Bacterial wilt caused by R. solanacearum is one of the most devastating diseases of many economically important crops in Thailand such as ginger, pepper, tomato, potato and Curcuma alismatifolia Gagnep. At present, protection from losses by bacterial wilt is achieved mainly by early detection and subsequent eradication by destroying the host usually by using chemical bacteriocides.

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To find an alternative to chemical bacteriocides, scientists explored the use of bacteriophages as biological control agents for R. solanacearum. Fourteen phages infecting R. solanacearum were isolated from soil samples collected in tomato fields in Chiang Mai, Thailand. The phages showed different host ranges when tested against 59 R. solanacearum strains isolated from Thailand and Japan. These phages were characterized as nine podoviruses and five myoviruses based on their morphology. The podoviruses isolated in this study showed strong lytic activity and wide host ranges. Therefore, these phages have potential uses in the decontamination of pathogen-infected field soils. Phage J2 demonstrated an ability to prevent bacterial wilt of tomato in pot experiments.

This study is a collaboration between BIOTEC, Kasetsart University and Hiroshima University (Japan).

Ref: Bhunchoth, A., Phironrit, N., Leksomboon, C., Chatchawankanphanich, O., Kotera, S., Narulita, E., Kawasaki, T., Fujie, M. and Yamada, T. (2015) Isolation of Ralstonia solanacearum-infecting bacteriophages from tomato fields in Chiang Mai, Thailand, and their experimental use as biocontrol agents. Journal of Applied Microbiology, 118(4), 1023-33.