Strains and plasmids used in this study

Strain or plasmidDescriptionReference, source, or product no.
    E. coli DH5αChemically competent cloning strainNew England Biolabs item no. C2987H
    B. subtilis 168Legacy strain derived from B. subtilis Marburg39
    GBS CNCTC 10/84Serotype V, sequence type 2640
    GBS A909Serotype Ia, sequence type 741
    GBS AR1598Serotype V, sequence type 26 10/84 mutant with barcoded premature stop codon in cylE geneThis study
    pDC123Shuttle vector with the chloramphenicol acetyltransferase gene used as PCR template42
    pHY304Broad-host-range, temperature-sensitive mutagenesis plasmid; pWV01 derivative; erythromycin resistant12
    pMBsacBpHY304 with p23-sacB cassette cloned into AvaII site, for sucrose-counterselectable GBS mutagenesisThis study
    pORI23Shuttle vector with oriColE1 and Lactococcus-derived Gram-positive origin of replication; erythromycin resistant; p23 promoter adjacent to BamHI restriction site43
    pSacB23pORI23 with sacB cloned into BamHI site for expression off p23 promoterThis study