Chapter 39, Problem 4CHI

While many Vibrio cholerae strains are found in aquatic environments, only a small fraction of these cause human disease. When in aquatic ecosystems, V. cholerae is frequently found attached to the exoskeleton of zooplankton, which is made of chitin. Indeed, V. cholerae produces an extracellular chitinase, so zooplanktonassociated growth presumably provides a good source of organic carbon and nitrogen. Growth on zooplankton and in the human gut shares the requirement for attachment proteins. Remarkably, the same protein, called GbpA, has been shown to bind to both the N-acetylglucosamine (GlcNAc) of zooplankton chitin and to epithelial cells. The glycoproteins and lipids on the surface of epithelial cells are commonly modified with GlcNAc. How would you show whether or not GbpA binds specifically to epithelial GlnNAc? How would you determine if GbpA is needed for virulence? How would you test the hypothesis that GbpA is produced by pathogenic strains but not, or to a lesser extent, by nonpathogenic strains of V. cholerae?

Read the original paper: Kirn, T. J., et al. 2005. A colonization factor links Vibrio cholerae environmental survival and human infection. Nature 438:863.