High-throughput analysis of growth differences among phage strains

Area of Science:

• Microbiology
• Virology
• Evolutionary Biology

Background:

• Spectrophotometry is established for bacterial growth analysis.
• High-throughput methods for bacteriophage (virus) growth assessment are lacking.
• Understanding viral fitness differences is crucial for phage research.

Purpose of the Study:

• To develop an in vitro high-throughput method for indirectly assessing bacteriophage strain growth differences.
• To identify bacterial growth curve features indicative of phage fitness.
• To validate the method using known bacteriophage genotypes.

Main Methods:

• Utilized automated spectrophotometry to monitor bacterial host growth.
• Employed computer simulations of a mathematical model for phage growth.
• Inferred phage growth traits from bacterial growth curve dynamics.
• Tested inferred traits against known fitness differences of RNA phage phi-6 infecting Pseudomonas syringae.

Main Results:

• Identified 'time-to-extinction' as a key inferred phage trait.
• Demonstrated a reliable correlation between time-to-extinction and absolute phage fitness (titer).
• Validated the method's ability to rank phage genotypes by fitness.

Conclusions:

• Automated spectrophotometry provides a valuable high-throughput approach for distinguishing bacteriophage growth differences.
• The developed method is particularly useful for analyzing phage fitness in liquid culture environments.
• This technique facilitates high-throughput screening and evolution studies of viruses.