Resilience of the Hand Microbiome: Pilot Study on the Effects of Alcohol Based Hand Sanitizer

Assessing ecological responses to hand hygiene events is important in understanding the development of the hand microbiome as well as in assessing mildness and efficacy of hygiene products. This process of recovery and approaches for assessing it have not been well explored, though its understanding is essential to improved hand hygiene practices. Here we combined 16S rDNA qPCR with 16S rDNA sequencing to obtain semi-quantitative data on microbial shifts related to hand hygiene. Six female subjects underwent high-frequency alcohol-base hand sanitizer use (forty times in four hours), with microbiome samples collected before, immediately after, and 3 hours-post treatment, utilizing glovejuice and swab collection methods which were randomized to dominant/nondominant hand. Using pattern-based clustering, response of individual OTUs to alcohol based hand sanitizer was classified, with six resultant temporal patterns. Glovejuice sampling was highly effective for microbiome collection but appeared to remove natural reservoirs that allow efficient recovery of the microbiome. For shorter-term timeseries studies, swabs were less destructive sampling method, showing quicker recovery in both total bacterial yield and in prevalence of OTUs. Refinement and development of methods for quantifying the ecological response to perturbations will further our understanding of this complex community and its relation to hand health.