A large cholera outbreak due to a new cholera toxin variant of the Vibrio cholerae O1 El Tor biotype in Orissa, Eastern India
A large cholera outbreak due to a new cholera toxin variant of the Vibrio cholerae O1 El Tor biotype in Orissa, Eastern India
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DOI：
10.1099/jmm.0.002089-0
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发表时间：
2009-02-01
影响因子：
3
通讯作者：
Nair, G. B.
中科院分区：
文献类型：
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作者：
Kumar, P.;Jain, M.;Nair, G. B.
在印度东部最近的一次大规模霍乱爆发中，共收集了32株霍乱弧菌分离株。生化和血清学研究表明，所有分离株均属于血清群O 1，生物型El Tor，血清型Ogawa。两种多重PCR检测证实了所有分离株中存在多种致突变基因和致病基因- ace、ctxAB、h1 yA、ompU、ompW、rfbO 1、rtx、tcp、toxR和zot。对分离株ctxB基因进行测序，发现该基因存在一种新的突变。测序还证实了在所有El Tor分离株中存在经典生物型的改变的霍乱毒素B，表明分离株被经典CTX Phi感染。肠细菌重复基因间一致序列PCR、BOX-PCR和随机扩增多态性DNA分析的分子多样性一致地显示了霍乱弧菌O 1分离株之间的克隆关系。这项研究的结果表明，引起霍乱的霍乱弧菌菌株在流行地区不断演变，突出了出现更具毒性菌株的潜力。
A total of 32 Vibrio cholerae isolates were collected during a recent large cholera outbreak in Eastern India. Biochemical and serological studies revealed that all of the isolates belonged to serogroup O1, biotype El Tor, serotype Ogawa. Two multiplex PCR assays confirmed the presence of various toxigenic and pathogenic genes - ace, ctxAB, h1yA, ompU, ompW, rfbO1, rtx, tcp, toxR and zot - in all of the isolates. Sequencing of the ctxB gene from the isolates revealed a novel mutation in the gene. Sequencing also confirmed the presence of altered cholera toxin B of the classical biotype in all of the El Tor isolates, suggesting infection of isolates by classical CTX Phi. The molecular diversity of V. cholerae isolates studied by enterobacterial repetitive intergenic consensus sequence PCR, BOX-PCR and randomly amplified polymorphic DNA analysis uniformly showed the clonal relationship among the outbreak V. cholerae O1 isolates. The results of this study suggest that cholera-causing V. cholerae strains are constantly evolving in epidemic areas, highlighting the potential of the emergence of more virulent strains.