Orbital cellulitis with emm1-type M1UK sublineage group A Streptococcus detected in a blood culture: a case report.

Invasive group A streptococcal infection (iGAS) increases in Europe and it causes skin and soft-tissue infection, including orbital cellulitis. In this study, we report a case of a 7-year-old girl with orbital cellulitis and invasive emm1-type M1UK sublineage group A Streptococcus (GAS) detected in a blood culture. The patient was initially treated with a combination of cefotaxime (CTX) and clindamycin (CLDM). We changed antibiotics from CTX to ampicillin after susceptibility results were known. After discharge, oral clavulanic acid/amoxicillin was continued as an oral medication, and antibiotics were administered for a total of 21 days. The bacterium was isolated from a blood culture and identified as an emm1-type M1UK sublineage GAS. This case is unusual in that it involved bloodstream infection in a pediatric orbital cellulitis, and M1UK's highly toxin-producing and highly transmissible may have been implicated. In rapidly exacerbating orbital cellulitis, iGAS infection should be considered.