嗜水气单胞菌AraC家族转录调控因子AetY的功能

Functional analysis of Aeromonas hydrophila AraC-family transcriptional factor AetY

摘要:

为研究嗜水气单胞菌中国流行菌株NJ-35的AraC家族转录调控因子AetY （U876_01475）的功能，本实验采用同源重组技术构建了该基因的缺失株ΔaetY及互补株CΔaetY，并对野生株、缺失株及互补株生物被膜形成能力、自凝集活性、对恩诺沙星的耐药性和对斑马鱼的致病力进行检测。结果显示，与野生株相比，ΔaetY生物被膜形成能力、自凝集活性、对恩诺沙星的最小抑菌浓度（MIC）均显著降低，对斑马鱼致病力明显降低，半数致死量（LD₅₀）增加400余倍。CΔaetY各项指标均恢复至野生株水平。本研究首次针对嗜水气单胞菌AraC家族成员进行了基因功能分析，为进一步探究该菌的致病机理提供参考。

Abstract:

In order to investigate the function of AraC-family transcriptional factor AetY (U876_01475), we constructed the aetY deletion mutant strain ΔaetY using homologous recombination with Aeromonas hydrophila Chinese epidemic strain NJ-35 as a parental strain. The corresponding gene-complemented strain CΔaetY was also constructed. Biofilm formation ability, auto-aggregation activity, drug resistance to enrofloxacin and pathogenicity were detected in NJ-35, ΔaetY and CΔaetY strains. The inactivation of aetY caused a significant decrease in biofilm formation, auto-aggregation and MIC value for enrofloxacin. The virulence of ΔaetY to Danio rerio was significantly reduced, and the LD₅₀ value had an increase of more than 400 times. The above characteristics of CΔaetY were restored to the same level of the wide type strain. This study for the first time investigated the function of AraC-family transcriptional factor AetY in A. hydrophila, which will provide a basis for further exploration of AetY role in pathogenic mechanism.