Chemistry

Streptococcus mutans

Antimicrobial

Physics

Raman microspectroscopy

Microbiology

Antibiotics

Optics

Ampicillin

Raman spectroscopy

Organic chemistry

Bacteria

Biology

Minimum inhibitory concentration

Bacterial growth

Streptococcus pneumoniae

Genetics

Biochemistry

Analytical Chemistry

To combat the spread of antibiotic resistance, methods that quantitatively assess the metabolism-inhibiting effects of drugs in a rapid and culture-independent manner are urgently needed. Here using four oral bacteria as models, we show that heavy water (D2O)-based single-cell Raman microspectroscopy (D2O-Raman) can probe bacterial response to different drugs using the Raman shift at the C–D (carbon–deuterium vibration) band in 2040 to 2300 cm–1 as a universal biomarker for metabolic activity at single-bacterial-cell resolution. The "minimum inhibitory concentration based on metabolic activity" (MIC-MA), defined as the minimal dose under which the median ΔC–D-ratio at 8 h of drug exposure is ≤0 and the standard deviation (SD) of the ΔC–D ratio among individual cells is ≤0.005, was proposed to evaluate the metabolism-inhibiting efficacy of drugs. In addition, heterogeneity index of MIC-MA (MIC-MA-HI), defined as SD of C–D ratio among individual cells, quantitatively assesses the among-cell heterogeneity of met...

Metabolic-Activity-Based Assessment of Antimicrobial Effects by D<sub>2</sub>O-Labeled Single-Cell Raman Microspectroscopy

Metabolic-Activity-Based Assessment of Antimicrobial Effects by D2O-Labeled Single-Cell Raman Microspectroscopy

Metabolic-Activity-Based Assessment of Antimicrobial Effects by D₂O-Labeled Single-Cell Raman Microspectroscopy