Bacterial Fingerprinting: A Microbial Future on CSI?
In 1915, detectives dusted for physical fingerprints. In 1990, they started using PCR (polymerase chain reaction) to determine DNA fingerprints from bits of hair and skin. In 2020, scientists might be identifying culprits with a whole new type of fingerprint: a bacterial fingerprint.
A bacterial fingerprint is a unique mix of microbes by which an individual person can be identified. Recently, Rob Knight, Noah Fierer, and their colleagues at University of Colorado in Bounder swabbed bacteria off of computer mice and used the DNA of that bacteria to identify individual subjects.1 The scientists also showed that these bacterial fingerprints are durable: even after bacteria were left on the exposed surface for two weeks, the scientists could still swab, extract, and match the bacterial DNA to its correct human origin.
Bacterial fingerprints can also be used to “catch” people in ways other than just linking them to the scene of a crime. Molecular epidemiology (the use of molecular biology to trace outbreaks of microbial diseases) already helps to identify cases such as:
- medical negligence resulting in patient infection, or
- negligent or intentional contamination of food, resulting in disease.
To make bacterial fingerprints useful, a repository of microbial DNA with which samples can be matched is necessary. Such initiatives are already underway, such as Pulsenet, run by the U.S. Centers for Disease Control, which collects the DNA identities of disease-causing bacteria such as E. coli, Salmonella, and Listeria. Additionally, the NIH-funded Human Microbiome Project aims to analyze and record 1000 bacterial genomes.
Read “The four faces of microbial forensics,” an article describing potential uses for microbial forensics in the context of law enforcement and national security.2
Read “Microbial Forensics: A Scientific Assessment,” a report by the American Academy of Microbiology concerning the future of microbial forensics.
Watch a slideshow to learn more about molecular epidemiology.
1. Fierer, N., Lauber, C., Zhou, N., McDonald, D., Costello, E., & Knight, R. (2010). From the Cover: Forensic identification using skin bacterial communities Proceedings of the National Academy of Sciences, 107 (14), 6477-6481 DOI: 10.1073/pnas.1000162107
2. Tucker JB, & Koblentz GD (2009). The four faces of microbial forensics. Biosecurity and bioterrorism : biodefense strategy, practice, and science, 7 (4), 389-97 PMID: 20028247