A sensitive and rapid bacterial antibiotic susceptibility test method by surface enhanced Raman spectroscopy

Area of Science:

• Analytical Chemistry
• Microbiology
• Nanotechnology

Background:

• Antibiotic resistance necessitates rapid diagnostic methods.
• Traditional antibiotic susceptibility testing (AST) is time-consuming.
• Surface-enhanced Raman spectroscopy (SERS) offers ultrasensitive detection.

Purpose of the Study:

• To develop a rapid bacterial antibiotic susceptibility test (AST) method.
• To utilize Bacteria-aptamer@AgNPs-SERS for bacterial detection.
• To evaluate antibiotic influence on bacterial Raman intensity.

Main Methods:

• Employing Bacteria-aptamer@AgNPs-SERS for detecting Escherichia coli O157:H7 and Staphylococcus aureus.
• Measuring bacterial Raman intensity in the presence of varying antibiotic concentrations.
• Correlating Raman signal changes with minimum inhibitory concentration (MIC) and colony-forming unit (CFU) data.

Main Results:

• A rapid AST method was developed, determining MIC values in 1 hour.
• Bacterial Raman signals at 735 cm⁻¹ were key indicators.
• Sub-MIC antibiotic concentrations showed similar enhancements in bacterial Raman signal growth and CFU counts within 2 hours.

Conclusions:

• The Bacteria-aptamer@AgNPs-SERS method provides a rapid and ultrasensitive approach for AST.
• This technique is valuable for evaluating antibiotic efficacy and potentially discovering new antibiotic drugs.
• The observed enhancement effects offer insights into bacterial responses to antibiotics.