Table 1.

Strains and plasmids used in this study

Strain or plasmidDescriptionReference(s) or source
S. pneumoniae strains
    D39Avery strain, clinical isolate, capsular serotype 26, 26
    R6D39-derivative, unencapsulated laboratory strain26
    TIGR4Invasive clinical isolate, capsular serotype 449
    SPJV01D39/pMV158GFP TetrThis study
    EJ3D39-derivative luxS-null mutant, Specr21
    SPJV02EJ3/pPP2 Specr TetrThis study
    SPJV04EJ3/pJVPP9 Specr TetrThis study
    SPJV05D39-derivative luxS-null mutant, EryrThis study
    SPJV06SPJV05/pJVR6 Eryr SpecrThis study
    SPJV07SPJV05/pJVPP9 Eryr TetrThis study
    SPJV08SPJV05/pMV158GFP Eryr TetrThis study
E. coli strains
    TOP10Cloning hostInvitrogen
    ECJV10TOP10/pJVR6This study
    ECJV11TOP10/pJVPP9This study
Plasmids
    pCR2.1-TOPOCloning vectorInvitrogen
    pReg696Low-copy-number plasmid for Gram-positive bacteria14
    pPP2Integrative plasmid for S. pneumoniae strains15
    pJVPP9pPP2 containing the WT luxS gene from strain D39This study
    pJVR6pReg696 containing the WT luxS gene from strain D39This study
    pLux-ery-LuxpCR2.1-TOPO containing the luxS-ery-luxS cassetteThis study
    pMV158GFPS. pneumoniae mobilizable plasmid containing the green fluorescent protein gene36