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.

噬菌体是通过扰乱细菌的新陈代谢或通过引起细菌死亡的病毒 细菌裂解。噬菌体的这些独特性质已被用作抗菌剂已有多年 一百年了。近年来抗生素耐药性的出现和新抗生素的缺乏， 对基于噬菌体的临床治疗方法的开发重新产生了兴趣，在临床情况下，抗生素 已经不再有效了。这项提案的总体目标是鉴定一组能够 进一步被开发为治疗由革兰氏阴性细菌引起的致命人类疾病图拉热症的疗法， TularFrancisella tularensis(Ft.)FT是一种高度普遍的、具有传染性的胞内细菌，流行于整个北方 美国。FT被美国疾病控制与预防中心列为一级A类精选特工，原因是其武器化历史由 几个国家，以及它被用作生物恐怖毒剂的可能性。9/11事件后炭疽粉袭击事件 重新唤起了人们对Ft研究的医学和科学兴趣。图拉热症在美国是一种应呈报的疾病。 除夏威夷外，美国所有州都报告了自然发生的图拉热症。目前，还没有疫苗是 可用于兔热病的预防。不幸的是，抗生素治疗对重症并不是特别有效。 呼吸性图拉热症，如果一种武器化的抗药性菌株用于生物恐怖，可能根本没有效果 攻击会导致疫情暴发。总而言之，这些都表明制定有效的治疗措施 对抗这种可怕的生物制剂是必要的。噬菌体可能会提供一种很好的替代 治疗图拉热症的传统抗生素疗法，其附加优点是 无毒，自我复制，在感染部位放大，不扰乱微生物区系。然而， 到目前为止，文献中还没有针对弗朗西塞氏菌的噬菌体的报道。作为概念验证，我们 已经从环境样本中分离出一组弗朗西斯氏菌特异性裂解噬菌体种群。以特定的目标 在这项提议中，我们将从这些样本中分离出一组单独的Ft特异性噬菌体，并鉴定 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 属性。具体地说，我们将确定它们的生长特征、宿主范围和潜在的细胞表面 感受器。我们将配制一种Ft特异性噬菌体鸡尾酒，并开发测试噬菌体能力的方法 鸡尾酒(S)，杀死细胞内的弗朗西丝菌。这是第一个全面的研究，旨在刻画 FT特异性噬菌体。抗A类Tier-1 SELECT抗体Ft特异性噬菌体的分离和鉴定 Ft SchuS4试剂及其新型胞内杀灭Ft特异性噬菌体鸡尾酒的研制 细菌构成了这一提案最具创新性的方面。我们预计，拟议的 研究将为开发一种新的治疗图拉热症的方法铺平道路。 人类。