Phage modeling

(Bacterio)Phages

• Are viruses of bacteria
• Often kill bacteria (lytic phage)
• Have been considered as treatment options
• Have been studied with models

Phage modeling example

Modeling the Phage Properties Best for Therapy

“…The approach here involves three conceptual steps. The first is to construct a computa- tional model to represent an infection and possible treatments. Second, a criterion is chosen to represent success versus failure from treatment. Third, different possible treatment designs or variables (i.e., phage characteristics) are numerically investigated to decide how often success results…”

A phage model

\[ \begin{aligned} \textrm{Uninfected Bacteria} \qquad \dot{B} & = rB - dB - kBP \\ \textrm{Infected Bacteria} \qquad \dot{I} & = kBP - d I - \lambda I\\ \textrm{Phage} \qquad \dot{P} & = b \lambda I - \delta P - kBP \end{aligned} \]

A phage model

Outcome as function of phage property

• Outcome = number of phages needed to reduce bacteria 100-fold
• Phage property = parameter values of the model

Results

Results

Conclusion

A mathematical model of phage therapy suggests which phage characteristics are most likely to impact treatment outcomes and thus should be prioritized when trying to improve phages.