Oral Presentation ANZBA Annual Scientific Meeting 2025

Evaluating the antimicrobial effects of selenium nanoparticles on commercial bacterial strains and clinical bacterial strains isolated from burn wound infections. (23062)

Bravien Arrudsivah 1 2 , Tao Huang 3 , Sophia Rizzo 4 , Alexandra Boyling 1 2 , Xin Li 3 , Genevieve Mckew 2 , Zhe Li 1 2 4 , Joanneke Maitz 1 2 5 , Brooke Farrugia 3 , Daniel E Heath 3 , Neil O'Brien-Simpson 6 , Andrea J O'Connor 3 7 , Peter Maitz 2 5
  1. Burns and Reconstructive Surgery Research Group, ANZAC Research Institute, Sydney Local Health District, NSW, Australia
  2. Faculty of Medicine and Health, Univeristy of Sydney, Sydney, NSW, Australia
  3. Department of Biomedical Engineering, Graeme Clark Institute, The University of Melbourne, Parkville, VIC, Australia
  4. Department of Microbiology and Infectious Disease, Concord Hospital, Concord, NSW, Australia
  5. Burns Unit, Concord Repatriation General Hospital, Concord, NSW, Sydney
  6. ACTV Research Group, Melbourne Dental School and The Bio21 Institute of Molecular Science and Biotechnology, The Univeristy of Melbourne, Parkville, VIC, Australia
  7. Aikenhead Centre of Medical Discovery (ACMD),, St. Vincent's Hospital Melbourne, Fitzroy, Victoria, Australia

Introduction

Wound infections contribute to up to 75% of morbidity in patients with severe burns (Church et al., 2006). Due to poor vascularity in burn tissue, topical antibiotics are preferred, with silver-based agents being the conventional first-line treatment. However, the emergence of clinically significant silver resistance among bacterial strains has raised concerns about its long-term efficacy (Norton and Finley, 2021). Recent in vitro studies suggest that selenium nanoparticles can exhibit broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria (Huang et al., 2020). This study aimed to evaluate the antimicrobial effects of novel selenium nanoparticles against commercial and clinically isolated bacterial strains from burn wound infections.

 

 

Methods

Selenium nanoparticles with different surface chemistries (SeNP1 and SeNP2) were synthesised by the Department of Biomedical Engineering at the University of Melbourne. Antimicrobial testing was performed against clinical bacterial strains isolated from the burn wounds of patients at the Burns Department, Concord Repatriation Hospital, Sydney. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined using standard broth microdilution methods.

 

 

Results

Two selenium nanoparticle formulations were tested against clinical isolates of Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa (including multidrug-resistant strains), Staphylococcus lugdunensis, Enterobacter cloacae complex, and Streptococcus agalactiae. Both nanoparticles exhibited inhibitory and bactericidal activity, with SeNP1 consistently demonstrating lower MIC and MBC values. When compared to the results collected by Huang et al. (2020), the MICs were comparable between laboratory and clinical strains of S. aureus and P. aeruginosa, however the MBCs were higher for the clinical isolates.

 

Conclusion

Our findings suggest that selenium nanoparticles have potential as alternative topical antimicrobials to silver for managing burn wound infections. However, further in vitro and in vivo studies are needed to thoroughly evaluate their cytotoxicity and safety before clinical application.