Rapid Real-Time Antimicrobial Susceptibility Testing with Electrical Sensing on Plastic Microchips with Printed Electrodes

Abstract

Rapid antimicrobial susceptibility testing is important for efficient and timely therapeutic decision making. Due to globally spread bacterial resistance, the efficacy of antibiotics is increasingly being impeded. Conventional antibiotic tests rely on bacterial culture, which is time-consuming and can lead to potentially inappropriate antibiotic prescription and up-front broad range of antibiotic use. There is an urgent need to develop point-of-care platform technologies to rapidly detect pathogens, identify the right antibiotics, and monitor mutations to help adjust therapy. Here, we report a biosensor for rapid (<90 min), real time, and label-free bacteria isolation from whole blood and antibiotic susceptibility testing. Target bacteria are captured on flexible plastic-based microchips with printed electrodes using antibodies (30 min), and its electrical response is monitored in the presence and absence of antibiotics over an hour of incubation time. We evaluated the microchip with Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) as clinical models with ampicillin, ciprofloxacin, erythromycin, daptomycin, gentamicin, and methicillin antibiotics. The results are compared with the current standard methods, i.e. bacteria viability and conventional antibiogram assays. The technology presented here has the potential to provide precise and rapid bacteria screening and guidance in clinical therapies by identifying the correct antibiotics for pathogens.

Identification and Antibiotic‐Susceptibility Profiling of Infectious Bacterial Agents: A Review of Current and Future Trends

“…The frequency of rotation of the beads when a magnetic field is applied, changes as a function of bacterial growth . Finally, the impedance measurement assay evaluates the changes in emission of electrical signals by bacterial cells captured inside a microchip, in the presence and absence of antibiotic treatment …”

Quantitative and synthetic biology approaches to combat bacterial pathogens

“…These technologies are based on phenotypic signatures from either cell populations [68-70] or single cells [71]. Bacterial growth in terms of biomass accumulation can be detected using cantilever fluctuation patterns [68].…”

“…With its ultra-sensitivity, this method can return drug susceptibility test results within an hour and can also profile bacterial metabolism [69]. Furthermore, the increase in biomass can also be detected by electrical impedance, which enables another method to quantify bacterial antibiotic response [70]. Besides population-level phenotypes, single cell morphology can also indicate antibacterial susceptibility.…”

A Rapid Unraveling of the Activity and Antibiotic Susceptibility of Mycobacteria

“…Many options are emerging to achieve a rapid, accurate, and cost-effective pathogen characterization of bacterial responses to drugs, ranging from molecular to rapid phenotypic techniques to plasmonic single-cell assays (8)(9)(10)(11). The conventional AST molecular techniques rely mainly on the determination of the genetic fingerprint associated with resistance to a specific antibiotic, including real-time PCR (RT-PCR), DNA microarrays, next-generation sequencing (NGS), cell lysis-based approaches, wholegenome sequencing, and MALDI-TOF MS (12)(13)(14)(15)(16).…”