To this day, numerous medical TV shows are based on the difficulties of diagnosing diseases quickly. What if a device could allow a precise and instantaneous diagnosis of a disease?

Viewing a more serious and realistic situation, today, someone dies of sepsis every 5 seconds in the world. Sepsis is a clinical syndrome of organ malfunction potentially fatal provoked by a deregulated host response to the infection. Its current diagnosis relies on haemoculture, a slow process, while every hour spent to detect which strain is responsible for the infection greatly enhances the risks of neurological and muscular complications and drastically reduces the chances of survival. In this context, we decided to create DIANE (Diagnosis is Now Easier): a swift diagnosis device which aims at allowing the doctors to get almost immediate results of the body fluid sample analysis and to quickly provide the proper treatment to the patient.

Time is a crucial element. The doctors often have to act even before getting the results of the analysis and launch a broad empirical antibiotic treatment based on hypothesis regarding the origin of the infection. This can lead to an inadequate and thus inefficient treatment, a loss of time and can eventually result in the diminution of the patient’s chances of survival.

DIANE would be a major tool against sepsis, but not only. More broadly, it could be used for any situation suggesting a bacterial infection with the advantages of being almost instantaneous, specific and selective. A rapid diagnosis would allow to provide the proper antibiotic treatment immediately and therefore to enhance the chances of survival, to reduce the complications due to the infection, as well as contributing to the fight against antimicrobial resistance, which is one of the biggest current threats for the global public health.

This device relies on an electrochemical detection of bacteria in a specific way using aptamers, single-strand RNA or DNA capable of binding to a specific ligand, connected to carbon nanotubes electrodes.

Aptamers bound to a carbon nanotube

We will perform the SELEX (Systematic Evolution of Ligands By Exponential Enrichment) method to obtain these aptamers and with them build electrodes with high specificity.

Simplified operating principle for specific bacteria detection using a regular electrode and another one with our aptamers bound to carbon nanotubes

Our job will not settle for making a electrod-aptamers system capable of detecting and quantifying specific bacteria but it will also consist in the creation of an actual prototype capable of indicating which strain is responsible for the infection to a doctor, taking into account the user scenari, security, and the ethical responsibility linked to the device. We also aim at creating this device in such a way that it could be used in remote locations during humanitarian missions.

References:

Gustavo A. Zelada-Guillén and al., “Immediate Detection of Living Bacteria at Ultralow Concentrations Using a Carbon Nanotube Based Potentiometric Aptasensor”, Angew. Chem. Int. Ed., 2009, vol 48, pages 7334 –7337

Kwame Sefah, Dihua Shangguan, Xiangling Xiong, Meghan B O’Donoghue & Weihong Tan, “Development of DNA aptamers using Cell-SELEX”, Nature Protocols, 2010, vol 5, pages 1169–1185

Team:Pasteur Paris/Description

Project Inspiration and Description