Characterization of Francisella tularensis-specific bacteriophages

土拉弗朗西斯菌特异性噬菌体的表征

• 批准号: 10380125
• 负责人: Chandra Shekhar Bakshi
• 金额: $ 8.22万
• 依托单位: NEW YORK MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10380125
• 关键词: Adverse effects; Animals; Anthrax disease; Antibiotic Resistance; Antibiotic Therapy; Antibiotics; Applications Grants; Arthropods; Bacteria; Bacteriophages; Biochemical; Biological; Biological Assay; Bioterrorism; Categories; Cell Surface Receptors; Centers for Disease Control and Prevention (U.S.); Cessation of life; Characteristics; Chronic; Clinical; Collection; Country; Cytolysis; Development; Disease; Disease Outbreaks; Emerging Communicable Diseases; Ensure; Floods; Formulation; Francisella; Francisella tularensis; Genetic; Genome; Genomics; Goals; Gram-Negative Bacteria; Growth; Hawaii; Human; Incidence; Individual; Infection; Inhalation; Lesion; Literature; Lytic; Measures; Medical; Metabolism; Mucous Membrane; North America; Organism; Outcome; Phenotype; Population; Powder dose form; Property; Prophylactic treatment; Pulmonary tularemia; Recording of previous events; Reporting; Research; Resistance; Sampling; Site; Skin; Testing; Time; Tularemia; Vaccines; Virulence; Virulent; Virus; Western Europe; antimicrobial drug; base; biothreat; bioweapon; design; efficacy validation; emerging antibiotic resistance; experience; human disease; human pathogen; innovation; interest; lymphadenopathy; microbiota; mortality; novel; novel therapeutic intervention; pathogen; pathogenic bacteria; physical property; public database; resistant strain; soil sampling; therapeutically effective; water sampling; weapons

Bacteriophages are viruses that infect and kill bacteria either by disrupting their metabolism or by causing bacterial lysis. These unique properties of bacteriophages have been exploited as antimicrobial agents for over 100 years. The emergence of antibiotic resistance and the lack of introduction of new antibiotics in recent years, has renewed interest in the development of bacteriophage-based therapies in clinical situations where antibiotics are no longer effective. The overall goal of this proposal is to characterize a panel of bacteriophages that could further be developed as a therapy to treat fatal human disease tularemia caused by a Gram-negative bacterium, Francisella tularensis (Ft). Ft is a highly ubiquitous, infectious, intracellular bacterium prevalent throughout North America. Ft is classified as a Tier 1 Category A select agent by the CDC due to its history of weaponization by several countries, and its potential to be used as a bioterror agent. Anthrax powder attacks after 9/11 incidence have renewed the medical and scientific interest in Ft research. Tularemia is a notifiable disease in the USA. Naturally occurring tularemia is reported from all the states of the USA, except Hawaii. Currently, no vaccine is available for tularemia prophylaxis. Unfortunately, antibiotic treatment is not particularly effective against severe respiratory tularemia and may not be effective at all, if a weaponized antibiotic-resistant strain used in a bioterror attack causes an outbreak. Together, these indicate that the development of effective therapeutic measures against this dreaded biothreat agent is necessary. Bacteriophages may provide an excellent alternative to the conventional antibiotic therapy for the treatment of tularemia with the added advantage being that they are innocuous, self-replicating, amplify at the site of infection, and do not perturb microbiota. However, bacteriophages against Francisella have not been reported in the literature to-date. As a proof-of-concept, we have isolated a panel of Francisella-specific lytic phage populations from environmental samples. In specific aim 1 of this proposal, we will isolate a collection of individual Ft-specific phages from these samples and characterize their genetic, biochemical, and physical properties. In specific aim 2, we will characterize their biological properties. Specifically, we will determine their growth characteristics, host-range, and potential cell surface receptors. We will formulate an Ft-specific phage cocktail and develop assays to test the ability of phage cocktail(s) to kill intracellular Francisella. This is a first comprehensive study directed at the characterization of Ft-specific bacteriophages. Isolation and characterization of Ft-specific phages against Category A Tier-1 select agent Ft SchuS4 and formulation of novel Ft-specific bacteriophage cocktail capable of killing intracellular bacteria constitute the most innovative aspects of this proposal. We expect that the outcome of the proposed studies will pave the way for the development of a novel therapeutic approach for the treatment of tularemia in humans.

噬菌体是通过破坏细菌的新陈代谢或引起细菌感染和杀死细菌的病毒。 细菌裂解。噬菌体的这些独特性质已被用作抗菌剂超过 100 年。近年来抗生素耐药性的出现以及新抗生素的缺乏， 人们对在抗生素使用的临床情况下开发基于噬菌体的疗法重新产生了兴趣 不再有效。该提案的总体目标是表征一组噬菌体，这些噬菌体可以 进一步开发为治疗由革兰氏阴性细菌引起的致命人类疾病兔热病的疗法， 土拉弗朗西斯菌 (Ft)。 Ft 是一种高度普遍存在的、传染性的细胞内细菌，在整个北部地区普遍存在。 美国。 Ft 因其武器化历史而被 CDC 归类为 1 级 A 类精选代理。 几个国家及其被用作生物恐怖剂的潜力。 9/11 事件后炭疽粉末袭击 重新燃起了人们对《金融时报》研究的医学和科学兴趣。兔热病在美国是一种法定传染病。 除夏威夷外，美国所有州均报告有自然发生的兔热病。目前还没有疫苗 可用于兔热病预防。不幸的是，抗生素治疗对于严重的疾病并不是特别有效。 呼吸道兔热病，如果在生物恐怖中使用武器化的抗生素抗性菌株，可能根本不起作用 攻击导致爆发。总之，这些表明有效治疗措施的开发 对抗这种可怕的生物威胁剂是必要的。噬菌体可能提供一种极好的替代品 治疗兔热病的传统抗生素疗法的另一个优点是它们 无害、自我复制、在感染部位扩增，并且不会扰乱微生物群。然而， 迄今为止，文献中尚未报道针对弗朗西斯菌的噬菌体。作为概念验证，我们 从环境样本中分离出了一组弗朗西斯菌特异性裂解噬菌体群体。在特定目标下 根据该提案的第 1 部分，我们将从这些样本中分离出一组单独的 Ft 特异性噬菌体，并表征 它们的遗传、生化和物理特性。在具体目标 2 中，我们将描述它们的生物学特性 特性。具体来说，我们将确定它们的生长特征、宿主范围和潜在的细胞表面 受体。我们将配制 Ft 特异性噬菌体混合物并开发检测方法来测试噬菌体的能力 杀死细胞内弗朗西斯氏菌的混合物。这是第一项针对特征的综合研究 Ft 特异性噬菌体。针对 A 类 Tier-1 select 的 Ft 特异性噬菌体的分离和表征 Ft SchuS4 试剂和能够杀死细胞内噬菌体的新型 Ft 特异性噬菌体混合物的配方 细菌构成了该提案最具创新性的方面。我们期望拟议的结果 研究将为开发治疗兔热病的新方法铺平道路 人类。