Objective: Group A Streptococcus (GAS) is a pathogen responsible for both invasive and non-invasive diseases, particularly in the pediatric age group. This study was designed to identify the current circulating serotypes of this pathogen, which has over 200 serotypes defined by emm gene sequence variations, investigate their association with disease progression and gather data on the coverage of developing vaccines.

Methods: GAS strains isolated in our laboratory between June and August 2023 were included in the study. Serotyping was performed using a qPCR (quantitative Polymerase Chain Reaction) kit designed according to the CDC (Centers for Disease Control and Prevention) protocol from cultured colonies.

Results: A total of 31 isolates (22 throat, 9 non-throat) were included in the study. Three isolates could not be serotyped (throat, wound, bronchoalveolar lavage fluid). Among throat isolates, the most frequently identified serotypes were emm1 (n=7), emm2 (n=3), emm3 (n=3), emm89 (n=3) and other (n=5). Non-throat isolates showed serotypes emm28 (n=2), emm2 (n=1), emm3 (n=1), emm6 (n=1), emm12 (n=1) and emm89 (n=1). It was found that 89% of the isolates are covered by the 26-valent vaccine candidates.

Conclusion: We have provided current data on the circulating emm serotypes. Further large-scale studies are needed to obtain more reliable data on the association of these serotypes with disease progression and the effective use of vaccines in the general population.