Rapid assessment of antibiotic susceptibility using a fully 3D-printed impedance- based biosensor

The sustained misuse and overuse of antibacterial agents is accelerating the emergence of antimicrobial resistance (AMR), which is becoming one of the major threats to public health. Abuse of antibiotics drives spontaneous evolution, bacterial mutation, and exchange of resistant genes through lateral gene transfer. Mitigating the worldwide impact of AMR requires enhanced antibiotic stewardship through faster diagnostic testing. In this work, we aim to tackle this issue via development of a fully 3D-printed electrochemical, gel-modified biosensor for rapid bacterial growth monitoring. By using electrochemical impedance spectroscopy, we have successfully identified growth profiles and confirmed antibiotic susceptibility of two ESKAPE pathogens, Escherichia coli and Pseudomonas aeruginosa, following overnight culture it was possible to determine antibiotic sensitivity in 90 min, altogether faster than the 24–48 h current gold standard of culture-based antimicrobial susceptibility testing with significant scope for optimisation. Results show a clear distinction between growth profiles in the presence and absence of amoxicillin, gentamicin, and fosfomycin, therefore demonstrating a rapid, cost-efficient platform for phenotypic antibiotic susceptibility testing within clinically relevant concentration ranges for conditions such as urinary tract infections and pneumonia.