Designer Bugs: Structural Engineering to Build a Better Mouse Model

Many animal models of bacterial diseases are hampered by differences in tissue tropism and the course of pathogenesis. In a recent issue of Cell , by rationally mutating a surface invasion protein (InlA) to have higher binding affinity for its cognate host receptor (E-cadherin), Wollert et al. were able to "murinize" Listeria monocytogenes , creating a strain capable of invading intestinal epithelial cells in mice, mimicking the route of infection in humans.