Group A streptococcal infection: Difference between revisions
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{{Group A streptococcal infection}} | {{Group A streptococcal infection}} | ||
{{CMG}} | {{CMG}}; {{AE}} {{AEL}} | ||
==[[ | ==Overview== | ||
Group A streptcocci or streptoccus pyogenes causes a wide range of diseases in many organs in the body. It is important to classify the [[infections]] caused by the [[Bacterial|bacteria]] in order to understand every disease separately. Classification of the group A streptococcal infections will be based on the pathogenesis of the infection and the organ infected. According to the pathogenesis of the infection, they can be classified into [[pyogenic]], toxogenic or [[Immunogenicity|immunogenic]] infections. Based on the location, the streptococcus pyogenes affects the [[lungs]], [[ear]], [[nose]], [[throat]], [[blood]], female genital system and the [[central nervous system]]. | |||
The pathophysiology of the disease depends on various virulence factors. These factors include protein M, streptolysins O and S, hyalourinidase and C5a peptidase. | |||
== | ==Classification== | ||
Group A streptococcal infections can be classified according to the pathogenesis of the infection and the organ infected. According to the pathogenesis of the infection, they can be classified into pyogenic, toxogenic or immunogenic infections. Based on the location, the streptococcus pyogenes affects the lungs, ear, nose, throat, blood, female genital system and the central nervous system. | |||
<small><small><small> | |||
{{Family tree/start}} | |||
{{Family tree | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A01 | | | | | | | |A01= '''Group A streptococcal infections'''}} | |||
{{Family tree | | | | | | | | | | | | | | | | | | | | | | | | |,|-|-|-|-|-|-|-|-|-|-|-|-|-|-|^|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|.| |}} | |||
{{Family tree | | | | | | | | | | | | | | | | | | | | | | | | B01 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | B02 |B01= Pathogenesis| B02= Organ based|}} | |||
{{Family tree | | | | | | | | | | | | | | | | | | | | | | | | |!| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |!| | | | | | | | | |}} | |||
{{Family tree | | | | | | |,|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|+|-|-|-|-|-|-|-|-|-|.| | | | | | | | | |,|-|-|-|-|-|-|-|v|-|-|-|-|-|-|-|v|-|-|-|-|+|-|-|-|-|-|v|-|-|-|-|-|-|-|.| |}} | |||
{{Family tree | | | | | | C01 | | | | | | | | | | | | | | | | C02 | | | | | | | | C03 | | | | | | | | C04 | | | | | | C05 | | | | | | C06 | | | C07 | | | | C08 | | | | | | C09 | |C01= [[Pyogenic]]|C02= Toxogenic|C03= Immunogenic|C04= [[Lungs]]|C05= [[Ear]], [[nose]] and [[throat]]|C06=[[Bone]]|C07= [[Blood]] |C08= Female genital system |C09= [[Brain]]|}} | |||
{{Family tree | | | | | | |!| | | | | | | | | | | | | | | | | |!| | | | | | | | | |!| | | | | | | | | |!| | | | | | | |!| | | | | | | |!| | | | |!| | | | | |!| | | | | | | |!| | |}} | |||
{{Family tree | | |,|-|-|-|+|-|-|-|v|-|-|-|.| | | | | |,|-|-|-|+|-|-|-|.| | | |,|-|^|-|.| | | | | | | D01 | | |,|-|-|-|+|-|-|-|.| | | D02 | | | D03 | | |,|-|^|-|.| | | |,|-|^|-|.| |D01=[[Pneumonia]]|D02=[[Osteomyelitis]]|D03=[[Bacteremia]]|}} | |||
