Paeoniflorin reduce luxS/AI-2 system-controlled biofilm formation and virulence in Streptococcus suis

• Published in: Virulence Vol. 12; no. 1; pp. 3062 - 3073
• Main Authors: Li, Jinpeng, Fan, Qingying, Jin, Manyu, Mao, Chenlong, Zhang, Hui, Zhang, Xiaoling, Sun, Liyun, Grenier, Daniel, Yi, Li, Hou, Xiaogai, Wang, Yang
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 31.12.2021; Taylor & Francis Group
• Subjects: Animals; Bacterial Proteins - genetics; Bacterial Proteins - pharmacology; biofilm; Biofilms; Carbon-Sulfur Lyases - genetics; Carbon-Sulfur Lyases - pharmacology; Glucosides; Homoserine; Lactones - pharmacology; LuxsS/Ai-2 system; Mice; Molecular Docking Simulation; Monoterpenes - pharmacology; Paeoniflorin; Quorum Sensing; Research Paper; Streptococcus suis; Swine; Virulence; virulence factor; LuxsS/Ai-2 system; Paeoniflorin; virulence factor; Streptococcus suis; biofilm
• ISSN: 2150-5594; 2150-5608; 2150-5608
• DOI: 10.1080/21505594.2021.2010398

Streptococcus suis (S. suis), more specifically serotype 2, is a bacterial pathogen that threatens the lives of pigs and humans. Like many other pathogens, S. suis exhibits quorum sensing (QS) system-controlled virulence factors, such as biofilm formation that complicates treatment. Therefore, impairing the QS involving LuxS/AI-2 cycle in S. suis, may be a promising alternative strategy for overcoming S. suis infections. In this study, we investigated paeoniflorin (PF), a monoterpenoid glycoside compound extracted from peony, as an inhibitor of S. suis LuxS/AI-2 system. At a sub-minimal inhibitory concentration (MIC) (1/16 MIC; 25 μg/ml), PF significantly reduced biofilm formation by S. suis through inhibition of extracellular polysaccharide (EPS) production, without affecting bacterial growth. Moreover, evidence was brought that PF reduces AI-2 activity in S. suis biofilm. Molecular docking indicated that LuxS may be the target of PF. Monitoring LuxS enzymatic activity confirmed that PF had a partial inhibitory effect. Finally, we showed that the use of PF in a mouse model can relieve S. suis infections. This study highlighted the anti-biofilm potential of PF against S. suis, and brought evidence that it may as an inhibitor of the LuxS/AI-2 system to prevent S. suis biofilm-related infections. PF can thus be used as a new type of natural biofilm inhibitor for clinical application.