The Skin Microbiota in Patients Hospitalized for Cellulitis and Association With Outcome.

BACKGROUND: The skin microbiota plays a key role in the pathogenesis of several skin diseases, but its role in cellulitis remains unknown. We investigated the skin microbiota in patients with cellulitis, studied whether its analysis could help determine the causative pathogen, and explored whether skin microbiota composition was associated with clinical outcomes.

METHODS: We prospectively included 58 patients hospitalized for cellulitis. Skin swabs obtained from the lesion sites were compared with swabs from identical sites on the contralateral unaffected limbs and with swabs obtained from 19 age- and sex-matched control subjects without cellulitis. Bacterial profiling of the skin microbiota was performed by interspacer profiling (IS-pro).

RESULTS: A large interpersonal variation in the skin microbiota composition of patients hospitalized with cellulitis was observed. Firmicutes were the dominant phylum, and Staphylococcus and Streptococcus the dominant genera. In most patients, a strong correlation between the microbiota of the affected lesion and the microbiota of the unaffected, contralateral limb was seen. Overall, the composition of the cellulitis microbiota could not be distinguished from the skin microbiota of controls. No consistent association could be found between traditional culture results and skin microbiota signatures in patients with cellulitis. Lastly, we found that neither microbiota composition nor diversity were associated with clinical parameters and outcomes in patients with cellulitis.

CONCLUSIONS: In this exploratory study on the skin microbiota in patients hospitalized with cellulitis, we were unable to identify a typical cellulitis microbiota. The diagnostic and prognostic information that could be derived from skin microbiota profiling in this patient cohort was limited.

CLINICAL TRIALS REGISTRATION: NCT02032654.