Quorum sensing (QS) is a chemical communication process that Pseudomonas aeruginosa uses to regulate virulence and biofilm formation. Disabling of QS is an emerging approach for combating its pathogenicity. Silver nanoparticles (AgNPs) have been widely applied as antimicrobial agents against human pathogenic bacteria and fungi, but not for the attenuation of bacterial QS. Here we mycofabricated AgNPs (mfAgNPs) using metabolites of soil fungus Rhizopus arrhizus BRS-07 and tested their effect on QS-regulated virulence and biofilm formation of P. aeruginosa. Transcriptional studies demonstrated that mfAgNPs reduced the levels of LasIR-RhlIR. Treatment of mfAgNPs inhibited biofilm formation, production of several virulence factors (e.g. LasA protease, LasB elastrase, pyocyanin, pyoverdin, pyochelin, rhamnolipid, and alginate) and reduced AHLs production. Further genes quantification analyses revealed that mfAgNPs significantly down-regulated QS-regulated genes, specifically those encoded to the secretion of virulence factors. The results clearly indicated the anti-virulence property of mfAgNPs by inhibiting P. aeruginosa QS signaling.
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http://dx.doi.org/10.1038/srep13719 | DOI Listing |
Front Pharmacol
January 2025
Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin, China.
Background: Lipids are vital biomolecules involved in the formation of various biofilms. Seizures can cause changes in lipid metabolism in the brain. In-depth studies at multiple levels are urgently needed to elucidate lipid composition, distribution, and metabolic pathways in the brain after seizure.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Basic Medical Sciences, Faculty of Medicine, Abadan University of Medical Sciences, Abadan, Iran.
Background: This study aimed to evaluate the biofilm formation abilities of clinical strains, assess their antibiotic susceptibility patterns, and identify the prevalence of adhesion-associated genes.
Methodology: In this study, a total of 60 strains were collected from urine, pus, wounds, blood, body fluid, and sputum in health centers affiliated with Abadan University of Medical Sciences, Iran. Strains were identified via microbiological methods and polymerase chain reaction (PCR) to target the gene.
Heliyon
January 2025
Department of Biological Sciences, Faculty of Science, Beirut Arab University, Tripoli, 1300, Lebanon.
The present study reports the characterization of the phytochemical content and the antibacterial activity of ethanolic extracts from the leaves (LE) and stems (SE) of against Methicillin resistant (MRSA. Important functional groups were determined by analyzing the FTIR spectra of LE and SE. The phytochemical profiles were analyzed by GC-MS, and these characterized the chemicals according to retention periods and peak regions.
View Article and Find Full Text PDFBiofilm
June 2025
DTU Bioengineering, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
Surfactin is a biosurfactant produced by many strains with a wide variety of functions from lowering surface tension to allowing motility of bacterial swarms, acting as a signaling molecule, and even exhibiting antimicrobial activities. However, the impact of surfactin during biofilm formation has been debated with variable findings between studies depending on the experimental conditions. B.
View Article and Find Full Text PDFiScience
January 2025
Department of Oral Biology, Dr. Gerald Niznick College of Dentistry, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0W2, Canada.
Bacterial interspecies interactions shape microbial communities and influence the progression of polymicrobial infections. FemI-FemR-FemA, a cell-surface signaling system, in , is involved in the uptake of iron-chelating mycobactin produced by spp. In this report, we present the data that indicates the -PA1909 operon is positively regulated by ExsA, a master regulator for the type three secretion system (T3SS), connecting the Fem system with T3SS.
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