TABLE 1.
Characteristics of the bacterial strains and plasmids used in this study
| Strain or plasmid | Description | Source or reference |
|---|---|---|
| Strains | ||
| S. agalactiae | ||
| GD201008-001 serotype Ia strain | Virulent strain isolated from tilapia with meningoencephalitis in China | Collected in our laboratory |
| GD201008-001 ΔhylB mutant | hylB gene deletion mutant of GD201008-001 | This study |
| ΔhylB complemented strain | GD201008-001 ΔhylB complemented with vector pSET2::hylB; Spcr | This study |
| E. coli DH5α | Production of recombinant plasmids | Invitrogen |
| Plasmids | ||
| pSET4S | Thermosensitive suicide vector for gene replacement in Streptococcus replication of pG+host3 and pUC19; lacZ′ Spcr | 28 |
| pSET2 | E. coli-Streptococcus shuttle vector; Spcr | 29 |
| pSET4S::hylB | Recombinant vector with pSET4S background, designed for knockout of hylB; Spcr | This study |
| pSET2::hylB | Complementation vector with pSET2 background, containing promoter followed by full-length hylB ORF | This study |