食源性金黄色葡萄球菌在酸胁迫下的交叉适应机制研究

食源性致病菌在某种环境压力的胁迫下可获得交叉适应（cross adaptation）能力，增强对其他逆境的耐受性，从而可能在常规杀菌条件下得以存活，对食品安全造成潜在威胁。酸性环境是食品中微生物最常遭遇的逆境之一，文献报道和申请人前期研究发现酸胁迫可促使食源性金黄色葡萄球菌（S. aureus）分别对热和氧化逆境产生交叉适应性，但其分子机制尚不明确。本项目针对这一科学问题，系统开展酸胁迫诱导食源性S. aureus对热和氧化逆境产生交叉适应的机制研究，综合运用转录组学、蛋白组学和生物信息学分析筛选出S. aureus在酸胁迫下调控产生交叉适应的关键基因和蛋白，并通过构建突变体对关键基因和蛋白进行功能学验证，系统揭示酸胁迫S. aureus交叉适应的分子调控机制，为评估和控制杀菌过程中交叉适应状态S. aureus的潜在风险提供理论依据，确保食品加工过程中的微生物安全。

After exposure to stresses encountered in the food environment, pathogens can acquire the cross-adaptation and develop the resistance to other stresses. Cross-adaptation phenomenon enables the pathogens to survive from the conventional sterilization, leading to a potential risk to food safety. Acid is one of the most common stresses encountered by foodborne pathogens. From previous literature and our preliminary research, acid stress was found to induce the cross-adaptation of Staphylococcus aureus to heat and oxidative stresses. However, the regulatory mechanisms underlying acid induced cross-adaptation in S. aureus still remain unclear. Considering this, the project aims to investigate the acid induced cross adaptation of foodborne S. aureus to the treatments of heat and oxidizing disinfectants. The combination of transcriptomics, proteomics and bioinformatics technologies will be employed to identify the key genes or proteins for the acid induced cross adaptation of S. aureus. Finally, the mutants will be constructed to verify the functions of differentially expressed genes and proteins in order to further identify the key regulatory network for the acid induced cross adaptation of S. aureus. This project will provide the theoretical foundation for the occurrence of cross adaptation during food processing and ultimately lead to effective strategies to assure the maximum microbiological safety.