Cutibacterium Adaptation to Life on Humans Provides a Potential C acnes Infection Biomarker.

Area of Science:

• Microbial evolution and adaptation
• Human-skin microbiome dynamics
• Pathogen identification and diagnostics

Background:

• Propionibacteriaceae, including Cutibacterium acnes (C. acnes), adapted to humans during cattle domestication.
• C. acnes colonizes 25% of human skin, requiring the unique protein RoxP for survival.
• C. acnes is an emerging opportunistic pathogen causing infections in medical devices.

Purpose of the Study:

• To extensively assess RoxP orthologs and understand their function in C. acnes.
• To elucidate the role of RoxP in C. acnes adaptation to sebaceous skin and pathogenicity.
• To develop diagnostic tools for detecting C. acnes infections.

Main Methods:

• Comparative analysis of 21 RoxP orthologs.
• Investigation of conserved molecular surfaces related to heme-dependent oligomerization and pH stability.
• Development of immunoassays to detect RoxP in human biofluids.

Main Results:

• Identified conserved molecular surfaces in RoxP linked to heme-dependent oligomerization and low pH stability.
• RoxP's function in C. acnes dominance on sebaceous skin was suggested.
• An ortholog associated with an acne vulgaris-related pathobiont subspecies was identified.
• Developed sensitive immunoassays for RoxP detection in relevant biofluids.

Conclusions:

• RoxP is crucial for C. acnes adaptation and colonization of human skin.
• The study provides insights into the evolution of skin commensals into pathogens.
• Developed immunoassays offer a novel method for diagnosing C. acnes infections, particularly in prosthetic devices.