Streptococcus pyogenes: Difference between revisions
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Streptococcus pyogenes
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== Microbiology == |
== Microbiology == |
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* [[Has Gram stain::Gram-positive]] coccus, typically in |
* [[Has Gram stain::Gram-positive]] coccus, typically in short chains |
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* Non-motile, non–spore forming, catalase-negative, and facultatively anaerobic |
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* [[Has hemolysis pattern::β hemolytic]] on blood agar (complete hemolysis) |
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== Pathophysiology == |
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=== Virulence factors === |
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* Capsular hyaluronic acid is similar to human |
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* M protein is the main factor imparting virulence |
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** M protein differences given ''S. pyogenes'' its serotypes |
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** Confers resistance to phagocytosis by modulating host immune response |
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== Clinical Presentation == |
== Clinical Presentation == |
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== Prognosis == |
== Prognosis == |
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* Highest risk of streptococcal toxic shock syndrome (TSS) or death |
* Highest risk of streptococcal [[toxic shock syndrome]] (TSS) or death |
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** Necrotizing fasciitis (50% and 50%) |
** [[Necrotizing fasciitis]] (50% and 50%) |
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** Pneumonia (30% and 30%) |
** Pneumonia (30% and 30%) |
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** Bacteremia (15% and 25%) |
** Bacteremia (15% and 25%) |
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Revision as of 01:13, 12 September 2019
- 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.
