European Journal of Clinical Microbiology & Infectious Diseases
Predominance of M1UK type strains and their clinical associations in invasive Streptococcus pyogenes infections in Japan, 2023–2025
Abstract Purpose The clinical relevance of M1 UK type strains of Streptococcus pyogenes in Japan remains insufficiently defined. We investigated the molecular epidemiology of M1 UK type strains and evaluated their clinical associations among adults with invasive group A Streptococcus (iGAS) infections. Methods We conducted a nationwide multicenter surveillance study of iGAS infections from December 2023 to March 2025. Molecular typing, profiling of M1 UK -associated single-nucleotide polymorphisms (SNPs) in the rof …