Analysis of Volatile Metabolites during Phage-Bacteria Infection via Gas Chromatography/Mass Spectrometry

There are currently no methods for the rapid and specific analysis of potential biological weapons in a field setting. While not yet tested, solid-phase microextraction (SPME) coupled with field-portable mass spectrometry (MS) provide a strong platform to rapidly sample, analyze and specifically detect these possible threats. This project involves the development of a method based on the production of volatile metabolites during the infection of a bacterial species with a specific phage. Lytic bacteriophages infect cells and cause them to rupture, releasing intracellular metabolites not otherwise externally detectable. Given that bacterial taxa produce a variety of metabolites, it is hypothesized that the introduction of a phage mixture to bacteria can be used for fast and accurate identification using the bacterial-infection-specific volatile metabolite fingerprint. Working with Escherichia coli and Lactococcus lactis as bacterial model systems, we sample the headspace of both infected and non-infected cultures using SPME, then use gas chromatography/mass spectrometry (GC/MS) to analyze the metabolites present. Current work is aimed at detecting differences in the metabolites produced under different infection states. Viability of this approach will lead to future work applying this method for the detection of human bacterial pathogens, such as Bacillus anthracis (anthrax).