Streptococcus pyogenes Dr Kamran Afzal FCPS Microbiology
<ul><li>Case history </li></ul><ul><li>A 10-year-old female patient presents with a 2-day history of fever and sore joints...
The Genus Streptococcus <ul><li>FAMILY Streptococcaceae  </li></ul><ul><li>Some important pathogens, commensals of mucous ...
Clinically Important Streptococcus species γ No S. mutans Mutans α D S. bovis Bovis γ K S. salivarius Salivarius α G, F S....
Typing of Streptococci <ul><li>Haemolytic activity </li></ul><ul><ul><li>Haemolysis on sheep blood agar </li></ul></ul><ul...
Haemolytic Activity <ul><li>β  Haemolysis </li></ul><ul><ul><li>Complete lysis/clearing of RBCs induced by bacterial haemo...
Characteristics -  S. pyogenes <ul><li>Gram positive </li></ul><ul><li>Arranged in chains </li></ul><ul><li>β  hemolytic o...
Pathogenesis <ul><li>Virulence factors </li></ul><ul><ul><li>Evasion of host immunity </li></ul></ul><ul><ul><li>Adherence...
Virulence Factors <ul><li>F protein </li></ul><ul><ul><li>Adhesion with fibronectin </li></ul></ul><ul><li>M protein </li>...
<ul><li>C5a peptidase </li></ul><ul><ul><li>Cleaves human C5a, which is a potent chemo-attractant </li></ul></ul><ul><li>P...
 
Clinical Features
Transmission <ul><li>Spread </li></ul><ul><ul><li>Person to person </li></ul></ul><ul><ul><ul><li>Respiratory droplets </l...
Diseases caused by  S. pyogenes
Diseases caused by  S. pyogenes <ul><li>Invasive disease   </li></ul><ul><ul><li>Cellulitis </li></ul></ul><ul><ul><li>Nec...
Risk Groups <ul><li>Invasive disease </li></ul><ul><ul><li>Elderly, immuno-suppressed, persons with chronic cardiac or res...
Strep Throat <ul><li>Most common of all Strep diseases </li></ul><ul><li>Spread by saliva or nasal secretions </li></ul><u...
Impetigo <ul><ul><li>Lesions on extremities </li></ul></ul><ul><ul><li>Common on face </li></ul></ul><ul><ul><li>Pustular ...
Erysipelas <ul><li>Acute infection and inflammation of the dermal layer of skin </li></ul><ul><li>Painful red patches whic...
Scarlet  Fever <ul><li>Diffuse erythematous rash over skin and mucous membranes </li></ul><ul><li>Rash develops within 1-2...
<ul><li>“ Flesh-eating bacteria” </li></ul><ul><li>Progresses very rapidly destroying fat and fascia </li></ul><ul><li>Rap...
Streptococcal Myositis <ul><li>Post-pharyngitis </li></ul><ul><li>Bacteraemic spread to the muscle </li></ul><ul><li>Infec...
Streptococcal Toxic Shock Syndrome <ul><li>Due to the release of streptococcal toxins into the bloodstream </li></ul><ul><...
Treatment <ul><li>Penicillin G parenterally (Sensitive) </li></ul><ul><li>Other beta-lactam antibiotics </li></ul><ul><li>...
Post-Streptococcal diseases (Sequelae)
Post-streptococcal Diseases Immune Mediated <ul><li>Acute rheumatic fever (ARF)  </li></ul><ul><li>Post-streptococcal glom...
Rheumatic Fever <ul><li>Most common cause of permanent heart valve damage in children </li></ul><ul><li>Antibody cross rea...
Pathogenesis <ul><li>Follows GAS pharyngitis </li></ul><ul><li>Antibody against M-protein cross react with host tissue </l...
Pathology <ul><li>Acute Rheumatic Fever   </li></ul><ul><ul><li>Acute inflammatory phase </li></ul></ul><ul><ul><li>Heart ...
Acute Rheumatic Carditis <ul><li>Aschoff bodies  </li></ul><ul><ul><li>Aschoff giant cells </li></ul></ul><ul><ul><li>Anit...
Jones Criteria of Diagnosis <ul><li>Major Criteria </li></ul><ul><li>Migratory polyarthritis </li></ul><ul><li>Carditis </...
Laboratory Investigations <ul><li>No  specific  laboratory investigations </li></ul><ul><li>Cultures are usually negative ...
<ul><li>Anti-streptococcal therapy </li></ul><ul><ul><li>Benzathine penicillin (long acting) 1.2 million units once  (IM i...
Post-Streptococcal Glomerulonephritis <ul><li>Pathogenesis </li></ul><ul><li>Follows GAS infection of skin (or pharynx) </...
