Novel gene-silencing therapeutics for multidrug-resistant gram-negative pathogens

描述（由申请人提供）：对新抗菌剂的需求日益迫切。多药耐药病原体的比率继续增加，导致世界各地的显著发病率和死亡率。此外，目前新抗菌剂的管道仍然非常狭窄。美国传染病协会在他们的“坏虫子，没有药物”运动中发现了一组对当前抗生素越来越耐药的病原体。该组包括革兰氏阴性病原体鲍氏不动杆菌和大肠杆菌。抗生素发现和设计的新范式最近已被证明对许多细菌有效。这种新方法基于一种名为肽-磷二酰胺基莫酚低聚物（PPMO）的平台技术。PPMO是合成的DNA模拟物，以序列特异性、反义方式与RNA结合，并抑制细菌必需基因的表达。PPMO已成功用于杀灭多种细菌病原体，包括革兰氏阴性细菌大肠杆菌、鼠伤寒沙门氏菌、洋葱伯克霍尔德氏菌复合体和鲍氏不动杆菌。PMOS在培养物中是杀菌的，并且在感染的动物模型中减少菌血症和提高存活率。PPMO比许多传统抗生素（如氨苄青霉素）更有效。该项目的目标是开发PPMO用于治疗多重耐药病原体大肠杆菌和鲍曼不动杆菌。本研究的具体目标是设计、制备和筛选针对多重耐药病原菌大肠杆菌中各种基因靶点的PPMOS。coli和A.鲍曼不动杆菌。实验方法是靶向已知或怀疑对生物体生长至关重要的途径中的基因，包括脂多糖、肽聚糖和脂肪酸生物合成的基因。另一种方法将是使用PPMO作为连续疗法，并靶向特定的抗生素耐药机制，以恢复对目前使用的抗生素的敏感性。这项技术提供了一个方法上的优势，因为许多PMOs可以快速合成，并同时测试对许多目标。这使得靶向单一生物体中的多个基因或开发靶向多种病原体的PPMO鸡尾酒成为可能。本项目将确定E. coli和A.鲍曼不动杆菌，可以推进到临床前和临床研究。

DESCRIPTION (provided by applicant): The need for new antimicrobials is increasingly urgent. The rate of multidrug resistant pathogens continues to increase leading to significant morbidity and mortality throughout the world. Furthermore, the current pipeline for new antimicrobials remains very narrow. The Infectious Diseases Society of America has identified in their "Bad Bugs, No Drugs" campaign, a group of pathogens that have become increasingly resistant to current antibiotics. This group includes the Gram-negative pathogens Acinetobacter baumannii and Escherichia coli. A new paradigm in antibiotic discovery and design has recently been shown effective against numerous bacteria. This new approach is based on a platform technology called peptide-phosphorodiamidate mopholino oligomers (PPMOs). PPMOs are synthetic DNA mimics that bind to RNA in a sequence-specific, antisense manner and inhibit expression of essential bacterial genes. PPMOs have already been used successfully to kill a variety of bacterial pathogens including the Gram-negative bacteria Escherichia coli, Salmonella typhimurium, Burkholderia cepacia complex and Acinetobacter baumannii. PPMOS are bactericidal in culture, and reduce bacteremia and improve survival in animal models of infection. PPMOs are more potent than many traditional antibiotics such as ampicillin. The goal of this project is to develop PPMOs for therapeutic use against the multidrug resistant pathogens Escherichia coli and Acinetobacter baumannii. The specific aims are to design, produce and screen PPMOS against various gene targets in the multidrug-resistant pathogens E. coli and A. baumannii. The experimental approach is to target genes in pathways that are known or suspected to be essential for the growth of the organism, including genes for biosynthesis of lipopolysaccharide, peptidoglycan, and fatty acids. Another approach will be to use PPMOs as adjunctive therapies and target specific antibiotic resistance mechanisms in order to restore susceptibility to currently used antibiotics. This technology provides a methodological advantage because many PPMOs can be rapidly synthesized and simultaneously tested against numerous targets. This allows for the possibility of targeting multiple genes in a single organism or the development of cocktails of PPMOs that target multiple pathogens. This project will identify lead target PPMOs in E. coli and A. baumannii that can be moved forward to pre-clinical and clinical studies.