Fig. 1
From: Outside-host phage therapy as a biological control against environmental infectious diseases
Bifurcation diagrams of the model dynamics in the absence of the phage-resistant bacteria population (B = 0), presenting equilibrium values of the susceptible host (S), the infected hosts (I), the pathogen (P) and the bacteriophage (F) population densities for the phage transmission rate, 10− 8<β F < 10− 4. The x-axis is log10 scale. When the phage transmission rate is low (β F < 10− 7), the susceptible and the infected hosts go asymptotically extinct while there is a stable coexistence of the pathogen and the phage. When the phage transmission rate increases, the pathogen population size decreases while the susceptible host population increases, close to their carrying capacity at higher phage transmission rates. The number of the infected hosts abruptly increases as phage transmission increases, but decrease asymptotically towards zero at higher phage transmission rates. The parameter values used are shown in Table 1. Pathogen level in the absence of the host and phage is indicated by “◊”. The coexistence equilibria of the pathogen and the phage in the absence of the host are denoted by “o”. The equilibrium solutions of all populations in the presence of the phage are denoted by “*”