What’s Really on Our Hands?

Despite intense focus on improving hand-hygiene compliance among healthcare workers, little is known about hand-surface bacterial communities. Investigators at the University of Colorado used sophisticated molecular techniques to survey these communities.

Swabs were obtained from each palm of 51 undergraduate students who had just completed a 1-hour exam. The samples were analyzed using PCR amplification with universal 16S rRNA primers and subsequent high-throughput molecular sequencing. Similar analyses were performed for eight individuals from whom palm-surface swabs were obtained immediately after hand-washing and again 2, 4, and 6 hours later.

The average palm had >150 distinct bacterial species-level phylotypes — a number at least an ord…