Isolation and Characterization of Virulent Phage vB_Eco_ZCEC02 targeting Extensively Drug-Resistant Uropathogenic Escherichia coli: T-24 Cell Model Evaluation.

Urinary Tract Infections (UTIs) are among the most prevalent bacterial diseases associated with serious health complications, particularly those caused by antibiotic resistant Uropathogenic Escherichia coli (UPEC). Antibiotic resistant UPEC infections present significant treatment challenges due to multiple pathogenic factors and resistance mechanisms to various antibiotics. Consequently, bacteriophages have emerged as a promising alternative for controlling antibiotic resistant bacterial infection. In this study, a virulent phage (vB_Eco_ZCEC02) was isolated and characterized on both the physical and molecular aspects to combat Extensively Drug Resistant (XDR) UPEC isolate (EC-02). The vB_Eco_ZCEC02 phage, classified within the Autographiviridae family and Kayfunavrius genus, possesses a short non-contractile tail with a narrow host range (EC-02, EC-08, EC-23). The phage exhibits strong temperature stability (from -80 °C to 60 °C) and pH values (from 3 to 12). Also, the time-kill assay showed that vB_Eco_ZCEC02 phage has a potent lytic activity against its host (EC-08) at MOIs of 0.1, 1, and 10 for 8.5 hours. A whole-genome study of the 39,488 bp vB_Eco_ZCEC02 phage revealed 48 predicted Open Reading Frames (ORFs), with no lysogeny, antibiotic resistance, or bacterial virulence genes. Further, vB_Eco_ZCEC02 phage demonstrated high safety in the T-24 cell model at different MOIs (0.1, 1, 10 and100). However, the bacterial-phage dynamics on T-24 cells indicated that lower MOIs (such as 0.1) could induce bacterial reduction without affecting the cell viability, to higher MOIs (such as 100). In conclusion, this study suggests an in vitro, comprehensively characterized virulent phage that can be used to treat antibiotic resistant UPEC infections.