A GROUP-II INTRON IN A CONJUGATIVE TRANSPOSON FROM THE GRAM-POSITIVE BACTERIUM, CLOSTRIDIUM-DIFFICILE

We have been studying the conjugative transposon Tn5397, originally is olated from the Gram-positive pathogen Clostridium difficile. Physical analysis of this transposon demonstrated that it contained a group II intron. This is the first report of an intron in a conjugative transp oson and the first report of a group II intron in Gram-positive bacter ia. The intron interrupted a gene in Tn5397 that is almost identical t o orf14 from Tn916. DNA hybridisation analysis showed that elements re lated to Tn5397, containing the group II intron, were present in five other C. difficile strains from different geographical locations sugge sting that the element is likely to be widely distributed.