TABLE 1.

Bacterial strains and plasmids used in this study

Strain or plasmidRelevant characteristicsaDerivation, source, or reference
Strains
    E. coli
        χ6212F λ φ80 Δ(lacZYA-argF) endA1 recA1 hsdR17 deoR thi-1 glnV44 gyrA96 relA1 ΔasdA436
        MGN-617thi-1 thr-1 leuB6 fhuA21 lacY1 glnV44 ΔasdA4 recA1 RP4 2-Tc::Mu [λpir]; Kmr44
    S. enterica serovar Typhimurium
        χ3339SL1344 hisG22
        χ4550SR-11 gyrA1816 Δcrp-1 ΔasdA1 Δ(zhf-4::Tn10) Δcya-147
        χ4746χ3339 nadA540::Tn10 Δ(galE-chl-uvrB)-1005; TetrLab collection
        χ8499hisG Δcrp-28χ3339
        χ8501hisG Δcrp-28 ΔasdA16χ8499
        χ8554hisG ΔasdA16χ3339
        χ8599hisG ΔasdA16 atrB13::MudJχ8554
        JF2430LT2 atrB13::MudJ15
    S. pneumoniae WU2Wild-type virulent, encapsulated type 36
Plasmids
    pYA3193Asd+ vector harboring 1.5-kb C-terminally truncated pspA gene; pUCori37
    pYA3333Asd+; pBRoriLab collection
    pYA3334Asd+; pUCoriLab collection
    pYA3341Asd+; pUCoriThis study
    pYA3342Asd+; pBRoriThis study
    pYA3493pYA3342 derivative β-lactamase signal sequence-based periplasmic secretion plasmidThis study
    pYA34940.7-kb DNA encoding the α-helical region of PspA in pYA3493This study
    pYA34960.7-kb DNA encoding the α-helical region of PspA in pYA3342 for the expression of His-tagged PspAThis study
    pBR322Cloning vector; Apr Tcr3
    pMEG-443Recombinant suicide plasmid to generate Salmonella ΔasdA16 mutant; Apr Cmr27
    pMEG-493Recombinant suicide plasmid to generate Salmonella Δcrp-28 mutant; Apr CmrMegan Health Inc.
  • a Apr, ampicillin resistance; Cmr, chloramphenicol resistance; Kmr, kanamycin resistance; Tcr, tetracycline resistance.