TABLE 1.
Bacterial strains and plasmids used in this study
| Strain or plasmid | Relevant genotype or characteristic | Source or reference |
|---|---|---|
| Strains | ||
| PAO1 | Wild type; produces MexAB-OprM | 51 |
| PAO238 | PAO1 derivative with Δ(mexAB-oprM) nfxB Δ(mexCD-oprJ)a | 5 |
| PAO238-1 | Spontaneous Trir derivative of PAO238 | This study |
| PAO298 | PAO238-1 with mexJ::Tn<TET-1> | This study |
| PAO314 | PAO238-1 with ΔmexJKL::FRT | This study |
| PAO315 | PAO314 with chromosomal mexJ′-′lacZ transcriptional fusion integrated at attB | This study |
| PAO318 | PAO238 with ΔmexL::FRT | This study |
| PAO325 | PAO314 with Δ(mexXY::FRT) | This study |
| PAO327 | PAO238-1 with Δ(mexXY::FRT) | This study |
| Plasmids | ||
| pADD948 | Cbr; broad-host-range in vivo cloning vector | 6 |
| pAK1900 | Cbr; broad-host-range cloning vector | 35 |
| pBluescript SK(−) | Apr; cloning vector | Stratagene, La Jolla, Calif. |
| pBSP II SK(−) | Apr; broad-host-range cloning vector | 45 |
| pUC18 | Apr; cloning vector | 54 |
| pPS856 | Cbr Gmr; source of FRT-Gmr cassette | 17 |
| pKMM128 | Cbr; pAK1900 expressing oprM from Placb | 25 |
| pTZ110 | Cbr; broad-host-range lacZ fusion vector | 44 |
| pUCP20T | Cbr; broad-host-range cloning vector | 46 |
| pVLT35 | Smr Spr; broad-host-range expression vector | 7 |
| pJ22 | Cbr; pADD948 carrying the triclosan resistance determinant from PAO238-1 on an ∼32-kb chromosomal DNA fragment | This study |
| pJ22::Tn<TET-1> | Cbr Tcr; pJ22 with mexJ::Tn<TET-1> | This study |
| pJZ110 | Cbr; pTZ110 with 655-bp BamHI-XhoI fragment from pPS1176 containing the mexJK operon regulatory region | This study |
| pPS1150 | Cbr; pBSP II SK(−) carrying the mexL-mexJK genes on a 6,945-bp NotI fragment from pJ22 | This study |
| pPS1151 | Cbr Tcr; pBSP II SK(−) with a NotI fragment from pJ22::Tn<TET-1> carrying mexJ::Tn<TET-1> | This study |
| pPS1152 | Apr Tcr; pBluescript SK(−) with a NotI fragment from pJ22::Tn<TET-1> carrying mexJ::Tn<TET-1> | This study |
| pPS1153 | Cbr; pUCP20T with 816-bp mexL fragment | This study |
| pPS1162 | Cbr; pAK1900 expressing oprN from Plac | This study |
| pPS1163 | Cbr; pAK1900 expressing oprJ from Plac | This study |
| pPS1168 | Cbr; pUC18 with a 2, 145-bp BglII-HindIII fragment from pPS1150 carrying the 5′ end of mexL, all of mexJ, and the 5′ end of mexK in pUC18 | This study |
| pPS1169 | Cbr; pPS1168 with 1,414-bp NcoI-XhoI deletion removing the 5′ end of mexL, all of mexJ and the 5′ end of mexK replaced with FRT-Gmr fragment from pPS856 | This study |
| pPS1175 | Cbr; pBluescript SK(−) with 1,342-bp EcoRI-ClaI fragment from pPS1150 carrying all of mexL and the 5′ end of mexJ | This study |
| pPS1176 | Cbr; deletion of a 725-bp XhoI fragment internal to mexL from pPS1175 | This study |
| pPS1177 | Gmr; mini-CTX3-lacZ with 643-bp Xhol-PstI fragment from pPS1176 containing the mexJK regulatory region | This study |
| pPS1180 | Smr Spr; pVLT35 expressing oprM from Ptacc | This study |
| pPS1234 | Cbr; pUCP20T with 1,231-bp KpnI-PstI PCR fragment expressing mexJ from Plac | This study |
| pPS1235 | Smr Spr; pVLT35 with 3,759-bp EcoRI-SalI fragment from pPS1150 expressing mexK from Ptac | This study |
a
This strain and its derivatives contain a 1.58-Mb chromosomal inversion between the mexAB-oprM and mexCD-oprJ operons (2). This inversion has no effect on efflux pump function or any other phenotype since there is no net loss or gain of genetic information.
b
Plac, E. coli lac operon promoter.
c
Ptac, E. coli lac operon and trp operon hybrid promoter.