The extent and limits of natural transformation in Haemophilus influenzae

流感嗜血杆菌自然转化的程度和限制

• 批准号: 8423948
• 负责人: Joshua Chang Mell
• 金额: $ 0.79万
• 依托单位: UNIVERSITY OF BRITISH COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8423948
• 关键词: AIDS/HIV problem; Address; Alleles; Antibiotic Resistance; Bacteria; Bacterial Chromosomes; Bacterial Meningitis; Bacterial Pneumonia; Biochemical; Cells; Chromosomes; Clinical; Competence; DNA; DNA Sequence; DNA Sequence Rearrangement; Data Set; Disease; Elderly; Environment; Epidemiologic Studies; Epitopes; Eukaryota; Evaluation; Event; Evolution; Explosion; Frequencies; Funding; Genes; Genetic; Genetic Recombination; Genetic Variation; Genome; Genomics; Haemophilus influenzae; Haemophilus influenzae type b bacteria; Host Defense; Human; Immune; Individual; Infant; Life; Link; Malaria; Measurement; Measures; Meningitis; Mismatch Repair; Molecular; Molecular Genetics; Mutation; Natural Selections; Pathway interactions; Pneumonia; Population Genetics; Property; Public Health; Recombinants; Recording of previous events; Reproduction; Research; Role; Route; Serotyping; Surface; Surveys; System; Therapeutic Intervention; Upper respiratory tract; Vaccines; Variant; Virulence Factors; Virulent; Work; burden of illness; cell transformation; ear infection; genome sequencing; genome wide association study; homologous recombination; novel; pathogen; pathogenic bacteria; research study

DESCRIPTION (provided by applicant): Bacterial meningitis and pneumonia are responsible for a large worldwide disease burden, greater than other better-funded pathogenic diseases like HIV/AIDS and malaria. One of these pathogens, Haemophilus influenzae, inhabits the upper respiratory tract of most people, usually with no negative effect, but can cause several diseases-including meningitis, pneumonia, and ear infections-in infants, the elderly, and immune- compromised individuals. Like many other bacterial pathogens, H. influenzae can consume DNA by transporting it into their cells, breaking it down and reusing the subunits. But some of this DNA can recombine with a cell's own chromosome, interchanging versions of genes and adding or deleting genes. This natural competence mechanism allows related bacteria living in the same host to share genes, hastening their adaptation to host defenses and therapeutic interventions. The proposed research will link molecular studies of transformation with epidemiological studies of natural genetic diversity by experimentally measuring the chromosome-wide consequences of natural transformation. I will use the genomic DNA of clinical isolates to transform the chromosomes of competent recipient cells, and I will then apply massively parallel DNA sequencing to measure the extent and limits of natural transformation. I will use two complementary approaches: (1) measure the extent of transformation in a set of individual recombinant clones, and (2) measure the frequency of transformation across the chromosome from cultures of transformed cells. This research will be the first comprehensive experimental evaluation of genetic exchange in a human pathogenic bacterium (or any bacteria).

描述（由申请人提供）：细菌性脑膜炎和肺炎是造成世界范围内巨大疾病负担的原因，超过了其他资金更充足的病原性疾病，如艾滋病毒/艾滋病和疟疾。其中一种病原体流感嗜血杆菌（Haemophilus influenzae）存在于大多数人的上呼吸道，通常没有负面影响，但可在婴儿、老年人和免疫受损个体中引起几种疾病，包括脑膜炎、肺炎和耳部感染。与许多其他细菌病原体一样，H.流感病毒可以通过将DNA运送到它们的细胞中，将其分解并重新使用亚基来消耗DNA。但其中一些DNA可以与细胞自身的染色体重组，交换基因版本并添加或删除基因。这种天然的感受态机制允许生活在同一宿主中的相关细菌共享基因，加速它们对宿主防御和治疗干预的适应。拟议的研究将通过实验测量自然转化的全染色体后果，将转化的分子研究与自然遗传多样性的流行病学研究联系起来。我将使用临床分离株的基因组DNA转化感受态受体细胞的染色体，然后我将应用大规模并行DNA测序来测量自然转化的程度和限度。我将使用两种互补的方法：（1）测量一组单个重组克隆的转化程度，（2）测量转化细胞培养物中染色体上的转化频率。这项研究将是第一次对人类致病细菌（或任何细菌）的基因交换进行全面的实验评估。