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Sinorhizobium meliloti factors that affect biofilm formation and symbiosis efficiency

影响生物膜形成和共生效率的苜蓿中华根瘤菌因子

基本信息

批准号：
10672247
负责人：
Joseph Chiung-Chu Chen
金额：
$ 11.63万
依托单位：
SAN FRANCISCO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10672247
关键词：
Adherence Adhesions Affect Alphaproteobacteria Antibiotic Resistance Antimicrobial Resistance Bacteria Bacterial Adhesins Brucella Carbon Cell Aggregation Cell Polarity Cell model Cell physiology Cells Chemicals Citrus Desiccation Development Disadvantaged Disease Elements Environment Environmental Risk Factor Expression Profiling Fabaceae Funding Genes Genetic Genetic Models Genetic Transcription Goals GpGp Gram-Negative Bacteria Grant Health Heterogeneity Homeostasis Horizontal Gene Transfer Human Immune response Industrialization Infection Invaded Investigation Laboratories Length Link Medical Device Microbe Microbial Biofilms Modeling Molecular Monitor Mutagenesis Mutation Nitrogen Nodule Nonsense Mutation Nutrient Organism Pathogenesis Pathway interactions Periodicity Phenotype Physiological Plants Play Poison Polymers Preparation Prevention Process Production Productivity Property Public Health Regulation Research Research Personnel Research Training Role Scientific Advances and Accomplishments Second Messenger Systems Signal Transduction Sinorhizobium meliloti Stress Students Surface Symbiosis System Tissues antimicrobial drug career cell community cell motility chronic infection diguanylate cyclase experience host colonization host-microbe interactions human pathogen improved insight medical implant microbial microbial disease microorganism mutant mutation correction pathogen phosphoric diester hydrolase prevent protein function recurrent infection symbiont transcription factor

项目摘要

Project Summary / Abstract The proposed project will elucidate the mechanisms that control polar adhesin production, biofilm formation, and host colonization in alpha-proteobacteria, a physiologically heterogeneous group that includes a number of significant human pathogens. Particularly relevant to public health, biofilm formation plays a crucial role in the survival of bacteria in diverse environments: cells in biofilms attach recalcitrantly to biotic and abiotic surfaces, develop increased resistance to antimicrobial agents, and contribute to persistent infections. Although limiting biofilm formation has the potential to prevent and restrict microbial diseases, little is known about biofilm formation by alpha-proteobacteria and how it facilitates host colonization. We previously discovered a biofilm-associated mutation common in laboratory strains of Sinorhizobium meliloti, a model alpha-proteobacterium that forms mutualistic symbiosis with compatible legumes by colonizing root tissues and fixing nitrogen in exchange for nutrients from plant hosts. Correcting the mutation restored full-length production of the conserved polarity factor PodJ, thus enabling synthesis of the holdfast (a polar adhesin) and assembly of robust biofilms, phenotypes never observed before. We found that biofilm- competent strains possess a competitive advantage over biofilm-deficient strains during host infection. Via transposon mutagenesis, we identified a number of genes involved in biofilm development, including one encoding a conserved transcription factor (LdtR) and another encoding a diguanylate cyclase and phosphodiesterase, known to modulate levels of the c-di-GMP second messenger. The goals of this proposal are (a) to decipher the responsibilities of key regulators during biofilm formation and host colonization and (b) to establish a system for monitoring the relationship between symbiosis and environmental factors. We plan to achieve these goals by accomplishing the following three specific aims. (1) We will determine how LdtR expression is regulated and what cellular functions it performs. (2) We will assess how factors that modulate c- di-GMP levels contribute to biofilm formation and host infection. (3) We will evaluate whether symbiosis affects host response to toxic compounds and how chemical stress and other microbes influence host-symbiont interactions. Results from the investigation will provide a better model of how cellular and external factors can contribute to adhesion, biofilm formation, and host invasion in alpha-proteobacteria. In addition to accomplishing the scientific objectives described above, funding of this proposal will enhance the research productivity and grant competitiveness of the investigator and allow students, particularly those from underrepresented backgrounds, to gain research training and preparation for biomedical careers.

项目摘要/摘要

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Optical disassembly of cellular clusters by tunable 'tug-of-war' tweezers.

DOI：
10.1038/lsa.2016.158
发表时间：
2016
期刊：
Light, science & applications
影响因子：
0
作者：
通讯作者：

Jungle Express is a versatile repressor system for tight transcriptional control.

Jungle Express是一种用于紧密转录控制的多功能阻遏系统。

DOI：
10.1038/s41467-018-05857-3
发表时间：
2018-09-06
期刊：
Nature communications
影响因子：
16.6
作者：
Ruegg TL;Pereira JH;Chen JC;DeGiovanni A;Novichkov P;Mutalik VK;Tomaleri GP;Singer SW;Hillson NJ;Simmons BA;Adams PD;Thelen MP
通讯作者：
Thelen MP

Evaluating the toxic effect of an antimicrobial agent on single bacterial cells with optical tweezers.