TABLE 1

Summary of bile resistance mechanisms in enteric pathogens

PathogenFunction of outer membrane proteins (reference[s])Mechanism of induction of stress response genes (reference[s])Efflux pump(s) (reference[s])Additional resistance mechanism(s) (reference[s])
Escherichia coli Repression of ompF (23) sulA to correct DNA damage (35)AcrAB (23, 38)MqsR/MqsA toxin/antitoxin system (34); basRS two-component system (23)
Shigella To be determined
Vibrio Regulated expression of ompU and ompT (76)RpoS in V. vulnificus (102)AcrAB (77, 78), BreAB (79, 80), VexAB (81, 101), VprAB (82), Vme pumps (99, 100)Induction of transcriptional regulator LeuO (75) and biofilm formation (84)
Salmonella Repression of OmpF and OmpC (3); utilization of TolA and TolC (3, 125)SoxRS (132) and OxyR (133)AcrAB (119 121); AcrEF, MdtABC, MdsCBA, EmrAB, MdtK, and MacAB (118)Alterations of LPS, including remodeling of lipid A (3), elongation of O-chains through fepE (129), and Vi antigen production (130)
Campylobacter CmeABC and CmeDEF (154, 155)Utilization of the two-component regulator CbrR (159)
Clostridium To be determined; spores are naturally resistant (169)
Listeria Induced stress response genes encoding DNA repair proteins, protein folding chaperones, and oxidative stress response proteins (176)MdrT (177)BrtA transcriptional regulator (177); bile salt hydrolase enzyme (178); biofilm formation genes induced (35)