Elucidating the factors and mechanisms influencing the formation of biofilms in food systems

阐明影响食品系统中生物膜形成的因素和机制

• 批准号: RGPIN-2015-06270
• 负责人: Korber, Darren
• 金额: $ 2.91万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614048
• 关键词: Elucidating; factors; mechanisms; influencing; formation

Background. With expanding production and distribution systems in Canada, foodborne pathogens have multiple access points into our food system. Linkages of biofilms (diverse microorganisms which attach to, and grow on, surfaces) to outbreaks of foodborne disease are on the rise due to their ubiquity and their resilience to sanitization and removal attempts. Efforts to derive biofilm-specific control strategies have not been successful; thus, more information on how biofilms survive stress is necessary. My discovery grant research seeks to advance such knowledge, with the long-range goal of developing strategies for industry to help prevent outbreaks. Program.  My research focuses on adaptive stress responses used by pathogenic bacteria when exposed to antimicrobial treatments after having been pre-conditioned by stresses experienced outside of the gastrointestinal tracts of their natural hosts. In these transient environments (e.g., during production, transport, storage) bacteria encounter various sub-optimal conditions (e.g., temperature abuse, pH, low nutrients), challenging them to adapt to a more stress-resistant form. Biofilms may be key in stress resistance; however, their role remains unclear, as do the role(s) played by other organisms that co-exist within complex biofilm communities. My research program therefore has two long-term objectives: 1) to elucidate physiological and molecular mechanisms involved in biofilm and bacterial adaptive resistance to antimicrobial agents, nanoparticles and environmental stressors, and 2) to improve the understanding of community-level responses and cross-protective interactions between pathogenic and non-pathogenic biofilm-forming organisms during stress events. Experiments will be conducted using known pathogens to elucidate responses, determined using proteomics, in bacteria and biofilms exposed to two phases of stress – a “conditioning” stress phase (low temperature and slow growth) like that found in the food production chain, followed by an "imposed" stress phase (i.e., antimicrobials or nanoparticles). Inducing mutations in proteins thought to play a role in stress resistance in the test organisms will allow functional (gene expression and survival) analyses to confirm which response elements are critical. These proteins will then be probed in biofilm communities exposed to stresses to determine their function in more complex systems. A comprehensive understanding of microbial stress response pathways will identify molecular targets for engineered biofilm control strategies. Other benefits to Canada resulting from this research includes improving the safety of the food supply, as well as training the next generation of scientists in the area of food safety to support industry growth in the agri-food sector as well as the sciences.

背景：随着加拿大生产和分销系统的扩大，食源性病原体有多种途径进入我们的食品系统。生物膜（附着在表面并在表面生长的各种微生物）与食源性疾病爆发的联系正在增加，这是由于它们的普遍性及其对消毒和清除尝试的适应性。努力获得生物膜的具体控制策略尚未成功，因此，更多的信息如何生物膜生存的压力是必要的。我的发现补助金研究旨在推进此类知识，长期目标是为行业制定战略，以帮助预防疫情。 程序. 我的研究重点是病原菌在经过天然宿主胃肠道外的压力预处理后暴露于抗菌治疗时所使用的适应性压力反应。在这些瞬态环境中（例如，在生产、运输、储存期间）细菌遇到各种次优条件（例如，温度滥用，pH值，低营养素），挑战他们适应更抗应激的形式。生物膜可能是抗应激的关键;然而，它们的作用仍然不清楚，复杂的生物膜群落中共存的其他生物体所发挥的作用也是如此。因此，我的研究计划有两个长期目标：1）阐明生物膜和细菌对抗菌剂、纳米颗粒和环境应激物的适应性抗性中涉及的生理和分子机制，和2）提高对社区水平的反应以及致病性和非致病性生物膜之间的交叉保护相互作用的理解-在压力事件期间形成生物体。将使用已知的病原体进行实验以阐明反应，使用蛋白质组学确定，在暴露于两个阶段的应激的细菌和生物膜中-“调节”应激阶段（低温和缓慢生长），如在食品生产链中发现的，随后是“施加”应激阶段（即，抗微生物剂或纳米颗粒）。在被认为在测试生物体的抗逆性中发挥作用的蛋白质中诱导突变将允许功能（基因表达和存活）分析以确认哪些响应元件是关键的。然后，这些蛋白质将在暴露于压力的生物膜群落中进行探测，以确定它们在更复杂的系统中的功能。对微生物应激反应途径的全面理解将确定工程生物膜控制策略的分子靶点。加拿大从这项研究中获得的其他好处包括改善食品供应的安全性，以及培训食品安全领域的下一代科学家，以支持农业食品部门和科学的产业增长。