TABLE 1.

Bacterial strains and plasmids used in this study

Strain or plasmidCharacteristic(s)Source or reference
S. enterica serovar Typhi strains
    ISP1820Wild typeR. Curtiss III (Arizona State University)
    DEF004ISP1820 ΔstgThis study
    DEF033ISP1820(pSIF018)This study
    DEF064ISP1820(pCR2.1)This study
    DEF066DEF004(pSIF026)This study
    DEF068ISP1820::PstgA-lacZ(::pSIF020)This study
S. enterica serovar Typhimurium strains
    χ3339Mouse-passaged isolate of SL1344 rpsL hisG 9
    DEF047χ3339(pSIF018)This study
    DEF048χ3339(pCR2.1)This study
E. coli strains
    DEF045ORN172(pCR2.1)This study
    DEF049ORN172(pSIF018)This study
    MGN-617SM10 λpir asd thi thr leu tonA lacY supE recA RP4 2-Tc::Mu[λpir] ΔasdA4 15
    ORN172 thr-l leuB thi-1 Δ(argF-lac)U169 xyl-7 ara-13 mtl-2 gal-6 rpsL tonA2 supE44 Δ(fimBEACDFGH)::kan pilG1 42
Plasmids
    pCR2.1High-copy-number cloning vector, Kmr AprInvitrogen
    pFUSE lacZYA mob + (RP4), R6K ori (suicide vector), Cmr 2
    pMEG-375 sacRB mobRP4 oriR6K, Cmr AprMegan Health (St. Louis, MO)
    pSIF004Suicide vector with flanking region of stgA in 5′ end and stgD in 3′ end used for stg deletionThis study
    pSIF016pCR2.1 carrying a 530-bp fragment of stgAThis study
    pSIF018pCR2.1 carrying a 5-kb fragment of stg (pCR2.1stg)This study
    pSIF020pFUSE carrying a 530-bp fragment of stgA, CmrThis study
    pSIF026pWSK29 carrying a 5-kb fragment of stg (pWSKstg)This study
    pWSK29Low-copy-number cloning vector, Ampr 41