A chromosomally integrated copy of the IncP plasmid RP4 was shown to mediate the conjugative transfer of shuttle plasmids containing an oriT site from Escherichia coli to the anaerobic pathogen Clostridium perfringens. Two versatile shuttle plasmids, pJIR1456 and pJIR1457, which will be invaluable for the introduction of cloned genes into C. perfringens, were constructed.