Bayesian Integrated Microbial Forensics

In the aftermath of the 2001 anthrax letters, researchers have been exploring ways to predict the production environment of unknown-source microorganisms. Culture medium, presence of agar, culturing temperature, and drying method are just some of the broad spectrum of characteristics an investigator might like to infer. The effects of many of these factors on microorganisms are not well understood, but the complex way in which microbes interact with their environments suggests that numerous analytical techniques measuring different properties will eventually be needed for complete characterization. In this work, we present a Bayesian statistical framework for integrating disparate analytical measurements. We illustrate its application to the problem of characterizing the culture medium of Bacillus spores using three different mass spectral techniques. The results of our study suggest that integrating data in this way significantly improves the accuracy and robustness of the analyses.