Transfer of antibiotic resistance by transformation with eDNA within oral biofilms


  • Editor: John Costerton

  • Present addresses: Saad Hannan, Department of Neuroscience, Physiology, and Pharmacology, University College London, London, WC1E 6BT, UK.
    Michelle Rogers, 4.28 Royal School of Mines, Department of Bioengineering, Imperial College London, South Kensington, London, SW7 2AZ, UK.

Correspondence: Adam P. Roberts, Department of Microbial Diseases, UCL Eastman Dental Institute, University College London, 256 Gray's Inn Road, London, WC1X 8LD, UK. Tel.: +44 207 915 1044; fax: +44 207 915 1127; e-mail:


We demonstrate that live donor Veillonella dispar cells can transfer the conjugative transposon Tn916 to four different Streptococcus spp. recipients in a multispecies oral consortium growing as a biofilm in a constant depth film fermentor. Additionally, we demonstrate that purified V. dispar DNA can transform Streptococcus mitis to tetracycline resistance in this experimental system. These data show that transfer of conjugative transposon-encoded antibiotic resistance can occur by transformation in addition to conjugation in biofilms.