Table 1.

Strains and plasmids used in this study

Strain or plasmid	Relevant characteristics	Source or reference
C. difficile strains
630Δerm	Wild-type strain	Obtained from Peter Mullany [29]
630-911 (mfd mutant)	630Δerm mfd::ermB	This study
630 tcdA tcdB	630Δerm tcdA::catP tcdB::erm	Obtained from Nigel Minton; [43]
Plasmids
pMTL960	Plasmid vector for complementation studies	Obtained from Nigel Minton; [38]
pSEW070	pMLT960 carrying wild type mfd gene under control of Pcwp2	This study