Ongoing emergence of M1UK lineage among invasive group A streptococcus isolates in England, 2020 and use of allele-specific PCR†. AS-PCR

Amid increasing reports of invasive Streptococcus pyogenes infections, wider surveillance for toxigenic lineage M1UK is required. An allele-specific PCR was developed to distinguish M1UK from other emm1 strains. This demonstrated the M1UK lineage to be dominant among emm1 isolates in England, representing 91% of invasive emm1 isolates by end 2020.