Imaging the propagation of viruses

Area of Science:

• Microbiology
• Virology
• Biophysics

Background:

• Viral propagation in plaques is fundamental to understanding virus-host interactions.
• Quantifying plaque growth dynamics aids in studying viral evolution and spread.
• Traditional methods for plaque measurement can be labor-intensive and lack spatial resolution.

Purpose of the Study:

• To develop and validate a digital image acquisition and analysis system for measuring viral plaque propagation.
• To Spatially resolve the dynamics of viral evolution during plaque growth.

Main Methods:

• Utilized a digital image acquisition and analysis system with a charge-coupled device (CCD) camera.
• Monitored phage T7 plaques incubated at 37°C against a dark field background of host bacteria (Escherichia coli).
• Acquired images at 1-hour intervals over a 24-hour period to track plaque development.

Main Results:

• Plaque growth initially coincided with host bacterial growth (measured by gray value reduction) for the first 10 hours.
• After 10 hours, the average radial velocity of plaque growth stabilized at 0.059 mm/h.
• The standard deviation of the radial velocity increased over time, indicating variations in growth patterns.

Conclusions:

• The developed digital imaging system is suitable for spatially resolving viral plaque growth dynamics.
• The system provides quantitative data on viral propagation, essential for studying viral evolution.
• This method offers a precise and efficient approach to analyzing virus-host dynamics in plaque formation.