Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Naumburger Str. 96a, 07743, Jena, Germany.
Institute for Infectious Diseases and Infection Control, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany.
BMC Microbiol. 2021 Jul 10;21(1):210. doi: 10.1186/s12866-021-02270-7.
Acinetobacter baumannii ability to develop and acquire resistance makes it one of the most critical nosocomial pathogens globally. Whole-genome sequencing (WGS) was applied to identify the acquired or mutational variants of antimicrobial resistance (AMR) genes in 85 German A. baumannii strains utilizing Illumina technology. Additionally, the whole genome of 104 German isolates deposited in the NCBI database was investigated.
In-silico analysis of WGS data revealed wide varieties of acquired AMR genes mediating resistance mostly to aminoglycosides, cephalosporins, carbapenems, sulfonamides, tetracyclines and macrolides. In the 189 analyzed genomes, the ant (3″)-IIa conferring resistance to aminoglycosides was the most frequent (55%), followed by bla (38.6%) conferring resistance to cephalosporin, bla (29%) and the bla variant of the intrinsic bla (26.5%) conferring resistance to carbapenems, the sul2 (26%) conferring resistance to sulfonamides, the tet. B (19.5%) conferring resistance to tetracycline, and mph. E and msr. E (19%) conferring resistance to macrolides. bla variants conferring resistance to cephalosporins were found in 12% of genomes. Thirteen variants of the intrinsic bla carbapenemase gene, bla and bla genes were found in isolates obtained from dried milk samples.
The presence of strains harboring acquired AMR genes in dried milk raises safety concerns and highlights the need for changes in producing dried milk. Acquired resistance genes and chromosomal gene mutation are successful routes for disseminating AMR determinants among A. baumannii. Identification of chromosomal and plasmid-encoded AMR in the genome of A. baumannii may help understand the mechanism behind the genetic mobilization and spread of AMR genes.
鲍曼不动杆菌能够产生和获得耐药性，使其成为全球最重要的医院获得性病原体之一。本研究利用 Illumina 技术对 85 株德国鲍曼不动杆菌菌株的全基因组测序（WGS）数据进行分析，以确定获得性或突变型抗菌药物耐药（AMR）基因变异。此外，还对 NCBI 数据库中 104 株德国分离株的全基因组进行了研究。
WGS 数据分析的结果显示，介导耐药性的获得性 AMR 基因种类繁多，主要针对氨基糖苷类、头孢菌素类、碳青霉烯类、磺胺类、四环素类和大环内酯类药物。在分析的 189 个基因组中，对氨基糖苷类药物耐药的 ant（3″）-IIa 最为常见（55%），其次是 bla（38.6%），可介导头孢菌素类药物耐药；bla（29%）和固有 bla 的 bla 变体（26.5%），可介导碳青霉烯类药物耐药；sul2（26%），可介导磺胺类药物耐药；tet. B（19.5%），可介导四环素类药物耐药；mph. E 和 msr. E（19%），可介导大环内酯类药物耐药。在 12%的基因组中发现了 bla 变体，可介导头孢菌素类药物耐药。在从干奶样中分离到的菌株中发现了 13 种内在 bla 碳青霉烯酶基因、bla 和 bla 基因的变体。
干奶中存在携带获得性 AMR 基因的菌株，引起了安全方面的担忧，并强调了需要改变干奶的生产方式。获得性耐药基因和染色体基因突变是鲍曼不动杆菌中 AMR 决定因素传播的成功途径。在鲍曼不动杆菌基因组中鉴定染色体和质粒编码的 AMR 有助于了解 AMR 基因遗传转移和传播的机制。
