Table_1_Genotypic and Phenotypic Characterization of Clinical Escherichia coli Sequence Type 405 Carrying IncN2 Plasmid Harboring blaNDM-1.DOCX

We report a blaNDM-carrying ST405 Escherichia coli recovered from the abdominal fluid of a patient in Shandong, China. This strain belonged to the high-risk phylogenetic group D and carried the virulence genes, papG II, papG III, papC, and iroN. In addition to blaNDM-1, this isolate carried the quinolone resistance gene acc(6′)-Ib and extended-spectrum β-lactamase (ESBL) genes blaCTX-M-15 and blaCTX-M-14. blaNDM-1 was located on a 41 Kb IncN2 self-transmissible plasmid. The IncN2 plasmid named as pJN24NDM1 was fully sequenced and analyzed. Genome comparative analysis showed that IncN2 plasmids harboring carbapenem-resistance genes possessed conserved backbones and variable accessory regions. Phylogenetic analysis of 87 IncN plasmids based on orthologous genes indicated that 9 IncN2 plasmids fell into one phylogenetic clade, while 4 IncN3 plasmids were in two phylogenetic clades of the 74 IncN1 plasmids. The presence of IncN2 plasmids harboring blaNDM in the high-risk clone ST405 E. coli raises serious concerns for its potential of dissemination.

本研究报道一株分离自中国山东某患者腹腔积液的携带blaNDM的序列型405（ST405）大肠杆菌（Escherichia coli）。该菌株属于高危系统发育群D，携带有papG II、papG III、papC及iroN毒力基因。除blaNDM-1外，该分离株还携带喹诺酮类耐药基因acc(6′)-Ib以及超广谱β-内酰胺酶（ESBL）基因blaCTX-M-15与blaCTX-M-14。blaNDM-1定位于一条41 kb的IncN2型可自主转移质粒上。该命名为pJN24NDM1的IncN2型质粒已完成全基因组测序与分析。基因组比较分析显示，携带碳青霉烯类耐药基因的IncN2型质粒具有保守的骨架区域与可变的附属区域。基于直系同源基因（orthologous genes）对87株IncN型质粒开展的系统发育分析结果表明：9株IncN2型质粒归为单个系统发育分支，74株IncN1型质粒中有4株IncN3型质粒分属两个系统发育分支。在高危克隆ST405型大肠杆菌中携带blaNDM的IncN2型质粒的出现，使其传播潜力引发了严重担忧。