A research group led by Assistant Professor Kensaku Maejima of the University of Tokyo discovered that temporary attenuation was involved in the invasion and spread of plum pox virus (PPV) from overseas.
In recent years, unexpected outbreaks of infectious diseases that do not reside in Japan, such as dengue fever and classical swine fever, have become a social problem.
Plum pox virus (PPV), one of the most important pathogens of fruit trees and was wary of invasion, was first confirmed in 1.After that, a total of about 2009 million nationwide surveys associated with the eradication project found infected trees in 300 prefectures from Kanto to Kansai, but the reason for the infection was unknown in most of them, and the invasion and spread of PPV in Japan. The cause and route were unknown.
This time, the researchers determined the entire genome sequence of more than 200 PPV isolates comprehensively collected from the outbreak areas in Japan, and performed large-scale and highly accurate molecular epidemiological analysis.The results showed that there were two different populations that were presumed to have invaded separately from Western Europe, and that PPV invasion occurred twice from Western Europe.
In addition, it was found that these two populations are distributed mainly in the Kanto and Kansai regions, respectively, and the distribution has expanded to various places centered on Tokyo in the Kanto region and Osaka prefecture in the Kansai region.In addition, PPV in Kansai mutates a specific amino acid site to an attenuated form when it invades Japan, and in the subsequent diffusion process in Japan, it restores the original pathogenicity or develops a new pathogenicity that has never existed before. It turned out that I was getting it.Such temporary attenuation is thought to have favored the PPV as it passed through the quarantine and expanded its distribution, and in the expansion of the distribution of infectious diseases in which the pathogenicity is restored or diversified after the temporary attenuation. A new mechanism has been revealed.
Since unexpected invasion of infectious diseases may occur in the future by the same mechanism, it is necessary to further enhance countermeasures such as development and dissemination of ultra-sensitive inspection technology that can detect even a very small amount of pathogen. It can be said that the sex was shown.
Paper information:[Molecular Plant Pathology] Intra-strain biological and epidemiological characterization of plum pox virus
