Phenotypically distinguishing ESBL-producing pathogens using paper-based surface enhanced Raman sensors.

Area of Science:

• Analytical Chemistry
• Microbiology
• Biotechnology

Background:

• Antimicrobial stewardship is crucial for combating bacterial infections and preserving treatment options.
• Current methods for determining antimicrobial susceptibility are time-consuming, relying on multiple culture rounds and expensive equipment.
• The rise of multi-drug resistance necessitates faster and more accessible diagnostic tools.

Purpose of the Study:

• To develop a rapid, low-cost phenotypic method for discriminating multi-drug resistance in bacterial infections.
• To utilize paper-based surface-enhanced Raman spectroscopy (SERS) sensors and portable instrumentation for bacterial susceptibility testing.
• To enable faster and more precise selection of effective antimicrobial agents.

Main Methods:

• Development of paper-based SERS sensors incorporating barcoded beta-lactam molecular reporters.
• Detection of beta-lactamase enzyme activity through the hydrolysis of beta-lactams, releasing SERS barcodes.
• Utilizing portable instrumentation for SERS detection of released barcodes to identify resistance mechanisms.

Main Results:

• Successful differentiation of E. coli strains with extended-spectrum beta-lactamase (ESBL), narrow-spectrum beta-lactamase, and no resistance in a single measurement.
• Demonstrated the ability to identify resistance to various generations of beta-lactam antibiotics.
• Validated an approach for expanding the reporter library through chemical synthesis of new barcoded beta-lactams.

Conclusions:

• The developed SERS-based method provides a rapid, cost-effective phenotypic approach for antimicrobial susceptibility testing.
• This technology aligns with clinical microbiology standards by detecting enzymatic activity, enabling precise antibiotic selection.
• The use of portable instrumentation and simple assay steps offers a promising alternative to conventional methods for combating antimicrobial resistance.