Environmental Engineering, Institute of Science Tokyo, 2-12-1, Meguro- Ku, Tokyo, 152-8552, Japan. Electronic address:
Intimately coupled photocatalytic biodegradation (ICPB) has been recently developed as an efficient wastewater treatment technique, particularly for removing persistent organic pollutants. However, photocatalyst/biofilm interaction in terms of photoelectron transfer and its effect on the overall performance of ICPB has not been explored. To investigate these points, interface-engineered composites of bismuth vanadate and reduced graphene oxide with low degree (BiVO/rGO-LC) and high degree of their contact (BiVO/rGO-HC) were fabricated and applied for ICPB.
View Article and Find Full Text PDFJ Indian Soc Pedod Prev Dent
October 2024
Department of Pedodontics and Preventive Dentistry, Sardar Patel Post Graduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India.
J Wound Care
January 2025
Jobst Vascular Institute, ProMedica Health Network, Wound Care Program, Toledo, Ohio, US.
Objective: The presence of microorganisms in a wound may lead to the development of pathologically extensive inflammation, and either delay or prevent the healing of hard-to-heal (chronic) wounds. The aim of this case series is to explore the use of topical gentamicin ointment, an aminoglycoside with activity against aerobic Gram-negative bacteria, as an option to address hard-to-heal wounds.
Method: We present a retrospective case series of patients with hard-to-heal wounds of varying pathophysiologies treated with topical gentamicin.
Expert Opin Drug Deliv
January 2025
Drug Transport and Delivery Research Group, Department of Pharmacy, Faculty of Health Sciences, University of Tromsø The Arctic University of Norway, Tromsø, Norway.
Introduction: Liposomal hydrogels are novel drug delivery systems that comprise preformed liposomes incorporated in hydrogels destined for mostly localized drug therapy, herewith antimicrobial therapy. The formulation benefits from versatility of liposomes as lipid-based nanocarriers that enable delivery of various antimicrobials of different lipophilicities, and secondary vehicle, hydrogel, that assures better retention time of formulation at the infection site. Especially in an era of alarming antimicrobial resistance, efficient localized antimicrobial therapy that avoids systemic exposure of antimicrobial and related side effects is crucial.
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