Poster Presentation Lancefield International Symposium for Streptococci and Streptococcal Diseases 2025

Development of a prototype for rapid point-of-care diagnosis of antibiotic-resistant Group A streptococcal and staphylococcal skin infections (#202)

Kalindu Rodrigo 1 , Stephanie Enkel 1 , Hannah Thomas 1 , Gillian Woods 1 , Lisa Wiese 1 , Janessa L Pickering 1 , Asha C Bowen 1 2 , Jonathan R Carapetis 1 2 , Timothy C Barnett 1 3
  1. Wesfarmers Centre of Vaccines and Infectious Diseases, The Kids Research Institute Australia, University of Western Australia, Nedlands, WA, Australia
  2. Department of Infectious Diseases, Perth Children’s Hospital, Nedlands, Western Australia , Australia
  3. The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, Australia

Background

Antimicrobial resistance (AMR) is a global public health threat which is predicted to kill 10 million people by 20501. AMR burden is further aggravated by the limited availability of rapid diagnostic tools to diagnose antibiotic resistant infections at the point-of-care. This is especially true in resource limited Australian remote settings where the burden of infections caused by Group A Streptococcus (GAS) and Staphylococcus aureus is very high2. Here, we developed a molecular based rapid test to detect antibiotic resistant skin infections.

Methods

A rapid DNA extraction method for GAS and S. aureus was developed and optimised using a combination of bacteriophage lysins and bacteriocins. Recombinase Polymerase Amplification (RPA) assays were developed to detect bacterial species-specific genes and six associated AMR genes and point mutations.

Results

Rapid DNA extraction using combined lysin treatment at 30°C for 5 minutes yielded sufficient DNA for downstream RPA gene identification.  RPA assay detected all eight target genes and point mutations under 20 minutes with a limit of detection of 103 and 104 gene copies against GAS and S. aureus targets respectively.

Conclusions

Our prototype molecular test can diagnose antibiotic resistant skin infections within 30 minutes of sample collection. In vitro benchmarking of the prototype demonstrated high sensitivity and specificity against all the target genes. This test will serve as a model for development of rapid diagnostic tools for AMR infections in low-resource settings.

  1. Antimicrobial Resistance Collaborators. Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. Lancet 399, 629–655 (2022).
  2. Carapetis, J. R., Steer, A. C., Mulholland, E. K. & Weber, M. The global burden of group A streptococcal diseases. Lancet Infect Dis 5, 685–694 (2005).