Bio-Inspired Fluorescent Carbon Dots as Probes for Rapid Detection of Bacteria in Physiological Samples

仿生荧光碳点作为探针快速检测生理样本中的细菌

• 批准号: EP/S026215/1
• 负责人: M. Carmen Galan
• 金额: $ 115.37万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FS026215%2F1
• 关键词: Bio; Inspired; Fluorescent; Carbon; Dots

Bacterial infections have great public health and economic impact. While at present most can be treated with antibiotics, doing so requires cases of bacterial infections to be recognised early so that they can be treated with the right drugs, while ensuring that antibiotics are not given unnecessarily. With the growth in antibiotic resistance, it is becoming essential that we use these drugs appropriately. At present growth of organisms from patient samples (e.g. urine), a process which takes 18 hours or more, is usually required before specific infecting bacteria can identified. A device able to rapidly detect the presence of bacteria in such samples, and identify which species are present, without this growth step would enable doctors to make rapid and informed decisions about when antibiotic treatment is necessary and which drug should be used.Here we propose to develop and evaluate a technology for identifying bacteria in patient samples. We will combine a novel series of chemical probes (fluorescent carbon dots, FCDs) that can attach to bacteria to make them fluorescent, with an ultra-sensitive quantum photonic sensor (QPS) developed by our industrial partner, FluoretiQ Ltd., that is able to detect these fluorescent bacteria in patient samples. In order to identify individual species of bacteria we will attach specific sugars (glycans) to the surface of FCDs, exploiting the fact that different bacteria recognise particular sugar molecules as part of the process of binding to the cells of their host. We base our trials around E coli bacteria causing urinary tract infections as these are common conditions that create high workloads for NHS laboratories (our clinical partner processes up to 1000 urine samples per day) and if improperly treated can lead to severe conditions such as sepsis.We will test this methodology by assessing in the laboratory whether specific bacteria can bind to specific glycan-FCDs. A second series of laboratory experiments will then seek to replicate patient samples by suspending bacteria derived from patients, and cultured human cells, in liquid media designed to mimic the composition of human urine and testing whether glycan-FCDs bind bacteria under these conditions. Finally, with support from clinical microbiologists, we will test whether the glycan-FCD/QPS method can detect and identify bacteria in urine samples from human patients and evaluate its effectiveness compared to methods currently in use. As future users they will also help us to optimise the method and associated instrumentation to ensure that this can be used easily in the clinical laboratory, and provide guidance on how to ensure that our method can be validated against appropriate comparators and demonstrated to comply with NHS quality management systems.In parallel we will test whether glycan-FCDs can be used as the basis for new treatments for bacterial infections. We have already demonstrated that FCDs can bind to and enter bacteria; preliminary experiments show that they can also kill bacteria, in a light-dependent process. Hence we will investigate whether our modified glycan-FCDs retain the ability to kill bacteria, and whether this killing is specific to the species targeted by the particular surface sugar. We will also attach antibiotics to the surface of FCDs to test whether this represents a method to deliver drugs to specific bacteria, many of which are difficult to kill with antibiotics because the drug is unable to enter the bacterial cell.The project will establish whether glycan-FCDs can form the basis of a rapid method for detecting infecting bacteria in patient samples in the clinical microbiology laboratory, and whether these can also be used to improve the effectiveness of antibiotics against many of these organisms. In so doing we will also develop new methods for synthesising complex sugar molecules that may be applied in multiple other research areas including drug and vaccine development.

