| Description: |
Background An increase in invasive Group A Streptococcus (iGAS) and non-invasive GAS cases has been reported worldwide, especially among children, since 2022. The aim of this study was the genetic characterization of GAS isolates in the pediatric population of Greece. Methods GAS isolates from children with iGAS reported to National Public Health Organization (NPHO) and a representative number of GAS from non-invasive infections were prospectively collected during 01-12/2023. Isolates were examined for antimicrobial susceptibility with Etest and the emm types were determined by Sanger Sequencing. Whole-genome Sequencing (WGS) was performed to selected GAS isolates to detect the toxin profile regarding 47 virulence factors, among them 11 superantigens. Results GAS isolates from 511 children [266/467 (57%) males, median (IQR) age: 5.6 (3.8-8.0) years] were tested. iGAS represented 66/511 (12.9%) of isolates and among them 9/66 (13.6%) deaths were recorded. The most common GAS isolation sites were the following: throat (294/511, 57.5%), ear infusion (84/511, 16.4%) and skin lesions (60/511, 11.7%). All isolates were sensitive to penicillin. The resistance rates in erythromycin, clindamycin and tetracycline were 25/511 (4.9%), 18/511 (3.5%), and 61/511 (11.9%), respectively. We detected 29 different emm types, with the most prevalent being emm12 (232/511, 45.4%) and emm1 (135/511, 26.4%). Among the deceased children with iGAS, the emm1 (7/9, 77.8%) and emm12 (2/9, 22.2%) types were detected. Toxins profiles were examined with WGS in 6 non-invasive GAS isolates, 11 iGAS isolates and 7 iGAS isolates from deceased children. All isolates contained the speB gene (24/24, 100%). The speA, speC, ssa genes were detected: in 3/6 (50%), 3/6 (50%), 1/6 (16.6%) non-invasive GAS isolates, in 4/11 (36.4%), 4/11 (36.4%) and 0/11 (0%) iGAS isolates and in 5/7 (71.4%), 2/7 (28.6%) and 1/7 (14.3%) isolates from deceased children. Conclusion During 2023, although several emm types caused infections in Greek children, the most ... |