Table_3_Type 1, 2, and 1/2-Hybrid IncC Plasmids From China.DOCX

A collection of 11 IncC plasmids from China were fully sequenced herein and compared with reference plasmids pR148 and pR55. These 13 plasmids could be assigned into three different subgroups: type 1, type 2, and type 1/2 hybrid. Type 1/2-hybrid plasmids most likely emerged from homologous recombination between type 1 and type 2 plasmids. Different IncC plasmids had evolved to acquire quite different profiles of accessory modules and thus different collections of resistance genes. The accessory resistance modules included not only the blaCMY-carrying region, the ARI-A island, and the ARI-B island, but also various additional kinds of resistance islands such as the blaCTX–M-carrying regions and the MDR regions. Insertion of accessory modules was sometimes accompanied by deletion, inversion, and translocation of surrounding backbone regions. pR148 and pR55 were confirmed to have the most complete backbones for type 1 and type 2, respectively. This was the first report of a blaIMP–8-carrying IncC plasmid, and that of three novel mobile elements: a Tn1696-derived unit transposon Tn6395, a class 2 integron In2-76, and an insertion sequence ISEcl10.

本研究对11株来自中国的IncC质粒（IncC plasmid）完成了全基因组测序，并与参考质粒pR148和pR55进行比对分析。本次纳入分析的13株质粒可被划分为3个不同亚型：1型、2型及1/2型杂合质粒。1/2型杂合质粒极有可能由1型与2型质粒通过同源重组产生。不同IncC质粒经演化获得了差异显著的附属模块谱型，因此携带了种类各异的耐药基因集合。附属耐药模块不仅涵盖携带blaCMY的区域（blaCMY-carrying region）、ARI-A岛（ARI-A island）与ARI-B岛（ARI-B island），还包含多种其他类型的耐药岛，例如携带blaCTX–M的区域（blaCTX–M-carrying region）以及多重耐药区（MDR region）。附属模块的插入有时会伴随其侧翼骨架区域的缺失、倒位与易位事件。经证实，pR148与pR55分别为1型与2型IncC质粒中骨架最为完整的参照株。本研究首次报道了携带blaIMP–8的IncC质粒，同时还发现了3种新型可移动遗传元件：源自Tn1696的单位转座子Tn6395、2类整合子In2-76（class 2 integron In2-76）以及插入序列ISEcl10（insertion sequence ISEcl10）。