Observations on the adherence of Proteus mirabilis onto polymer surfaces

Area of Science:

• Microbiology
• Biomaterials Science
• Urology

Background:

• Proteus mirabilis infection in catheterized urinary tracts leads to catheter blockage by crystalline bacterial biofilms.
• Developing effective anti-biofilm surface coatings for urinary catheters is crucial for patient care.

Purpose of the Study:

• To identify a catheter surface coating resistant to Proteus mirabilis colonization.
• To understand the conditions under which Proteus mirabilis forms biofilms on potential catheter surfaces.

Main Methods:

• Utilized a parallel-plate flow-cell and phase contrast microscopy to observe bacterial adhesion on polymer films.
• Tested adhesion of urease-negative and wild-type Proteus mirabilis strains in buffer and urine at varying pH levels.

Main Results:

• Agarose was identified as a polymer that prevented biofilm formation by urease-negative Proteus mirabilis.
• Wild-type Proteus mirabilis showed no initial adhesion to agarose in urine, but rapid crystalline biofilm formation occurred as urine pH rose above 8.2.
• Biofilm formation on agarose was inhibited in urine with pH below 8.0.

Conclusions:

• Agarose-coated surfaces resist Proteus mirabilis adhesion in urine at pH below 8.0.
• Alkaline conditions (pH > 8.2) in urine promote the formation of crystalline aggregates and subsequent biofilm deposition on surfaces.
• Preventing crystalline biofilm formation on catheters requires considering both surface properties and methods to avoid urine alkalinization.