Persistence in phage-bacteria communities with nested and one-to-one infection networks

We show that a bacteria and bacteriophage system with either a perfectly nested or a one-to-one infection network is permanent, a.k.a uniformly persistent, provided that bacteria that are superior competitors for nutrient devote the least to defence against infection and the virus that are the most efficient at infecting host have the smallest host range. By ensuring that the density-dependent reduction in bacterial growth rates are independent of bacterial strain, we are able to arrive at the permanence conclusion sought by Jover et al [3]. The same permanence results hold for the one-to-one infection network considered by Thingstad [9] but without virus efficiency ordering. In some special cases, we show the global stability for the nested infection network, and obtain restrictions on the global dynamics for the one-to-one network.