Type III secretion in the verrucomicrobia

Our knowledge of bacterial pathogen evolution is biased towards well-characterized organisms, and novel bacterial groups for which pathogenic interactions have not been reported are classified as “free-living”. However, under-sampling of these groups may have skewed our perception of their ecological niches. The genomes of some “free-living” bacteria encode elements characteristic for microbial pathogens, such as a Type III secretion system (T3SS). In the absence of experimental data, we do not know whether these elements have a role in pathogenesis. This knowledge gap may have led to a gross underestimation of the extent of the pathosphere, including the reservoir of opportunistic pathogens from which obligate pathogens evolve.

Our long-term goal is to determine the relevance of these elements to the evolution of infectious disease. Our current focus is the Phylum Verrucomicrobia, a group found in association with humans, animals, and plants, but for which specific ecological niches remain undefined. Our  current research is directed towards characterization of predicted pathogenesis determinants in the verrucomicrobia by the integrated application of computational and experimental approaches.