Multidrug resistant bacterial infections are currently a global threat to human and animal health. Increasing resistance of pathogenic bacteria to multiple antibiotics has resulted in the urgent need to develop alternative, effective therapies e.g. the phage therapy. Phage therapy uses lytic bacteriophages to effectively treat chronic bacterial infections, and has no negative effects on eukaryotic cells.
The aim of this study was the characterization of a series of phages, isolated from environmental samples, in terms of their potential use in the treatment of domestic animals` infections. To achieve this goal, we used a chemostat system, which enabled us to analyze the kinetics of adsorption and development of phages in slowly growing bacteria under diverse conditions. This system more closely mimics the conditions occurring in the natural environment of phages than the so-called standard laboratory conditions (reach medium, great aeration and the optimal temperature) do.
We analyzed the development of a series of bacteriophages in slowly growing Staphylococcus pseudintermedius, Pseudomonas aeruginosa and Klebsiella pneumoniae cultures. The specific growth rate used was µ=0.2.The kinetics of adsorption and one-step growth experiments were carried out under aerobic and anaerobic conditions. The results obtained revealed that the adaptation of phage development to bacterial growth rate was is the range of good to very weak.
In our view, phages which demonstrate ability to develop in bacteria growing in a chemostat system show much greater potential for being used in phage therapy than phages identified in the standard plaque analyses and host range tests. Moreover, experiments in a chemostat system could be a good alternative to expensive analyses of the efficiency of phage therapy in animal models.