Effect of Bile on the Cell Surface Permeability Barrier and Efflux System of Vibrio cholerae
IR@IICB: CSIR-Indian Institute of Chemical Biology, KolkataView Archive Info
Effect of Bile on the Cell Surface Permeability Barrier and Efflux
System of Vibrio cholerae
Infectious Diseases and Immunology
Gram-negative bacteria are inherently impermeable to hydrophobic compounds, due to the synergistic
activity of the permeability barrier imposed by the outer membrane and energy dependent efflux systems. The
gram-negative, enteric pathogen Vibrio cholerae appears to be deficient in both these activities; the outer
membrane is not an effective barrier to hydrophobic permeants, presumably due to the presence of exposed
phospholipids on the outer leaflet of the outer membrane, and efflux systems are at best only partially active.
When V. cholerae was grown in the presence of bile, entry of hydrophobic compounds into the cells was
significantly reduced. No difference was detected in the extent of exposed phospholipids on the outer leaflet of
the outer membrane between cells grown in the presence or absence of bile. However, in the presence of energy
uncouplers, uptake of hydrophobic probes was comparable between cells grown in the presence or absence of
bile, indicating that energy-dependent efflux processes may be involved in restricting the entry of hydrophobic
permeants into bile grown cells. Indeed, an efflux system(s) is essential for survival of V. cholerae in the
presence of bile. Expression of acrAB, encoding an RND family efflux pump, was significantly increased in V.
cholerae cells grown in vitro in the presence of bile and also in cells grown in rabbit intestine.
American Society for Microbiology
Chatterjee, Arpita and Chaudhuri, Sohini and Saha, Gargi and Gupta, Satadeepa and Chowdhury, Rukhsana (2004) Effect of Bile on the Cell Surface Permeability Barrier and Efflux System of Vibrio cholerae. Journal of Bacteriology, 186 (20). pp. 6809-6814.