Streptococcus pyogenes
From IDWiki
- Also commonly referred to as Group A Streptococcus
Microbiology
- Gram-positive coccus, typically in short chains
- Non-motile, non–spore forming, catalase-negative, and facultatively anaerobic
- β hemolytic on blood agar (complete hemolysis)
Pathophysiology
Virulence factors
- Capsular hyaluronic acid is similar to human
- M protein is the main factor imparting virulence
- M protein differences given S. pyogenes its serotypes
- Confers resistance to phagocytosis by modulating host immune response
Clinical Presentation
- Skin and soft tissue infections, including necrotizing fasciitis
- Upper and lower respiratory tract infections
- Bacteremia without a focus
- Septic arthritis and osteomyelitis
- Pelvic infections, including postpartum endometritis
- Many other foci
Prognosis
- Highest risk of streptococcal toxic shock syndrome (TSS) or death
- Necrotizing fasciitis (50% and 50%)
- Pneumonia (30% and 30%)
- Bacteremia (15% and 25%)
References
- ^ Athanasios G. Michos, Chrysanthi G. Bakoula, Maria Braoudaki, Foteini I. Koutouzi, Eleftheria S. Roma, Anastasia Pangalis, Georgia Nikolopoulou, Elena Kirikou, Vassiliki P. Syriopoulou. Macrolide resistance in Streptococcus pyogenes: prevalence, resistance determinants, and emm types. Diagnostic Microbiology and Infectious Disease. 2009;64(3):295-299. doi:10.1016/j.diagmicrobio.2009.03.004.
- ^ Walter H. Traub, Birgit Leonhard. Comparative Susceptibility of Clinical Group A, B, C, F, and G β-Hemolytic Streptococcal Isolates to 24 Antimicrobial Drugs. Chemotherapy. 1997;43(1):10-20. doi:10.1159/000239529.
- a b Matthias Imöhl, Mark van der Linden. Jose Melo-Cristino. Antimicrobial Susceptibility of Invasive Streptococcus pyogenes Isolates in Germany during 2003-2013. PLOS ONE. 2015;10(9):e0137313. doi:10.1371/journal.pone.0137313.
- ^ A. C. Bowen, R. A. Lilliebridge, S. Y. C. Tong, R. W. Baird, P. Ward, M. I. McDonald, B. J. Currie, J. R. Carapetis. Is Streptococcus pyogenes Resistant or Susceptible to Trimethoprim-Sulfamethoxazole?. Journal of Clinical Microbiology. 2012;50(12):4067-4072. doi:10.1128/jcm.02195-12.
