基于特定菌种的氨基糖苷类药物协同敏感机制研究

近年来，人们发现细菌在抗菌药物选择性压力下耐药的同时，会发生协同敏感（collateral sensitivity），即对其他药物敏感性升高，但机制尚未明确，并且国内尚无相关研究。我们在前期研究中发现肺炎克雷伯菌和粪肠球菌在抗菌药物诱导耐药后，均表现出对氨基糖苷类药物敏感性显著升高。我们推测通过对协同敏感现象及其机制的阐明，能够帮助临床预测治疗中耐药性的变化，交替使用协同敏感药物可能延缓耐药性的发生发展。本研究中我们利用各类抗菌药物对肺炎克雷伯菌及粪肠球菌临床及标准菌株对进行耐药诱导，分析抗菌药物间的交叉敏感性；选取氨基糖苷类药物及其协同敏感的药物进行交替用药诱导，比较单药及多药诱导后细菌耐药性变化；随后对诱导前后菌株进行转录组、全基因组测序和基因重组，阐释协同敏感的发生机制；最后，结合药敏表型及基因型建立协同敏感预测模型。本项目将为临床制订合理有效的用药策略提供科学依据。

In recent years, researchers found that bacteria evolved resistant to antimicrobials under selective pressure, will give rise to collateral sensitivity, which exhibite increasing susceptibility to one or more antimicrobials. However, the mechanism of collateral sensitivity has not been clarified yet. And there is no related research in domestic. In our previous studies, we found that both Klebsiella pneumoniae and Enterococcus faecalis exhibited significant increase in susceptibility to aminoglycosides when evolved resistant to other antimicrobials. Thus, we speculated that through elucidating the mechanism and regularity of collateral sensitivity, it will help predicting resistance evolution in clinic. Alternating therapy based on collateral sensitivity may mitigate the evolution of resistance. In this study, clinical isolated and standard strains of Klebsiella pneumoniae and Enterococcus faecalis will be evolved resistant to various antimicrobials through adaptive laboratory evolution. The cross-susceptibility will be analyzed. Aminoglycosides and corresponding drugs which show collateral sensitivity are selected. Bacteria will be challenged repeatedly by two antibiotics. Subsequently, transcriptome analysis, whole genome sequencing and gene recombination are applied to clarify the mechanism of collateral sensitivity. Finally, a prediction model is going to be established by combining collateral sensitivity phenotype and genotype. This research will help provide scientific basis to carry out more reasonable and effective anti-infection treatment strategies in clinic.