AUTHOR=Li Hongdong , Li Xingyuan , Song Chao , Zhang Yunhui , Wang Zhengli , Liu Zhenqiu , Wei Hong , Yu Jialin 

TITLE=Autoinducer-2 Facilitates Pseudomonas aeruginosa PAO1 Pathogenicity in Vitro and in Vivo

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.01944

DOI=10.3389/fmicb.2017.01944

ISSN=1664-302X

ABSTRACT=<p>Bacterial communication systems, such as quorum sensing (QS), have provided new insights of alternative approaches in antimicrobial treatment. We recently reported that one QS signal, named as autoinducer-2 (AI-2), can affect the behaviors of <italic>Pseudomonas aeruginosa</italic> PAO1 in a dose-dependent manner. In this study, we aimed to investigate the effects of AI-2 on <italic>P. aeruginosa</italic> PAO1 biofilm formation and virulence factors production <italic>in vitro</italic>, and <italic>in vivo</italic> using a pulmonary infection mouse model. Exogenous AI-2 resulted in increased biofilms architecture, the number of viable cells, and the yield of pyocyanin and elastase virulence factors in wild type <italic>P. aeruginosa</italic> PAO1. However, no such effect was observed in <italic>P. aeruginosa lasR rhlR</italic> mutant strain. <italic>In vivo</italic>, the use of AI-2 significantly increased the mortality, lung bacterial count and histological lung damage of mice with acute <italic>P. aeruginosa</italic> PAO1 infection. Our data suggest that AI-2 promotes the formation of <italic>P. aeruginosa</italic> PAO1 biofilms and the production of virulence factors by interfering with <italic>P. aeruginosa</italic> QS systems, resulting in decreased host survival. AI-2 may be a therapeutic target for the clinical treatment of a co-infection of <italic>P. aeruginosa</italic> and AI-2 producing bacteria.</p>