Coexistence of bla(KPC-2)-IncN and mcr-1-IncX4 plasmids in a ST48 Escherichia coli strain in China
Coexistence of bla(KPC-2)-IncN and mcr-1-IncX4 plasmids in a ST48 Escherichia coli strain in China
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bla(KPC-2)-IncN 和 mcr-1-IncX4 质粒在中国 ST48 大肠杆菌菌株中的共存
DOI：
10.1016/j.jgar.2020.08.023
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发表时间：
2020
影响因子：
4.6
通讯作者：
Yan Jiang
中科院分区：
文献类型：
--
作者：
Yanfei Wang;Haiyang Liu;Qian Wang;Xiaoxing Du;Yunsong Yu;Yan Jiang
目的探讨携带ablaKPC-2-和mcr-1的大肠杆菌的基因组含量，阐明其多药耐药传播的分子机制。方法采用微量肉汤稀释法进行药敏试验，测定耐药谱。通过筛选偶联实验确认质粒的转移能力。全基因组序列数据由Illumina配对末端测序和Nanopore长读测序相结合获得。结果大肠杆菌QE11−421为mcr-1阳性粘菌素耐药分离株，共携带具有碳青霉烯抗性的blakpc -2基因。基因组序列数据证实QE11−421为48 (ST48)E型序列。大肠杆菌含有5个大的共轭质粒，编码几种多药耐药基因。blakpc -2基因位于tn3 - tn4401复合转座子上，该转座子是65kb多药耐药IncN质粒的一部分。他们的cr-1基因被隐藏在另一个33 kb的IncX4质粒上，该质粒更为保守，呈现出很少的抗微生物抗性决定因素。在mcr-1基因两侧未发现插入序列isapl1的拷贝，这降低了mcr-1基于其原tn6330转座子的迁移率。结论多药耐药质粒或与耐药相关的转座子单位的水平转移是导致这一臭名昭著的超级细菌出现的原因。blakpc -2 - incn和mcr-1 - incx4质粒在ST48E中的共存。大肠杆菌对人类构成巨大威胁。
ObjectivesThe aim of this study was to explore the genomic content of ablaKPC-2- andmcr-1-harbouringEscherichia colistrain and to clarify the molecular mechanism for the transmission of multidrug resistance.MethodsAntimicrobial susceptibility testing was conducted by the broth microdilution method to determine the resistance profile. Filter-mating conjugation assays were performed to confirm the plasmid transfer ability. Whole-genome sequence data were acquired by a combination of Illumina paired-end reads and Nanopore long-read sequencing.ResultsEscherichia colistrain QE11−421 was anmcr-1-positive colistin-resistant isolate that co-harboured theblaKPC-2gene conferring carbapenem resistance. Genome sequence data confirmed QE11−421 as a sequence type 48 (ST48)E. colithat harboured five large conjugative plasmids encoding several multidrug resistance genes. TheblaKPC-2gene was located on a Tn3–Tn4401composite transposon, which is part of a 65-kb multidrug-resistant IncN plasmid. Themcr-1gene was harboured on another 33-kb IncX4 plasmid that was more conserved and presented few antimicrobial resistance determinants. No copies of insertion sequence ISApl1were found flanking themcr-1gene, decreasing the mobility ofmcr-1based on its original Tn6330transposon.ConclusionsHorizontal transfer of multidrug resistance plasmids or resistance-related transposon units was responsible for the emergence of this notorious superbug. The coexistence ofblaKPC-2–IncN andmcr-1–IncX4 plasmids in a ST48E. colistrain in humans poses a great threat.