Pathology Post-streptococcal glomerulonephritis is immunologically mediated, and the immune deposits are distributed in th...
Clinical Features <ul><li>Most common in children 2-12 yrs </li></ul><ul><li>Symptoms occur 10-21 days after infection </l...
Laboratory Investigations <ul><li>No  specific  laboratory investigations </li></ul><ul><li>Cultures are usually negative ...
Treatment and Recovery <ul><li>Conservative management </li></ul><ul><li>Penicillin or Erythromycin to eradicate the resid...
Diseases caused by  S. pyogenes <ul><li>Invasive disease   </li></ul><ul><ul><li>Cellulitis </li></ul></ul><ul><ul><li>Nec...
<ul><li>Case history </li></ul><ul><li>A 10-year-old female patient presents with a 2-day history of fever and sore joints...
 
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Str Pyo+ Sequelae

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Str Pyo+ Sequelae

  1. 1. Streptococcus pyogenes Dr Kamran Afzal FCPS Microbiology
  2. 2. <ul><li>Case history </li></ul><ul><li>A 10-year-old female patient presents with a 2-day history of fever and sore joints. Further questioning reveals that she had a sore throat 3 weeks ago but did not seek any medical help at that time. Her current illness began with fever and a sore and swollen right knee. The following day her knee improved but her left elbow became sore and swollen. </li></ul>
  3. 3. The Genus Streptococcus <ul><li>FAMILY Streptococcaceae </li></ul><ul><li>Some important pathogens, commensals of mucous membranes </li></ul><ul><li>Opportunistic pathogens </li></ul><ul><li>40 species, in 6 clusters </li></ul><ul><li>Strong fermenters of carbohydrates -> Lactic acid </li></ul><ul><li>Facultative anaerobes </li></ul><ul><li>Peptostreptococci are obligate anaerobes </li></ul>
  4. 4. Clinically Important Streptococcus species γ No S. mutans Mutans α D S. bovis Bovis γ K S. salivarius Salivarius α G, F S. anginosus Anginosus α α α O O H S. pneumoniae S. mitis S. sanguis Mitis β β β A B C S. pyogenes S. agalactiae S. eqisimilus Pyogenic Type of Haemolysis Lancefield Group Species Group
  5. 5. Typing of Streptococci <ul><li>Haemolytic activity </li></ul><ul><ul><li>Haemolysis on sheep blood agar </li></ul></ul><ul><ul><li>α, β or γ </li></ul></ul><ul><li>Lancefield grouping </li></ul><ul><ul><li>Polysaccharide antigen in cell wall </li></ul></ul><ul><ul><li>21 serological groups (A-H and K-W) </li></ul></ul><ul><li>M protein </li></ul><ul><ul><li>80 serotypes </li></ul></ul><ul><li>Molecular biology </li></ul><ul><ul><li>PCR, RFLP, DNA sequencing </li></ul></ul>
  6. 6. Haemolytic Activity <ul><li>β Haemolysis </li></ul><ul><ul><li>Complete lysis/clearing of RBCs induced by bacterial haemolysins </li></ul></ul><ul><li>α Haemolysis </li></ul><ul><ul><li>Incomplete haemolysis of RBCs </li></ul></ul><ul><ul><li>H 2 O 2 oxidizes Hb -> Methaemoglobin (greenish) </li></ul></ul><ul><li>γ Haemolysis </li></ul><ul><ul><li>No </li></ul></ul><ul><ul><li>haemolysis </li></ul></ul>
  7. 7. Characteristics - S. pyogenes <ul><li>Gram positive </li></ul><ul><li>Arranged in chains </li></ul><ul><li>β hemolytic on blood agar </li></ul><ul><li>Bacitracin sensitive </li></ul><ul><li>Catalase negative </li></ul><ul><li>Lancefield Serological Group A </li></ul><ul><li>Non-motile </li></ul><ul><li>Non-sporing </li></ul><ul><li>PYR positive </li></ul>
  8. 8. Pathogenesis <ul><li>Virulence factors </li></ul><ul><ul><li>Evasion of host immunity </li></ul></ul><ul><ul><li>Adherence </li></ul></ul><ul><ul><li>Tissue damage </li></ul></ul>
