Analysis of Complete Genomes of Propionibacterium acnes Reveals a Novel Plasmid and Increased Pseudogenes in an Acne Associated Strain

Abstract EN

The human skin harbors a diverse community of bacteria, including the Gram-positive, anaerobic bacterium Propionibacterium acnes.

P.

acnes has historically been linked to the pathogenesis of acne vulgaris, a common skin disease affecting over 80% of all adolescents in the US.

To gain insight into potential P.

acnes pathogenic mechanisms, we previously sequenced the complete genome of a P.

acnes strain HL096PA1 that is highly associated with acne.

In this study, we compared its genome to the first published complete genome KPA171202.

HL096PA1 harbors a linear plasmid, pIMPLE-HL096PA1.

This is the first described P.

acnes plasmid.

We also observed a five-fold increase of pseudogenes in HL096PA1, several of which encode proteins in carbohydrate transport and metabolism.

In addition, our analysis revealed a few island-like genomic regions that are unique to HL096PA1 and a large genomic inversion spanning the ribosomal operons.

Together, these findings offer a basis for understanding P.

acnes virulent properties, host adaptation mechanisms, and its potential role in acne pathogenesis at the strain level.

Furthermore, the plasmid identified in HL096PA1 may potentially provide a new opportunity for P.

acnes genetic manipulation and targeted therapy against specific disease-associated strains.