Cloning of tetracycline-resistance genes from various strains of Clostridium perfringens and expression in Escherichia coli

Abstract

One hundred strains of Clostridium perfringens and 52 strains of other Clostridia of human and animal origins were screened for tetracycline resistance. Fifty-six strains were resistant to tetracycline in the C. perfringens group. Ten strains were selected for their high level of resistance. In all of them, the tetracycline-resistance genes were found to be residing in large plasmids of about 50 kb, all showing homologies. Several tetracycline-resistance genes from plasmids of various strains of C. perfringens were cloned in plasmid pUC19 and the resistance was expressed in Escherichia coli. Hybridization analysis showed these genes to be homologous among themselves and also to tetP gene from the PCW3-type plasmid. Key words: tetracycline resistance, Clostridium perfringens, gene cloning, recombinant plasmids.