Impact of the C. difficile small acid soluble proteins on spore physiology

艰难梭菌小酸溶蛋白对孢子生理学的影响

基本信息

批准号：
10677790
负责人：
Joe Sorg
金额：
$ 47.81万
依托单位：
TEXAS A&M UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-08 至 2027-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10677790
关键词：
Acids Affect Alleles Amino Acids Bacillus subtilis Bacteria Binding Binding Proteins Biology Cells Characteristics Chemicals Chromosomes Clostridium Clostridium difficile Clostridium perfringens DNA DNA Binding DNA Sequence Data Desiccation Development Disease Endospore-Forming Bacteria Environment Event Formaldehyde Future Gel Genes Genetic Transcription Genome Germination Hamsters Healthcare Healthcare Systems Hospitals Hydrogen Peroxide In Vitro Individual Infection Life Lyase Metabolism Minor Modeling Mothers Mutation Nature Nitrous Acid Organism Oxygen Pathogenesis Patients Peptide Hydrolases Phase Phase-Contrast Microscopy Phenotype Physiology Polymerase Process Production Property Proteins Publishing Reproduction spores Resistance Role Site Source Specificity Structure Surface Testing Thymidine Time Toxin UV Radiation Exposure UV induced DNA damage UV sensitive Ultraviolet Rays Ultraviolet Therapy United States Work adduct antibiotic-associated diarrhea cost crosslink design dimer experimental study extreme temperature genotoxicity health care settings mutant novel prevent programs repaired transmission process ultraviolet damage whole genome

项目摘要

Clostridioides difficile is the leading cause of antibiotic-associated diarrhea in the hospital and long term health care settings. In addition to the patient toll, the treatment-associated costs of C. difficile infections to the United States healthcare system have been estimated at $5 billion. Although the rate of C. difficile infection in the United States is rising, surprisingly little is known about the mechanisms by which C. difficile spores maintain their extreme resistance properties. C. difficile is believed to be acquired by the host in the form of a dormant spore which contaminates the nosocomial environment. In other organisms, a significant amount of resistant to UV and genotoxic chemicals is provided by the small acid soluble proteins (SASPs). SASPs are thought to nonspecifically bind to DNA and alter its form to prevent the formation of thymidyl-thymidine adducts (thymidine dimers) upon UV exposure. These proteins also provide resistances to reactive oxygen, acids, crosslinking agents and minor resistance to heat. In C. difficile, however, nothing is known about how these important proteins contribute to the C. difficile spore resistance spectrum. C. difficile SspA provides resistance to UV but SspA & SspB play a role in spore formation. The C. difficile ΔsspA ΔsspB double mutant strain does not produce mature spores suggesting that these SASPs regulate, at some level, the sporulation program. This application will analyze the impact of SASPs on spore biology in three aims. Aim 1 investigates how SspA & SspB contributes to spore formation and how the C. difficile SASPs protect the C. difficile genome from UV damage. Aim 2 investigates mechanisms by which the SASPs contribute to spore formation. Aim 3 investigates how the protease that degrades the SASPs during germination is regulated and its spectrum of activity in the spore. Successful completion of these aims will thoroughly characterize the impact of SASPs on spore resistance and lead to the future design of agents that can clean a contaminated environment.

艰难梭菌是医院抗生素相关性腹泻的主要原因除了患者死亡之外，长期医疗保健机构还需要支付与治疗相关的费用。据估计，艰难梭菌感染给美国医疗系统造成的损失达 50 亿美元。尽管美国的艰难梭菌感染率正在上升，但令人惊讶的是我们对此知之甚少关于艰难梭菌孢子保持其极端抵抗特性的机制。据信，艰难梭菌以休眠孢子的形式被宿主获得，在其他生物体中，存在大量的耐药性。抗紫外线和遗传毒性化学物质的能力是由小酸溶蛋白 (SASP) 提供的。被认为与 DNA 非特异性结合并改变其形式以防止形成紫外线照射后胸苷基-胸苷加合物（胸苷二聚体）也提供蛋白质。耐活性氧、酸、交联剂和轻微的耐热性。然而，对于这些重要的蛋白质如何对艰难梭菌做出贡献，我们一无所知。艰难梭菌孢子耐药谱。艰难梭菌 SspA 具有抗紫外线能力，但 SspA 和 SspB 具有抗性。艰难梭菌 ΔsspA ΔsspB 双突变菌株在孢子形成中不发挥作用。产生成熟孢子，表明这些 SASP 在某种程度上调节孢子形成该应用程序将从三个目标来分析 SASP 对孢子生物学的影响。 1 研究了 SspA 和 SspB 如何促进孢子形成以及艰难梭菌 SASP 如何形成目标 2 研究保护艰难梭菌基因组免受紫外线损伤的机制。 SASP 有助于孢子形成。目标 3 研究蛋白酶如何降解孢子。萌发过程中的 SASP 受到调节，并且其在孢子中的活性谱是成功的。完成这些目标将彻底表征 SASP 对孢子抗性的影响并导致未来能够清洁受污染环境的药剂的设计。