In a study published in the Journal of Clinical Microbiology, the scientists described strains of group A streptococcus that are less susceptible to commonly used antibiotics.
According to the Centers for Disease Control and Prevention (CDC) in the US, group A streptococcus causes 20-30 per cent of sore throats in children and 5-15 per cent of sore throats in adults.
"If this germ becomes truly resistant to these antibiotics, it would have a very serious impact on millions of children around the world," said lead author of the study James Musser, Chair of the Department of Pathology and Genomic Medicine at the Houston Methodist Hospital in the US.
"That is a very concerning but plausible notion based on our findings. Development of resistance to beta-lactam antibiotics would have a major public health impact globally," Musser said.
Musser and his colleagues collaborated with nearly a dozen institutions across seven countries for this research.
Research published earlier in 2019 describing two related bacterial strains compelled Musser's group at Houston Methodist Research Institute and his collaborators to undertake this sizeable international project.
They exploited their genome sequence library derived from 7,025 group A streptococcus strains collected over several decades from countries around the world.
Of these, they discovered approximately two per cent with gene mutations of interest.
The researchers then tested the strains in the clinical microbiology laboratory to confirm their decreased susceptibility to beta-lactam antibiotics.
The findings of reduced susceptibility in some strains suggest that penicillin and related antibiotic treatments for strep throat may eventually become less effective or completely ineffective.
These findings underscore the urgent need for a vaccine that protects humans against group A streptococcus.
"We could be looking at a worldwide public health infectious disease problem," said Musser.
"When strep throat doesn't respond to frontline antibiotics such as penicillin, physic must start prescribing second-line therapies, which may not be as effective against this organism," Musser added.
( With inputs from IANS )