Axe des Maladies Infectieuses et Immunitaires du Centre de Recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Québec, Canada.
Microb Genom. 2020 Nov;6(11). doi: 10.1099/mgen.0.000454.
We report on the combination of chemical mutagenesis, azithromycin selection and next-generation sequencing (Mut-Seq) for the identification of small nucleotide variants that decrease the susceptibility of to the macrolide antibiotic azithromycin. Mutations in the 23S ribosomal RNA or in ribosomal proteins can confer resistance to macrolides and these were detected by Mut-Seq. By concentrating on recurrent variants, we could associate mutations in genes implicated in the metabolism of glutamine with decreased azithromycin susceptibility among mutants. Glutamine synthetase catalyses the transformation of glutamate and ammonium into glutamine and its chemical inhibition is shown to sensitize to antibiotics. A mutation affecting the ribosomal-binding site of a putative ribonuclease J2 is also shown to confer low-level resistance. Mut-Seq has the potential to reveal chromosomal changes enabling high resistance as well as novel events conferring more subtle phenotypes.
我们报告了化学诱变、阿奇霉素选择和下一代测序（Mut-Seq）的组合，用于鉴定降低 对大环内酯类抗生素阿奇霉素敏感性的小核苷酸变异。核糖体 RNA 或核糖体蛋白中的突变可赋予对大环内酯类药物的抗性，这些通过 Mut-Seq 检测到。通过集中研究反复出现的变异，我们可以将与谷氨酰胺代谢相关的基因中的突变与 突变体中阿奇霉素敏感性降低相关联。谷氨酰胺合成酶催化谷氨酸和铵转化为谷氨酰胺，其化学抑制作用被证明可使 对抗生素敏感。影响推定的核糖核酸酶 J2 的核糖体结合位点的突变也显示出低水平的抗性。Mut-Seq 有可能揭示导致高抗性的染色体变化以及赋予更微妙表型的新型事件。
