Transcriptional regulation of the efflux pump operon: importance for antimicrobial resistance.

This review focuses on the mechanisms of transcriptional control of an important multidrug efflux pump system (MtrCDE) possessed by , the aetiological agent of the sexually transmitted infection termed gonorrhoea. The operon that encodes this tripartite protein efflux pump is subject to both - and -acting transcriptional factors that negatively or positively influence expression. Critically, levels of MtrCDE can influence levels of gonococcal susceptibility to classical antibiotics, host-derived antimicrobials and various biocides. The regulatory systems that control can have profound influences on the capacity of gonococci to resist current and past antibiotic therapy regimens as well as virulence. The emergence, mechanisms of action and clinical significance of the transcriptional regulatory systems that impact expression in gonococci are reviewed here with the aim of linking bacterial antimicrobial resistance with multidrug efflux capability.