速冻食品中VBNC状态大肠杆菌O157:H7形成的分子机制研究

项目名称： 速冻食品中VBNC状态大肠杆菌O157:H7形成的分子机制研究

项目编号： No.31501582

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 农业科学

项目作者： 赵喜红

作者单位： 武汉工程大学

项目金额： 19万元

中文摘要： 速冻食品中大肠杆菌O157:H7在低温诱导下可进入活的不可培养状态（Viable But Nonculturable State,VBNC)，在适当条件下可能复苏，从而恢复致病性，成为食品安全的潜在威胁。目前对其VBNC形成的分子机制并不清楚，缺乏系统性研究。本项目拟综合运用转录组学、蛋白组学和生物信息学的手段，构建差异表达谱，解析状态转变中的细胞物质基础及代谢特征；通过转录组和蛋白质组比较关联分析，筛选调控VBNC状态形成的特异性基因，构建特异性基因的缺失突变株，研究突变株在正常状态和VBNC状态时的生物学特性和致病性；利用反转录实时荧光定量PCR研究在低温下诱导培养不同时段这些基因的转录特征，进一步研究其生存能力与特异性基因表达的关系。在以上工作基础上，最终阐明VBNC状态大肠杆菌O157:H7形成的分子机制，为速冻食品中大肠杆菌O157:H7的生存和致病的发生机制提供理论依据。

中文关键词： 食源性致病菌；食品微生物安全；活的不可培养；分子机制；组学

英文摘要： Escherichia coli O157:H7 could enter into the viable but nonculturable (VBNC) state induced at low temperature in quick-frozen food. It may be able to recovery under certain conditions, thereby retain its pathogenicity and play a potential threat to food safety. However, the molecular mechanism of E. coli O157:H7 VBNC formation still is not clear, lack of systematic research. In this project the transcriptional profiles and protein expression profiles of E. coli O157:H7 are studied by comprehensive transcriptomics, proteomics and bioinformatics methods, to reveal the cellula materials and metabolic characteristics. With the comparative transcriptome and proteome analyses, the specific genes in regulation of the VBNC state formation are selected. The mutants are constructed and studied the the biological characteristics and pathogenicity in normal and VBNC state. Real-time RT-PCR is used to detect the expression levels of the specific genes during induced by the room temperature, to further investigate the relationship of the specific genes and E. coli O157:H7 viability. Based on the above work, the aim is to clarify finally the molecular mechanism of E. coli O157:H7 VBNC formation, to provide a theoretical basis for the existence and occurrence of pathogenic mechanisms in quick-frozen food.

英文关键词： Foodborne pathogen;Food microbiology safety;Viable but nonculturable;Molecular mechanism;Omics