title: Microbiota fingerprints lose individually identifying features over time.
abstract: Humans host individually unique skin microbiota, suggesting that microbiota traces transferred from skin to surfaces could serve as forensic markers analogous to fingerprints. While it is known that individuals leave identifiable microbiota traces on surfaces, it is not clear for how long these traces persist. Moreover, as skin and surface microbiota change with time, even persistent traces may lose their forensic potential as they would cease to resemble the microbiota of the person who left them. We followed skin and surface microbiota within households for four seasons to determine whether accurate microbiota-based matching of individuals to their households could be achieved across long time delays.
  
  
  
  While household surface microbiota traces could be matched to the correct occupant or occupants with 67% accuracy, accuracy decreased substantially when skin and surface samples were collected in different seasons, and particularly when surface samples were collected long after skin samples. Most OTUs persisted on skin or surfaces for less than one season, indicating that OTU loss was the major cause of decreased matching accuracy. OTUs that were more useful for individual identification persisted for less time and were less likely to be deposited from skin to surface, suggesting a trade-off between the longevity and identifying value of microbiota traces.
  
  
  
  While microbiota traces have potential forensic value, unlike fingerprints they are not static and may degrade in a way that preferentially erases features useful in identifying individuals.
authors.affiliation: School of Energy and Environment, City University of Hong Kong, B5423-AC1, Tat Chee Avenue, Kowloon, Hong Kong, Special Administrative Region of China.
authors.forename: David
authors.initials: D
authors.lastname: Wilkins
authors.affiliation: School of Energy and Environment, City University of Hong Kong, B5423-AC1, Tat Chee Avenue, Kowloon, Hong Kong, Special Administrative Region of China.
authors.forename: Marcus H Y
authors.initials: MH
authors.lastname: Leung
authors.affiliation: School of Energy and Environment, City University of Hong Kong, B5423-AC1, Tat Chee Avenue, Kowloon, Hong Kong, Special Administrative Region of China. patrick.kh.lee@cityu.edu.hk.
authors.forename: Patrick K H
authors.initials: PK
authors.lastname: Lee
mesh_terms: D000391:Air Microbiology; D016172:DNA Fingerprinting; D000068598:Data Accuracy; D005191:Family Characteristics; D044707:Forensic Sciences / Q000379:methods; D006801:Humans; D064307:Microbiota / Q000235:genetics*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012621:Seasons; D012867:Skin / Q000382:microbiology*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: Built environment; Forensics; Microbiota; Skin microbiota