  9. 9. Virulence Factors <ul><li>F protein </li></ul><ul><ul><li>Adhesion with fibronectin </li></ul></ul><ul><li>M protein </li></ul><ul><ul><li>Resist phagocytosis </li></ul></ul><ul><li>Capsule </li></ul><ul><ul><li>Hyaluronic acid, producing mucoid colonies </li></ul></ul><ul><ul><li>Anti-phagocytic effect </li></ul></ul><ul><li>Streptolysins </li></ul><ul><ul><li>Streptolysin O (O 2 labile) </li></ul></ul><ul><ul><ul><li>ASOT of antibodies detected in serum after severe infection </li></ul></ul></ul><ul><ul><li>Streptolysin S (Serum-soluble) </li></ul></ul><ul><ul><ul><li>β haemolysis </li></ul></ul></ul>
  10. 10. <ul><li>C5a peptidase </li></ul><ul><ul><li>Cleaves human C5a, which is a potent chemo-attractant </li></ul></ul><ul><li>Pyrogenic exotoxins </li></ul><ul><ul><li>SPE A, SPE B and SPE C </li></ul></ul><ul><ul><li>Release of IL-1, IL-2, INF- γ and TNF </li></ul></ul><ul><li>Hyaluronidase </li></ul><ul><ul><li>Degrade hyaluronic acid, spread in fascial planes </li></ul></ul><ul><li>Streptokinase </li></ul><ul><ul><li>Degrades building up of fibrin barriers, rapid spread </li></ul></ul><ul><li>Lipoproteinase </li></ul><ul><ul><li>Opacity factor: induces opalescence in serum </li></ul></ul><ul><li>DNAse </li></ul><ul><ul><li>Hydrolyses nucleic acids, spread by liquifying viscious exudates </li></ul></ul>
  11. 12. Clinical Features
  12. 13. Transmission <ul><li>Spread </li></ul><ul><ul><li>Person to person </li></ul></ul><ul><ul><ul><li>Respiratory droplets </li></ul></ul></ul><ul><ul><li>Direct contact </li></ul></ul><ul><ul><ul><li>Infected wounds/sores </li></ul></ul></ul><ul><li>Asymptomatic pharyngeal carriage </li></ul><ul><ul><li>All age groups, most common among children </li></ul></ul>
  13. 14. Diseases caused by S. pyogenes
  14. 15. Diseases caused by S. pyogenes <ul><li>Invasive disease </li></ul><ul><ul><li>Cellulitis </li></ul></ul><ul><ul><li>Necrotizing fasciitis [NF] </li></ul></ul><ul><ul><li>Myositis </li></ul></ul><ul><ul><li>Toxic shock-like syndrome [STSS] </li></ul></ul><ul><ul><li>Bacteraemia </li></ul></ul><ul><ul><li>Pneumonia </li></ul></ul><ul><ul><li>Puerperal sepsis </li></ul></ul><ul><li>Non-invasive disease </li></ul><ul><ul><li>Strep throat </li></ul></ul><ul><ul><li>Impetigo </li></ul></ul><ul><ul><li>Erysipelas </li></ul></ul><ul><li>Non-suppurative sequelae </li></ul><ul><ul><li>Acute rheumatic fever </li></ul></ul><ul><ul><li>Post-streptococcal glomerulonephritis </li></ul></ul>
  15. 16. Risk Groups <ul><li>Invasive disease </li></ul><ul><ul><li>Elderly, immuno-suppressed, persons with chronic cardiac or respiratory disease, diabetes, skin lesions (i.e. children with varicella [chicken pox], persons with penetrating trauma or surgical wounds, intravenous drug users) </li></ul></ul><ul><li>Non-invasive disease </li></ul><ul><ul><li>Children (5-10 yrs) at highest risk </li></ul></ul>
  16. 17. Strep Throat <ul><li>Most common of all Strep diseases </li></ul><ul><li>Spread by saliva or nasal secretions </li></ul><ul><li>Abrupt onset of sore throat, fever, malaise </li></ul><ul><li>Posterior pharynx is reddened with enlarged tonsils and pus/exudate in crypts </li></ul><ul><li>Important to treat immediately to avoid post strep diseases </li></ul><ul><li>20% school children carriers </li></ul>
  17. 18. Impetigo <ul><ul><li>Lesions on extremities </li></ul></ul><ul><ul><li>Common on face </li></ul></ul><ul><ul><li>Pustular and crusty </li></ul></ul>
  18. 19. Erysipelas <ul><li>Acute infection and inflammation of the dermal layer of skin </li></ul><ul><li>Painful red patches which enlarge and thicken </li></ul><ul><ul><li>Infection involves the dermis and lymphatics </li></ul></ul><ul><ul><li>Characterized by intense erythema, induration and a sharply demarcated border </li></ul></ul>
  19. 20. Scarlet Fever <ul><li>Diffuse erythematous rash over skin and mucous membranes </li></ul><ul><li>Rash develops within 1-2 days following pharyngitis , initially on upper chest, then spreads to extremities </li></ul><ul><li>The tongue becomes red and denuded – Strawberry tongue </li></ul><ul><li>Erythrogenic toxins: rash of scarlet fever </li></ul>
