BorMax, a Novel Dhillonvirus Infecting MDR Escherichia coli: Genomic Insights, Taxonomic Position, and Anti-CRISPR Repertoire

Escherichia coli is a major pathogen responsible for urinary tract infections, septicemia, and other clinically relevant conditions, with increasing multidrug resistance (MDR) limiting available treatment options. In this context, bacteriophages represent a valuable resource for exploring novel antimicrobial and biotechnological tools. Here, we report the isolation and genomic characterization of BorMax, a novel lytic phage infecting multiple MDR E. coli. Transmission electron microscopy revealed a tailed morphology consistent with Dhillonvirus. Whole genome sequencing and de novo assembly showed a linear double-stranded DNA genome of 45,502 bp, encoding 70 predicted coding sequences (CDSs) and lacking tRNAs. Bioinformatic analyses confirmed the absence of lysogeny-associated genes, as well as virulence and antimicrobial resistance determinants. Comparative genomics using classified BorMax within the genus Dhillonvirus as a new species, sharing