Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland.
Int J Mol Sci. 2021 Apr 27;22(9):4606. doi: 10.3390/ijms22094606.
pCTX-M3 is the archetypic member of the IncM incompatibility group of conjugative plasmids (recently referred to as IncM2). It is responsible for the worldwide dissemination of numerous antibiotic resistance genes, including those coding for extended-spectrum β-lactamases and conferring resistance to aminoglycosides. The IncM plasmids acquired during evolution diverse mobile genetic elements found in one or two multiple resistance regions, MRR(s), grouping antibiotic resistance genes as well as mobile genetic elements or their remnants. The IncM plasmids can be found in bacteria inhabiting various environments. The information on the structure and biology of pCTX-M3 is integrated in this review. It focuses on the functional modules of pCTX-M3 responsible for its replication, stable maintenance, and conjugative transfer, indicating that the host range of the pCTX-M3 replicon is limited to representatives of the family Enterobacteriaceae (Enterobacterales ord. nov.), while the range of recipients of its conjugation system is wide, comprising Alpha-, Beta-, and Gammaproteobacteria, and also Firmicutes.
pCTX-M3 是可移动质粒 IncM 不相容群的典型代表（最近被称为 IncM2）。它负责在全球范围内传播许多抗生素耐药基因，包括编码扩展谱β-内酰胺酶的基因和对氨基糖苷类药物的耐药性。在进化过程中，IncM 质粒获得了多种存在于一个或两个多重耐药区（MRR）中的移动遗传元件，这些移动遗传元件将抗生素耐药基因以及移动遗传元件或其残余物分组。IncM 质粒可在栖息于各种环境的细菌中找到。本文整合了有关 pCTX-M3 的结构和生物学信息。它重点介绍了负责其复制、稳定维持和接合转移的 pCTX-M3 的功能模块，表明 pCTX-M3 复制子的宿主范围仅限于肠杆菌科（肠杆菌目 nov.）的代表，而其接合系统的受体范围很广，包括α-、β-和γ-变形菌以及Firmicutes。
