Phages as a potential biocontrol of phytobacteria

The ability of agriculture to continuously feed a growing world population depends essentially on the use of effective and sustainable strategies to control crop diseases. Currently used bacterial infection control strategies, involving antibiotics, pose a real threat to the environment and to human health, and are losing efficiency due to the appearance of bacterial resistance to these agents. The use of bacteriophages presents an attractive option to control plant bacterial pathogens. Numerous successful experiments and comprehensive studies have been published on bacteriophage-based biocontrol measures, discussing detailed results of phage application practices in pest management. They have led to a renewed interest in phages for the control of plant diseases caused by phytobacteria. The present review highlights the application of phages as a new therapy strategy, and looks at different challenges facing phages as biocontrol agents in agriculture. We emphasize the use of phage cocktails to prevent bacteriophage resistance and to enhance efficacy, and we discuss the different methods for the development of phage cocktails. We present protective formulations used inprevious research on stabilization and storage of phage, and propose lyophilization as a privileged method for maintaining phage viability. Herein we focus on bacteriophage-mediated control of fire blight, the most destructive bacterial disease of apples and pears, which is caused by Erwinia amylovora.