Ladder-shaped microfluidic system for rapid antibiotic susceptibility testing

Abstract Rapid identification of antibiotic-resistant bacteria will play a key role in solving the global antibiotic crisis by providing a route to targeted antibiotic administration. However, current bacterial infection diagnoses take up to 3 days which can lead to antibiotic treatment that is less effective. Here we report a microfluidic system with a ladder shaped design allowing us to generate a twofold serial dilution of antibiotics comparable to current national and international standards. Our consolidated design, with minimal handling steps cuts down the testing time for antibiotic susceptibility from 16–20 h to 4–5 h. Our feasibility testing results are consistent with the commercial antibiotic susceptibility testing (AST) results, showing a 91.75% rate of agreement for Gram-negative and Gram-positive bacterial isolated from canine urinary tract infections (UTI) and may be used without prior isolation or enrichment. This platform provides an adaptable and efficient diagnostic tool for antibiotic susceptibility testing.