Rapid Antimicrobial Susceptibility Testing Techniques

Conventional antimicrobial susceptibility testing, reliant on broth microdilution and disk diffusion, can take 24–72 hours, delaying targeted therapy and contributing to inappropriate antibiotic use. Rapid techniques seek to compress this timeline to minutes or hours by harnessing novel phenotypic and biophysical markers of bacterial response. Phenotypic platforms measure growth, metabolic shifts or mechanical vibrations at the single-cell level, using microfluidic chips, impedance cytometry or nanomechanical sensors. Optical and spectroscopic approaches, including stimulated Raman scattering, permit direct observation of metabolic incorporation of stable isotopes. Integration of machine learning further accelerates interpretation. Rapid AST innovations promise to guide timely treatment, reduce empirical prescribing and stem the rise of resistance, although they must navigate regulatory validation and cost-effectiveness hurdles before clinical implementation.

Research from Nature Portfolio

Researchers have introduced a growth-independent phenotypic assay that employs a nanomotion sensing platform to detect sub-nanometre vibrations of bacterial cells exposed to antibiotics. Coupled with machine learning algorithms trained on thousands of recordings, this system distinguishes susceptible from resistant strains of Escherichia coli and Klebsiella pneumoniae with over 90 % accuracy in under two hours, including direct analysis of positive blood cultures. In a complementary foundational review, the developmental roadmap for rapid AST highlights barriers to translation—such as standardisation of new methods, reagent stability, regulatory approval and integration into existing laboratory workflows—and proposes strategies to advance pioneering technologies from proof-of-concept to routine clinical practice.

Rapid Antimicrobial Susceptibility Testing Techniques publication trend

The graph below shows the total number of articles in rapid antimicrobial susceptibility testing techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Antimicrobial susceptibility testing (AST): Assessment of bacterial sensitivity or resistance to antibiotics, traditionally by measuring growth inhibition.

Phenotypic AST: Testing based on observable bacterial responses—growth, morphology or metabolic activity—rather than genetic markers.

Nanomotion technology: Detection of bacterial nanometre-scale vibrations as an indicator of viability and antibiotic effect.

Reflectometric interference spectroscopy (iPRISM): Label-free optical technique measuring phase-shift changes due to bacterial colonisation on microstructured surfaces.

Stimulated Raman scattering (SRS): Non-invasive imaging method that detects molecular vibrations, enabling measurement of deuterium incorporation into biomolecules.

References

1. Accurate and rapid antibiotic susceptibility testing using a machine learning-assisted nanomotion technology platform. Nature Communications (2024).
2. Developmental roadmap for antimicrobial susceptibility testing systems. Nature Reviews Microbiology (2018).
3. Accurate Prediction of Antimicrobial Susceptibility for Point‐of‐Care Testing of Urine in Less than 90 Minutes via iPRISM Cassettes. Advanced Science (2023).
4. Rapid Determination of Antimicrobial Susceptibility by Stimulated Raman Scattering Imaging of D2O Metabolic Incorporation in a Single Bacterium. Advanced Science (2020).