Forensic Analysis in Bacterial Pathogens

Microbiology began as the study of organisms that could not be easily seen with the naked eye. It then evolved into a science focused on microbes that impacted human health and industrial processes that could also be isolated, cultured, and studied in detail. The bacterium Bacillus anthracis, the causative agent for anthrax, had an important role in the beginnings of medical microbiology. It has been more than 115 years since seminal studies helped lay the foundation for research in bacterial pathogenesis, but a highly visible anthrax letter attack case and evolution of drug-resistant markers means that these same pathogens are still at a forefront that demands significant research efforts. Significant progress has been made since the anthrax-letter attacks (2001, USA) in defining molecular forensic approaches to investigate potential biocrimes. Here the current status is described for genotyping and analysis of the bacterial pathogens Bacillus anthracis, Yersinia pestis, Francisella tularensis, Brucellaspp., Burkholderia pseudomallei, and Clostridium botulinum. C. botulinumis unusual in that genomes represent several distinct species and the clonal nature of the organism is somewhat obscured by the diverse toxin complexes. With the exception of B. pseudomallei, these bacterial pathogens are basically clonal organisms that do not possess the mating properties and the independent assortment statistics that enhance human and plant forensic analyses greatly. Despite this, a hierarchical approach can now be proposed for most of these pathogens to provide the highest possible resolution for epidemiologic and forensics applications.