Salmonella Efflux Pumps
Stephanie Baugh and Laura J. V. Piddock
from: Microbial Efflux Pumps: Current Research (Edited by: Edward W. Yu, Qijing Zhang and Melissa H. Brown). Caister Academic Press, U.K. (2013)
Abstract
Salmonella has around 350 efflux pumps which are important in the physiology of the bacterial cell. Nine of these pumps are known to confer low-level antibiotic resistance to three or more unrelated classes of drugs and so are known as multidrug resistant (MDR) efflux pumps. Salmonella possesses at least one MDR efflux pump from four of the five MDR transporter families; RND family, MATE family, MF superfamily and ABC superfamily. The MDR efflux system of most clinical importance, AcrAB-TolC, can export a wide variety of substrates. Antibiotic susceptibility testing of mutants in which specific genes have been inactivated reveals some overlapping substrate specificity of MDR efflux pumps. The efflux systems are under tight and well-ordered control from a variety of local and global regulatory genes, typically transcriptional activators such as RamA, although the precise nature of control is still to be elucidated. As well as being important in resistance of Salmonella to many antibiotics, dyes and detergents, MDR efflux pumps are also involved in virulence and biofilm formation revealing that they are fundamental to the biology of this important pathogen. Furthermore, these data suggest that AcrAB-TolC, or regulation thereof, could be targets for new inhibitors read more ...
