Table_4_Emergence of blaNDM–1-carrying Enterobacter chengduensis in China.XLSX

IntroductionEnterobacter chengduensis was defined as a novel species in the genus. Enterobacter in 2019, however, antimicrobial resistance, such as carbapenem resistance, has rarely been described in E. chengduensis. This study described the molecular features of four carbapenem-resistant E. chengduensis strains collected from a tertiary health care hospital in Southwest China.MethodsWhole genome sequencing (WGS) was used to determine the genome sequence of four E. chengduensis strains. The precise species of strains were identified by average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH). The clonal relatedness of four E. chengduensis strains and additional 15 ones from NCBI were examined through phylogenetic analysis. The molecular features of E. chengduensis and genetic structure of carbapenemase- encoding plasmids were characterized through genomic annotation and analysis.ResultsThe results revealed the emergence of blaNDM–1-carrying E. chengduensis strains in China. Multilocus sequence typing (MLST) analysis showed that all 19 E. chengduensis belonged to the same sequence type of ST414. Core SNP analysis suggested the potential intrahospital clonal transmission of ST414 E. chengduensis. The carbapenemase-encoding gene blaNDM–1 was harbored by an IncC-type plasmid, which was experimentally confirmed to be able to conjugate.DiscussionThis study reports the first emergence and potential clonal transmission of blaNDM–1-carrying E. chengduensis. Further surveillance should be advocated to monitor the dissemination of carbapenem-resistant E. chengduensis and blaNDM–1-harboring IncC-type plasmids in China.

引言：成都肠杆菌（Enterobacter chengduensis）于2019年被定义为肠杆菌属（Enterobacter）中的一个新种。然而，在E. chengduensis中，诸如碳青霉烯耐药性等抗菌药物耐药性鲜有报道。本研究描述了从中国西南地区一家三级医疗机构收集的四株碳青霉烯耐药性E. chengduensis菌株的分子特征。方法：采用全基因组测序（WGS）技术确定了四株E. chengduensis的基因组序列。通过平均核苷酸一致性（ANI）和模拟DNA-DNA杂交（isDDH）方法精确鉴定了菌株的物种。通过系统发育分析考察了四株E. chengduensis菌株与NCBI中另外15株菌株的克隆相关性。通过基因组注释和分析，对E. chengduensis的分子特征和编码碳青霉烯酶的质粒的遗传结构进行了表征。结果：研究结果显示，在中国出现了携带blaNDM–1的E. chengduensis菌株。多位点序列分型（MLST）分析表明，所有19株E. chengduensis均属于ST414序列型。核心SNP分析提示ST414型E. chengduensis存在院内克隆传播的潜在风险。编码碳青霉烯酶的基因blaNDM–1被一个IncC型质粒携带，并通过实验证实该质粒能够进行接合。讨论：本研究报告了携带blaNDM–1的E. chengduensis首次出现及其潜在的克隆传播。应提倡进一步的监测，以监控中国碳青霉烯耐药性E. chengduensis及携带blaNDM–1的IncC型质粒的传播。