Both Quorum Sensing (Qs)-I and Ii Systems Regulate Escherichia coli Flagellin Expression
Both Quorum Sensing (Qs)-I and Ii Systems Regulate Escherichia coli Flagellin Expression
Yang Yang1,2, Yun Liu1, Mingxu Zhou1 and Guoqiang Zhu1,*
QS-1 and QS-II have differential impact on bacterial motility. A, motility diameters were quantified after 12 h growth on 0.3 % swim agar plates; B, AI-2 production, AI-2 activity was measured using a bioluminescence assay after growing the indicated bacterial strains to an OD600 of 1.3. AI-2 activity is expressed as relative light units measured; C, fliC expression. fliC expression was measured using qRT-PCR with data normalized to the endogenous reference gene gapA. Data are expressed relative to expression in the WT strain.
Host IL-8 and TNF expression in response to F18 E. coli infection. A-B, transcription of il8 and tnfa in Caco-2 cells after a 2 h infection with the indicated bacterial strains. Data were normalized to the housekeeping gene gapdh; C-D, ELISA, secretion of IL-8 and TNF into Caco-2 cell supernatants after a 2 h infection with the indicated bacterial strains was quantified using ELISAs.
AI-1 and flagella expression influence AI-2 expression. luxS and pfs expression were measured using qRT-PCR with data normalized to the endogenous reference gene gapA. Data are expressed relative to expression in the WT strain.
Coordinate regulation of flagella and QS expression. Transcription of the indicated genes was measured using qRT-PCR. Data are shown as expression in pyenI vs. WT.
