Analysis of Microbial Cell Viability in a Liquid Using an Acoustic Sensor

Area of Science:

• Biosensing
• Microbiology
• Analytical Chemistry

Background:

• Assessing bacterial viability is crucial in various fields.
• Existing methods for detecting bacteriophage-infected bacteria can be time-consuming.
• Rapid, direct detection methods are needed for real-time monitoring.

Purpose of the Study:

• To develop a rapid method for analyzing and evaluating the viability of bacteriophage-infected Escherichia coli (E.coli) XL-1.
• To utilize a slot-mode sensor for direct detection in conducting suspensions.
• To establish a quick assessment of bacterial infection and viability.

Main Methods:

• Developed a slot-mode sensor to record changes in resonant absorption peaks (depth and frequency).
• Analyzed frequency dependence of insertion loss before and after biological interaction.
• Utilized changes in peak depth as the optimal variable for estimating viable cell numbers.

Main Results:

• Successfully recorded E.coli infection by specific bacteriophages.
• Assessed bacterial viability in suspensions with conductivity ranging from 4.5-30 μS/cm.
• Achieved a detection limit of approximately 10^2-10^3 cells/mL within a 5-minute analysis time.
• Confirmed no sensor variable changes with non-specific E.coli-bacteriophage interactions.

Conclusions:

• The developed slot-mode sensor method enables rapid and accurate detection of bacteriophage-infected E.coli.
• The method is effective for assessing bacterial viability in low-conductivity solutions.
• This approach shows promise for real-time bacterial detection and viability assessment in various applications.