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

• 批准号: 10057794
• 负责人: DANIEL D ROCKEY
• 金额: $ 23.84万
• 依托单位: OREGON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-06 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10057794
• 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' 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

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会导致人类和 动物。人类感染沙眼衣原体的人数每年数以百万计，并导致 眼睛和生殖道有严重的病变。几个独特的特征定义了该属 衣原体，其中之一是形成大的、多倍体的、不可培养的持久细胞形式- 当生长中的细菌暴露在压力下时，就会发生异常形式。生物学的 衣原体(Chlamydia spp.)进化出这种不同寻常的生长形式是完全未知的。 基因组和基于实验室的研究表明，临床沙眼衣原体经历了高度的 物种内的横向基因转移(LGT)水平，但基本上没有与 物种以外的生物。任何与衣原体LGT相关的机制仍然存在 未被发现，这一过程的生物学原因也是如此。这项建议将探讨可能的 异常形式的形成与侧向基因过程的相互作用 衣原体系统中的转移/重组。我们最重要的假设是 多倍体异常形式促进种内LGT和重组，导致从 在细胞内持续期间的应激诱导的突变。种内LGT可以被建模 在实验室中非常有效地使用不同抗药性的父母，适度水平的 遗传多样性。这一建议是对该模型的扩展，使用体外条件来模拟压力 以及体内可能遇到的选择性作用力。在目标1中，我们将使用培养和基因组 测序以探索不同沙眼衣原体共培养中LGT的广度和深度，以及 定性和定量地评估不同应激源对过程的影响。这个 测试的条件包括色氨酸饥饿，β-内酰胺暴露，以及在 存在中和抗体。在目标2中，我们将使用质粒构建来探索 沙眼衣原体个体发育形式内的重组，其结构携带 不可翻译的耐药性标记转化为抗生素敏感菌株。我们将研究 在这些菌株中，在存在和不存在抗生素耐药性的情况下，表型的转变 压力源。这一目标将检验这样的假设，即个体发育中的重组 形式受到胁迫诱导的变异转化所引入的多倍体的影响。 总的来说，这些实验将探索压力和变异如何影响的不同方面。 沙眼衣原体的横向基因转移和重组率。我们将使用这些数据来 研究衣原体LGT和重组在应激生存中的可能作用 患者的持续性感染。