Surface association sensitizes Pseudomonas aeruginosa to quorum sensing.

TitleSurface association sensitizes Pseudomonas aeruginosa to quorum sensing.
Publication TypeJournal Article
Year of Publication2019
AuthorsChuang, SK, Vrla, GD, Fröhlich, KS, Gitai, Z
JournalNat Commun
Date Published2019 09 11
KeywordsBacterial Proteins, Fimbriae Proteins, Pseudomonas aeruginosa, Quorum Sensing, Surface Properties, Up-Regulation

<p>In the pathogen Pseudomonas aeruginosa, LasR is a quorum sensing (QS) master regulator that senses the concentration of secreted autoinducers as a proxy for bacterial cell density. Counterintuitively, previous studies showed that saturating amounts of the LasR ligand, 3OC12-HSL, fail to induce the full LasR regulon in low-density liquid cultures. Here we demonstrate that surface association, which is necessary for many of the same group behaviors as QS, promotes stronger QS responses. We show that lasR is upregulated upon surface association, and that surface-associated bacteria induce LasR targets more strongly in response to autoinducer than planktonic cultures. This increased sensitivity may be due to surface-dependent lasR induction initiating a positive feedback loop through the small RNA, Lrs1. The increased sensitivity of surface-associated cells to QS is affected by the type IV pilus (TFP) retraction motors and the minor pilins. The coupling of physical surface responses and chemical QS responses could enable these bacteria to trigger community behaviors more robustly when they are more beneficial.</p>

Alternate JournalNat Commun
PubMed ID31511506
PubMed Central IDPMC6739362
Grant ListDP1 AI124669 / AI / NIAID NIH HHS / United States