Microbial Forensics via Minority and Rare Varian Profiles
In situations where bacterial pathogens are used in a course of a criminal activity or a bioterrorism event, identification of the exact species and strain used (the “what is it?” question) is reasonably straightforward, provided that a sample with sufficient genetic material can be collected for testing. However, answering the “where did it come from?” question remains difficult, particularly for clonal bacterial pathogens (e.g. B. anthracis, F. tularensis) that are characterized by low genetic variability within bacterial strains. Our work aims to address one of the major questions in microbial forensics: “did query sample A come from source sample B”? Here, we leverage the advances in high throughput sequencing technologies to enable sample attribution via rare variants – SNPs and indels present in very low frequencies in bacterial populations (as low as 0.1%).