Longitudinal Dynamics of Skin Bacterial Communities in the Context of Staphylococcus aureus Decolonization

Decolonization with topical antimicrobials is frequently prescribed in health care and community settings to prevent Staphylococcus aureus infection. However, effects on commensal skin microbial communities remains largely unexplored. Within a household affected by recurrent methicillin-resistant S. aureus skin and soft tissue infections (SSTI), skin swabs were collected from the anterior nares, axillae, and inguinal folds of 14 participants at 1- to 3-month intervals over 24 months. Four household members experienced SSTI during the first 12-months (observational period) and were prescribed a 5-day decolonization regimen with intranasal mupirocin and bleach water baths at the 12-month study visit. We sequenced the 16S rRNA gene V1-V2 region and compared bacterial community characteristics between the pre- and post-intervention periods and between younger and older subjects. The median Shannon diversity index was stable during the 12-month observational period at all three body sites. Bacterial community characteristics (diversity, stability, and taxonomic composition) varied with age. Among all household members, not exclusively among the four performing decolonization, diversity was unstable throughout the year post-intervention. In the month after decolonization, bacterial communities were changed. Although communities largely returned to their baseline states, relative abundance of some taxa remained changed throughout the year following decolonization (e.g., more abundant Bacillus; less abundant Cutibacterium). This 5-day decolonization regimen caused disruption of skin bacteria, and effects differed in younger and older subjects. Some effects were observed throughout the year post-intervention, which emphasizes the need for better understanding of the collateral effects of decolonization for S. aureus eradication.