Dynamical types of bacteria and bacteriophages interaction: shielding by debris.

The dynamics of the bacteria and bacteriophages interaction process was explored in depth, and laid on a firm basis through simulation and analysis. A modified Campbell model of phage-bacteria interaction was used to simulate three interacting species: bacteria, phages and bacterial debris, and their time behavior in terms of three parameters, in selected range values: the phages burst size (beta), the dissolution rate of the bacterial debris (q), and the lysing time delay (tau). Six types of dynamical behavior were identified, occupying various zones in the two-dimensional (2D) plane (q, beta) for several values of tau, allowing the determination of the region where shielding by bacterial debris is in effect. The problem of the occurrence of stability transitions between stable and unstable dynamical regimes was also addressed analytically, and compared with simulation results.