On-Chip Raman Spectroscopy for Rapid Antimicrobial Susceptibility Testing from Blood Cultures

Area of Science:

• Microbiology and Infectious Diseases
• Spectroscopy and Analytical Chemistry
• Biotechnology and Diagnostics

Background:

• Bloodstream infections cause significant morbidity and mortality.
• Current antimicrobial susceptibility testing (AST) methods are often slow or lack phenotypic relevance.
• Rapid diagnostics are crucial for timely and effective antimicrobial therapy.

Purpose of the Study:

• To introduce the RamanBioAssay (RBA) platform for rapid phenotypic AST and bacterial identification (ID).
• To evaluate the RBA platform's performance and diagnostic turnaround time.
• To demonstrate the potential of label-free Raman spectroscopy in clinical diagnostics.

Main Methods:

• Integration of dielectrophoretic on-chip bacterial enrichment with label-free Raman spectroscopy.
• Testing on quality control strains and artificial blood cultures for AST concordance.
• Proof-of-concept evaluation using patient blood cultures for AST and ID accuracy.

Main Results:

• RBA platform delivered AST results within 3.5 hours, significantly faster than conventional methods.
• High concordance rates observed with conventional AST for quality control strains (up to 100%) and patient samples (up to 91.7%).
• Accurate family-level bacterial classification (e.g., E. coli, S. aureus) achieved with 97.2% accuracy.

Conclusions:

• The RBA platform is a promising tool for rapid phenotypic AST and bacterial ID.
• It offers comprehensive, clinically actionable results significantly faster than current diagnostics.
• This technology has the potential to improve patient outcomes by enabling quicker therapeutic adjustments.