Quorum-sensing mechanisms of Campylobacter

描述（由申请人提供）：该提案详细介绍了一项为期三年的培训补助金，重点是培养分子食品安全微生物学领域的独立调查员。主要研究者已经完成了兽医大型动物内科的结构化住院医师培训，并获得了美国兽医内科学院在该专业的董事会认证。他现在正在积极寻求分子微生物学领域的强化培训，以补充他在大型动物传染病方面的专业知识。 该计划旨在提供广泛的经典和当代分子技术，适用于食品安全微生物学的假设驱动研究。通过弯曲杆菌分子微生物学领域的领导者张启静博士的指导，首席研究员将培养他制定深思熟虑的假设的能力，设计稳健的实验来测试这些假设，并与同行交流科学结果。将特别强调负责任地进行研究方面的培训。在该计划完成后，预计他将准备在学术研究的独立职业生涯。 作为该提案的一部分进行的研究将集中在空肠弯曲菌（Campylobacter jejuni）所采用的群体感应机制上，空肠弯曲菌是美国人类食源性细菌性肠炎的主要原因。自诱导物-2（AI-2）介导的细菌通讯已在30多种细菌物种中被描述，并负责协调各种适应性反应的表达。基于主要研究者设计和进行的初步研究结果，本研究将1）确定G92 D氨基酸取代对C.空肠LuxS蛋白，2）表征了双组分传感器系统（与E.大肠杆菌）中的表达，以及3）使用体外和体内实验检查luxS无效突变对弯曲杆菌适应各种环境的影响。这些研究的结果将首次全面描述弯曲杆菌中的这种信号系统，并为研究者未来的独立研究工作提供坚实的基础。 爱荷华州州立大学的兽医微生物学和预防医学系是食品安全和公共卫生微生物学的领导者。该大学和当地USDA国家动物疾病中心的综合资源提供了一个在兽医领域无与伦比的专业知识和学习丰富的环境。鉴于导师实验室在研究领域的专业知识，肥沃的科学环境和强大的机构承诺，这个培训计划是成功的保证。

DESCRIPTION (provided by applicant): This proposal details a three year training grant focused on development of an independent investigator in the field of molecular food safety microbiology. The principal investigator has completed a structured residency in Veterinary Large Animal Internal Medicine and is board certified by the American College of Veterinary Internal Medicine in this specialty. He is now actively pursuing intensive training in the field of molecular microbiology to complement his expertise in large animal infectious disease. This program is designed to provide exposure to a broad range of classical and contemporary molecular techniques applicable to hypothesis driven research in food safety microbiology. Through the mentorship of Dr. Qijing Zhang, a leader in the field of Campylobacter molecular microbiology, the principal investigator will develop his ability to formulate thoughtful hypotheses, design robust experiments to test these hypotheses and communicate scientific results with peers. Special emphasis will be placed on training in responsible conduct of research. At the completion of the program it is expected that he will be prepared for an independent career in academic research. Research conducted as part of this proposal will focus on the quorum sensing mechanism employed by Campylobacter jejuni, a leading cause of human foodborne bacterial enteritis in the United States. Autoinducer-2 (AI-2) mediated bacterial communication has been described in over 30 bacterial species and is responsible for coordinating expression of a variety of adaptive responses. Building on the results of preliminary research designed and conducted by the principal investigator, this study will 1) determine the effect of the G92D amino acid substitution on the enzymatic activity of the C. jejuni LuxS protein, 2) characterize a two-component sensor system (homologous to a phosphorus responsive two-component sensor system of E. coli) regulated by the presence of AI-2, and 3) examine the effects of the luxS null mutation on the adaptation of Campylobacter to various environments using in vitro and in vivo experiments. Results of these studies will provide the first comprehensive description of this signaling system in Campylobacter and will provide a strong foundation for future independent research endeavors by the investigator. The Department of Veterinary Microbiology and Preventative Medicine at Iowa State University is a leader in food safety and public health microbiology. The combined resources of the University and the local USDA National Animal Disease Center provide an environment rich in expertise and learning unmatched in the veterinary field. Given the expertise of the mentor's laboratory in the field of study, the fertile scientific environment, and a strong institutional commitment, this training program is assured success.