Finegoldia magna and Corynebacterium kroppenstedtii are significantly enriched in rosacea independent of rosacea subtype: Results of a case-control study


BM Rainer1,2, EF Mongodin3, J Bui3, AH Fischer2, HB Pasieka2, LA Garza2, S Kang2, AL Chien2

1Dept of Derm, Med Univ Graz, Austria
2Dept of Derm, Johns Hopkins Univ, Baltimore
3Inst for Genome Sciences, Baltimore

Rosacea has long been associated with microorganisms, but the involvement of microbial communities in rosacea’s pathophysiology is unknown. Here, we performed a study to examine the skin microbiota (1) in rosacea patients compared to matched controls, and (2) in erythematous rosacea (ETR) versus papulopustular rosacea (PPR). We used bacterial 16S ribosomal RNA gene sequencing on DNA extracted directly from skin samples (nose/cheeks swabs) of participants (21 patients and 21 controls; mean 47.1 years). The V3V4 region of the 16S rRNA gene was targeted, sequenced using Illumina MiSeq, and analysed using the QIIME/Phyloseq software packages. Our final sequence dataset contained 4,036,167 16S rRNA sequences clustered into a total of 1,593 species-level operational taxonomic units. In-depth differential abundance analyses using DESeq2 revealed several statistically significant differences of discrete bacterial taxa between patients and controls, but did not reveal significant differences between ETR (n=12) and PPR (n=9) subtypes. Cheeks microbiota of rosacea patients was significantly enriched in bacteria from the genus Finegoldia magna (log2 mean fold change: 4.44; p<0.005), but had a significantly lower relative abundance of Propionibacterium acnes (-3.48; p<0.005) compared to controls. The nose microbiota of patients had significantly higher levels of Corynebacterium kroppenstedtii (4.35; p< 0.005). Our data demonstrate that specific bacterial genera are highly associated with rosacea, and other strains are enriched in healthy skin. Finegoldia magna and C. kroppenstedtii may have important roles in rosacea pathophysiology and could be future targets for therapeutic interventions.

Finegoldia magna and Corynebacterium kroppenstedtii are significantly enriched in rosacea independent of rosacea subtype: Results of a case-control study