Microbial forensics: next-generation sequencing as catalyst: The use of new sequencing technologies to analyze whole microbial communities could become a powerful tool for forensic and criminal investigations.

Abstract

When Antonie van Leeuwenhoek experimented with his microscopes in the late 17th century, he observed, among many other small things, bacteria from the mouth cavity. van Leeuwenhoek's detailed descriptions of bacteria, spermatozoa, and cells marked the beginning of microbiology; his successors Robert Koch and Louis Pasteur stoked further interest in the microbial world with their discoveries of the role of bacteria in disease and fermentation. The light microscope was eventually augmented by ever more powerful tools—electron microscopes, fluorescence microscopy, RNA arrays, and DNA sequencers—to study the members of the microbial world and their interactions with each other and their host organisms, particularly humans. One technique in particular has revolutionized microbiology: next‐generation sequencing (NGS) or massive parallel sequencing [1]. The ability to sequence a mixture of millions of DNA molecules within one analytical run has created new opportunities to analyze whole communities of microbes rapidly and efficiently, including many species that cannot be cultured in the laboratory. New methods for RNA analysis have also tremendously improved microbiologists' ability to look at the molecular activities not just within single cells but whole bacterial communities. In addition to inspiring new research in microbiology, NGS will likely have a major impact on forensic science and eventually become a new tool in police work and court cases. The forensic value of microbiology became apparent during the investigation of the anthrax attacks 1 week after the terrorist attack on September 11, 2001. Letters that contained spores of Bacillus anthracis were mailed to two US Democratic senators and various media offices in the USA. Twenty‐two persons who opened these letters were infected with B. anthracis and five people died. The major challenge for forensic science, as part of the FBI's investigation, was to attribute the source of the bacterial spores in order to identify …