科研人員對(duì)痢疾菌宋內(nèi)痢疾桿菌（Shigella sonnei）進(jìn)入越南人群并且在15年的時(shí)間里進(jìn)化過程中的基因組進(jìn)行了高分辨率觀察,。Stephen Baker及其同事對(duì)宋內(nèi)痢疾桿菌的263個(gè)分離株的基因組進(jìn)行了測(cè)序,，這種細(xì)菌每年造成超過1.6億個(gè)痢疾病例和與其相關(guān)的100萬人的死亡,。
自從16世紀(jì)在歐洲出現(xiàn)以來，宋內(nèi)痢疾桿菌已經(jīng)產(chǎn)生了耐多藥進(jìn)化枝，稱為全球III型，如今它是全世界地方流行痢疾的許多地區(qū)的主要的痢疾病因。這組作者在15年的時(shí)間里從越南多家醫(yī)院治療的病人身上獲得了宋內(nèi)痢疾桿菌的分離株,，這些分離株只有兩個(gè)屬于大流行全球III型進(jìn)化枝。這項(xiàng)分析揭示出宋內(nèi)痢疾桿菌在20世紀(jì)80年代傳入越南之后經(jīng)歷了多個(gè)變化,。越南某些地區(qū)的細(xì)菌種群積累了促進(jìn)發(fā)病機(jī)理的突變,，被這些細(xì)菌復(fù)制和在地理上擴(kuò)散的時(shí)候保留了下來，逐漸成為了當(dāng)?shù)厮蝺?nèi)痢疾桿菌的遺傳固定組成部分,。這組作者說,，這項(xiàng)研究就一種人類病原體在一個(gè)新的人類人群立足過程中的的微進(jìn)化提供了見解。（生物谷Bioon.com）
生物谷推薦英文摘要：
PNAS doi: 10.1073/pnas.1308632110
Tracking the establishment of local endemic populations of an emergent enteric pathogen
Shigella sonnei is a human-adapted pathogen that is emerging globally as the dominant agent of bacterial dysentery. To investigate local establishment, we sequenced the genomes of 263 Vietnamese S. sonnei isolated over 15 y. Our data show that S. sonnei was introduced into Vietnam in the 1980s and has undergone localized clonal expansion, punctuated by genomic fixation events through periodic selective sweeps. We uncover geographical spread, spatially restricted frontier populations, and convergent evolution through local gene pool sampling. This work provides a unique, high-resolution insight into the microevolution of a pioneering human pathogen during its establishment in a new host population.