  20. 21. <ul><li>“ Flesh-eating bacteria” </li></ul><ul><li>Progresses very rapidly destroying fat and fascia </li></ul><ul><li>Rapid development of shock, MODS </li></ul>Necrotizing Fasciitis
  21. 22. Streptococcal Myositis <ul><li>Post-pharyngitis </li></ul><ul><li>Bacteraemic spread to the muscle </li></ul><ul><li>Infection may be precipitated by trauma or muscle sprain </li></ul>
  22. 23. Streptococcal Toxic Shock Syndrome <ul><li>Due to the release of streptococcal toxins into the bloodstream </li></ul><ul><li>Severe pain at the site of infection, soft tissue </li></ul><ul><li>Fever, malaise, vomiting, diarrhea, dizziness, confusion </li></ul><ul><li>A flat rash over large parts of the body </li></ul><ul><li>May progresses to shock and MODS </li></ul><ul><li>Multi-organ failure (2 or more of the following) </li></ul><ul><ul><ul><li>Hepatic involvement </li></ul></ul></ul><ul><ul><ul><li>Renal involvement </li></ul></ul></ul><ul><ul><ul><li>ARDS </li></ul></ul></ul><ul><ul><ul><li>Hematologic involvement </li></ul></ul></ul>
  23. 24. Treatment <ul><li>Penicillin G parenterally (Sensitive) </li></ul><ul><li>Other beta-lactam antibiotics </li></ul><ul><li>Erythromycin or other macrolides </li></ul><ul><li>Surgical resection/debridement </li></ul><ul><li>Supportive care </li></ul>
  24. 25. Post-Streptococcal diseases (Sequelae)
  25. 26. Post-streptococcal Diseases Immune Mediated <ul><li>Acute rheumatic fever (ARF) </li></ul><ul><li>Post-streptococcal glomerulonephritis (AGN) </li></ul><ul><li>Post- streptococcal reactive arthritis </li></ul><ul><li>Sydenhams chorea </li></ul><ul><li>Erythema nodosum </li></ul><ul><li>Cutaneous polyarteritis nodosa (PAN) </li></ul><ul><li>Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infection (PANDAS) </li></ul>
  26. 27. Rheumatic Fever <ul><li>Most common cause of permanent heart valve damage in children </li></ul><ul><li>Antibody cross reactivity between the cell wall of S. pyogenes and heart muscle or joint tissue </li></ul><ul><li>Diagnosis is based on symptoms and is difficult </li></ul><ul><li>Ages 6 - 15 </li></ul>
  27. 28. Pathogenesis <ul><li>Follows GAS pharyngitis </li></ul><ul><li>Antibody against M-protein cross react with host tissue </li></ul><ul><li>2-3 weeks after pharyngitis – immune mediated </li></ul><ul><li>Fibrinoid degeneration, inflammation mediated by T lymphocytes and macrophages </li></ul><ul><li>Heart, skin, brain and joints </li></ul>
  28. 29. Pathology <ul><li>Acute Rheumatic Fever </li></ul><ul><ul><li>Acute inflammatory phase </li></ul></ul><ul><ul><li>Heart – Pancarditis </li></ul></ul><ul><ul><li>Skin – Erythema marginatum </li></ul></ul><ul><ul><li>CNS – Sydenham’s chorea </li></ul></ul><ul><ul><li>Migratory polyarthritis </li></ul></ul><ul><li>Chronic Rheumatic Fever </li></ul><ul><ul><li>Deforming fibrotic valvular disease </li></ul></ul><ul><ul><ul><li>Fish Mouth Mitral Stenosis </li></ul></ul></ul>
  29. 30. Acute Rheumatic Carditis <ul><li>Aschoff bodies </li></ul><ul><ul><li>Aschoff giant cells </li></ul></ul><ul><ul><li>Anitschkow cells </li></ul></ul><ul><ul><li>Fibrinoid degeneration </li></ul></ul><ul><ul><li>T lymphocytes </li></ul></ul>
  30. 31. Jones Criteria of Diagnosis <ul><li>Major Criteria </li></ul><ul><li>Migratory polyarthritis </li></ul><ul><li>Carditis </li></ul><ul><li>Subcutaneous nodules </li></ul><ul><li>Erythema marginatum </li></ul><ul><li>Sydenham’s chorea </li></ul><ul><li>Minor Criteria </li></ul><ul><li>Nonspecific symptoms </li></ul><ul><li>Fever </li></ul><ul><li>Arthralgia </li></ul><ul><li>Acute phase reactants </li></ul><ul><li>High ESR </li></ul>For Diagnosis: Two Major or One Major and Two Minor Criteria following GAS pharyngitis
