Table 1.
Bacterial strains and plasmids used in this study.
| Strains and plasmids | Characteristics or functiona | Source or reference |
|---|---|---|
| SS2 STRAINS | ||
| SS2-1 | Serotype 2, clinical isolated virulent strain, MRP+EF+SLY+ | Our laboratory |
| Δrex | The Rex-deficient mutant with a background of SS2-1, Cm R | This study |
| CΔrex | Complemented strain of Δrex ,Spc R, CmR | This study |
| E. coli | ||
| DH5α | Cloning host for recombinant plasmid | Vazyme |
| BL21(DE3) | Host for overexpressed recombinant Rex protein | Vazyme |
| PLASMIDS | ||
| pMD18 T | Clone vector | Takara |
| pET28a | Expression vector; Kan R | Novagen |
| pET28a-Rex | pET-28a containing Rex, cloned from SS2-1 genome | This study |
| pSET4s | Temperature-sensitive E. coli-S. suis shuttle vector ,SpcR | Takamatsu et al., 2001b |
| pSET4sΔRex | Derived from pSET4s for deleting Rex in SS2-1 | This study |
| pSET2 | E. coli- S. suis shuttle vector; SpcR | Takamatsu et al., 2001a |
| pSET2-Rex | pSET2 containing the intact Rex and promoter; SpcR | This study |
a
MRP, Muramidase released protein; EF, Extracellular factor; SLY, Suilysin; CmR, chloramphenicol resistance; SpcR, spectinomycin resistant; KanR, kanamycin resistant.