Investigating some molecular and immunological parameters in patients infected with Streptococcus pyogenes

Background: Streptococcus pyogenes is an important pathogen causing a wide range of human diseases. It is classified as a danger to school-age children due to the recurrent annual infection. Aim: detect the virulence genes of S. pyogenes and some inflammatory mediators in clinically diagnosed patients in Samarra City, from November 2024 to April 2025, utilizing PCR and ELISA techniques. Methods: 100 throat swab were collected from patients and cultured on blood agar aerobically and anaerobically. From all patients and 25 healthy people 5 ml of venous blood was obtained, 3 ml were put in a plain tube for serological tests and 2 ml were put in EDTA tube for PCT and ESR tests. PCR technique is used to investigate some virulence factors. Results: The diagnosis confirmed the presence of S. pyogenes in 15% of the specimens, the study revealed a significant elevation in ASO, ESR and PCT levels among patients compared to other groups. The IL-23 was also significantly higher in S. pyogenes patients than in the control group. The emm gene was detected in all S. pyogenes isolates, whereas amplification of the sof gene was observed in ten isolates. Conclusions: The severity and ability of this bacteria to cause local and systemic infections requires attention to the immunological and molecular aspects to understand the progression of the disease and detect virulence genes to determine the extent of the spread of virulent species in a particular area.