Treatment of multi-drug-resistant Gram-negative bacterial infections using capsule depolymerases

使用胶囊解聚酶治疗多重耐药革兰氏阴性细菌感染

• 批准号: MR/N012542/1
• 负责人: Peter Taylor
• 金额: $ 48.8万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FN012542%2F1
• 关键词: Treatment; multi; drug; resistant; Gram

A group of bacteria have recently emerged as a major threat to global human health. These "Gram-negative bacteria (GNB)" exploit the decreased capacity of critically ill patients to ward off infections; they are particularly dangerous as they accumulate genes that confer resistance to front-line antibiotics. Some of these infections are untreatable and morbidity and mortality are common. These bacteria are also becoming more virulent and are beginning cause serious infections outside critical care facilities. They impose a particularly severe burden on healthcare in Thailand: for example, in 2010 in excess of 90,000 hospitalized patients acquired infections with drug resistant GNB, around one third died and these infections resulted in excess of three million days of hospitalization. Because they have evolved so quickly, we do not have sufficient means to control these infections and to treat critically ill patients. Most of the bacteria that cause these infections are protected from the patients' already compromised immune defences by the presence of a sugar-containing capsule; we know that removal of this protective outermost layer from the bacterial cell by capsule-degrading enzymes will enable the host to eliminate the attenuated pathogen. For this proposal, we wish to investigate the capacity of such enzymes ("capsule depolymerases") to strip the capsule from drug resistant strains of two of these bacterial species, Klebsiella pneumoniae and Acinetobacter baumannii. To begin the project, we will collect recent Thai isolates of these bacteria from hospitals in Bangkok and elsewhere in the country and sequence their genomes to enable us to compare them with global populations of similar bacteria. This analysis will inform on the range of capsule types carried by these "local" strains. We will then isolate bacterial viruses ("bacteriophage") that carry capsule depolymerases to enable them to dock onto the surface of their bacterial hosts prior to killing them. Once we have characterised a range of these enzymes, we will purify them and use molecular genetic techniques to engineer proteins in sufficient bulk for experiments in animal models of infection. If we are able to demonstrate that dosing infected rats with engineered enzymes favourably alters the course of infection, we will promote these novel agents as potential therapeutics for the treatment of these devastating infections in the human host.

一组细菌最近成为全球人类健康的主要威胁。这些“革兰氏阴性菌（GNB）”利用重症患者抵御感染的能力下降;它们特别危险，因为它们积累了对一线抗生素产生耐药性的基因。其中一些感染是无法治疗的，发病率和死亡率很常见。这些细菌的毒性也越来越强，并开始在重症监护设施外引起严重感染。它们对泰国的医疗保健造成了特别严重的负担：例如，在2010年，超过90，000名住院患者感染了耐药性GNB，约三分之一死亡，这些感染导致超过300万天的住院治疗。由于它们进化得如此之快，我们没有足够的手段来控制这些感染和治疗重症患者。大多数引起这些感染的细菌都受到保护，免受患者已经受损的免疫防御的影响，因为存在含糖胶囊;我们知道，通过胶囊降解酶从细菌细胞中去除这种保护性最外层将使宿主能够消除减毒病原体。对于该提议，我们希望研究这样的酶（“胶囊解聚酶”）从这些细菌物种中的两种（肺炎克雷伯氏菌和鲍曼不动杆菌）的耐药菌株剥离胶囊的能力。为了开始这个项目，我们将从曼谷和泰国其他地方的医院收集这些细菌的最新分离株，并对它们的基因组进行测序，使我们能够将它们与全球类似细菌的种群进行比较。该分析将告知这些“本地”菌株携带的胶囊类型的范围。然后，我们将分离携带胶囊解聚酶的细菌病毒（“噬菌体”），使它们能够在杀死它们之前停靠在细菌宿主的表面。一旦我们确定了一系列这些酶的特征，我们将纯化它们，并使用分子遗传技术设计足够大的蛋白质，用于动物感染模型的实验。如果我们能够证明给受感染的大鼠服用工程酶可以有利地改变感染过程，我们将促进这些新药物作为治疗人类宿主这些破坏性感染的潜在疗法。

项目成果

Characterisation of Bacteriophage-Encoded Depolymerases Selective for Key Klebsiella pneumoniae Capsular Exopolysaccharides.

• DOI: 10.3389/fcimb.2021.686090
• 发表时间: 2021
• 期刊: Frontiers in cellular and infection microbiology
• 影响因子: 5.7
• 作者: Blundell-Hunter G;Enright MC;Negus D;Dorman MJ;Beecham GE;Pickard DJ;Wintachai P;Voravuthikunchai SP;Thomson NR;Taylor PW
• 通讯作者: Taylor PW

Non-invasive three-dimensional imaging of Escherichia coli K1 infection using diffuse light imaging tomography combined with micro-computed tomography.

使用漫射光成像断层扫描结合微型计算机断层扫描对大肠杆菌 K1 感染进行无创三维成像。

• DOI: 10.1016/j.ymeth.2017.05.005
• 发表时间: 2017
• 期刊: Methods (San Diego, Calif.)
• 作者: Witcomb LA

Genome-Wide Identification by Transposon Insertion Sequencing of Escherichia coli K1 Genes Essential for In Vitro Growth, Gastrointestinal Colonizing Capacity, and Survival in Serum.

• DOI: 10.1128/jb.00698-17
• 发表时间: 2018-04-01
• 期刊: Journal of bacteriology
• 影响因子: 3.2
• 作者: McCarthy AJ;Stabler RA;Taylor PW
• 通讯作者: Taylor PW

Complement Susceptibility in Relation to Genome Sequence of Recent Klebsiella pneumoniae Isolates from Thai Hospitals.

与泰国医院最近分离的克雷伯氏菌分离株的基因组序列有关的补体敏感性。

• DOI: 10.1128/msphere.00537-18
• 发表时间: 2018-11-07
• 期刊: mSphere
• 影响因子: 4.8
• 作者: Loraine J;Heinz E;De Sousa Almeida J;Milevskyy O;Voravuthikunchai SP;Srimanote P;Kiratisin P;Thomson NR;Taylor PW
• 通讯作者: Taylor PW