Table 1.

Bacterial strains and plasmids used in this study

Strain or plasmidGenotype or propertiesReference
S. maltophilia
    KJWild type, a clinical isolate from Taiwan9
    KJΔL1ΔL2S. maltophilia KJ double mutant of L1 and L2 genes; ΔL1 ΔL2This study
    KJΔ5S. maltophilia KJ smeU1-V-W-U2-X mutant; ΔsmeU1 ΔsmeV ΔsmeW ΔsmeU2 ΔsmeXThis study
    KJ09CS. maltophilia KJ spontaneous chloramphenicol-selected mutantThis study
    KJ09CΔL1ΔL2S. maltophilia KJ09C with double mutations of L1 and L2 genes; ΔL1 ΔL2This study
    KJ09CΔ5S. maltophilia KJ09C smeU1-V-W-U2-X mutant; ΔsmeU1 ΔsmeV ΔsmeW ΔsmeU2 ΔsmeXThis study
    KJ09CΔRvS. maltophilia KJ09C smeRv mutant; ΔsmeRvThis study
    KJ09CΔU1S. maltophilia KJ09C smeU1 mutant; ΔsmeU1This study
    KJ09CΔVWS. maltophilia KJ09C smeV-smeW mutant; ΔsmeV ΔsmeWThis study
    KJ09CΔU2S. maltophilia KJ09C smeU2 mutant; ΔsmeU2This study
    KJ09CΔXS. maltophilia KJ09C smeX mutant; ΔsmeXThis study
    KJ09CΔ5L2::U1S. maltophilia KJ09CΔ5 with L2 gene replaced with smeU1 gene; ΔL2::smeU1This study
    KJ09CΔ5L2::U2S. maltophilia KJ09CΔ5 with L2 gene replaced with smeU2 gene; ΔL2::smeU2This study
    KJ09CΔ5L2::XS. maltophilia KJ09CΔ5 with L2 gene replaced with smeX gene; ΔL2::smeXThis study
Escherichia coli
    DH5αF φ80dlacZΔM15 Δ(lacZYA-argF)U169 deoR recA1 endA1 hsdR17 (rk mk+) phoA supE44 λ thi-1 gyrA96 relA1Invitrogen
    S17-1λ pir-positive mating strain34
Plasmids
    pEX18TcsacB oriT Tcr8
    pRK415Mobilizable broad-host-range plasmid cloning vector, RK2 origin; Tcr12
    pX1918GTPlasmid containing xylE-gentamicin resistance cassette; Ampr Gmr33
    pU1pEX18Tc with a 1,341-bp DNA fragment of S. maltophilia KJ containing complete smeRv-smeU1 intergenic region and smeU1 gene; TcrThis study
    pU2pEX18Tc with a 1,074-bp DNA fragment of S. maltophilia KJ containing intact smeU2 gene; TcrThis study
    pXpEX18Tc with a 1,591-bp DNA fragment of S. maltophilia KJ containing intact smeX gene; TcrThis study
    pRvpEX18Tc with a 1,308-bp DNA fragment of S. maltophilia KJ containing partial smeRv gene and upstream 227-bp fragment; TcrThis study
    pΔU1pEX18Tc with an internal deletion smeU1 gene; TcrThis study
    pΔU2pEX18Tc with an internal deletion smeU2 gene; TcrThis study
    pΔXpEX18Tc with an internal deletion smeX gene; TcrThis study
    pΔRvpEX18Tc with an internal deletion smeRv gene; TcrThis study
    pΔVWpEX18Tc with a 2,426-bp DNA fragment of S. maltophilia KJ containing complete smeU1 gene, partial 3′ terminus of smeW gene, and smeU2 gene; TcrThis study
    pΔ5pEX18Tc with a 1,982-bp DNA fragment of S. maltophilia KJ containing partial 5′ terminus of smeU1 gene and partial 3′ terminus of smeX gene; TcrThis study
    p371RvxylEpRK415 with a 371-bp intergenic region of smeRv and smeU1 genes and a transcriptional fusioned xylE gene; smeRv::xylE fusion constructThis study
    p371U1xylEpRK415 with a 371-bp intergenic region of smeRv and smeU1 genes and a transcriptional fusioned-xylE gene; smeU1::xylE fusion constructThis study
    p272XxylEpRK415 with a 272-bp upstream of smeX gene and a transcriptional fusioned xylE gene; smeX::xylE fusion constructThis study
    pYWpEX18Tc with a 1,352-bp DNA fragment of S. maltophilia KJ containing 697 bp upstream of L2 gene and 655 bp downstream of L2 gene; ΔL2 TcrThis study
    pΔL2::U1pYW with an inserted intact smeU1 geneThis study
    pΔL2::U2pYW with an inserted intact smeU2 geneThis study
    pΔL2::XpYW with an inserted intact smeX geneThis study