Fermented sausage-derived Latilactobacillus sakei postbiotic inhibits biofilm formation and quorum sensing-related virulence in clinical antibiotic-resistant Pseudomonas aeruginosa.

A single-center in vitro study was performed using 50 clinically-derived Pseudomonas aeruginosa isolates to evaluate the antimicrobial, antibiofilm, and modulation of quorum sensing (QS)-related phenotypes of a fermented sausage-originated Latilactobacillus sakei postbiotic. A total of 50 antibiotic-resistant clinical P. aeruginosa isolates were evaluated. Thirty isolates (60%) were identified as strong biofilm producers. Biofilm formation was inhibited in all strong biofilm-producing isolates following treatment with the MIC/2 concentration of the L. sakei postbiotic. Application of the postbiotic at the MIC/2 concentration reduced biofilm formation and attenuated QS-regulated virulence traits, including pyocyanin production, exoprotease activity, swimming motility, and rhamnolipid production, in strong biofilm-forming isolates. These findings indicate that L. sakei-derived postbiotic may serve as a promising in vitro anti-virulence candidate against antibiotic-resistant P. aeruginosa by reducing biofilm formation and quorum sensing-related phenotypes. Nevertheless, further chemical, molecular, safety, and in vivo studies are needed to confirm its potential applications.