Babosan Anamaria, Fruchard Louna, Krin Evelyne, Carvalho André, Mazel Didier, Baharoglu Zeynep
Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, 25 rue du Dr Roux 75015 Paris, France.
Sorbonne Université, Collège Doctoral, F-75005 Paris, France.
Microlife. 2022 Sep 14;3:uqac019. doi: 10.1093/femsml/uqac019. eCollection 2022.
Antimicrobial resistance develops as a major problem in infectious diseases treatment. While antibiotic resistance mechanisms are usually studied using lethal antibiotic doses, lower doses allowing bacterial growth are now considered as factors influencing the development and selection of resistance. Starting with a high-density Tn insertion library in and following its evolution by TN-seq in the presence of subinhibitory concentrations of antibiotics, we discovered that RNA modification genes can have opposite fates, being selected or counter-selected. We, thus have undertaken the phenotypic characterization of 23 transfer RNA (tRNA) and ribosomal RNA (rRNA) modifications deletion mutants, for which growth is globally not affected in the absence of stress. We uncover a specific involvement of different RNA modification genes in the response to aminoglycosides (tobramycin and gentamicin), fluoroquinolones (ciprofloxacin), β-lactams (carbenicillin), chloramphenicol, and trimethoprim. Our results identify t/rRNA modification genes, not previously associated to any antibiotic resistance phenotype, as important factors affecting the bacterial response to low doses of antibiotics from different families. This suggests differential translation and codon decoding as critical factors involved in the bacterial response to stress.
抗菌药物耐药性已成为传染病治疗中的一个主要问题。虽然抗生素耐药机制通常是使用致死剂量的抗生素进行研究，但现在认为允许细菌生长的较低剂量是影响耐药性发展和选择的因素。从一个高密度Tn插入文库开始，并通过在亚抑制浓度抗生素存在下的TN-seq跟踪其进化，我们发现RNA修饰基因可能有相反的命运，即被选择或被反选择。因此，我们对23个转移RNA（tRNA）和核糖体RNA（rRNA）修饰缺失突变体进行了表型特征分析，在没有应激的情况下，它们的生长总体上不受影响。我们发现不同的RNA修饰基因在对氨基糖苷类（妥布霉素和庆大霉素）、氟喹诺酮类（环丙沙星）、β-内酰胺类（羧苄青霉素）、氯霉素和甲氧苄啶的反应中具有特定作用。我们的结果确定了以前与任何抗生素耐药表型无关的t/rRNA修饰基因，是影响细菌对不同家族低剂量抗生素反应的重要因素。这表明差异翻译和密码子解码是细菌应激反应中的关键因素。
