Development of Droplet-Based Microfluidic Platforms Towards Accelerating Clinical Diagnoses of Infectious Diseases
Johns Hopkins University
The emergence of multi-drug resistant bacteria due to indiscriminate use of broad-spectrum antibiotics has grown into a global healthcare crisis. This is due in part to clinical reliance on century-old culture-based methods for pathogen identification (ID) and antimicrobial susceptibility testing (AST) which necessitate several days for definitively diagnosing patients and guiding targeted antimicrobial treatments. To overcome this bottleneck, improve patient outcomes, and increase antimicrobial stewardship, there is an urgent need for rapid diagnostic methods for pathogen ID and AST that can be easily operated, with minimal sample preparation. This thesis investigates the use of droplet microfluidics for expediting definitive diagnoses of infectious diseases, via single-cell detection of bacterial pathogens. We demonstrate the utility of droplet-based measurements of single-bacterial cells towards achieving multiplexed and quantitative molecular detection (ID) of bacteria and towards accelerating AST to the timescale of bacterial replication. In expanding the clinical utility of these methods, we present facile filtration-based strategies for direct evaluation of clinical urine samples using our droplet platforms. Next, we integrate our findings to develop a rapid sample-to-answer platform to achieve both ID and AST directly from patient urine samples for urinary tract infections. Finally, we present a strategy for further enhancing the throughput, multiplexability, and hence the clinical translatability of our sample-to-answer platform. The strategies outlined herein represent an important step in bringing droplet-based technologies to the clinic, and we hope that this work can help pave the way for droplet-based solutions to increasingly life-threatening infectious diseases.
diagnostics, infectious disease, urinary tract infection, microfluidics, droplet