{{Family tree | | E01 | | E02 | | E03 | | E04 | | | | E05 | | E06 | | E07 | | E08 | | E09 | | | | | | | | | | E10 | | E11 | | E12 | | | | | | | | | | | E13 | | E14 | | E15 | | E16 ||E01=[[Pharyngitis]] ([[Strep throat]])|E02=[[Cellulitis]]|E03=[[Impetigo]]|E04=[[Erysipelas]]|E05=[[Scarlet fever]]|E06=[[Toxic shock like syndrome]]|E07=[[Necrotizing fasciitis]]|E08=[[Rheumatic fever]]|E09=[[Glomerulonephritis]]|E10=[[Sinusitis]]|E11=[[Tonsilitis]]|E12=[[Otitis media]]|E13=[[Postpartum]] [[endometritis]]|E14=[[Vaginitis]]|E15=[[Meningitis]]|E16=[[Brain abscess]]|}} | |||
{{Family tree/end}} | |||
</small></small></small> | |||
== | ==Pathophysiology== | ||
===Transmission=== | |||
Group A streptococcal infection can be transmitted by the following:<ref name="pmid27312939">{{cite journal| author=Brouwer S, Barnett TC, Rivera-Hernandez T, Rohde M, Walker MJ| title=Streptococcus pyogenes adhesion and colonization. | journal=FEBS Lett | year= 2016 | volume= 590 | issue= 21 | pages= 3739-3757 | pmid=27312939 | doi=10.1002/1873-3468.12254 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27312939 }} </ref> | |||
*Direct inoculation transmission | |||
*Infected airborne droplets | |||
== | ===Virulence factors=== | ||
Group A streptococcus are responsible for various diseases ranging from mild to life threatening cases. The bacteria depends mainly on many virulence factors which are responsible for the pathogenesis of the infections.<ref name="pmid27312939">{{cite journal| author=Brouwer S, Barnett TC, Rivera-Hernandez T, Rohde M, Walker MJ| title=Streptococcus pyogenes adhesion and colonization. | journal=FEBS Lett | year= 2016 | volume= 590 | issue= 21 | pages= 3739-3757 | pmid=27312939 | doi=10.1002/1873-3468.12254 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27312939 }} </ref> | |||
== | {| class="wikitable" | ||
!Virulence factors | |||
!Mechanism of action | |||
|- | |||
|[[M protein]] | |||
| | |||
* The most important virulence factor. | |||
* It prevents the [[phagocytosis]] of the [[bacteria]] by binding to the [[fibrinogen]] and prevents binding the [[complement]] to the [[bacterial]] [[cell wall]]. | |||
|- | |||
|Streptolysin O and S | |||
| | |||
* Streptolysin O works on killing the differecnt cells like the [[neutrophils]], [[platelets]] and the sub-cellular [[organelles]]. | |||
|- | |||
|Streptococcal pyrogenic exotoxins A and C | |||
| | |||
* SpeA and SpeC are superantigens secreted by many strains of ''S. pyogenes''. These pyrogenic [[exotoxins]] are responsible for the [[rash]] of [[scarlet fever]] and many of the symptoms of streptococcal [[toxic shock syndrome]]. | |||
|- | |||
|Streptokinase | |||
| | |||
* Enzymatically activates [[plasminogen]] which is a [[proteolytic enzyme]] into [[plasmin]] which in turn digests [[fibrin]] and other proteins. | |||
|- | |||
|Hyalourinidase | |||
| | |||
* It helps the [[bacteria]] to spread through the tissue by destroying the [[hyaluronic acid]] which is a [[connective tissue]] component.<ref name=Starr_2006>{{cite journal |author=Starr C, Engleberg N |title=Role of hyaluronidase in subcutaneous spread and growth of group A streptococcus |journal=Infect Immun |volume=74 |issue=1 |pages=40-8 |year=2006 |id=PMID 16368955}}</ref> | |||
|- | |||
|Streptodornase | |||
| | |||
* Most strains of ''S. pyogenes'' secrete up to four different [[DNase]]s, which are sometimes called ''streptodornase''. The DNases protect the bacteria from being trapped in [[neutrophil extracellular traps]] (NETs) by digesting the NET's web of DNA, to which are bound [[neutrophil]] [[serine protease]]s that can kill the bacteria.<ref name=Buchanan_2006>{{cite journal |author=Buchanan J, Simpson A, Aziz R, Liu G, Kristian S, Kotb M, Feramisco J, Nizet V |title=DNase expression allows the pathogen group A Streptococcus to escape killing in neutrophil extracellular traps |journal=Curr Biol |volume=16 |issue=4 |pages=396-400 |year=2006 |id=PMID 16488874}}</ref> | |||
