The emergence of multidrug-resistant (MDR) Proteus mirabilis poses a significant threat in porcine farming and public health, highlighting the need for alternative biocontrol agents. This study aimed to isolate and characterize a lytic bacteriophage with therapeutic potential against MDR P. mirabilis. Using the clinical MDR P. mirabilis strain Pm 07 as host, a bacteriophage, vBPmcP-07 (P-07), was successfully isolated from fecal and sewage samples via an enrichment protocol. Phage P-07 forms plaques surrounded by a distinct translucent “halo, ” suggesting the production of depolymerase. It achieved high titers of up to 1. 40 × 108 PFU/mL and exhibited a narrow host range, high stability across a broad range of temperatures (40–60 °C) and pH (4–12), as well as considerable anti-biofilm activity. An optimal multiplicity of infection (MOI) of 0. 001 was determined. Whole-genome sequencing revealed a linear double-stranded DNA genome of 58, 582 bp with a GC content of 46. 91%, encoding 63 open reading frames. Crucially, no virulence or antibiotic resistance genes were detected, supporting its safety profile. Phylogenetic analysis classified P-07 within the Casjensviridae family, closely related to phages PM87 and pPM01. These findings indicate that phage P-07 is a novel, safe, and effective lytic phage with strong potential as a biocontrol agent against biofilm-forming MDR P. mirabilis in swine.
Liang et al. (Sat,) studied this question.