Spotlight Microbiology A Systems Approach

VWB Blog 6 years ago 5

What if instead of fingerprints, crime scene investigators looked for patterns of specific bacteria left behind by suspects?  Noah Fierer at the University of Colorado, Boulder studied the variability in bacterial communities on human fingertips, and found that this scenario isn’t as unlikely as you may think.

Fierer and his colleagues took samples from computer keyboards and computer mice, analyzed the bacterial DNA from the samples, and came up with a bacterial “fingerprint” that could be matched to the individual that had used the keyboard or mouse.  His analysis showed that there is only about a 13{0769f9e165250301569ce67f54c3b81bedf5c586a0e9647f6b8ae1e655ecebb0} correspondence of bacterial species between any two individuals and that these communities of bacteria on the skin are stable over time, recovering within a few hours after washing.

Current forensic analysis requires  DNA from a crime scene (blood, semen, tissue, or saliva) to amplify, analyze, and match to a suspect.  Bacterial cells are highly abundant on skin surfaces and their DNA is much easier to recover and amplify.  Further testing is needed to determine if these methods could actually be feasible for use in forensics, but Fierer brings up an excellent question:  “Could our microbial fingerprint be more personally identifying than our human genome?”

Fierer’s work is part of a much larger project designed to identify and study the microbes that live on and in our bodies:  The Human Microbiome Project (HMP).  Using techniques such as concentration measurement developed for the Human Genome Project and J. Craig Venter’s quest to discover novel microbes in the oceans, the HMP was launched to study all of the microbes colonizing the human body.  The goal of the HMP is to sequence as many as 3000 genomes from cultured and uncultured bacteria as well as other microbes such as archaea, fungi, and protozoa that make up the human microbiome.  This preliminary genome collection will serve as a reference to determine if there is a “core microbiome” common to all human beings.  The main body sites that are being studied are the oral cavity, skin, vagina, gut, and nasal/lung cavities.  At the same time, the HMP is studying the relationship between diseases and changes in the human microbiome.  Thousands of peer-reviewed publications have been generated from this project.


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