Placentrex disrupts the biofilm formation of Pseudomonas aeruginosa through multi-target transcriptional reprogramming.

Abstract

AimsPseudomonas aeruginosa biofilm-associated infections pose a significant clinical challenge due to their inherent antibiotic tolerance. This study aimed to evaluate the antibacterial and antibiofilm activity of Placentrex, a standardised aqueous placental extract, against P. aeruginosa and to elucidate its molecular mechanism of action using RNA sequencing (RNA-seq). Methods and ResultsPlacentrex exhibited potent bactericidal activity against P. aeruginosa at 50 {micro}g/mL. Biofilm formation was significantly inhibited by [~]87% at 50 {micro}g/mL after 72 hours. Preformed biofilms were eradicated by [~]93% and [~]89% at 50 and 25 {micro}g/mL, respectively. Interestingly, biofilm viability was reduced by [~]93% and [~]87% upon treatment with 50 {micro}g/mL and 25 {micro}g/mL of Placentrex, respectively. EPS characterisation revealed that the EPS contain a single large polysaccharide, and chromatography data suggested that it is made up of glucose as a monomer. RNA-seq identified coordinated downregulation of seven key genes, namely, flp major pilin (surface attachment), extracellular solute binding protein (ABC transporter-mediated nutrient sensing and biofilm maintenance), gntP permease (carbon metabolism), AraC family transcriptional regulator (quorum sensing and polysaccharide biosynthesis), ureE (urease nickel metallochaperone), aromatic amino acid permease (pyoverdine and PQS biosynthesis), and MFS transporter (efflux and autoinducer export). ConclusionsPlacentrex exerts comprehensive antibiofilm and antibacterial activity through simultaneous disruption of surface attachment, nutrient-sensing-driven biofilm maintenance, quorum sensing, carbon metabolism, urease virulence maturation, and efflux-mediated persistence. This polypharmacological mechanism supports Placentrex as a promising multi-target antibacterial agent against P. aeruginosa biofilm-associated infections. Impact statementPlacentrex is a potential anti-biofilm agent against Pseudomonas aeruginosa.