Medical genetics

The study find that “A Cell-Free DNA Metagenomic Sequencing Assay that Integrates the Host Injury Response to Infection,” published Aug. 26 in Proceedings of the National Academy of Sciences, presents a technique to identify viruses and bacteria in the human body and quantify injuries to organs by using dead fragments of DNA, called cell-free DNA, that roam throughout the bloodstream and urine. Therefore The resulting test is simple, fast, low cost and generalizable enough to identify thousands of bacteria and viruses.

Cell-Free DNA Detects

“This really came about through collaboration with clinicians who explained to us this common problem in infectious disease diagnosis;” said co-senior author Iwijn De Vlaminck, the Robert N. Noyce Assistant Professor in Life Science and Technology in the Meinig School of Biomedical Engineering. “So we developed an assay that would simultaneously inform us about the presence or absence of a wide range of pathogens; but at the same time would also tell us about the injury of different host tissues. The combined information enables us to more definitively say whether a person is dealing with disease or not.”

De Vlaminck and his team partnered with researchers at Weill Cornell Medicine and focused on urinary tract infections in kidney transplant patients. But Lead author and Ph.D. student Alex Cheng used high-throughput DNA sequencing to identify any microorganisms that were present in clinical samples and distinguish them from the host DNA via bisulfite sequencing; a process in which the cell-free DNA is treat with salt to reveal methylation marks.

Part of normal biology

These marks helped the researchers trace the cell-free DNA’s tissues of origin and measure the degree of injury to different host tissues. “In the field; doctors who try to diagnose infectious diseases and people who run microbiology labs are getting more and more excite about the use of genomic medicine approaches for diagnosis;” De Vlaminck said. “But there was still a big gap to assess whether that organism is actually causing disease. Because “That’s really a critical question;” he said. “Because some organisms are just commensals, they live side by side with the host.

Our guts are fill with microbes, but those microbes may not be the reason you’re suffering from disease. In a way; you’re infected. You’re colonize; but that’s just part of normal biology.” The test is so generalizable that virtually any organism that has a DNA genome can be identified.”Infectious diseases are a leading cause of disease burden worldwide;” Cheng said. “They affect almost every single demographic, and they are not very easy to understand. So to have a test that can potentially help this large amount and wide range of people is exciting.”