Department of Plant Medicine, Sunchon National University, Sunchon 57922, Republic of Korea.
Department of Biochemistry, University of Otago, Dunedin 9054, New Zealand.
J Med Microbiol. 2020 Jan;69(1):132-138. doi: 10.1099/jmm.0.001115. Epub 2019 Dec 20.
The bacterial pathogen, pv. actinidiae (Psa), has emerged as a major threat to kiwifruit cultivation throughout the world. One pandemic strain (from the Psa3 group) has occurred in various geographical regions. It is important to understand how this pathogen is being transmitted. Although Psa has been found in Korea since 1992, the isolates were until recently of a distinct type (Psa2). Recently, the more virulent Psa3 type has been detected. The purpose of this study was to describe the variety of Psa3 now found in Korea. Strains were isolated from kiwifruit plants in Korea and from pollen imported into Korea from New Zealand. The genomes of 10 isolates were sequenced using the Illumina platform and compared to the completely assembled genomes of pandemic Psa3 strains from New Zealand and China. Comparisons were also made with pandemic strains from Chile and non-pandemic Psa3 isolates from China. Six of the 10 Psa3 isolates from Korea show a clear relationship with New Zealand isolates. Two isolates show a distinct relationship to isolates from Chile; one further isolate has a sequence that is highly similar to that of M228, a strain previously isolated in China; and the last isolate belongs to the Psa3 group, but is not a member of the pandemic lineage. This analysis establishes that there have been multiple routes of transmission of the Psa3 pandemic strain into Korea. One route has involved the importation of pollen from New Zealand. A second route probably involves importation from Chile.
细菌性病原体 pv. actinidiae (Psa) 的出现，对全球范围内的猕猴桃种植构成了重大威胁。一种流行菌株（来自 Psa3 组）已在不同地理区域发生。了解这种病原体是如何传播的非常重要。尽管 1992 年以来韩国就已发现 Psa，但直到最近，分离株都是明显不同的类型（Psa2）。最近，检测到了毒力更强的 Psa3 型。本研究的目的是描述目前在韩国发现的 Psa3 多样性。从韩国猕猴桃植物和从新西兰进口到韩国的花粉中分离出菌株。使用 Illumina 平台对 10 个分离株的基因组进行测序，并与新西兰和中国的大流行 Psa3 流行株的完全组装基因组进行比较。还与智利的流行株和中国的非流行 Psa3 分离株进行了比较。从韩国分离的 10 个 Psa3 分离株中的 6 个与新西兰分离株有明显的关系。两个分离株与智利的分离株有明显的关系；另一个分离株的序列与 M228 高度相似，M228 是以前在中国分离的一株；最后一个分离株属于 Psa3 组，但不属于大流行谱系。该分析表明，Psa3 大流行株已通过多种途径传入韩国。一种途径涉及从新西兰进口花粉。另一种途径可能涉及从智利进口。
