Comparative genomics analysis of six Cutibacterium acnes strains isolated from contaminated platelet concentrates.

Cutibacterium acnes is a bacterial skin commensal that is often isolated during routine testing of blood products like platelet concentrates (PCs). Due to the slow-growing nature of this bacterium in culture media, C. acnes contaminated PCs are often transfused into vulnerable patients before retrieval of these units can be initiated. This study aimed at obtaining the whole-genome sequence of six C. acnes isolates derived from contaminated PCs, comparing and assessing their genetic backgrounds. Furthermore, the whole genomes of the PC isolates were compared to clinical isolates obtained from different sites and types of infection. The results indicate that these PC isolates assessed belong to four phylotypes, namely IA, IB, II and III. Whole-genome comparisons identified differences in the virulence profiles of the isolates and provide a foundation for future studies aimed at evaluating the risk to transfusion patients by determining whether the expression of virulence factors is impacted in the PC storage environment.