Development of deterministic and stochastic models for a T7 phage-E. coli system with vaccination strategy implementation

Abigail Smith, from Carnegie Mellon University, worked with Reni Kaul in the lab of Dr. John Drake to develop models to study the effectiveness of vaccination strategies.

Abigail L. Smith1, RajReni B. Kaul2 and John M. Drake2

1Carnegie Mellon University, 2Odum School of Ecology, University of Georgia

Vaccination is widely considered the most effective method of preventing the spread of infectious disease.  Pulse vaccination strategy, the repeated application of a vaccine over a defined population at a set time interval is gaining prominence as a strategy for the elimination of diseases such as measles, hepatitis, and smallpox. In order to study the effectiveness of this strategy, a bench experiment will be designed using E.coli bacteria and T7 bacteriophage, and studying the interactions and mechanisms in a chemostat. Using this system allows us to study the spread of infectious disease in laboratory setting. To test vaccination in system, a concentration of IPTG will be used to induce expression of the rcsA gene (immunity) in E. coli. Results can be generalized from an experimental bench system (E. coli bacteria and T7 phage) by developing a deterministic compartmental model, and then factoring in noise to form a stochastic model. Additional classes were added to track phage populations and experiment with vaccination strategy.  Preliminary studies were designed to study early warning signs for approaching a bifurcation point and critical slowing down, by examining the phage being driven to extinction.


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Photo credit: School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry, CV4 7AL