Numerous pathogens perturb mitochondrial activity as part of their specific virulence programs. The Haynes Lab has found that one mechanism by which metazoans differentiate commensal and toxic bacteria such as Pseudomonas aeruginosa is by monitoring mitochondrial activity. Because nearly all mitochondrial toxins are produced by microbes, this mechanism allows cells to simply monitor an intra-cellular activity rather than evolve strategies to detect millions microbes simultaneously. Researchers in the Haynes Lab use C. elegans and mammalian models to examine mitochondria-pathogen interactions.