Innovative antimicrobial susceptibility testing method using surface plasmon resonance.

Area of Science:

• Biomedical Engineering
• Microbiology
• Analytical Chemistry

Background:

• Antibiotic resistance is a growing global health threat.
• Rapid and accurate antimicrobial susceptibility testing (AST) is crucial for effective patient treatment.
• Conventional AST methods can be time-consuming, delaying appropriate therapy.

Purpose of the Study:

• To develop and evaluate a novel Surface Plasmon Resonance (SPR) biosensor for rapid bacterial antibiotic resistance detection.
• To demonstrate the utility of SPR in distinguishing between susceptible and resistant bacterial strains.
• To establish a faster alternative to conventional AST methods.

Main Methods:

• Bacteria (Escherichia coli, Staphylococcus epidermidis) were adhered to a gold thin film on an SPR sensor.
• Antibiotic solutions were flowed over the bacteria, and optical property changes were measured via SPR.
• SPR angle shifts were analyzed to differentiate between susceptible and resistant bacterial responses.

Main Results:

• Susceptible E. coli showed >3x greater SPR angle shift compared to resistant strains.
• Susceptible S. epidermidis exhibited irregular SPR shifts, while resistant strains showed minimal change.
• The SPR method completed antimicrobial susceptibility testing in under 2 hours.

Conclusions:

• The developed SPR biosensor provides a rapid and sensitive method for detecting bacterial antibiotic resistance.
• This technique eliminates the need for specific antibodies, simplifying the assay.
• The reduced testing time offers significant advantages over conventional AST, potentially improving patient outcomes.