A technology that can diagnose bacterial infection in blood within three hours has been developed. It is a technology that dramatically accelerates the diagnosis time, which used to take up to 2-3 days.
It became possible to analyze the type and quantity of bacteria at once without additional testing. It is attracting attention as a new diagnostic technology that will not miss the golden time of sepsis treatment, which has a high fatality rate.
UNIST (President Lee Yong-hoon) and the research team at Seoul National University Bundang Hospital developed a diagnostic chip technology that quickly detects infectious bacteria in the blood, and also demonstrated the clinical usefulness of this technology using animal models and the blood of patients with bacterial infection.
The results of this research, conducted by Professor Joo-Heon Kang, Tae-Jun Kwon, and Ha-Jin Kim of the Department of Biomedical Engineering at UNIST and Professor Jae-Hyeok Lee of Seoul National University Bundang Hospital, were published on March 18th in the world-renowned academic journal Small Methods.
Determining whether the blood is infected with a bacterial infection (bacteremia) is essential to lower the mortality rate of sepsis, which is caused by an exacerbation of a bacterial infection. Sepsis, a symptom of systemic inflammation, has a high fatality rate and is considered one of the top 10 causes of death, but it can be cured if detected early.
However, the blood culture method, which is widely used to diagnose bacterial infection, takes at least a day, and additional tests or time are needed to find out the causative organism for accurate prescription.
The research team has developed a technology that can detect the type of causative bacteria within 3 hours by grafting the genetic material detection (FISH) technology to the microfluidic chip technology. Blood is flowed in a chip the size of a finger to separate and concentrate blood bacteria, and then detect it with FISH technology.
It uses the principle that a FISH probe binds to a specific bacterial gene (nucleic acid sequence) and fluoresces. It is a method to determine whether a specific bacterial infection is present by looking at this color change. In addition, by comparing the fluorescence intensity, it is possible to know not only the fact of infection but also the amount of infected bacteria.
Using this diagnostic technology, the research team succeeded in quantitatively detecting bacteria in the blood of suspected sepsis patients who tested negative with the existing diagnostic technology.
Thanks to the magnetic nanoparticles in the microfluidic chip, this diagnostic method can isolate and rapidly concentrate only bacteria from the blood. The immune protein is coated on the surface of the particle, so only bacteria stick to the magnetic nanoparticles. In this state, a magnetic field (magnet) is used to separate the bacteria.
The research team said, “We have developed a quick and convenient test method that can compensate for the shortcomings of the existing blood culture method or complex genome-based diagnostic test, which took more than a day.” “Genome-based tests such as PCR, which are faster than blood culture methods, are still A time-consuming and complex process was required, but this technology greatly reduces the time and simplifies the testing process with rapid bacterial isolation and concentration and immediate detection technology.”
In addition, the research team said, “We are planning additional research to improve the type and accuracy of the FISH probe and to develop a type of device that can be used in the medical field.” .
Lee Min-seok, Hyun-hwi, Kim Seong-ho, researchers in the Department of Biomedical Engineering at UNIST, and Park In-won, a professor at Seoul National University Bundang Hospital participated as the first authors for this study. The research was carried out with support from the Ministry of Science and ICT’s next-generation medical device platform technology development project.
