Comparative genomic analysis of 2016 Vibrio cholerae outbreak in South Korea.

In August 2016, Korea experienced a cholera outbreak that caused three people with acute watery diarrhea. It was the first time in 15 years that local Korean citizens have infected with Vibrio cholerae without having traveled overseas. To track down the cause and find the epidemiological relevance of this outbreak, we sequenced the whole genomes of V. cholerae isolates, three from the different patients and one from a seawater sample. The comparative genomic analysis has shown that the genome sequences of three patients and seawater isolate are highly similar and form a monophyletic clade with V. cholerae strains that have caused an outbreak in the Philippines in 2011. The Korean and Philippines outbreak strains have almost identical gene contents in which two unique genomic islands were shared. We confirmed that seawater is the likely source of this outbreak, which strongly suggests the necessity of routine surveillance over seashore of South Korea in the future.

2016年8月，韩国暴发霍乱疫情，导致3名患者出现急性水样腹泻症状。这是15年来首次出现韩国本土居民未赴海外旅行却感染霍乱弧菌（Vibrio cholerae）的病例。为追溯本次疫情的源头并明确其流行病学关联，研究团队对霍乱弧菌分离株开展全基因组测序：3株分离自不同患者，1株分离自海水样本。比较基因组分析显示，3株患者来源分离株与海水分离株的基因组序列高度相似，且与2011年菲律宾暴发疫情的霍乱弧菌菌株同属一个单系群（monophyletic clade）。韩国与菲律宾的本次暴发菌株基因组成几乎完全一致，二者共享两个独特的基因组岛（genomic islands）。本研究证实海水为本次疫情的潜在传染源，该结果强烈提示，未来需对韩国沿海地区开展常规监测工作。