Sex and virulence in Escherichia coli: an evolutionary perspective.
Sex and virulence in Escherichia coli: an evolutionary perspective.
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DOI：
10.1111/j.1365-2958.2006.05172.x
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发表时间：
2006-06
影响因子：
3.6
通讯作者：
Achtman M
中科院分区：
文献类型：
--
作者：
Wirth T;Falush D;Lan R;Colles F;Mensa P;Wieler LH;Karch H;Reeves PR;Maiden MC;Ochman H;Achtman M
致病性大肠杆菌每年导致超过 1.6 亿例痢疾和 100 万人死亡，而非致病性大肠杆菌构成健康哺乳动物和鸟类正常肠道菌群的一部分。通过对全球分离株进行多位点序列分型，研究了细菌生活方式中这种二分法背后的进化途径。特定的病原体类型[肠出血性大肠杆菌、肠致病性大肠杆菌、肠侵袭性大肠杆菌、K1 和志贺氏菌]在几个谱系中独立且重复地出现，而其他谱系仅含有很少的病原体。致病谱系的进化速度加快，最终形成高毒力的生物体，其基因组内容因同源重组率的增加而频繁改变；因此，毒力的进化与细菌的性别有关。这种长期的进化模式是在分布于整个基因组的基因中观察到的，因此可能是对能够逃避宿主免疫反应的菌株进行间歇性选择的结果。
Pathogenic Escherichia coli cause over 160 million cases of dysentery and one million deaths per year, whereas non-pathogenic E. coli constitute part of the normal intestinal flora of healthy mammals and birds. The evolutionary pathways underlying this dichotomy in bacterial lifestyle were investigated by multilocus sequence typing of a global collection of isolates. Specific pathogen types [enterohaemorrhagic E. coli, enteropathogenic E. coli, enteroinvasive E. coli, K1 and Shigella] have arisen independently and repeatedly in several lineages, whereas other lineages contain only few pathogens. Rates of evolution have accelerated in pathogenic lineages, culminating in highly virulent organisms whose genomic contents are altered frequently by increased rates of homologous recombination; thus, the evolution of virulence is linked to bacterial sex. This long-term pattern of evolution was observed in genes distributed throughout the genome, and thereby is the likely result of episodic selection for strains that can escape the host immune response.