Isolation of Nine Bacteriophages Shown Effective against Erwinia amylovora in Korea.

Erwinia amylovora is a devastating bacterial plant pathogen that infects Rosaceae including apple and pear and causes fire blight. Bacteriophages have been considered as a biological control agent for preventing bacterial infections of plants. In this study, nine bacteriophages (ΦFifi011, ΦFifi044, ΦFifi051, ΦFifi067, ΦFifi106, ΦFifi287, ΦFifi318, ΦFifi450, and ΦFifi451) were isolated from soil and water samples in seven orchards with fire blight in Korea. The genetic diversity of bacteriophage isolates was confirmed through restriction fragment length polymorphism pattern analysis. Host range of the nine phages was tested against 45 E. amylovora strains and 14 E. pyrifoliae strains and nine other bacterial strains. Among the nine phages, ΦFifi044 and ΦFifi451 infected and lysed E. amylovora only. And the remaining seven phages infected both E. amylovora and E. pyrifoliae. The results suggest that the isolated phages were different from each other and effective to control E. amylovora, providing a basis to develop biological agents and utilizing phage cocktails.