Abstract：
OBJECTIVE: The blaNDM gene was prevalent among children and became the predominant cause of severe infection in infants and children. This study aimed to investigate the epidemiology and molecular characteristics of blaNDM in Enterobacteriaceae among children in China.
METHODS: Carbapenem-resistant Enterobacteriaceae (CRE) were collected in the Children\'s Hospital of Fudan University from January 2016 to December 2022. Five carbapenemase genes (blaKPC, blaNDM, blaVIM, blaIMP, blaOXA-48) were screened by PCR method. Multilocus sequence typing (MLST) was conducted for phylogenetic analyses. blaNDM-carrying plasmids were typed by PCR-based Incompatibility (Inc) typing method. Moreover, plasmid comparison was performed with 213 publicly available IncX3 plasmids.
RESULTS: A total of 330 CRE strains were enrolled, 96.4% of which carried carbapenemase genes. blaNDM gene accounted for 64.8% (214 strains) and included four variants, including blaNDM-1 (59.8%), blaNDM-5 (39.3%), blaNDM-7 (0.5%), and blaNDM-9 (0.5%). There were no predominant MLST lineages of blaNDM carrying strains. IncX3 was the major plasmid carrying blaNDM-1 (68.0%) and blaNDM-5 (72.6%) and was dominant in blaNDM-Klebsiella penumoniae (79.8%), blaNDM-Escherichia coli (58.2%), and blaNDM-Enterobacter cloacae (61.0%), respectively. Most (79.0%) clinical IncX3 plasmids in the world carried blaNDM, and the prevalence of blaNDM in IncX3 plasmids was more common in China (95.8%) than other countries (58.1%, P <0.01).
CONCLUSIONS: blaNDM is highly prevalent in CRE among children in China. The spread of blaNDM was mainly mediated by IncX3 plasmids. Surveillance and infection control on the spread of blaNDM among children are important.
METHODS: Carbapenem-resistant Enterobacteriaceae (CRE) were collected in the Children\'s Hospital of Fudan University from January 2016 to December 2022. Five carbapenemase genes (blaKPC, blaNDM, blaVIM, blaIMP, blaOXA-48) were screened by PCR method. Multilocus sequence typing (MLST) was conducted for phylogenetic analyses. blaNDM-carrying plasmids were typed by PCR-based Incompatibility (Inc) typing method. Moreover, plasmid comparison was performed with 213 publicly available IncX3 plasmids.
RESULTS: A total of 330 CRE strains were enrolled, 96.4% of which carried carbapenemase genes. blaNDM gene accounted for 64.8% (214 strains) and included four variants, including blaNDM-1 (59.8%), blaNDM-5 (39.3%), blaNDM-7 (0.5%), and blaNDM-9 (0.5%). There were no predominant MLST lineages of blaNDM carrying strains. IncX3 was the major plasmid carrying blaNDM-1 (68.0%) and blaNDM-5 (72.6%) and was dominant in blaNDM-Klebsiella penumoniae (79.8%), blaNDM-Escherichia coli (58.2%), and blaNDM-Enterobacter cloacae (61.0%), respectively. Most (79.0%) clinical IncX3 plasmids in the world carried blaNDM, and the prevalence of blaNDM in IncX3 plasmids was more common in China (95.8%) than other countries (58.1%, P <0.01).
CONCLUSIONS: blaNDM is highly prevalent in CRE among children in China. The spread of blaNDM was mainly mediated by IncX3 plasmids. Surveillance and infection control on the spread of blaNDM among children are important.
摘要：
背景：blaNDM基因在儿童中普遍存在，并成为婴儿和儿童严重感染的主要原因。本研究旨在调查我国儿童肠杆菌科细菌blaNDM的流行病学及分子特征。
方法：收集2016年1月至2022年12月复旦大学附属儿科医院收治的耐碳青霉烯类肠杆菌（CRE）。五个碳青霉烯酶基因(blaKPC，blaNDM,BlaVIM,blaIMP,blaOXA-48）通过PCR方法筛选。进行多位点序列分型（MLST）进行系统发育分析。通过基于PCR的不相容性(Inc)分型方法对携带blaNDM的质粒进行分型。此外，用213个可公开获得的IncX3质粒进行质粒比较。
结果：共纳入330个CRE菌株，其中96.4%携带碳青霉烯酶基因。blaNDM基因占64.8%(214株)，包括4种变异，包括blaNDM-1（59.8%），blaNDM-5（39.3%），blaNDM-7(0.5%)和blaNDM-9(0.5%)。携带blaNDM的菌株没有主要的MLST谱系。IncX3是携带blaNDM-1(68.0%)和blaNDM-5(72.6%)的主要质粒,在blaNDM-K中占主导地位肺炎(79.8%)，blaNDM-E.大肠杆菌（58.2%）和blaNDM-E。泄殖腔(61.0%)，分别。世界上大多数（79.0％）的临床IncX3质粒携带blaNDM，IncX3质粒中blaNDM的患病率在中国（95.8％）比其他国家（58.1％，p<0.01)。
结论：blaNDM在中国儿童CREs中非常普遍。blaNDM的散布主要由IncX3质粒介导。监测和控制blaNDM在儿童中的传播非常重要。
方法：收集2016年1月至2022年12月复旦大学附属儿科医院收治的耐碳青霉烯类肠杆菌（CRE）。五个碳青霉烯酶基因(blaKPC，blaNDM,BlaVIM,blaIMP,blaOXA-48）通过PCR方法筛选。进行多位点序列分型（MLST）进行系统发育分析。通过基于PCR的不相容性(Inc)分型方法对携带blaNDM的质粒进行分型。此外，用213个可公开获得的IncX3质粒进行质粒比较。
结果：共纳入330个CRE菌株，其中96.4%携带碳青霉烯酶基因。blaNDM基因占64.8%(214株)，包括4种变异，包括blaNDM-1（59.8%），blaNDM-5（39.3%），blaNDM-7(0.5%)和blaNDM-9(0.5%)。携带blaNDM的菌株没有主要的MLST谱系。IncX3是携带blaNDM-1(68.0%)和blaNDM-5(72.6%)的主要质粒,在blaNDM-K中占主导地位肺炎(79.8%)，blaNDM-E.大肠杆菌（58.2%）和blaNDM-E。泄殖腔(61.0%)，分别。世界上大多数（79.0％）的临床IncX3质粒携带blaNDM，IncX3质粒中blaNDM的患病率在中国（95.8％）比其他国家（58.1％，p<0.01)。
结论：blaNDM在中国儿童CREs中非常普遍。blaNDM的散布主要由IncX3质粒介导。监测和控制blaNDM在儿童中的传播非常重要。
