Recombinant plasmid DNA variation of Clostridium oncolyticum--model experiments of cancerostatic gene transfer

The specific germinating capacity of spores of Clostridium oncolyticum in tumours in vivo, and various reports on concomitant partial oncolysis (tumour lysis) have prompted us to propose a concept of equipping C. oncolyticum with genes of other organisms producing cancerostatics. As an example we used Colicin E3, whose structural genes lies in the E. coli plasmid pCo1E3-CA38. After in vitro recombination of restrictase EcoRI-fragmented pCo1E3-CA38 DNA with an uncharacterized plasmid fraction from C. concolyticum a plasmid-free strain of C. oncolyticum was infected with recombinant DNA. A special microbiological selection system allows the identification of C. oncolyticum clones with Colicin E3-similar formation of cleared haloes.