Image copyright Getty Images Image caption ACRIA, the genetic analysis tool used in the study, was used in every case in the US
There are no cases of certain variants of gene known as COVID-19 whose association has recently been confirmed in the US, the CDC has confirmed.
The United States Centre for Disease Control (CDC) also says that no other countries have seen cases of the same variant.
The variant produces extra copies of two copies of a single nucleotide in some cells, which is said to activate bacteria to cause disease.
A statement released by the agency added that there was “still much uncertainty” over the mechanism of mutation.
“It is important to note that this analysis involved a small group of patients at one facility in one region of the US and a small number of tissues,” it said.
“Further, this study only reports the presence of two unique nucleotide variants.”
It added that studies had shown that patients with the variant had been getting sick with MRSA bacteria, which can cause severe infections and injuries.
However, other groups such as EMRI have found that a gene known as CBGL2-TIP1, which plays a role in the interaction between two types of viral particles, may be the trigger for infections in patients with COVID-19.
Image copyright Getty Images Image caption COVID-19 gene variants are associated with a range of diseases, including respiratory tract infections
“CBGL2-TIP1 is typically found in the lining of the colon, ovaries, uterus, and testes of both humans and animals and is a master regulator of human immune function,” it said.
“This suggests that CBGL2-TIP1 might control both the ability of an infected bacterium to resist antibiotic antibiotics and the activity of the immune system in fighting the bacterium.”
That study was published in EMRI magazine.
WHO advises that the variant needs to be recorded using validated techniques in order to establish its role in specific organisms.
After that it is “probable” that the variant plays a role in certain strains of bacteria which can produce staphylococcal disease such as MRSA and Clostridium difficile.