TABLE 1.

Strains and plasmids used in this study

Strain or plasmidRelevant characteristic(s)Reference
Strains
    S. aureus
        15981Biofilm-positive clinical strain45
        ΔσB strain15981 ΔσB45
        ΔσB+ strain15981 ΔσB with a restored σB geneThis study
        icaC::Tn917 strain15981 icaC::Tn91745
    E. coli XL1-BlueUsed for cloning assays
Plasmids
    pBT2E. coli-S. aureus shuttle vector with a thermosensitive origin of replication for gram-positive bacteria5
    pMADE. coli-S. aureus shuttle vector with a thermosensitive origin of replication for gram-positive bacteria and the bgaB gene from Bacillus stearothermophilus encoding a thermostable β-galactosidase1
    pLA1Plasmid that carries the IS256 element containing the erythromycin cassette (IS256r)This study
    pLA1-ΔTnpPlasmid that carries the IS256r element with a site-specifically mutated transposaseThis study