Genomic Variation and Evolution of Vibrio parahaemolyticus ST36 over the Course of a Transcontinental Epidemic Expansion.
Genomic Variation and Evolution of Vibrio parahaemolyticus ST36 over the Course of a Transcontinental Epidemic Expansion.
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DOI：
10.1128/mbio.01425-17
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发表时间：
2017-11-14
期刊：
影响因子：
6.4
通讯作者：
Gonzalez-Escalona N
中科院分区：
文献类型：
--
作者：
Martinez-Urtaza J;van Aerle R;Abanto M;Haendiges J;Myers RA;Trinanes J;Baker-Austin C;Gonzalez-Escalona N
副溶血性弧菌是导致与海鲜有关的疾病的主要原因，这些疾病正在经历地理扩张。在这一扩张过程中，最根本的变化是从地方菌株引起的感染转变为大流行性克隆类型的激增。大流行克隆序列类型3（ST 3）是跨大陆传播的唯一例子，直到2012年，ST 36在美国太平洋西北部流行地区以外被检测到，导致美国东北海岸和西班牙沿着出现感染。在这里，我们使用全基因组分析来重建副溶血性弧菌ST 36克隆在过去25年的地理扩张过程中的进化历史。这一谱系的起源估计在1985年左右。到1995年，该地区出现了一种新的变种，并迅速取代了旧的克隆，自2000年以来一直没有发现。新的太平洋西北部（PNW）血统负责太平洋西北地区以外与该克隆相关的第一个病例。在几次引入东北海岸后，新的PNW克隆分化成一个高度活跃的群体，继续在美国东北海岸引起疾病。令人惊讶的是，2012年在欧洲检测到的菌株在2000年左右从这个祖先群体中分离出来，并且具有仅存在于旧PNW谱系中的保守遗传特征。气候变化被认为是多样化的主要驱动力，一些初步观察表明，有一种更专业化的生活方式的趋势，这可能是沿海变暖情景下流行病蔓延的一个关键因素。副溶血性弧菌和霍乱弧菌是源自海洋环境的人类病原体大流行性扩张的仅有两个实例。然而，虽然目前的霍乱弧菌大流行出现在50多年前，但副溶血性弧菌的全球扩张是最近的现象。这些现代的扩张提供了一个难得的机会来研究这些病原体的进化过程的第一手资料，并获得这些疾病的流行动力学的机制，特别是，出现，分散，并成功地引入新的地区，促进全球传播的感染。在这项研究中，我们使用基因组分析，以检查在最近的横贯大陆的致病性弧菌的扩张过程中发生的进化分歧，传播的副溶血性弧菌序列类型36克隆从该地区是地方病的北美太平洋沿岸的美国东海岸，最后到欧洲西海岸。
Vibrio parahaemolyticus is the leading cause of seafood-related infections with illnesses undergoing a geographic expansion. In this process of expansion, the most fundamental change has been the transition from infections caused by local strains to the surge of pandemic clonal types. Pandemic clone sequence type 3 (ST3) was the only example of transcontinental spreading until 2012, when ST36 was detected outside the region where it is endemic in the U.S. Pacific Northwest causing infections along the U.S. northeast coast and Spain. Here, we used genome-wide analyses to reconstruct the evolutionary history of the V. parahaemolyticus ST36 clone over the course of its geographic expansion during the previous 25 years. The origin of this lineage was estimated to be in ~1985. By 1995, a new variant emerged in the region and quickly replaced the old clone, which has not been detected since 2000. The new Pacific Northwest (PNW) lineage was responsible for the first cases associated with this clone outside the Pacific Northwest region. After several introductions into the northeast coast, the new PNW clone differentiated into a highly dynamic group that continues to cause illness on the northeast coast of the United States. Surprisingly, the strains detected in Europe in 2012 diverged from this ancestral group around 2000 and have conserved genetic features present only in the old PNW lineage. Recombination was identified as the major driver of diversification, with some preliminary observations suggesting a trend toward a more specialized lifestyle, which may represent a critical element in the expansion of epidemics under scenarios of coastal warming. Vibrio parahaemolyticus and Vibrio cholerae represent the only two instances of pandemic expansions of human pathogens originating in the marine environment. However, while the current pandemic of V. cholerae emerged more than 50 years ago, the global expansion of V. parahaemolyticus is a recent phenomenon. These modern expansions provide an exceptional opportunity to study the evolutionary process of these pathogens at first hand and gain an understanding of the mechanisms shaping the epidemic dynamics of these diseases, in particular, the emergence, dispersal, and successful introduction in new regions facilitating global spreading of infections. In this study, we used genomic analysis to examine the evolutionary divergence that has occurred over the course of the most recent transcontinental expansion of a pathogenic Vibrio, the spreading of the V. parahaemolyticus sequence type 36 clone from the region where it is endemic on the Pacific coast of North America to the east coast of the United States and finally to the west coast of Europe.