Genetic diversity of environmental Vibrio cholerae O1 strains isolated in Northern Vietnam
Genetic diversity of environmental Vibrio cholerae O1 strains isolated in Northern Vietnam
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越南北部环境霍乱弧菌 O1 菌株的遗传多样性
DOI：
10.1016/j.meegid.2017.06.017
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Yamashiro Tetsu
中科院分区：
文献类型：
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作者：
Takemura Taichiro;Murase Kazunori;Maruyama Fumito;Tran Thi Luong;Ota Atsushi;Nakagawa Ichiro;Nguyen Dong Tu;Ngo Tu Cuong;Nguyen Thi Hang;Tokizawa Asako;Morita Masatomo;Ohnishi Makoto;Nguyen Binh Minh;Yamashiro Tetsu
在第七次霍乱大流行期间，越南定期记录霍乱疫情。由于霍乱是一种通过水传播的疾病，系统监测环境水中霍乱弧菌的存在对于预测和预防霍乱疫情非常重要。我们进行了V病毒的监测、分离和基因特征研究。2013年7月至2015年2月，越南北部南定省发生霍乱疫情。在本研究中，四个V。从110份经分析的水样中检出霍乱O1菌株(3.6%)，但没有一株在基因组中携带霍乱毒素基因ctxA。全基因组测序和系统发育分析表明，4株O1分离株被分成两个独立的类群，其中一个分离株与流行株有共同的祖先。对毒力岛(CTX噬菌体、VPI-I、VPI-II、VSP-I和VSP-II)的分析表明，1株(VNND_2014Jun_6SS)含有一个未知的类似噬菌体的序列，与分别从孟加拉国和美国鉴定的KSF-1 Phi和Vcy Phi具有高度同源性，而另外3株携带tcpA基因，具有不同的序列，显示出不同的克隆谱系。这些结果表明，水环境可能存在高度多样性。霍乱并作为多种病毒的蓄水池。可能通过移动遗传元件交换的霍乱致病相关基因。因此，对该病的持续监测和基因特征研究。环境中的霍乱应有助于及早发现感染源和预防霍乱暴发，并有助于了解V的自然生态和进化。霍乱弧菌。
Cholera epidemics have been recorded periodically in Vietnam during the seventh cholera pandemic. Since cholera is a water-borne disease, systematic monitoring of environmental waters forVibrio choleraepresence is important for predicting and preventing cholera epidemics. We conducted monitoring, isolation, and genetic characterization ofV. choleraestrains in Nam Dinh province of Northern Vietnam from Jul 2013 to Feb 2015. In this study, fourV. choleraeO1 strains were detected and isolated from 110 analyzed water samples (3.6%); however, none of them carried the cholera toxin gene,ctxA, in their genomes. Whole genome sequencing and phylogenetic analysis revealed that the four O1 isolates were separated into two independent clusters, and one of them diverged from a common ancestor with pandemic strains. The analysis of pathogenicity islands (CTX prophage, VPI-I, VPI-II, VSP-I, and VSP-II) indicated that one strain (VNND_2014Jun_6SS) harbored an unknown prophage-like sequence with high homology to vibriophage KSF-1 phi and VCY phi, identified from Bangladesh and the USA, respectively, while the other three strains carriedtcpAgene with a distinct sequence demonstrating a separate clonal lineage. These results suggest that the aquatic environment can harbor highly divergentV. cholerastrains and serve as a reservoir for multipleV. choleraevirulence-associated genes which may be exchangedviamobile genetic elements. Therefore, continuous monitoring and genetic characterization ofV. choleraestrains in the environment should contribute to the early detection of the sources of infection and prevention of cholera outbreaks as well as to understanding the natural ecology and evolution ofV. cholerae.