TY - JOUR
T1 - Gene cloning and characteristics of the RND-type multidrug efflux pump MuxABC-OpmB possessing two RND components in Pseudomonas aeruginosa
AU - Mima, Takehiko
AU - Kohira, Naoki
AU - Li, Yang
AU - Sekiya, Hiroshi
AU - Ogawa, Wakano
AU - Kuroda, Teruo
AU - Tsuchiya, Tomofusa
PY - 2009
Y1 - 2009
N2 - muxA-muxB-muxC-opmB (formerly PA2528-PA2527-PA2526-opmB), encoding a putative resistance nodulation cell division (RND)-type multidrug efflux pump system, was cloned from Pseudomonas aeruginosa PAO1. Introduction of muxABC-opmB into P. aeruginosa YM64, a drug-hypersusceptible strain, led to elevated MICs of aztreonam, macrolides, novobiocin and tetracycline. Since muxB and muxC, both of which encode RND components, were essential for function, MuxABC-OpmB is thought to be a drug efflux pump with four components. One novobiocin-resistant mutant, PMX725, isolated from P. aeruginosa PMX7 showed elevated resistance not only to novobiocin but also to aztreonam, macrolides and tetracycline. Increased mRNA expression of muxABC-opmB was observed in the mutant PMX725 compared with the parental strain. Sequencing analysis revealed that a single-nucleotide insertion had occurred in the deduced promoter region for muxABC-opmB in PMX725. In this study, we have characterized the last RND-type multidrug efflux pump predicted from the genome sequence in P. aeruginosa.
AB - muxA-muxB-muxC-opmB (formerly PA2528-PA2527-PA2526-opmB), encoding a putative resistance nodulation cell division (RND)-type multidrug efflux pump system, was cloned from Pseudomonas aeruginosa PAO1. Introduction of muxABC-opmB into P. aeruginosa YM64, a drug-hypersusceptible strain, led to elevated MICs of aztreonam, macrolides, novobiocin and tetracycline. Since muxB and muxC, both of which encode RND components, were essential for function, MuxABC-OpmB is thought to be a drug efflux pump with four components. One novobiocin-resistant mutant, PMX725, isolated from P. aeruginosa PMX7 showed elevated resistance not only to novobiocin but also to aztreonam, macrolides and tetracycline. Increased mRNA expression of muxABC-opmB was observed in the mutant PMX725 compared with the parental strain. Sequencing analysis revealed that a single-nucleotide insertion had occurred in the deduced promoter region for muxABC-opmB in PMX725. In this study, we have characterized the last RND-type multidrug efflux pump predicted from the genome sequence in P. aeruginosa.
UR - http://www.scopus.com/inward/record.url?scp=70450265183&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70450265183&partnerID=8YFLogxK
U2 - 10.1099/mic.0.031260-0
DO - 10.1099/mic.0.031260-0
M3 - Article
C2 - 19713238
AN - SCOPUS:70450265183
VL - 155
SP - 3509
EP - 3517
JO - Microbiology
JF - Microbiology
SN - 1350-0872
IS - 11
ER -