Erwinia amylovora bacteriophages as biological agents for targeted and sustainable fire blight management.

Fire blight, caused by the Gram-negative bacterium Erwinia amylovora, is one of the most destructive diseases of pome-fruit crops worldwide. Despite decades of research, its management remains challenging because efficient and sustainable control options are limited, and many commercially important apple and pear cultivars remain highly susceptible. Conventional treatments for bacterial disease suppression are often hindered by inconsistent efficacy, phytotoxic effect, environmental concerns and regulatory restrictions, necessitating new sustainable alternative options. Virulent bacteriophages have emerged as promising biocontrol agents for controlling E. amylovora due to their unique biological properties, including a distinct mode of action, capacity to replicate within bacterial cells and high host specificity. These features enable effective suppression of pathogen populations, while potentially minimizing impact on non-target microbiota, depending on their host range and ecological interactions. However, further research is needed to better understand phage-host interactions, safety issues, and the environmental factors that influence phage efficacy in field application. Furthermore, combining phages with other compatible management approaches may improve disease control and help mitigate the emergence of resistant pathogen populations. This narrative review summarizes the key characteristics of E. amylovora phages, and recent advances in phage-based fire blight control, highlighting their potential role in integrated and sustainable disease management strategies.