Bile Salts Modulate Expression of the CmeABC Multidrug Efflux Pump inCampylobacter jejuni

• DOI: 10.1128/jb.187.21.7417-7424.2005
• Publication Date: 2005-10-19T18:57:54Z
• Authors: Jun Lin; Cédric Cagliero; Baoqing Guo; Yi-Wen Barton; Marie-Christine M...; Sophie Payot; Qijing Zhang
• Keywords: Efflux

ABSTRACT CmeABC, a multidrug efflux pump, is involved in the resistance of Campylobacter jejuni to broad spectrum antimicrobial agents and essential for colonization animal intestine by mediating bile resistance. Previously, we have shown that expression this pump under control transcriptional repressor named CmeR. Inactivation CmeR or mutation cmeABC promoter (P ) region derepresses , leading overexpression pump. However, it unknown if can be conditionally induced substrates extrudes. In study, examined presence various compounds. Although majority antimicrobials tested did not affect salts drastically elevated operon. The induction was observed with both conjugated unconjugated dose- time-dependent manner. Experiments using surface plasmon resonance demonstrated inhibited binding P suggesting compounds are inducing ligands interaction between likely triggers conformational changes CmeR, resulting reduced affinity . Bile transcription cmeR indicating altered factor bile-induced addition CmeR-dependent induction, some (e.g., taurocholate) also activated CmeR-independent pathway. Consistent production culture media resulted increased multiple antimicrobials. These findings reveal new mechanism modulates further support notion natural function CmeABC.