Complete Nucleotide Sequences of blaCTX-M-Harboring IncF Plasmids from Community-Associated Escherichia coli Strains in the United States
Complete Nucleotide Sequences of blaCTX-M-Harboring IncF Plasmids from Community-Associated Escherichia coli Strains in the United States
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DOI：
10.1128/aac.04772-14
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发表时间：
2015-06-01
影响因子：
4.9
通讯作者：
Doi, Yohei
中科院分区：
文献类型：
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作者：
Li, Jun-Jie;Spychala, Caressa N.;Doi, Yohei
在美国，由产生 CTX-M 型超广谱 β-内酰胺酶的大肠杆菌引起的社区相关感染越来越受到重视。 bl(aCTX-M) 基因经常携带在 IncF 组质粒上。在本研究中，对携带 bla(CTX-M-15) 的质粒 pCA14（序列类型 131 [ST131]）和 pCA28 (ST44) 以及携带 bla(CTX-M-14) 的质粒 pCA08 (ST131) 进行了测序和表征。这三个质粒与来自美国以外大陆的其他 IncFII 质粒在保守主干区和多抗性区 (MRR) 方面密切相关。每个携带 bla(CTX-M-15) 的质粒 pCA14 和 pCA28 都属于 F31:A4:B1（FAB [FII、FIA、FIB] 式），并且显示出高度的相似性（pCA14 的覆盖度为 92%，核苷酸同一性为 99% 至 100%），表明可能存在共同起源。携带bla(CTX-M-14)的质粒pCA08属于F2:A2:B20，与中国的pKF3-140高度相似(pCA08覆盖率88%，核苷酸同一性99%至100%)。所有三个质粒都携带多个与毒力和生化途径相关的抗菌素耐药基因和模块，这可能为其宿主菌株赋予选择优势。与美国社区相关感染有关的携带 bla(CTX-M) 的 IncFII-IA-IB 质粒与其他大陆鉴定的质粒具有关键的结构特征，强调了这种质粒流行的全球性。
Community-associated infections due to Escherichia coli producing CTX-M-type extended-spectrum beta-lactamases are increasingly recognized in the United States. The bl(aCTX-M) genes are frequently carried on IncF group plasmids. In this study, bla(CTX-M-15)-harboring plasmids pCA14 (sequence type 131 [ST131]) and pCA28 (ST44) and bla(CTX-M-14)-harboring plasmid pCA08 (ST131) were sequenced and characterized. The three plasmids were closely related to other IncFII plasmids from continents outside the United States in the conserved backbone region and multiresistance regions (MRRs). Each of the bla(CTX-M-15)-carrying plasmids pCA14 and pCA28 belonged to F31:A4:B1 (FAB [FII, FIA, FIB] formula) and showed a high level of similarity (92% coverage of pCA14 and 99% to 100% nucleotide identity), suggesting a possible common origin. The bla(CTX-M-14)-carrying plasmid pCA08 belonged to F2:A2:B20 and was highly similar to pKF3-140 from China (88% coverage of pCA08 and 99% to 100% nucleotide identity). All three plasmids carried multiple antimicrobial resistance genes and modules associated with virulence and biochemical pathways, which likely confer selective advantages for their host strains. The bla(CTX-M)-carrying IncFII-IA-IB plasmids implicated in community-associated infections in the United States shared key structural features with those identified from other continents, underscoring the global nature of this plasmid epidemic.