  31. 32. Laboratory Investigations <ul><li>No specific laboratory investigations </li></ul><ul><li>Cultures are usually negative </li></ul><ul><li>High ASO titre </li></ul><ul><li>High Anti-DNAse B titres </li></ul><ul><li>High Acute phase reactants – </li></ul><ul><ul><li>CRP, SAP, Complements, Coagulation Proteins </li></ul></ul>
  32. 33. <ul><li>Anti-streptococcal therapy </li></ul><ul><ul><li>Benzathine penicillin (long acting) 1.2 million units once (IM injection) or oral penicillin 10 days, if allergic to penicillin erythromycin for 10 days </li></ul></ul><ul><li>Antibiotic is given even if throat culture is negative </li></ul><ul><li>Salicylates (Aspirin derivatives) </li></ul><ul><li>Corticosteroids to decrease inflammation and fever </li></ul>Treatment
  33. 34. Post-Streptococcal Glomerulonephritis <ul><li>Pathogenesis </li></ul><ul><li>Follows GAS infection of skin (or pharynx) </li></ul><ul><li>Antibody against M protein cross reacts between the cell wall of S. pyogenes and glomeruli of the kidney </li></ul><ul><li>Deposition of Ag-Ab complexes, activation of complement (C3) </li></ul><ul><li>Characterized by damage to glomeruli of kidneys due to inflammatory response </li></ul>
  34. 35. Pathology Post-streptococcal glomerulonephritis is immunologically mediated, and the immune deposits are distributed in the capillary loops in a granular, bumpy pattern because of the focal nature of the deposition process
  35. 36. Clinical Features <ul><li>Most common in children 2-12 yrs </li></ul><ul><li>Symptoms occur 10-21 days after infection </li></ul><ul><ul><li>Haematuria </li></ul></ul><ul><ul><li>Proteinuria </li></ul></ul><ul><ul><li>Decreased GFR, oliguria </li></ul></ul><ul><ul><li>Hypertension </li></ul></ul><ul><ul><li>Edema around eyes, feet and ankles </li></ul></ul><ul><ul><li>Ascites or pleural effusion </li></ul></ul>
  36. 37. Laboratory Investigations <ul><li>No specific laboratory investigations </li></ul><ul><li>Cultures are usually negative </li></ul><ul><li>Low C3 </li></ul><ul><li>Normal C4 </li></ul><ul><li>Normal/High Antistreptolysin O titre (ASOT) </li></ul><ul><li>Kidney biopsy </li></ul><ul><ul><li>Immune complex mediated inflammation and proliferation of glomeruli </li></ul></ul>
  37. 38. Treatment and Recovery <ul><li>Conservative management </li></ul><ul><li>Penicillin or Erythromycin to eradicate the residual strep infection </li></ul><ul><li>99% complete recovery in children and 85% in adults </li></ul><ul><li>Kidney damage in the remainder is often permanent resulting in chronic glomerular nephritis </li></ul>
  38. 39. Diseases caused by S. pyogenes <ul><li>Invasive disease </li></ul><ul><ul><li>Cellulitis </li></ul></ul><ul><ul><li>Necrotizing fasciitis [NF] </li></ul></ul><ul><ul><li>Myositis </li></ul></ul><ul><ul><li>Toxic shock-like syndrome [STSS] </li></ul></ul><ul><ul><li>Bacteraemia </li></ul></ul><ul><ul><li>Pneumonia </li></ul></ul><ul><ul><li>Puerperal sepsis </li></ul></ul><ul><li>Non-invasive disease </li></ul><ul><ul><li>Strep throat </li></ul></ul><ul><ul><li>Impetigo </li></ul></ul><ul><ul><li>Erysipelas </li></ul></ul><ul><li>Non-suppurative sequelae </li></ul><ul><ul><li>Acute rheumatic fever </li></ul></ul><ul><ul><li>Post-streptococcal glomerulonephritis </li></ul></ul>
  39. 40. <ul><li>Case history </li></ul><ul><li>A 10-year-old female patient presents with a 2-day history of fever and sore joints. Further questioning reveals that she had a sore throat 3 weeks ago but did not seek any medical help at that time. Her current illness began with fever and a sore and swollen right knee. The following day her knee improved but her left elbow became sore and swollen. </li></ul><ul><li>Acute Rheumatic Fever </li></ul>

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