Poster Presentation 12th Australian Peptide Conference 2017

Enhancing vancomycin potency via complexation with silver ions (#206)

Zyta M Ziora 1 , Yifang Zhao 1 , Shaoyang Zhang 1 , Yuxue Cao 2 , Wanida Phetsang 1 , Hans Laroo 3 , James Cameron 4 , Alan White 4 , Christian Fercher 5 , Michael Whitehouse 4 , Ross T Barnard 5 , David Fairlie 1 , Laurence J Walsh 2 , Helen He 2 , Rink-Jan Lohman 1 , Mark A T Blaskovich 1 , Matthew A Cooper 1
  1. Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
  2. School of Dentistry, The University of Queensland, Herston Rd, QLD, Australia
  3. Security Research Pty Ltd, One Mile, QLD, Australia
  4. Instrumental Chemistry Laboratory, Griffith University, Nathan Campus, QLD, Australia
  5. School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia

The leading causes of the recent rise in bacterial resistance to antibiotics are the over-prescription of antibiotics and poor patient compliance during antibiotic treatment regimens. There are very few novel antibiotics in the clinical pipeline, thus there is a growing demand for the development of alternative approaches to tackle the increasing incidence of infections with MDR bacteria.

The possibility of modifying existing commercially available drugs to overcome MDR is a favourable approach, saving time and money compared to the design and development of completely new drugs. As one possible solution, we propose building antibiotic complexes using silver ions to enhance antimicrobial effectiveness against MDR bacteria.

 

In this study, vancomycin was complexed with various forms of silver ions. Isothermal titration calorimetry was used to determine the interactions between Ag(I) and the antibiotic. The complex was also tested in vitro for its antimicrobial activity against biofilms and ex vivo on excised rat skin biopsies, in order to determine the potential for topical application in wound healing treatments for complicated skin infections.

 

Preliminary results suggest that silver ions enhance the effectiveness of various existing antibiotics, particularly vancomycin, against bacteria, both in vitro and ex vivo. We now aim to utilise the same silver complexes in an in vivo model of wound healing to assess efficacy and safety.