Table 1

Strains and plasmids used in this study

Strain or plasmidCharacteristicsSource
Strains
    E. coli CA434Conjugation donor26
    C. difficile
        Wild-type 630Virulent and multidrug-resistant PCR ribotype 012, isolated from a patient with pseudomembranous colitis in Zurich, Switzerland (1985)29
        630Erythromycin-sensitive derivative of wild-type C. difficile 63016
        R20291Hypervirulent and epidemic PCR ribotype 027, isolated from a hospital outbreak in Stoke Mandeville, UK (2004–2005)33
        630Δspo0AC. difficile 630ΔermB spo0A::ermBThis study
        R20291Δspo0AC. difficile R20291 spo0A::ermBThis study
        630Δspo0A+pspo0AComplemented 630Δspo0A mutantThis study
        R20291Δspo0A+pspo0AComplemented R20291Δspo0A mutantThis study
Plasmids
    pMTL007First-generation ClosTron plasmid with catP marker and intron containing ermB RAM; intron expression is induced using IPTG.14
    pMTL007C-E2Second-generation ClosTron plasmid with catP marker and intron containing ermB RAM; contains a constitutive fdx promoter to direct intron expression13
    pRPF101E. coli-C. difficile shuttle vectorThis study
    pspo0ApRPF101 containing the 825-bp spo0A coding region (and upstream promoter)This study