Table 1.

Bacterial strains and plasmids used in this study

Strain or plasmidDescriptionaSource or reference
P. aeruginosa strains
 PAO1Prototroph
 OCR1MexAB-OprM-overproducing nalBmutant 13
 KG2225 mexA::Ω of PAO1Unpublished datab
 KG2239ΔmexR-mexA-mexB-oprM of PAO1 6
 N101ΔmexXY of PAO1This study
 N102ΔmexXY of KG2225This study
 N103ΔmexXY of KG2239, ΔmexRAB-oprM of PAO1This study
 N126ΔmexAB of OCR1Submittedc
 N128ΔmexXY of a MexXY-overproducing mutant of N126 called N127This study
 N135MexXY-overproducing mutant of PAO1This study
 N136ΔmexXY of N135This study
Plasmids
 pMT5059pBend2 derivative carrying the multiple-cloning site and NotI site; Cbr 27
 pMT5071pMOB3 derivative carrying Ω-Cm instead of Cm; Cmr 28
 pNS001pMT5059 with 1.2-kb PCR fragment with 3′ flanking region of mexY inSpeI-HindIII; Cbr This study
 pNS002pNS001 with 1.0-kb PCR fragment with 5′ flanking region of mexX in MluI-NheI; Cbr This study
 pNS003pNS002 with Mob cassette in NotI; Cbr Cmr This study
 pAK1900 E. coli-P. aeruginosa shuttle cloning vector; Cbr 22
 pKMM128pAK1900 derivative carrying the partialmexR, XbaI linker, and oprM gene on a 4.3-kb fragment; Cbr 7
  • a Abbreviations: Cbr, carbenicillin resistant; Cmr, chloramphenicol resistant.

  • b K. Okamoto, N. Gotoh, H. Tsujimoto, and T. Nishino.

  • c Masuda et al.