Mostly Biomathematics Lunchtime Seminar

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Modeling biofilms in medical environments

Speaker: Ana Carpio, Universidad Complutense de Madrid

Location: Warren Weaver Hall 1314

Date: Tuesday, October 30, 2018, 12:30 p.m.

Synopsis:

Biofilms are a major cause of hospital acquired infections. In their biofilm habitat, bacteria attach to moist surfaces, and to each other, enveloped by a self-produced polymeric matrix which shelters them from antibiotics and disinfectants. Understanding the way biofilms form and propagate may help to fight them. Biofilms spreading in flows often start as filaments, whereas biofilms growing at interfaces usually expand forming sheets. We want to develop mathematical models for both types of biofilm spreading behavior.  Firstly, we will see that discrete rod models capture the formation of helical biofilms in medical flow circuits, as well as basic features of the interaction of biofilm filaments with the current. The observed patterns are equilibria of adequate energy functionals.  The spread of biofilm sheets at interfaces is more complex because it combines solid-like and fluid-like behaviors. By considering the biofilm a solid-fluid mixture (or a poroelastic material, as many tissues), we can simulate the observed formation of wrinkled biofilm sheets that expand due to bacterial division and water intake from the environment by osmosis. Biofilm dynamics is governed by a system of conservation laws, coupled to elasticity and reaction-diffusion equations. The motion of the biofilm boundaries can be tracked by a combination of Von Karman and thin film approximations. Terms representing cellular activities may be estimated from agent-based models by filtering techniques.