Alert for a hypervirulent clone of pharyngitis bacteria in Argentina

Alert for a hypervirulent clone of pharyngitis bacteria in Argentina

Infection by the bacteria Streptococcus pyogenes It can cause angina or tonsillitis, pharyngitis, and skin infections. In addition, some people may trigger invasive infections.

Since December last year there has been an increase in cases with invasive strep infections in Europe, North America and Uruguay.

In the Argentina, the number of cases in 2023 represented an increase of 281% compared to the same period in 2019. There were already 16 deaths reported in July passed through the Ministry of Health of the Nation. It was not yet known what the reason for this outbreak occurred in the country. After an investigation with genomic sequencing, scientists from the bacteriology department of the ANLIS/Malbrán Institute They provided an answer.

They found 3 isolates from samples from patients with the hyper-virulent M1UK clone of the bacterium. It is a clone that has had a rapid expansion in other countries and has been linked to the increase in cases of scarlet fever and invasive infections. That clone corresponds to a new lineage of the pandemic strain M1T1 (M1global).

The United States, Canada, the Netherlands, Denmark and Australia are the countries that have so far reported the emergence of this successful virulent clone that is displacing the global epidemic clone M1 3 of the bacterium. It is also known that strains with M1UK produce more so-called “superantigenic exotoxin SpeA” than those of the M1global strain.

The Argentine researchers specified that the 3 isolates with the hypervirulent clone M1UK represent 8% of the 36 samples studied with the Streptococcus pyogenes M1 that they received in the laboratory between January and June.

ANLIS/Malbrán researchers also identified a group of 7 isolates of Streptococcus pyogenes M1 genetically related. That group acquired “a mobile genetic element that codes for the superantigenic toxin SpeC,” the group of experts clarified in the latest epidemiology bulletin of the Health portfolio.

That means it is another M1 sublineage and those isolates do not show molecular characteristics of the emerging M1UK (UK) or M1DK (Denmark) strains.

The study by the scientists in Argentina implies that they found the hypervirulent clone M1UK and a sublineage of the M1 clone in the samples of patients analyzed.

Faced with the results, researchers recommended intensifying genomic surveillance across the country. This would allow “determining the expansion and prevalence of strains” as well as epidemiological surveillance of cases of infections by the bacterium in general.

The transmission of the Streptococcus pyogenes occurs by close contact with an infected person and can be spread through coughing, sneezing, or contact with a wound, according to the national health portfolio.

The most common symptoms of angina or tonsillitis are fever, sore throat or when swallowing, and enlarged neck nodes. In the case of superficial infections of the skin, it may occur: fever, pain located in one area, redness and if it progresses small blisters and some crusts.

For people who have been close to patients affected by Streptococcus, ANLIS/Malbrán researchers recommended that they should receive information about prevention measures and signs and symptoms of the disease.

“Contacts of cases are advised that, upon the appearance of symptoms: fever, sore throat, localized muscle pain, or any other manifestation of infection by S. pyogenes, consult quickly with the health system,” they said.

The period of incubation For the disease varies according to the clinical presentation, between 1 to 3 days. Treating infected people with antibiotics for at least 24 hours usually eliminates their ability to spread.

The Recommendations for the prevention of Streptococcal infection of the Ministry of Healthn the following:

– Wash your hands frequently with soap and water.

– Clean and ventilate all environments daily.

– Maintain rest if there are symptoms. Not attending work or school while symptoms last.

– Do not self-medicate.

– Cough or sneeze into the crook of the elbow or into a tissue to avoid spreading it to other people.

There are no vaccines against Streptococcus pyogenes yet. However, it is important to have the vaccines of the calendar up to date to avoid other diseases that favor the invasion by this bacterium.

Treatment is with antibiotics, which must be indicated by a doctor. It is important not to self-medicate, nor to abandon or shorten antibiotic treatments, since it predisposes to a greater number of relapses and / or complications.


Please enter your comment!
Please enter your name here