Several virologists have dismissed reports of a new COVID variant called “Deltakron” on the grounds that it is likely to be a data error.
The DeltaCron reports first surfaced last week, Bloomberg cited Leondios Kostrikis, a professor of biological sciences at the University of Cyprus, as having Omicron-like features within their delta variant genome.
Kostrikis said he and his team had found 25 cases of the virus and defended their findings, saying the samples were processed in multiple sequencing procedures in more than one country.
They also noted that the cases they identified “indicate an evolutionary pressure for an ancestral strain to acquire these mutations and” [were] not the result of a single recombination event,” in an emailed statement to bloomberg, A recombination event occurs when mutations from different strains of a virus come together.
But virologists have told newsweek They are certain that the conclusions are flawed. Krista Queen is director of viral genomics and surveillance at Louisiana State University Shreveport. She explained that the possible source of the error can be traced back to the sequencing technology used to identify the COVID samples collected by the Cyprus team.
When researchers want to identify COVID variants, they have to sequence the genetic information of a sample of the virus because this genetic information varies between different types. To make this as efficient as possible, sequencing technology uses primers that amplify certain parts of the genome.
A specialized sequencing protocol, known as ARTIC V3, is known to be unable to locate a specific part of the delta genome, Queene said. This dropout region is called amplicon #72. In particular, it is at this location that the Omicron-like features of the “Deltakron” version appeared.
Rani suspects that the Omicron-like features in the data were actually the result of Omicron-type samples being present in the same plate that the Cyprus team was using to sequence the delta.
“It is very impossible,” said the Queen. “Viruses are prone to recombination, and we’ve actually seen it quite a bit with the MERS coronavirus. We haven’t seen it with SARS-CoV-2. So it’s not outside the realm of possibilities. But the fact remains that That’s where an amplicon region just doesn’t seem likely.”
Queen said later versions of the ARTIC sequencing protocol have been updated to avoid these drop-out zones that occur between variants.
Jeremy Kamil, associate professor of microbiology and immunology also at Louisiana State University Shreveport, described DeltaCron’s discovery as “100% a mistake—of course an innocent one. It’s great.” [the Cyprus researchers] Genomic surveillance – the media if anything is equally or more responsible for causing alarm.”
Doubts on the findings come from elsewhere as well. Dr. Krutika Kuppalli, a member of the World Health Organization’s COVID-19 technical team, tweeted on Sunday that “there is no such thing as a Deltachron” and described the discovery as the result of “laboratory contamination of Omicron fragments in a Delta sample”. . ,
And, reiterating the amplicon 72 theory, Thomas Peacock, a virologist at Imperial College London, tweeted: “Since Delta’s amplicon 72 is very poorly picked up, any contamination, even on a small scale also, preferably will increase and you will end up with a hybrid sequence.”
newsweek Kostrikis has been contacted for comment.
Meanwhile, the highly infectious Omicron variant is causing disruption in the US and elsewhere due to the high number of COVID cases.