|- | |||
|[[C5a]] [[peptidase]] | |||
| | |||
*C5a peptidase cleaves a potent [[neutrophil]] chemotaxin called [[C5a]], which is produced by the complement system.<ref name=Wexler_1985>{{cite journal |author=Wexler D, Chenoweth D, Cleary P |title=Mechanism of action of the group A streptococcal C5a inactivator |journal=Proc Natl Acad Sci U S A |volume=82 |issue=23 |pages=8144-8 |year=1985 |id=PMID 3906656}}</ref> C5a peptidase is necessary to minimize the influx of neutrophils early in infection as the bacteria are attempting to colonize the host's tissue.<ref name="Ji 1996">{{cite journal |author=Ji Y, McLandsborough L, Kondagunta A, Cleary P |title=C5a peptidase alters clearance and trafficking of group A streptococci by infected mice |journal=Infect Immun |volume=64 |issue=2 |pages=503-10 |year=1996 |id=PMID 8550199}}</ref>. | |||
|- | |||
|Streptococcal chemokine protease | |||
| | |||
*The affected tissue of patients with severe cases of [[necrotizing fasciitis]] are devoid of [[neutrophil]]s.<ref name=Hidalgo-Grass_2004>{{cite journal |author=Hidalgo-Grass C, Dan-Goor M, Maly A, Eran Y, Kwinn L, Nizet V, Ravins M, Jaffe J, Peyser A, Moses A, Hanski E |title=Effect of a bacterial pheromone peptide on host chemokine degradation in group A streptococcal necrotising soft-tissue infections |journal=Lancet |volume=363 |issue=9410 |pages=696-703 |year=2004 |id=PMID 15001327}}</ref>. The [[serine protease]] ScpC, which is released by ''S. pyogenes'', is responsible for preventing the migration of neutrophils to the spreading infection.<ref name="Hidalgo-Grass 2006">{{cite journal |author=Hidalgo-Grass C, Mishalian I, Dan-Goor M, Belotserkovsky I, Eran Y, Nizet V, Peled A, Hanski E |title=A streptococcal protease that degrades CXC chemokines and impairs bacterial clearance from infected tissues |journal=EMBO J |volume=25 |issue=19 |pages=4628-37 |year=2006 |id=PMID 16977314}}</ref> ScpC degrades the [[chemokine]] [[IL-8]], which would otherwise attract [[neutrophil]]s to the site of infection. C5a peptidase, although required to degrade the neutrophil chemotaxin C5a in the early stages of infection, is not required for ''S. pyogenes'' to prevent the influx of neutrophils as the bacteria spread through the [[fascia]].<ref name="Ji 1996"/><ref name="Hidalgo-Grass 2006"/> | |||
|} | |||
== | ==References== | ||
{{Reflist|2}} | |||
== | ==References== | ||
{{Reflist|2}} | |||
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Latest revision as of 06:52, 20 October 2020
Group A streptococcal infection Microchapters |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]
Overview
Group A streptcocci or streptoccus pyogenes causes a wide range of diseases in many organs in the body. It is important to classify the infections caused by the bacteria in order to understand every disease separately. Classification of the group A streptococcal infections will be based on the pathogenesis of the infection and the organ infected. According to the pathogenesis of the infection, they can be classified into pyogenic, toxogenic or immunogenic infections. Based on the location, the streptococcus pyogenes affects the lungs, ear, nose, throat, blood, female genital system and the central nervous system.
