Cowley Lauren A, Oresegun Damilola R, Chattaway Marie A, Dallman Timothy J, Jenkins Claire
Gastrointestinal Bacteria Reference Unit, Public Health England, Colindale, London, UK.
School of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire, UK.
J Med Microbiol. 2018 Jun;67(6):884-888. doi: 10.1099/jmm.0.000739.
We compared the genomes of 60 isolates of enteroinvasive (EIEC) in order to better understand the step-wise evolutionary process from non-pathogenic to host-adapted pathogenic . All isolates belonged to either sequence type (ST) 6, ST99 or ST270. Each ST was located on different branches of the phylogeny and had invasion plasmids (pINVs) belonging to FII-21 (ST99, ST270), FII-27 (ST270) or FII-28 (ST6, ST270) incompatibility groups. A higher number of insertion sequence (IS) elements were identified in ST6 and ST270 than in ST99, and appeared to be driving the loss of functional genes. Comparison of the pINV from each ST revealed different degrees of gene loss, with pINV from ST270 being most similar to that found in species. We captured three EIEC STs at different stages of patho-adaptation, with ST270 being the most 'shigella-like' and the most divergent from non-pathogenic , and ST99 being the least divergent.
我们比较了60株肠侵袭性大肠杆菌（EIEC）的基因组，以便更好地了解从非致病性到宿主适应性致病性的逐步进化过程。所有分离株均属于序列型（ST）6、ST99或ST270。每个ST位于系统发育树的不同分支上，并且具有属于FII-21（ST99、ST270）、FII-27（ST270）或FII-28（ST6、ST270）不相容群的侵袭质粒（pINVs）。在ST6和ST270中鉴定出的插入序列（IS）元件数量高于ST99，并且似乎在驱动功能基因的丧失。对每个ST的pINV进行比较发现基因丢失程度不同，其中ST270的pINV与在志贺氏菌属物种中发现的最为相似。我们捕获了处于致病适应性不同阶段的三种EIEC ST，其中ST270最像志贺氏菌，与非致病性大肠杆菌差异最大，而ST99的差异最小。
