Isolation and characterization of a novel Enterococcus phage Phi_Eg_SY1

Enterococcus gallinarum, a gut pathobiont, is an opportunistic pathogen that carries the risk of antibiotic resistance in the clinic and has been proven to drive autoimmunity in both mice and humans. Screening for novel bacteriophages targeting Enterococcus gallinarum is expected to provide a promising strategy for controlling such infections or regulating related chronic diseases. In the present study, we isolated a novel lytic Enterococcus gallinarum phage, Phi_Eg_SY1, which presents favourable thermostability and pH stability. Further assays indicated that Phi_Eg_SY1 can efficiently adsorb and lyse the host bacteria in vitro. Genomic and phylogenetic analyses suggested that Phi_Eg_SY1 does not contain virulence or lysogeny genes and presents a novel unassigned evolutionary lineage among the related dsDNA phages. Phi_Eg_SY1 is therefore considered to be suitable for further applications.