低温条件下灿烂弧菌JZ6致病性的初步研究

项目名称： 低温条件下灿烂弧菌JZ6致病性的初步研究

项目编号： No.31302224

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 农业科学

项目作者： 刘瑞

作者单位： 中国科学院海洋研究所

项目金额： 20万元

中文摘要： 我们在前期研究中分离获得一株在低温条件下有致病性的适冷灿烂弧菌JZ6。该菌分泌的金属蛋白酶（SPF1）经序列和结构分析与灿烂弧菌LGP32毒力因子金属蛋白酶Vsm的相似度为94%；与交替假单孢菌低温金属蛋白酶MCP-02具有相同结构域。因此，SPF1兼具有毒力因子和低温酶的结构特性。本项目拟采用现代分子生物学和微生物学等手段，克隆和体外重组表达灿烂弧菌JZ6金属蛋白酶SPF1，鉴定金属蛋白酶SPF1的致病性以及低温对其致病性的影响；研究温度对灿烂弧菌JZ6胞外蛋白产物和SPF1分泌量的调节作用；筛选参与低温条件下SPF1转录、表达以及分泌过程的关键分子，明确低温对这些关键分子功能的调节作用；比较分析在低温和高温条件下SPF1的转录、表达和分泌情况，探讨低温对SPF1致病性的调节作用，进一步揭示灿烂弧菌在低温条件下的致病机制，丰富和发展水产动物病原学内容。

中文关键词： 灿烂弧菌；低温条件；致病性；金属蛋白酶；

英文摘要： Metalloprotease is one of the most important virulence factors in pathogenic Vibrio splendidus, which has caused serious disease to many aquatic animals. In our previous studies, a cold-adapted pathogen, V. splendidus JZ6, was isolated and identified at low temperature. A kind of metalloprotease (named SPF1), which was secreted from strain JZ6, shared 94% similarity with the virulence factor Vsm of V. splendidus LGP32 in amino acid sequence. And the protein structure analysis showed that SPF1 possessed the same domains with the psychrotrophilic metalloprotease MCP-02 of Pseudoalteromonas sp. SM9913. Therefore, SPF1 might have both features of pathogenic factor and psychrotrophilic protease. Based on the previous studies, the metalloprotease SPF1 is used as the main object to study the primary reason for the pathogenicity of V. splendidus JZ6 at low temperature. And the theme of this research is to elucidate the regulatory mechanism of low temperature for the expression and secretion of SPF1. In this project, SPF1 will be cloned and expressed in Escherichia coli to identify the pathogenicity to the hemocyte of scallop, and test the influence for this pathogecity at different temperatures. Strain JZ6 will be cultured both at high and low temperatures to analyze the secretion of all extracellular proteins and SPF1.

英文关键词： Vibrio splendidus；Low temperature condition；Pathogenicity；Metalloprotease；