부산대학교 도서관

Simple Summary: Erwinia amylovora is a plant pathogenic bacterium responsible for fire blight, a devastating disease affecting economically important pome fruit trees such as apple, pear, and loquat. Chemical control of this pathogen has shown limited efficacy and poses risks to the environment and global health. The use of viruses that infect bacteria, named bacteriophages, can constitute an ecological alternative for fire blight control. This study aimed to search for E. amylovora-specific bacteriophages in Mediterranean environments where the disease was present. A collection of bacteriophages able to specifically infect and lyse E. amylovora was generated and characterized. The results allowed the description of the phages' biology, interaction with the pathogenic bacterial host, and the selection of some bacteriophages for their potential application in controlling fire blight in the host. Assays in fruits revealed that the preventive application of some of the bacteriophages or their combinations delayed the onset of symptoms and reduced the severity of the disease. This study provides the first European E. amylovora phage cocktails effective in plant material. Our results are an example that environmental microorganisms can offer effective and sustainable natural solutions for the biocontrol of phytopathogenic bacteria to provide safe and healthy food. Fire blight, caused by the plant-pathogenic bacterium Erwinia amylovora, is a highly contagious and difficult-to-control disease due to its efficient dissemination and survival and the scarcity of effective control methods. Copper and antibiotics are the most used treatments but pose environmental and human health risks. Bacteriophages (phages) constitute an ecological, safe, and sustainable fire blight control alternative. The goal of this study was to search for specific E. amylovora phages from plant material, soil, and water samples in Mediterranean environments. A collection of phages able to specifically infect and lyse E. amylovora strains was generated from former fire blight-affected orchards in Eastern Spain. Following in vitro characterization, assays in immature fruit revealed that preventively applying some of the phages or their combinations delayed the onset of fire blight symptoms and reduced the disease's severity, suggesting their biocontrol potential in Spain and other countries. The morphological and molecular characterization of the selected E. amylovora phages classified them as members of the class Caudoviricetes (former Myoviridae family) and genus Kolesnikvirus. This study reveals Mediterranean settings as plausible sources of E. amylovora-specific bacteriophages and provides the first effective European phage cocktails in plant material for the development of sustainable fire blight management measures. [ABSTRACT FROM AUTHOR]