Elimination of multidrug-resistant Proteus mirabilis biofilms using bacteriophages

Proteus mirabilis is responsible for a wide range of infections that affect the urinary tract, the respiratory tract, burns, wounds and the feet of individuals with diabetes. They are highly resistant to antimicrobial agents, and new therapeutic options are therefore needed to combat this pathogen. The use of bacteriophages is one option that may be useful in treating multidrug-resistant (MDR) Proteus mirabilis infections, especially biofilm-based infections. The aim of this study was to control biofilms formed by MDR Proteus mirabilis using bacteriophages. Proteus mirabilis isolates were identified based on biochemical tests, and their resistance profiles were determined by the disk diffusion method. The biofilm-forming capacity of the isolates was assessed by the spectrophotometric method. Bacteriophages attacking Proteus mirabilis were isolated from sewage. The effect of phage on biofilm formation was investigated by the viable count method. A high rate of drug resistance was found (87.2%). Strong biofilm formation was observed in 80.5% of isolates, while moderate production was found in 19.5%. Five bacteriophages were isolated from sewage and were tested for their ability to eliminate biofilms. Significant disruption of pre-formed biofilms was observed that reached up to 99.9% decrease in the number of viable cells. The use of bacteriophages is considered a promising strategy against the biofilm infections caused by MDR Proteus mirabilis isolates.