TABLE 1.
Bacterial strains and plasmids used in this study
| Bacterial strain or plasmid | Relevant property(ies) | Reference or source |
|---|---|---|
| S. typhi | ||
| BRD681 | S. typhi Ty2 ΔaroA | 4 |
| BRD691 | S. typhi Ty2 ΔaroAaroC | 4 |
| BRD1116 | BRD691 ΔhtrA | This work |
| E. coli | ||
| HB101 | F′ pro leu thi hsdSB20 recA endA rpsL20 (Strr) | 31 |
| DH5α | endA hsdR17 supE44 thi-1 recA1ϕ80dlacZ ΔM15 | Gibco-BRL |
| SM10λpir | λpir lysogen | 26 |
| Plasmids | ||
| pUC18 | Cloning vehicle | Boehringer Mannheim |
| pTYH1 | pUC18 plus 3.2-kb HindIII fragment of S. typhi htrA | This work |
| pΔTYAH4 | pTYH1 cut with EcoRV and religated | This work |
| pTYHTR | pTYH1 containing 659-bp deletion in htrA | This work |
| pGP704 | Suicide replicon; Apr | 26 |
| pTYHTG1 | pGP704 containing htrA gene with 659-bp deletion | This work |