A diagnostic technology capable of identifying infection-causing bacteria with nearly 100% accuracy within three hours has been developed. This method, significantly faster and more precise than traditional bacterial culture or PCR analysis, is expected to reduce mortality rates of diseases like sepsis, where timely antibiotic administration is critical.
On Wednesday, the Ulsan National Institute of Science and Technology (UNIST) announced that a team of biomedical engineering professors, including Hajin Kim, Taejun Kwon, and Jooheon Kang, has developed an innovative FISH diagnostic technology using artificially designed PNA molecules as probes.
FISH technology is a diagnostic technology that reads the fluorescence signals emitted when probe molecules bind to specific bacterial gene sequences. The newly developed FISH technology uses two PNA molecules simultaneously.
The research team analyzed the sequences of 20,000 bacterial genomes and designed the PNA sequences to attach exclusively to the ribosomal RNA of specific bacterial species. Compared to conventional DNA-based probes, PNA is more sensitive to sequence mismatch and performs better in penetrating bacteria’s cell walls.
Moreover, the signal is generated only when both PNAs adhere to the target site, minimizing crosstalk from incorrect binding.
This advancement boosts accuracy for both individual bacterial infection tests and situations involving multiple bacteria.
The diagnostic technology showed more than 99% detection accuracy in experiments that detected seven bacteria, including E. coli, Pseudomonas aeruginosa, and S. aureus, in individual samples.
Staphylococcus aureus was detected with an accuracy of 96.3%. Its performance was also verified when several types of bacteria were mixed. Enterococcus and E. coli were mixed, and both bacteria showed more than 99% detection accuracy.
The dual-PNA technology leverages Förster resonance energy transfer. When the two PNA molecules are in close proximity, energy transfers between them, with the resulting fluorescence measured to indicate bacterial presence.
Professor Hajin Kim expressed optimism about the technology’s potential, stating, “This breakthrough will help to diagnose infections requiring rapid antibiotic intervention, such as sepsis, urinary tract infections, and pneumonia, and reduce unnecessary antibiotic use.”
The team plans to conduct further studies using blood samples from actual patients to explore clinical applications.
UNIST researchers Seongho Kim and Hwi Hyun were co-first authors on the study, which received support from the National Research Foundation of Korea, the Institute for Basic Science (IBS), the National Institute of Health of Korea, and UNIST.
The findings were published in the international journal Biosensors and Bioelectronics on March 1.