1株产NDM-9和MCR-1的鸡源大肠杆菌的分子及生物学特征

Molecular and Biological Characteristics of a Chicken Source Escherichia coli Producing NDM-9 and MCR-1

为探究质粒介导耐药性的传播特征,本试验以1株分离自山东某肉鸡养殖场的产新德里金属β-内酰胺酶NDM-9和磷酸乙醇胺转移酶MCR-1的大肠杆菌(25R)为研究对象,通过全基因组序列分析、质粒接合转移试验、抗菌药物敏感性试验、大蜡螟毒性感染试验、质粒稳定性试验和生长动力学方法研究其质粒分子和生物学特征。结果显示,携带bla NDM-9和mcr-1的质粒可各自亦可共同转移至其他菌株,并且携带上述耐药基因的质粒对宿主菌造成的适应性代价和毒性较低,更有利于耐药基因的传播。本试验为更深入了解质粒介导的细菌耐药性传播机制提供理论依据。

To assess the molecular and biological characteristics of plasmid mediated antimicrobial resistance(AMR)spreading,this study examined Escherichia coli 25R strain isolated from chicken in a poultry farm of Shandong Province,producing NDM-9 and MCR-1,by using whole genome sequencing analysis,plasmid conjugation assay,antibiotic susceptibility test,Galleria mellonella infection test,plasmid stability test and growth kinetics method.The results showed that the 2 plasmids containing bla NDM-9 and mcr-1 readily transfered to recipient by conjugation individually or jointly,and exhibited low fitness cost and virulence.This study provides preliminary data for further investigation of plasmid mediated AMR.