The pathophysiology of the disease depends on various virulence factors. These factors include protein M, streptolysins O and S, hyalourinidase and C5a peptidase.
Classification
Group A streptococcal infections can be classified according to the pathogenesis of the infection and the organ infected. According to the pathogenesis of the infection, they can be classified into pyogenic, toxogenic or immunogenic infections. Based on the location, the streptococcus pyogenes affects the lungs, ear, nose, throat, blood, female genital system and the central nervous system.
Group A streptococcal infections | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pathogenesis | Organ based | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pyogenic | Toxogenic | Immunogenic | Lungs | Ear, nose and throat | Bone | Blood | Female genital system | Brain | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pneumonia | Osteomyelitis | Bacteremia | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pharyngitis (Strep throat) | Cellulitis | Impetigo | Erysipelas | Scarlet fever | Toxic shock like syndrome | Necrotizing fasciitis | Rheumatic fever | Glomerulonephritis | Sinusitis | Tonsilitis | Otitis media | Postpartum endometritis | Vaginitis | Meningitis | Brain abscess | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pathophysiology
Transmission
Group A streptococcal infection can be transmitted by the following:[1]
- Direct inoculation transmission
- Infected airborne droplets
Virulence factors
Group A streptococcus are responsible for various diseases ranging from mild to life threatening cases. The bacteria depends mainly on many virulence factors which are responsible for the pathogenesis of the infections.[1]
Virulence factors | Mechanism of action |
---|---|
M protein |
|
Streptolysin O and S |
|
Streptococcal pyrogenic exotoxins A and C |
|
Streptokinase |
|
Hyalourinidase |
|
Streptodornase |
|
C5a peptidase |
|
Streptococcal chemokine protease |
|
References
- ↑ 1.0 1.1 Brouwer S, Barnett TC, Rivera-Hernandez T, Rohde M, Walker MJ (2016). "Streptococcus pyogenes adhesion and colonization". FEBS Lett. 590 (21): 3739–3757. doi:10.1002/1873-3468.12254. PMID 27312939.
- ↑ Starr C, Engleberg N (2006). "Role of hyaluronidase in subcutaneous spread and growth of group A streptococcus". Infect Immun. 74 (1): 40–8. PMID 16368955.
- ↑ Buchanan J, Simpson A, Aziz R, Liu G, Kristian S, Kotb M, Feramisco J, Nizet V (2006). "DNase expression allows the pathogen group A Streptococcus to escape killing in neutrophil extracellular traps". Curr Biol. 16 (4): 396–400. PMID 16488874.
- ↑ Wexler D, Chenoweth D, Cleary P (1985). "Mechanism of action of the group A streptococcal C5a inactivator". Proc Natl Acad Sci U S A. 82 (23): 8144–8. PMID 3906656.
- ↑ 5.0 5.1 Ji Y, McLandsborough L, Kondagunta A, Cleary P (1996). "C5a peptidase alters clearance and trafficking of group A streptococci by infected mice". Infect Immun. 64 (2): 503–10. PMID 8550199.
- ↑ Hidalgo-Grass C, Dan-Goor M, Maly A, Eran Y, Kwinn L, Nizet V, Ravins M, Jaffe J, Peyser A, Moses A, Hanski E (2004). "Effect of a bacterial pheromone peptide on host chemokine degradation in group A streptococcal necrotising soft-tissue infections". Lancet. 363 (9410): 696–703. PMID 15001327.
- ↑ 7.0 7.1 Hidalgo-Grass C, Mishalian I, Dan-Goor M, Belotserkovsky I, Eran Y, Nizet V, Peled A, Hanski E (2006). "A streptococcal protease that degrades CXC chemokines and impairs bacterial clearance from infected tissues". EMBO J. 25 (19): 4628–37. PMID 16977314.