Rajesh Ramanathan and Pabudi Weerathunge examine color changes during a laboratory test used to identify golden staph strains. Credit: Will Wright, RMIT University
Researchers have developed a rapid color-changing test that can distinguish between different strains of golden staph, including those likely to be virulent and antibiotic resistant. Golden staph is a major human pathogen and is a leading cause of infection-related deaths globally, with more than 1 million fatalities each year.
The new test uses tiny gold particles that behave like artificial enzymes combined with short DNA molecular binders to create color “fingerprints” unique to each strain. These fingerprints can help separate high-risk strains from others and inform next steps of care. The fingerprint test can also indicate whether a strain carries markers associated with increased virulence, and whether it is likely to have antibiotic resistance.
In a study published in Small, the team tested their new sensor in simulated wound fluid spiked with different golden staph strains. The sensor produced comparable strain fingerprints in simulated wound fluid and showed stronger and faster responses in some cases.
“Speed matters when you’re dealing with serious bacterial infections, and today’s gold-standard tests take time, specialist infrastructure or both,” said Rajesh Ramanathan, professor in RMIT’s School of Science. “The rapid test gives clinicians an early, evidence-informed ‘heads-up’ if an infection may be more aggressive or harder to treat.”
The research team says their new platform could complement culture- and PCR-based tests. The test could also be modified to spot different dangerous strains of other pathogens. It was deliberately built to capture subtle biological differences without needing prior knowledge of the bacteria’s surface.
“Instead of hunting for one perfect target, we use a small panel of molecular binders that attach to different parts of the bacterial surface,” said Pabudi Weerathunge, RMIT professor who worked on the project. “This is a practical pathway toward point-of-care style screening across clinical settings.”
Data from RMIT University