Transcriptomic analysis of Propionibacterium acnes biofilms in vitro

Area of Science:

• Microbiology
• Bacteriology
• Skin Microbiome Research

Background:

• Propionibacterium acnes (P. acnes) is a skin commensal linked to acne and joint infections.
• P. acnes naturally exists in biofilms, yet is often studied in planktonic form.
• Understanding P. acnes biofilm behavior is crucial for treating associated infections.

Purpose of the Study:

• To develop an in vitro biofilm model for P. acnes.
• To investigate P. acnes biofilm characteristics, including growth, matrix, and antibiotic penetration.
• To analyze gene expression and antibiotic susceptibility within P. acnes biofilms.

Main Methods:

• Development of an in vitro P. acnes biofilm model.
• Analysis of biofilm matrix composition and antibiotic penetration using fluorescent labels.
• Gene expression profiling of biofilm cells.
• Assessment of antibiotic susceptibility under varying conditions, including glucose concentration.

Main Results:

• P. acnes biofilms exhibit up-regulated stress-induced genes.
• Genes associated with CAMP factors, potential virulence determinants, were upregulated.
• Biofilm cells demonstrated reversible tolerance to high concentrations of antibiotics, forming persister cells.
• Increased glucose concentrations enhanced antibiotic susceptibility of P. acnes biofilms.

Conclusions:

• The in vitro model effectively mimics P. acnes biofilm properties.
• P. acnes biofilms present a unique physiological state with implications for virulence and treatment resistance.
• Modulating environmental factors like glucose may offer strategies to enhance antibiotic efficacy against P. acnes biofilms.