title: Forensic analysis of the microbiome of phones and shoes.
abstract: BACKGROUND
  Microbial interaction between human-associated objects and the environments we inhabit may have forensic implications, and the extent to which microbes are shared between individuals inhabiting the same space may be relevant to human health and disease transmission. In this study, two participants sampled the front and back of their cell phones, four different locations on the soles of their shoes, and the floor beneath them every waking hour over a 2-day period. A further 89 participants took individual samples of their shoes and phones at three different scientific conferences.
  
  
  RESULTS
  Samples taken from different surface types maintained significantly different microbial community structures. The impact of the floor microbial community on that of the shoe environments was strong and immediate, as evidenced by Procrustes analysis of shoe replicates and significant correlation between shoe and floor samples taken at the same time point. Supervised learning was highly effective at determining which participant had taken a given shoe or phone sample, and a Bayesian method was able to determine which participant had taken each shoe sample based entirely on its similarity to the floor samples. Both shoe and phone samples taken by conference participants clustered into distinct groups based on location, though much more so when an unweighted distance metric was used, suggesting sharing of low-abundance microbial taxa between individuals inhabiting the same space.
  
  
  CONCLUSIONS
  Correlations between microbial community sources and sinks allow for inference of the interactions between humans and their environment.
authors.affiliation: Institute for Genomics and Systems Biology, Biosciences Department, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 USA ; Department of Ecology and Evolution, University of Chicago, 1101 E 57th Street, Chicago, IL 60637 USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Lax
authors.affiliation: Institute for Genomics and Systems Biology, Biosciences Department, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 USA.
authors.forename: Jarrad T
authors.initials: JT
authors.lastname: Hampton-Marcell
authors.affiliation: Institute for Genomics and Systems Biology, Biosciences Department, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 USA ; Graduate Program in Biophysical Sciences, University of Chicago, 5801 South Ellis Avenue, Chicago, USA.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Gibbons
authors.affiliation: Departamento de Biologia, Universidade Federal do Ceará, Avenida da Universidade, 2853 - Benfica, Fortaleza, CE 60440-900 Brazil.
authors.forename: Geórgia Barguil
authors.initials: GB
authors.lastname: Colares
authors.affiliation: Institute for Genomics and Systems Biology, Biosciences Department, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 USA ; Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030 USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Smith
authors.affiliation: Department of Evolution and Ecology, University of California, 1544 Newton Ct, Davis, CA USA ; Department of Medical Microbiology and Immunology, University of California, 1544 Newton Ct, Davis, CA USA ; UC Davis Genome Center, University of California, 1 Shields Avenue, Davis, CA USA.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Eisen
authors.affiliation: Institute for Genomics and Systems Biology, Biosciences Department, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 USA ; Department of Ecology and Evolution, University of Chicago, 1101 E 57th Street, Chicago, IL 60637 USA ; Graduate Program in Biophysical Sciences, University of Chicago, 5801 South Ellis Avenue, Chicago, USA ; Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543 USA ; College of Environmental and Resource Sciences, Zhejiang University, 38 Zheda Road, Hangzhou, 310058 China.
authors.forename: Jack A
authors.initials: JA
authors.lastname: Gilbert
keywords: Forensic microbiology; Microbial time series; Phone microbiome; Shoe microbiome; Source-sink dynamics