1] Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA [2] Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
School of Pathology, M504 University of Western Australia, Crawley, Western Australia 6009, Australia.
Nat Commun. 2014 Jun 13;5:4165. doi: 10.1038/ncomms5165.
The evolution rate and genetic changes that occur during chronic infection with Helicobacter pylori have been analysed, but little is known about the genomic changes during the initial, acute bacterial infection phase. Here we analyse the rate and pattern of genome evolution in H. pylori from the genomes of two input strains isolated from human volunteers with asymptomatic infection, and the genomes of two output strains collected 20 and 44 days after re-infection. Similarly, we analyse genome evolution in bacteria from the genome sequences of input and output strains sequentially taken after experimental infection of a rhesus macaque. The estimated mutation rate reveals a mutation burst during the acute infection phase that is over 10 times faster than the mutation rate during chronic infection, and orders of magnitude faster than mutation rates in any other bacteria. The elevated frequency of mutations in outer membrane protein genes suggests that the mutation burst facilitates rapid host adaptation of the bacteria.
幽门螺杆菌慢性感染过程中的进化速度和遗传变化已经得到了分析，但对于初始急性细菌感染阶段的基因组变化却知之甚少。在这里，我们分析了从两名无症状感染志愿者体内分离出的初始感染菌株和再感染 20 及 44 天后采集的两个输出菌株的基因组中幽门螺杆菌的基因组进化速度和模式。同样，我们还分析了对食蟹猴进行实验性感染后，从输入和输出菌株的基因组序列中连续采集的细菌的基因组进化情况。估计的突变率显示，急性感染阶段存在一个突变爆发，其速度比慢性感染阶段的突变率快 10 多倍，比其他任何细菌的突变率快几个数量级。外膜蛋白基因的突变频率升高表明，突变爆发促进了细菌对宿主的快速适应。
