嗜水气单胞菌中转录因子AHA_1581对细菌生理功能调控机制的研究

Study on the transcription factor AHA_1581 in Aeromonas hydrophila on the regulation mechanism of bacterial physiological functions

摘要:

[目的] LuxR家族转录因子能够抑制或刺激不同功能类型基因的表达，来维持细胞功能的稳定性。嗜水气单胞菌是水产养殖中重要的致病菌之一，目前对该菌中的LuxR家族转录因子功能的研究还较少。[方法] 本研究利用含有sacB标记的自杀载体pRE112和同源重组技术敲除LuxR家族转录因子AHA_1581基因。[结果] 生理表型测定结果发现，ΔAHA_1581的运动与胞外蛋白的酶活增强、生物被膜形成能力降低，且耐受低温、卡那霉素、庆大霉素胁迫，但是对K₂Cr₂O₇更加敏感。进一步对野生型Ah和ΔAHA_1581的定量蛋白质组学分析，共鉴定到2654个蛋白，其中59个蛋白下调表达，142个蛋白上调表达。生物信息学分析表明AHA_1581参与调控双组分调节系统、丙酮酸代谢、碳代谢、TCA循环等细菌重要生理过程，以及细菌耐药基因和毒力因子的差异表达。[结论] 了解AHA_1581基因在调控细菌毒力以及生物过程中所起的重要作用，对预防和控制嗜水气单胞菌引起疾病的发生和传播可能具有重要的科学意义。

关键词:嗜水气单胞菌;LuxR家族转录因子;AHA_1581;定量蛋白质组学;生理功能

Abstract:

LuxR family transcription factors can inhibit or stimulate the expression of various functional genes to maintain the stability of cell function. [Objective] To study the role of LuxR family transcription factors in Aeromonas hydrophila. [Methods] In this study, we have knocked out the AHA_1581 gene by homologous recombination technology to understand their role in virulence and drug resistance. [Results] The deletion of AHA_1581 gene not only enhanced the extracellular protease enzyme activity, the tolerance of A. hydrophila to survive under low temperature, different antibiotic stress, but also reduced the biofilm formation capability. Further the quantitative proteomic and bioinformatics analysis showed that the deletion of AHA_1581 gene 59 proteins were down-regulated and 142 proteins were up-regulated, which affected several important biological processes and virulence pathways in A. hydrophila. [Conclusion] Overall, the outcome of this study on the role of transcription factor AHA_1581 in the biological processes and virulence of A. hydrophila may pay the way for controlling their infections.

Key words:Aeromonas hydrophila;LuxR family transcription factor;AHA_1581;quantitative proteomics;physiological function