Transferable tetracycline resistance in Clostridium perfringens strains of porcine origin.

These studies represent the first systematic survey of the incidence of conjugative antibiotic resistance in Clostridium perfringens. Ninety-two antibiotic-resistant porcine strains were examined to see if they could donate their antibiotic-resistance determinants to sensitive recipient strains. Fifteen of the 89 tetracycline-resistant strains transferred their tetracycline resistance in mixed-plate mating experiments but no transfer of macrolide-lincosamide resistance was detected. The efficiencies of transfer of tetracycline resistance varied from 1.3 X 10(-3) to 1.9 X 10(-6) transconjugants per donor cell. Significantly higher transfer efficiencies were observed when both the donor and recipient strains were derivatives of strain CW 362. These values ranged from 3.7 X 10(-1) to 4.6 X 10(-2) transconjugants per donor cell. This high frequency transfer system should prove invaluable for further genetic studies on this microorganism.