Molecular Identification of Meningitis/Septicemia Due to Streptococcus spp. in Greece (2015–2024)

Background/Objectives: Meningitis due to the species Streptococcus is a severe central nervous system infection caused by various microorganisms belonging to Streptococcus spp. Its accurate identification is critical for effective clinical management. This study aimed to identify Streptococcus spp. causing meningitis in Greece over a nine-year period using PCR and sequencing-based methods. Methods: A total of 189 clinical samples, collected between 2015 and 2024 from patients suffering from meningitis and/or septicemia, were analyzed by the use of a combination of multiplex polymerase chain reaction (PCR) assays and tuf gene sequencing for further species identification. Results: Sample analysis identified 70 samples as S. pyogenes (18.52%) (GAS) and S. agalactiae (18.52%) (GBS), while 119 (62.96%) were recorded as non-typable Streptococcus spp. Further analysis using sequencing methods revealed that the most frequent Streptococcus spp. belonged to the mitis group (42.86%) and the pyogenic group (20.17%). A higher prevalence was observed in children aged 0–14 years old and adults over 50 years old. Conclusions: This study highlights the use of molecular diagnostics in identifying other Streptococcus spp., providing insights into age-related susceptibility and epidemiological trends. Future studies are needed to explore the pathogenic role of the identified Lactococcus spp.