Patogenicity mechanisms of Streptococcus pyogenes

The group A Streptococcus (Streptococcus pyogenes, GAS) is responsible for over 600 million infections and over half million deaths a year. GAS is a major human pathogen which causes diseases ranging from mild superficial infections of the throat or skin, up to severe systemic and invasive diseases such as necrotizing fasciitis and streptococcal toxic shock syndrome. Nowadays, post-infection sequelae such as glomerulonephritis and rheumatic fever are also alarming medical problems worldwide. Molecular analyses of streptococcal virulence carried by multiple centers worldwide, suggest the presence of a complex mechanism that coordinates pathogenesis. It involves a broad range of unique protein virulence factors, as M protein, superantigens, proteases and DNases, affecting tissues and the host's immune system. Detailed analyses of individual virulence factors as well as regulatory systems that coordinate expression of virulence factors are the first steps on the way to develop innovative strategies for diagnostics and treatment. This review aims to highlight the epidemiology of S. pyogenes and summarize the current state of knowledge about the mechanisms of its virulence.