In the middle of the year, San Luis researchers led by molecular biologist Maxi Jury Ayoub, of the National University of San Luis, developed a system “gatheringDesigned by analytical chemist Roberto Echinic and his team (which consists of performing PCR on several samples at the same time), and validated by the laboratory of Daniela Husbor, of the Faculty of Exact Sciences of the National University of La Plata, to identify only those containing delta variable.
But after the alarm was sounded in South Africa and the rapid global spread of Ómicron, which is already present in more than forty countries, Guri Ayoub got to work and with lightning speed devised a new strategy aimed at the rapid detection of a new, troubling alternative. . Something like a radar that listens to the horizon to set off alarms at the entrance to a potential danger. It was this system that made it possible to verify that the 38-year-old who arrived in the country from South Africa on November 30, and was vaccinated with a full chart and date of Covid-19 in March of this year, had acquired the virus.
Once Ómicron was announced as a variable of concern, Guri Ayoub began thinking about how to quickly discover it. One of the first things he noticed was that he shared some mutations with Alpha. Thus it occurred to him that this trait could be used as a ‘substitute’, as an indication of one’s presence in the presence of the trait that today worries half of humanity.
“Micron has a large number of mutations, but many of them are in common with other variants,” says the scientist. In particular, two already contain Alpha, Beta, and Lambda. There is one that only occurs in alpha. But since the latter is not in circulation anymore, then, if one now finds a sample with these deletions [segmentos faltantes de ARN], this means, with the highest probability, that it is a micron. The strategy is similar to what we did for Delta: we used “IgnitionThey are ‘stuck’ in a different area.
With this technology already in place, last Wednesday, Guri Ayoub went to his lab, assembled parts of the reagents and transported them to his county public health laboratory. The case of the injured appeared on Saturday, but he found it ready.
With this modification in PCR, the new variant can be detected
The PCR test (a system that amplifies a piece of the viral genome as if it were an RNA camera) consists of three parts: the sample, the reaction mixture (polymerase, an enzyme capable of transcribing or replicating nucleic acids) and the synthetic nucleotides (“bricks” or “linkers” of Nucleic acids) that guide the parts of the sample to be amplified. It is these oligonucleotides that give the specificity of the polymerase chain reaction. “We direct it precisely to the specific parts of this variable,” the researcher explains. That’s what I took to the public health lab. The reaction is identical, what are the changes in the oligonucleotides that indicate which region of the genome will be amplified: instead of using routine items for diagnosis, they use those specific for that variant.”
Fortunately, the country’s first Omicron patient had done everything mentioned: He arrived with two negative tests, traveled in comfort with a mask from Buenos Aires and, despite not showing symptoms, when he learned that his colleagues in South Africa had tested positive for Covid. Positive, contact the health system. “That’s why they scanned it and found it,” he says. He had four close contacts in isolation.
More importantly, this method can be widely used. “This is the idea,” Guri Ayoub confirms. I just finished talking to people from Formosa, with Mendoza … This time there will be no assembly tests, as we planned for Delta, but since there are not such a large number of cases, this is not a problem. The only thing that needs to be done is to do a second PCR with this design on all positives to identify variants.”