Zhejiang Provincial Center for Disease Control and Prevention, People's Republic of China, Hangzhou, China.
Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, Beijing Laboratory of Food Quality and Safety, College of Veterinary Medicine, China Agricultural University, Beijing, China.
Antimicrob Agents Chemother. 2020 Dec 16;65(1). doi: 10.1128/AAC.01872-20.
Increasing mobile colistin resistance, mediated by the gene family, in has become a global concern. Among the 10 reported genes, was first identified in , which could cause severe infections with high mortality. Information about the prevalence and genetic context of is still lacking. In this study, we found that was present in 9.83% of isolates of chicken origin. S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern blotting showed that the gene was located on a plasmid in all of the isolates. The genetic context of the plasmids exhibited considerable diversity from the whole-genome sequence through Illumina and MinION long-read sequencing. Mutations in two-component systems may function synergistically with , resulting in extremely high resistance to colistin. In addition to colistin resistance, these plasmids also contained genes conferring resistance to beta-lactams, tetracycline, aminoglycosides, sulfonamides, macrolides, chloramphenicol, and florfenicol. Therefore, these findings indicate that the genetic context of is heterogeneous and diverse and that and certain chromosomal mechanisms jointly contribute to high-level colistin resistance in strains, which provides new insights into the resistance mechanisms of .
基因家族介导的移动多粘菌素耐药性增加已成为全球关注的问题。在报道的 10 个 基因中，最早是在 中发现的 ，它可导致高死亡率的严重感染。关于 的流行情况和遗传背景的信息仍然缺乏。在本研究中，我们发现 9.83%的鸡源 分离株中存在 。S1 核酸酶脉冲场凝胶电泳（S1-PFGE）和 Southern 印迹显示，所有分离株中的 基因均位于质粒上。通过 Illumina 和 MinION 长读测序对质粒的遗传背景进行了全基因组序列分析，结果显示其具有很大的多样性。两个组件系统中的突变可能与 协同作用，导致对多粘菌素的极高耐药性。除了对多粘菌素的耐药性外，这些质粒还含有对β-内酰胺类、四环素类、氨基糖苷类、磺胺类、大环内酯类、氯霉素类和氟苯尼考类药物的耐药基因。因此，这些发现表明 的遗传背景具有异质性和多样性， 和某些染色体机制共同导致 菌株高水平的多粘菌素耐药性，这为 耐药机制提供了新的见解。
