Sean gave a seminar at the MathBio Seminar!

Speaker: Sean McMahon, VT

Date and place: Wednesday, April 1, 1:15-2:15 pm

Title: Modeling growth-mediated motility in Clostridium perfringens 

Abstract: Many bacteria species are able to expedite colony expansion through motility of the cells.  Clostridium perfringens, the primary cause of lethal gas gangrene, exhibit a unique mode of colony expansion.  Chains of cells continuously grow outward from the bacterial colony and curve. These bacteria appear to lack a direct motility mechanism in individual cells, and are hypothesized to rely on bacterial growth to push adjacent cells in the strongly connected cell chains.  Interestingly, these cell chains tend to curve as they grow. Using a “rigid-rod” model we simulate the growth dynamics of these bacteria chains. Our preliminary results suggest that the cell chain curvature cannot result from growth of the cell chain and its interaction with the substrate.  Motivated by the observation that multiple chains growing side-by-side appear to curve more than single chains, we hypothesize that chain curvature may be a result of lateral interactions between cell chains. An expanded version of the rigid-rod model is used to include these lateral interactions and also implements collision dynamics between cells in adjacent chains.  Ultimately, we will use these mathematical models to investigate if this expansion mode of C. perfringens could be advantageous for spreading and surviving on different substrates and environments the bacteria may encounter during their opportunistic life cycle.