New Way to Detect Viruses Uses Human Genome as Key

A new technique of analyzing the genomic sequence of blood serum offers potential for doctors to screen patients for viruses even without having identified a particular virus as the source of a pathogen.

Capitalizing on the complete deciphering of the human genome, researchers at Saint Louis Univeristy deployed what it calls a next-generation sequencing (NGS) approach dubbed "transcriptome subtraction," which is essentially a way to isolate genetic information through the process of elimination.

A key to the researchers' success, the university reports, was discovering how to amplify the genetic material in the blood. In the past, blood serum was not used to its full potential because RNA degrades too quickly. But the amplification process has led to new breakthroughs in genetic testing.

"We have discovered a technology that allows us to detect new viruses," Dr. Adrian Di Bisceglie, chairman of the department of internal medicine at Saint Louis University, said in a release.

"We isolate DNA and RNA, amplify the amount of genetic material present in the blood, do ultra-deep sequencing and use an algorithm to search for matches for every known piece of genetic code, both human and for microbes. Once we remove the known portions, we're ultimately left with new viruses."

When having to diagnose a patient with a particular illness, physicians can search for the presence of a virus by taking a tissue or blood sample from the patient and growing it in the lab. But that technique is only effective if there is a logical starting place to look for the virus. When sampling for a virus is not a good option, doctors can turn to NGS as a way to detect viruses.

By separating human genetic material from viral material, researchers have developed a way to compare the viral material against a database of known viruses. Any material left over from the subtraction that can't be attributed to a known virus is put though a second test to distinguish between bacteria, phages, viruses and other material. The researchers found that after running the second subtraction, they were often left with genetic markers for viruses previously known.

The isolation technique will contribute to the understanding of the many viruses that live in the human body, said Di Bisceglie.

"Just as the human microbiome project is chronicling the bacteria that live and co-exist in every person, we also are studying the human virome to know more about the viruses that live in all of us. We believe not all are harmful and some may even be beneficial," Di Bisceglie said.

Di Bisceglie and his colleagues' research is published in the journal Biochemical and Biophysical Research Communications.

Saint Loius University has reportedly sought patent protection for the new detection technology and plans to actively pursue commercialization of the product.