Identification and antimicrobial susceptibility testing of MRSA using miniaturized fluidic wells laser-patterned on transparent substrate

Existing bacterial detection methods unfortunately are limited in their inability to detect and identify pathogens that typically occur at low concentrations. Miniaturized microfluidic devices (or lab-on-a-chip systems) which use small volumes of liquid samples and reagents, are inexpensive to fabricate, easy to use and do not require expensive ancillary instrumentation, if included in point-of-care testing pathways within under-resourced settings, can provide timely guidance towards infectious disease management and thus a unique opportunity to combat the global crisis of antibiotic resistance. This work reports the identification and antibiotic susceptibility testing of methicillin-resistant Staphylococcus aureus (MRSA) using well-like structures (with ~mm2 dimensions) designed to miniaturise and mimic the bacteriological testing routinely performed using agar petri-plates. With optimally identified parameters for use with the laser direct-write patterned wells we report the detection of MRSA (ATCC 43300) spiked in fish samples with a limit-of-detection of 1000 CFU/ml and Minimum Inhibitory Concentration of 32μg/ml of Oxacillin.