Bacteria on skin new source of forensic ID
Sydney Morning Herald
Tuesday March 16, 2010
SCIENTISTS have found that the bacteria on your skin are so unique that when you touch an object you leave a bacterial "fingerprint". The research could lead to a new type of forensic identification.The lead researcher, Rob Knight of Colorado University, said recent research had established that the bacterial communities carried by humans differed between individuals and within a single human body."Only 13 per cent of bacterial [communities] on the [surface of the palm] are shared between any two individuals," wrote the authors of the study.Dr Knight and his colleagues then wondered if individuals could be identified by the bacteria found on their body, as they can from their fingerprints.Swabs were taken from individuals' fingers and the DNA of the bacteria was compared to the DNA of the bacteria found on the subjects' computer keyboards.Dr Knight said the bacterial communities on the keyboards were very similar to those on the fingertips of the keyboard users. But he said the bacteria found on both the keyboard and fingertips were quite different from person to person."As soon as we saw the degree of personalisation in the microbes we thought this could be really important for forensics."In the second part of the study Dr Knight collected bacteria samples from computer mice and compared them with a database of 270 other bacteria samples collected from people's palms, including the palms of the mice users. Dr Knight said they were able to match the bacteria on the mice with the bacteria on the hand of the mice users with a 90 per cent accuracy."When you type you are leaving behind a random selection of the bacteria that are on your fingertips. Those bacteria can be detected and traced back to you later on."Skin bacteria could be an effective source of identification because they could survive on keyboards for up to two weeks at room temperature, said Dr Knight, whose findings are published in the Proceedings of the National Academy of Science.
© 2010 Sydney Morning Herald
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