Scientists discover what causes strep to turn deadly in kids and new mothers

A vaccine to prevent strep deaths? Scientists discover what causes the infection to turn deadly in kids and new mothers – paving the way to a shot

  • The infection can develop into invasive group A strep, which can be fatal
  • Strep A kills 500,000 people every year, particularly kids and new mothers 
  • Experts warn that this is a growing concern as antibiotics become less effective
  • But US scientists have worked out why it develops – paving the way to a vaccine

A vaccine could be developed to prevent deadly complications from strep throat, scientists say after discovering how the infection transforms into a flesh-eating disease. 

More than 700 million people a year catch pesky sore throats from group A streptococcus bacteria, which can be passed through sneezing, coughing, kissing and touch. 

Most of the time it clears up in a few days with a dose of antibiotics. 

But in some – particularly children and new mothers – it can develop into invasive group A strep, moving from the throat into the muscles, lungs and blood and ravaging the healthy tissue, which proves fatal in 500,000 a year. 

Experts warn that this is an increasingly pressing concern as we hurtle towards a future where antibiotics are less effective. 

However, a new study has offered hope to curbing deadly cases of strep: scientists used artificial intelligence to sift through the largest data set ever collected on the group A strep genome, allowing them to finally map out the bacteria’s complex structure. 

Group A strep infection kills 500,000 a year. Experts warn that this is a growing concern as antibiotics become less effective. But US scientists have worked out how the bacteria develops – paving the way to a vaccine

‘We and others have been studying this problem for over 100 years, and we still don’t have an effective group A strep vaccine,’ said lead author Dr James Musser of Houston Methodist Hospital.

But AI allowed the team make ‘an important step toward ultimately having an effective vaccine to eradicate group A strep from the face of the earth.’

He added: ‘One of the very unexpected and exciting things we discovered was a strategy Group A strep uses to cause serious disease in humans.

‘This new mechanism we found controls virulence and determines whether the organism is just a pathogen or a really angry flesh-eating pathogen.

‘That discovery would not have been possible without having this unusually large data set available for analysis with artificial intelligence.’

To do this, they looked at the M28 strain of group A streptococcus, which causes a large number of invasive cases and a high incidence of childbed fever.

In many countries, it’s among the top five most common group A strep strains causing serious invasive disease in humans.

He said: ‘Numerically, the M28s are very important causes of human infections, so we wanted to get new insight on it, because if you begin to understand the molecular pathogenesis processes, then you have ability to begin potentially developing new therapeutics and diagnostics

‘We’re now able, using these very large data sets, to analyse them far more extensively and with different sets of eyes than we were able to in the past.’

The strategy was adopted from one commonly used in cancer research. 

‘History teaches us that the more we understand how cancer cells work, the better we’re able to generate new ways to inhibit them from causing human disease.

‘Until 20 years ago, we didn’t understand most of the genetic changes that result in cancers.

‘We now understand those in far more detail because of extensive research and analysis of cancer genes.

‘In cancer, you can appreciate that it’s going to be very important to not just analyse one aspect, such as the genome of a cancer cell, but also to analyse what proteins are being made by the cancer cell and then exactly how cancer is invading other areas of the body.

‘We were able to clearly show new routes about how the M28 strain of group A strep causes infection, and it gives us a roadmap for understanding how this organism causes maternal sepsis.

‘This extensive knowledge we now have gives us insight into how one might begin to attack important downstream research like developing a vaccine or new treatment to fight this organism and potentially eradicate it in the future.’

The study was published in the journal Nature Genetics.