Antimicrobial resistance is a growing global threat, making
once-treatable infections increasingly difficult to cure. Among the most
concerning resistant pathogens is methicillin-resistant Staphylococcus
aureus (MRSA), a bacterium responsible for severe hospital- and
community-acquired infections, including sepsis. Rapid and reliable
identification of MRSA is essential to guide treatment and limit the spread of
resistance, but current diagnostic tools remain slow or difficult to deploy
outside specialized laboratories.
Standard antibiotic susceptibility testing can take several
days, during which patients are often treated with broad-spectrum antibiotics.
This practice increases the risk of treatment failure and accelerates the
emergence of new resistant strains. Molecular methods such as PCR are faster,
but they require expensive equipment, trained personnel, and can be disrupted
by complex samples like blood, food, or environmental materials.
To address these limitations, researchers have developed a
microfluidic DNA detection platform that directly targets the mecA gene, a genetic signature responsible for methicillin resistance in Staphylococcus
aureus.
The new system combines Padlock Probe-based Rolling Circle
Amplification, an isothermal DNA amplification method, with a microfluidic
biosensor and fluorescent readout. Unlike PCR, this technique operates at a
constant temperature, simplifying the process and reducing energy and equipment
requirements.
All detection steps occur within a single microfluidic
device, enabling a streamlined workflow that delivers results in approximately
two hours. The platform demonstrated 100 % specificity compared to PCR and
successfully detected MRSA in clinical samples from sepsis patients, as well as
in complex matrices such as milk, serum, and salad wash water.
This technology opens the door to faster, more accessible
detection of antibiotic resistance, with potential applications in clinical
diagnostics, food safety, and environmental monitoring. Its microfluidic design
supports automation and miniaturization, making it a strong candidate for
future point-of-care or decentralized testing.
Beyond MRSA, the platform can be adapted to detect
additional resistance genes, offering a flexible tool to support surveillance
and early intervention in the fight against antimicrobial resistance.
Microfluidic Padlock Probe-based Rolling Circle Amplification for sensitive detection of mecA resistance gene in Staphylococcus aureus
Authors: Leo Baldenweck, Catarina Caneira, Jasmina Vidic
Full publication here
