Tailoring Effective Phage Cocktails for Long-Term Lysis of Escherichia coli Based on Physiological Properties of Constituent Phages.

Abstract

Bacteriophage (phage) therapy has regained attention as an alternative to antimicrobial agents for eliminating bacteria; however, the emergence of phage-resistant bacteria during the therapy is a major concern. One method to control this emergence is to create a cocktail composed of multiple phages. In this study, we isolated 28 phages infecting Escherichia coli and evaluated their bacteriolysis (lysis) activity, lytic spectrum, adsorption rate constant, burst size, and titer of a 1-day incubation, followed by clustering of the phages based on these physiological characteristics. The variation in lysis onset time and duration was more significant for cocktails of phages from different clusters than for phage cocktails from the same cluster. This suggests that a combination of phages with different physiological characteristics is necessary to create a cocktail that rapidly and continuously lyses bacteria over a prolonged duration while suppressing the emergence of resistant bacterial strains.