11 December 2019 - Seminars - Exploring post-primary infection in Mycobacterium tuberculosis using a hybrid discrete-continuum cellular automaton model


Speaker: Dr Ruth Bowness (University of St Andrews)

Time: Wednesday December 11, 13:00 - 14:00

Title: Exploring post-primary infection in Mycobacterium tuberculosis using a hybrid discrete-continuum cellular automaton model

Venue: MATH-103, First Floor, Department of Mathematical Sciences Building

Co-hosted by the Mathematical Biology seminar series

Abstract: Tuberculosis (TB) is an infectious bacterial disease caused by Mycobacterium tuberculosis.  Despite significant recent advances, TB is the biggest infectious killer globally with someone dying from the disease every 18 seconds.  

When Mycobacterium tuberculosis bacteria enter the lungs, a complex immune response ensues and results in the formation of granuloma structures.  When these granulomas are unable to contain the bacteria, active disease develops. At different degrees of disease severity, patients seek medical assistance, after which antibiotics are prescribed.  The degree of antibiotic penetration into and through the granuloma is uncertain.  The outcome of treatment is complicated by dormancy when the bacteria become temporarily resistant to antibiotics.  

We have developed a hybrid discrete-continuum cellular automaton model to study disease progression and treatment in the lung.  The model contains discrete agents, or individuals, which model the spatio-temporal interactions (migration, binding, killing etc.) of bacteria, macrophages and T cells.  The spatial movement of cells is governed by biased random walks, while the various cell-cell and cell-bacteria interactions are governed by cellular automaton rules.  Chemokine diffusion, oxygen diffusion and a Pharmacokinetic/ Pharmacodynamic model is also incorporated in the model via the numerical solution of appropriate PDEs.  Several definitions and theories regarding bacterial dormancy exist in the literature.  In this work, we use our hybrid cellular automaton model to explore several concepts of dormancy and their effect on treatment outcome. 

Biography: Dr Bowness is an MRC research fellow based in the School of Medicine at the University of St Andrews.  Her research interests lie in developing in host mathematical models for infectious diseases.  Also working with the Mathematical Biology group in the School of Mathematics, her research involves using partial and ordinary differential equations, and individual-based models, to describe infectious disease spread within the body and to simulate antibiotic treatment strategies.  Her current multidisciplinary project focuses on developing a spatial model to describe tuberculosis disease progression and treatment in the lungs.  Ultimately the model will be capable of simulating new therapeutic approaches for multi-drug resistant tuberculosis.