Escherichia Phage Mizar, an Enterobacteriophage that Infects Uropathogenic E. coli

Background: Urinary tract infections (UTIs) are among the most prevalent bacterial infections globally. UTIs are commonly caused by antibiotic-resistant uropathogenic Escherichia coli (UPEC). Phage therapy, using single phage or cocktails, has shown promise as an addition to our options for treating UTIs. Although many phage infecting lab strains of E. coli are known, those are rarely active against UPEC strains. Here, we introduce a newly isolated phage that infects multiple UPEC isolates. Materials and Methods: In this study, Escherichia phage Mizar was isolated from wastewater against the HM03 UPEC clinical isolate. We characterized phage Mizar virion morphology, lysis patterns, adsorption, and infectious cycle parameters via one-step growth assay. Its host range was tested on clinical UPEC isolates and reference strains. The phage Mizar genome was sequenced, annotated, and compared at the nucleotide and protein levels to other Caudoviricetes phages. Results: Mizar is a virulent T4-like myophage that adsorbs to its host HM03 cells within three minutes and completes lysis in 15 min to produce an average of ∼97 phages per cell. Mizar can infect 10 out of the 18 UPEC isolates and reference strains tested. Its double-stranded DNA genome is 170,012 base pairs with a G + C content of 38%. Comparative genomics revealed Mizar classifies within the Straboviridae and is most similar to Escherichia phage ATK47 at the nucleotide level. Conclusions: Phage Mizar effectively infects UPEC classified within both phylogroups A and B, expanding our collection of phages available to investigate for therapeutic use.