【摘要】 目的 检测某医院耐碳青霉烯类霍氏肠杆菌分离株的基因型和同源性及其碳青霉烯酶基因水平转移情况，为制定该菌的防控措施提供依据。方法 11株非重复耐碳青霉烯类阴沟肠杆菌（E.cloacae）于2016年9月-2017年5月分离自某医院住院患儿，编号Q1～Q11。菌株的全基因组测序采用Illumina和Nanopore平台。采用脉冲场凝胶电泳分析菌株间的同源性。采用质粒液相接合实验和S1核酸酶切脉冲场凝胶电泳检测该菌株碳青霉烯酶基因转移情况。结果 经平均核苷酸一致性鉴定，11株菌中1株为E.bugandensis（Q10菌株）,其余10株均为霍氏肠杆菌（E.hormaechei）。这11株菌株均携带碳青霉烯酶基因bla_NDM-1,有5种多位点序列分型，以ST177为主，占比63.6%（7/11）。脉冲场凝胶电泳分析结果显示，霍氏肠杆菌Q4～Q8菌株的Dice相似系数为100.0%,均为ST177,携带了相同的耐药基因。生物信息分析结果显示，Q4菌株（代表菌株）携带的碳青霉烯酶基因bla_NDM-1位于质粒上。质粒液相接合实验结果显示，携带bla_NDM-1基因的质粒可传递给E.coliJ53Azi^R。结论 携带碳青霉烯酶基因bla_NDM-1的ST177霍氏肠杆菌是导致新生儿医院感染暴发的病原体，且该基因可通过质粒介导在不同种细菌之间传播。更多还原

【Abstract】 Objective To investigate the genotype, homology, and horizontal carbapenemase gene transfer situation of carbapenem-resistant Enterobacter hormaechei isolates from a hospital, and to provide a basis for formulating prevention and control measures for this bacterium. Methods Eleven non-repeating Enterobacter cloacae strains were collected from the children who were hospitalized in a hospital from September 2016 to May 2017 and were numbered as Q1-Q11, and Illumina and Nanopore platforms were used for whole-genome sequencing. Pulsed-field gel electrophoresis（PFGE） was used to analyze the homology between strains, and liquid conjugation assay and S1 nuclease digestion followed by PFGE were used to analyze the carbapenemase gene transfer ability of the strains. Results The average nucleotide identity analysis showed that among the eleven strains, strain Q10 was identified as Enterobacter bugandensis, and the remaining ten strains were identified as Enterobacter hormaechei. All eleven strains carried the bla_NDM-1 gene and had five multi-locus sequence genotypes, among which ST177 was the main genotype and accounted for 63.6%（7/11）. The results of PFGE showed that the Q4-Q8 strains of Enterobacter hormaechei had a Dice similarity coefficient of 100.0%, all of which had the ST177 type and carried the same drug-resistance gene. The bioinformatics analysis showed that the bla_NDM-1 gene carried by strain Q4 was located on the plasmid. Liquid conjugation assay showed that the plasmid carrying bla_NDM-1 can be delivered to E.coliJ53Azi^R. Conclusion Enterobacter hormaechei ST177 harboring the bla_NDM-1 gene is the pathogen causing the outbreak of nosocomial infection in neonates, and the bla_NDM-1 gene can be transmitted between different species through mediation by plasmids.更多还原