模拟微重力对肺炎克雷伯菌表型和基因型的影响

Effects of simulated microgravity on phenotype and genotype of Klebsiella pneumoniae

目的探索肺炎克雷伯菌(K.pneumoniae)在模拟微重力(SMG)环境下的表型和基因型变化。方法利用旋转细胞培养系统(RCCS)建立地面上的SMG,分别在SMG和正常重力(NG)下培养K.pneumoniae,通过生长曲线、结晶紫染色、纸片扩散法测定2种环境下K.pneumoniae的生长速率、生物膜形成能力和对抗菌药物敏感性的变化;再对样本重测序以分析突变基因。结果和NG组相比,SMG中的K.pneumoniae生长速率变缓、结晶紫染色程度加深、对多种药物的敏感性明显改变;重测序结果显示共有19个基因发生突变;SMG下2个代谢相关基因发生突变;NG下多个突变基因与信号转导系统和生物膜形成有关。结论SMG下,K.pneumoniae生长变缓、生物膜形成能力增强、对多种抗菌药物的敏感性发生变化,代谢相关基因发生突变。

Objective To investigate the phenotypic and genotypic changes of Klebsiella pneumoniae under simulated microgravity(SMG).Methods SMG on the ground was established by using a rotary cell culture system(RCCS)and K.pneumoniae was cultured under SMG and normal gravity(NG).The growth rate,biofilm formation ability and drug sensitivity of K.pneumoniae were determined using the growth curve,crystal violet staining and paper diffusion method.The samples were sequenced by Illumina Miseq and analyzed for mutated genes.Results Compared with the NG group,the growth rate of K.pneumoniae under SMG slowed down,the degree of crystal violet staining deepened,and the sensitivity to various drugs changed significantly.Re⁃sequencing results showed that 19 genes were mutated.Two genes related to UDP⁃glucose and UDP⁃galactose were mutated under SMG,and the mutant genes under NG were more involved in signal transduction systems and biofilm formation pathways.Conclusion Under SMG,the growth rate of K.pneumoniae decreases,the ability of biofilm formation increases,the sensitivity of K.pneumoniae to various antimicrobial drugs changes,and two genes related to metabolism have been mutated.