细菌感染对公共卫生和经济都有很大影响。虽然目前大多数人可以用抗生素治疗，但要做到这一点，需要及早识别细菌感染的病例，以便用正确的药物进行治疗，同时确保不会不必要地使用抗生素。随着抗生素耐药性的增长，我们适当地使用这些药物变得至关重要。目前，通常需要从患者样本(例如尿液)中培养微生物，这一过程需要18小时或更长时间，然后才能识别特定的感染细菌。一种能够快速检测此类样本中细菌的存在并识别哪些物种存在的设备，而不需要这一生长步骤，将使医生能够快速且知情地决定何时需要抗生素治疗以及应该使用哪种药物。在此，我们建议开发和评估一种识别患者样本中细菌的技术。我们将把一系列新型的化学探针(荧光碳点，FCDs)与我们的工业合作伙伴FluoretiQ Ltd.开发的能够检测患者样本中这些荧光细菌的超灵敏量子光子传感器(QPS)相结合，这些探针可以附着在细菌上使其发出荧光。为了识别细菌的个别物种，我们将特定的糖(多糖)附着在FCD的表面，利用不同的细菌识别特定的糖分子作为与其宿主细胞结合的过程的一部分。我们的试验以导致尿路感染的大肠杆菌为基础，因为这些是为NHS实验室带来高工作量的常见情况(我们的临床合作伙伴每天处理多达1000个尿样)，如果治疗不当可能导致败血症等严重情况。我们将通过在实验室评估特定细菌是否能与特定的多糖-FCDs结合来测试这一方法。然后，第二系列实验室实验将寻求复制患者样本，方法是将来自患者和培养的人类细胞的细菌悬浮在液体介质中，以模拟人类尿液的成分，并测试在这些条件下多糖-FCDs是否与细菌结合。最后，在临床微生物学家的支持下，我们将测试Glycan-FCD/QPS方法是否可以检测和鉴定人类患者尿样中的细菌，并与目前使用的方法进行比较，评估其有效性。作为未来的用户，他们还将帮助我们优化方法和相关的仪器，以确保这可以在临床实验室中轻松使用，并提供指导，如何确保我们的方法可以通过适当的比较器进行验证，并证明符合NHS质量管理体系。同时，我们将测试Glycan-FCDs是否可以用作治疗细菌感染的新方法的基础。我们已经证明了FCDs可以与细菌结合并进入细菌；初步实验表明，它们还可以在光依赖的过程中杀死细菌。因此，我们将调查我们的修饰后的葡聚糖-FCDs是否保留了杀灭细菌的能力，以及这种杀灭是否针对特定表面糖所针对的物种。我们还将在FCDs的表面附着抗生素，以测试这是否代表一种将药物输送到特定细菌的方法，其中许多细菌很难用抗生素杀死，因为药物无法进入细菌细胞。该项目将确定，在临床微生物学实验室，葡聚糖-FCDs是否可以成为快速检测患者样本中感染细菌的方法的基础，以及这些方法是否也可以用于提高抗生素对许多此类细菌的有效性。在这样做的同时，我们还将开发合成复杂糖分子的新方法，这些方法可能会应用于包括药物和疫苗开发在内的多个其他研究领域。

项目成果

In vitro biosynthesis of poly-ß-1,4-glucan derivatives using a pro-miscuous glycosyltransferase

使用混杂糖基转移酶体外生物合成聚-β-1,4-葡聚糖衍生物

• DOI: 10.1101/2020.02.14.949545
• 发表时间: 2020
• 作者: Bulmer G

A 'glyco-fluorine' code revealing differential recognition by glycan binding partners

“糖氟”代码揭示了聚糖结合伙伴的差异识别

• DOI: 10.26434/chemrxiv-2023-4hn6k
• 发表时间: 2023
• 作者: Hollingsworth K

Carbon dot-based fluorescent antibody nanoprobes as brain tumour glioblastoma diagnostics.

• DOI: 10.1039/d2na00060a
• 发表时间: 2022-03-29
• 期刊: Nanoscale advances
• 影响因子: 4.7
• 作者: Ghirardello M;Shyam R;Liu X;Garcia-Millan T;Sittel I;Ramos-Soriano J;Kurian KM;Galan MC
• 通讯作者: Galan MC

Carbon Dot-based Fluorescent Antibody Nanoprobes as Brain Tumour Glioblastoma Diagnostics

基于碳点的荧光抗体纳米探针用于脑肿瘤胶质母细胞瘤诊断

• DOI: 10.1101/2021.11.29.470408
• 发表时间: 2021
• 作者: Ghirardello M

Multicolour dual-emission Photoluminescent Carbon Dots à la carte for biomedical applications

适用于生物医学应用的多色双发射光致发光碳点

• DOI: 10.26434/chemrxiv-2023-bvncz
• 发表时间: 2023
• 作者: Garcia-Millan T