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Genome-wide analysis of lateral gene transfer in Chlamydia trachomatis

沙眼衣原体横向基因转移的全基因组分析

基本信息

批准号：
10211129
负责人：
DANIEL D ROCKEY
金额：
$ 18.91万
依托单位：
OREGON STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-06 至 2023-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10211129
关键词：
Address Affect Animals Antibiotic Resistance Antibiotics Antibodies Back Bacteria Bacterial Genome Biological Biology Blindness Cells Characteristics Chlamydia Chlamydia Infections Chlamydia trachomatis Clinical Coculture Techniques Code Cytokinesis DNA Data Development Disease Engineering Event Excision Exposure to Eye Eye diseases Genes Genetic Genetic Recombination Genetic Variation Genome Genomics Goals Growth Health Horizontal Gene Transfer Human In Vitro Individual Infection Infertility Interruption Laboratories Lead Literature Measures Metabolic Modeling Molecular Mutagenesis Mutate Mutation Nature Organism Parents Pathology Patients Pattern Pelvic Inflammatory Disease Phenotype Physiological Plasmids Polyploidy Population Positioning Attribute Process Property Recovery Reproductive Health Resistance Rifampicin resistance Role Sequence Homologs Starvation Stress Structure System Testing Therapeutic Intervention Time Trachoma Tryptophan Vaccines Women&apos s Health base beta-Lactams chronic infection clinical sequencing design disorder prevention environmental stressor experimental study genome sequencing genome-wide analysis homologous recombination in vitro Model in vivo latent persistent infection neutralizing antibody novel pathogen pressure reproductive tract response stressor virtual

项目摘要

The obligate intracellular bacteria chlamydiae cause serious diseases in both humans and animals. Human infections by Chlamydia trachomatis number in the millions per year and lead to serious pathologies in the eye and genital tract. Several unique characteristics define the genus Chlamydia, one of which is the formation of large, polyploid, nonculturable persistent cell forms- termed aberrant forms- that occur when the growing bacteria are exposed to stress. The biological reasons that Chlamydia spp. have evolved this unusual growth form are completely unknown. Genomic and laboratory-based studies demonstrate that clinical C. trachomatis undergoes a high level of lateral gene transfer (LGT) within the species, but essentially no genetic exchange with organisms outside the species. Any mechanism associated with chlamydial LGT remains undiscovered, as does the biological reason for this process. This proposal will explore possible interactions between the formation of aberrant forms and the process of lateral gene transfer/recombination in the chlamydial system. Our overarching hypothesis is that that the polyploid aberrant form facilitates intraspecies LGT and recombination, leading to recovery from stress-induced mutagenesis during persistence inside cells. Intraspecies LGT can be modeled very effectively in the laboratory using differently antibiotic resistant parents with modest levels of genetic diversity. This proposal expands on that model, using in vitro conditions to mimic stresses and selective forces that might be encountered in vivo. In Aim 1 we will use culture and genome sequencing to explore the breadth and depth of LGT in cocultures of different C. trachomatis, and evaluate qualitatively and quantitatively the effects of different stressors on the process. The conditions to be tested include tryptophan starvation, beta-lactam exposure, and culture in the presence of neutralizing antibodies. In Aim 2, we will use plasmid constructs to explore recombination within individual C. trachomatis developmental forms, with constructs that carry untranslatable resistance markers transformed into antibiotic-sensitive strains. We will examine the phenotypic shift to antibiotic resistance within these strains, in the presence and absence of stressors. This aim will test the hypothesis that recombination within individual developmental forms is affected by the polyploidy introduced by a stress-induced transformation to aberrancy. Collectively, these experiments will explore different aspects of how stress and aberrancy affect the rate of lateral gene transfer and recombination in C. trachomatis. We will use these data to examine the possible roles that chlamydial LGT and recombination serve in stress survival during persistent infections of patients.

专性细胞内细菌衣原体在人类和哺乳动物中引起严重的疾病。动物每年有数百万人感染沙眼衣原体，眼睛和生殖道出现严重病变。几个独特的特征定义属衣原体，其中之一是形成大型，多倍体，不可培养的持久细胞形式- 称为异常形式-当生长的细菌暴露于压力时发生。生物 Chlamydia spp.进化出这种不寻常的生长形式是完全未知的。基因组和实验室研究表明，临床C。沙眼经历了一个高水平的横向基因转移（LGT）内的物种，但基本上没有遗传交换，物种之外的生物。与衣原体LGT相关的任何机制仍然存在这一过程的生物学原因也未被发现。该提案将探讨可能的变异形式的形成与侧基因的过程之间的相互作用衣原体系统中的转移/重组。我们的首要假设是，多倍体异常形式促进种内LGT和重组，导致从在细胞内持续存在期间的胁迫诱导的诱变。种内LGT可建模在实验室中，使用具有适度水平的抗生素抗性的不同亲本，遗传多样性这项提议扩展了该模型，使用体外条件来模拟压力以及在体内可能遇到的选择性力。在目标1中，我们将使用文化和基因组测序以探索LGT在不同C.沙眼，以及定性和定量地评估不同压力源对过程的影响。的待测试的条件包括色氨酸饥饿、β-内酰胺暴露和在培养基中培养。存在中和抗体。在目标2中，我们将使用质粒构建体来探索个体内的重组C.沙眼发育型，带有携带转化为抗生素敏感菌株的不可翻译的抗性标记。我们将研究在存在和不存在抗生素的情况下，压力源这一目标将检验个体发育过程中的重组形式受到由胁迫诱导的向异常转化所引入的多倍性的影响。总的来说，这些实验将探索压力和异常如何影响的不同方面。 C.沙眼我们将使用这些数据研究衣原体LGT和重组在压力下生存的可能作用，患者持续感染。