Proteus mirabilis is one of the most frequent causes of catheter-associated urinary tract infections (CAUTIs) owing to its
capability to colonize and develop crystalline multidrug-resistant (MDR) biofilms. Here, we report the isolation and partial
characterization of three novel bacteriophages, vB_PmiM-ES1a, vB_PmiM-ES1b, and vB_PmiM-ES1c, which were active
against the planktonic form and biofilms of the MDR P. mirabilis strain ES01, isolated from CAUTIs in Egypt. The antibiotic
susceptibility profile of the P. mirabilis isolates showed resistance to most of the antibiotics tested. The isolated phages were
identified morphologically using TEM, and each appeared to have myovirus-like morphology. The three phages displayed
strong lytic activity and a narrow host range, and they were stable at different ranges of temperatures and pH values. Onestep
growth kinetics showed a lysis time of 180 min with a burst size of 99.6, 95, and 86 PFU/cell for phage vB_PmiMES1a,
vB_PmiM-ES1b, and vB_PmiM-ES1c, respectively. The three phages exhibited different digestion patterns using
different restriction enzymes. The genome size was estimated to be 59.39 kb, 62.19 kb, and 52.07 kb for phage vB_PmiMES1a,
vB_PmiM-ES1b, and vB_PmiM-ES1c, respectively. A phage cocktail including the three phages showed a potential
ability to reduce and eradicate a biofilm formed by the MDR Proteus mirabilis EG-ES1. Accordingly, a phage cocktail of
vB_PmiM-ES1a, vB_PmiM-ES1b, and vB_PmiM-ES1c is considered a promising candidate for use as a biocontrol agent
against MDR Proteus mirabilis bacteria.