Characterization and complete genome sequence analysis of Enterococcus faecalis bacteriophage vB_E. faecalis_IME196

Abstract:

[Objective] We isolated a novel virulent bacteriophage specifically infecting antibiotics-resistant Enterococcus faecalis from hospital sewage, to study its morphology and to analyze its genome so as to provide basis for treatment and infection control of antibiotics-resistant E. faecalis. [Methods] We used E. faecalis as the host to isolate phage from raw sewage from the sewage treatment center of a hospital. Transmission electromicroscopy, optimal multiplicity of infection (optimal MOI) and one-step growth curve were conducted. The genome DNA was extracted and sequenced by high-throughput sequencing technology. The feature of whole genome, and evolutionary relationship were analyzed. [Results] A lytic bacteriophage designated as vB_E. faecalis_IME196 (IME196) was isolated. The optimal multiplicity of infection (optimal MOI) of IME196 is 0.01. One-step growth curve shows that IME196 has a burst size of 50 PFU and a latent period of 30 min. The genome of IME196 is a 38 895 bp in length, linear, terminally non-redundant double-stranded DNA and has a G+C content of 33.9%. [Conclusion] Isolation and characterization of a lytic Enterococcus faecalis phage will help supply a new way to prevent and control the infection of E. faecalis, and laid a foundation to the treatment of multiple drug resistant bacteria in the future.