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phage food safety directed evolution Listeria monocytogenes phage resistance

Overcoming hurdles for phage applications in food safety with directed evolution

Abstract ID: 54-OC

Thomas G. Denes 1*

  1. Department of Food Science, University of Tennessee, Knoxville, TN

Phage-based products are currently in use in the United States and globally to combat the foodborne pathogen, Listeria monocytogenes. However, their efficacy might be constrained by two critical hurdles. Firstly, the development of phage resistance is predictably selected for under the pressure of lytic phages. Secondly, the complexity of various food matrices may restrict the lytic capabilities of phages. In this presentation, I will explore the potential of directed evolution as a strategy to mitigate these hurdles, particularly in relation to phages infecting Listeria monocytogenes. I will specifically highlight how we used directed evolution to select Listeria phages capable of countering phage resistance. Additionally, I will share our experiences in selecting a mutant Listeria phage demonstrating enhanced binding efficiency in milk conditions through a similar approach.