Recombination and clonal groupings within Helicobacter pylori from different geographical regions
Recombination and clonal groupings within Helicobacter pylori from different geographical regions
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不同地理区域幽门螺杆菌的重组和克隆分组
DOI：
10.1046/j.1365-2958.1999.01382.x
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发表时间：
1999-05-01
影响因子：
3.6
通讯作者：
van Doorn, LJ
中科院分区：
文献类型：
--
作者：
Achtman, M;Azuma, T;van Doorn, LJ
为了更好地了解幽门螺杆菌的群体遗传结构和多样性，对来自世界几个地区的20株幽门螺杆菌进行了研究。（atpA、efp、mutY、ppa、trpC、urel、yphC）和两个毒力相关基因（cagA，vacA）显示高水平的同义序列变异（平均百分比K-s为10-27%）和较低水平的非同义变异（平均百分比K-a为0.2-5.6%），等位基因之间成对差异的聚类分析揭示了两个弱克隆分组的存在，其包括所研究的菌株的一半。从日本和中国沿海地区分离的6株菌株均归属于“亚洲”克隆群，可能反映了它们来自不同的共同祖先。根据同质性测试和相容性矩阵的测量，重组在所有测试的基因中都非常常见，除了cagA，尽管如此频繁的重组，克隆血统仍然可以被辨别的事实可能反映了奠基者效应和地理分离和/或对这些基因的特定等位基因的选择。
A collection of 20 strains of Helicobacter pylori from several regions of the world was studied to better understand the population genetic structure and diversity of this species, Sequences of fragments from seven housekeeping genes (atpA, efp, mutY, ppa, trpC, urel, yphC) and two virulence-associated genes (cagA, vacA) showed high levels of synonymous sequence variation (mean percentage K-s of 10-27%) and lower levels of non-synonymous variation (mean percentage K-a of 0.2-5.6%), Cluster analysis of pairwise differences between alleles revealed the existence of two weakly clonal groupings, which included half of the strains investigated. All six strains isolated from Japanese and coastal Chinese were assigned to the 'Asian' clonal grouping, probably reflecting descent from a distinct common ancestor, The clonal groupings were not totally uniform; recombination, as measured by the homoplasy test and compatibility matrices, was extremely common within all genes tested, except cagA, The fact that clonal descent could still be discerned despite such frequent recombination possibly reflects founder effects and geographical separation and/or selection for particular alleles of these genes.