Isolation and Genomic Analysis of Escherichia coli Phage AUBRB02: Implications for Phage Therapy in Lebanon.

BACKGROUND/OBJECTIVES: Escherichia coli (E. coli), a prevalent Gram-negative bacterium, is a frequent cause of illness. The extensive use of antibiotics has led to the emergence of resistant strains, complicating antimicrobial therapy and emphasizing the need for natural alternatives such as phages. METHODS: In this study, a novel Escherichia coli phage, AUBRB02, was isolated from sewage and characterized through whole-genome sequencing, host range assays, and biofilm elimination assays. The phage's stability and infectivity were assessed under various pH and temperature conditions, and different E. coli strains. RESULTS: Phage AUBRB02 has an incubation period of 45 min, a lysis period of 10 min, and a burst size of 30 phages/infected cell. It is stable across pH 5.0-9.0 and temperatures from 4 °C to 60 °C. Treatment with AUBRB02 significantly reduced post-formation E. coli biofilms, as indicated by lower OD values compared with the positive control. The whole genome sequencing revealed a genome size of 166,871 base pairs with a G + C (Guanine and Cytosine content) content of 35.47%. AUBRB02 belongs to the Tequatrovirus genus, sharing 93% intergenomic similarity with its closest RefSeq relative, and encodes 262 coding sequences, including 10 tRNAs. CONCLUSIONS: AUBRB02 demonstrates high infectivity and stability under diverse conditions. Its genomic features and similarity to related phages highlight its potential for phage therapy, offering promising prospects for the targeted treatment of E. coli infections.