Aix-Marseille University, UMR MD3, Marseilles, France.
Clin Microbiol Infect. 2014 May;20(5):373-9. doi: 10.1111/1469-0691.12610. Epub 2014 Mar 29.
Since 1817, seven cholera pandemics have plagued humankind. As the causative agent, Vibrio cholerae, is autochthonous in the aquatic ecosystem and some studies have revealed links between outbreaks and fluctuations in climatic and aquatic conditions, it has been widely assumed that cholera epidemics are triggered by environmental factors that promote the growth of local bacterial reservoirs. However, mounting epidemiological findings and genome sequence analysis of clinical isolates have indicated that epidemics are largely unassociated with most of the V. cholerae strains in aquatic ecosystems. Instead, only a specific subset of V. cholerae El Tor 'types' appears to be responsible for current epidemics. A recent report examining the evolution of a variety of V. cholerae strains indicates that the current pandemic is monophyletic and originated from a single ancestral clone that has spread globally in successive waves. In this review, we examine the clonal nature of the disease, with the example of the recent history of cholera in the Americas. Epidemiological data and genome sequence-based analysis of V. cholerae isolates demonstrate that the cholera epidemics of the 1990s in South America were triggered by the importation of a pathogenic V. cholerae strain that gradually spread throughout the region until local outbreaks ceased in 2001. Latin America remained almost unaffected by the disease until a new toxigenic V. cholerae clone was imported into Haiti in 2010. Overall, cholera appears to be largely caused by a subset of specific V. cholerae clones rather than by the vast diversity of V. cholerae strains in the environment.
自 1817 年以来，人类已经经历了七次霍乱大流行。由于病原体霍乱弧菌在水生生态系统中是本土的，并且一些研究表明暴发与气候和水生条件的波动之间存在关联，因此人们普遍认为霍乱流行是由促进当地细菌库生长的环境因素引发的。然而，越来越多的流行病学发现和临床分离株的基因组序列分析表明，流行与水生生态系统中的大多数霍乱弧菌菌株没有很大关系。相反，只有特定的霍乱弧菌 El Tor“型”似乎是当前流行的罪魁祸首。最近的一份报告检查了各种霍乱弧菌菌株的进化，表明当前的大流行是单系的，起源于一个单一的祖先克隆，它已在全球范围内连续传播。在这篇综述中，我们以美洲最近的霍乱历史为例，探讨了疾病的克隆性质。流行病学数据和基于基因组序列的霍乱弧菌分离株分析表明，南美洲 20 世纪 90 年代的霍乱流行是由一种致病性霍乱弧菌菌株的输入引发的，该菌株逐渐传播到整个地区，直到 2001 年当地暴发停止。拉丁美洲几乎没有受到这种疾病的影响，直到 2010 年海地输入了一种新的产毒霍乱弧菌克隆。总的来说，霍乱似乎主要是由特定的霍乱弧菌克隆亚群引起的，而不是由环境中大量的霍乱弧菌菌株引起的。
