The skin microbes that people leave behind may be used to identify them, even after other people have touched the same surface!
Microbe of the episode
Microbe of the episode: Actinobacillus lignieresii
The microbial communities in and on our bodies are highly complex and highly varied between people; this complexity has raised the question of whether the microbes that people transfer onto things they touch could be used in forensics, to track their movement and activity, like fingerprints or DNA evidence. One difficulty with this approach is that microbe communities are constantly changing as conditions change or other microbes are introduced.
This study simulated such microbial tracking in a couple of scenarios, such as touching door handles in an office building and touching various surfaces in a home in a mock burglary. Tracking a person on door handles worked fairly well for up to an hour after the contact, even if other people had also touched the same door handles. However, the accuracy of identifying the "burglar" in a home was not very high, but modifying the analysis from looking at the community as a whole to only rare microbes relatively unique to an individual improved the results.
Hampton-Marcell JT, Larsen P, Anton T, Cralle L, Sangwan N, Lax S, Gottel N, Salas-Garcia M, Young C, Duncan G, Lopez JV, Gilbert JA. 2020. Detecting personal microbiota signatures at artificial crime scenes. Forensic Sci Int 313:110351.
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