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STREPTOCOCCUS SEMINAR.pptx bgfhhgfghgfddfgghh
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- 2. Table of content: •General characteristics • Cultural characteristics • Pathogenic and Virulance factors • Classification • Group A Streptococci • Group B Streptococci • Viridance streptococci • Streptococcus pneumoniae • Enterococcus • Streptococcus mutans and dental caries
- 3. • Gram positivespherical or ovoid cocci arranged in long chains, commonly in pairs. • 0.5-1 µm in diameter. • Non spore forming bacteria. • Small, non pigmented colonies. • Sensitive to drying, heat, and disinfectants. • Catalase negative. • Excess grow on nutritional demands – Blood , serum , sugars (only acid , no gas) • It can be capsulated. GENERAL CHARACTERISTICS
- 4. Cultural characters : •Aerobe & fac. anerobe-growing best at 37C—growth only in media with fermentable sugers, enriched blood /serum. • Blood agar—incubet-24hrs—colonies are small-circular, semi transparent, low convex discs with an area of clear hemolysis around them. • Colonies are glistening and look like dewdrops. • Growth and hemolysis are promoted by10% Co2. • Capsulated—mucoid colonies
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- 6. • Structural components –M protein inhibits phagocytosis of bacteria – Lipo teichoic acid helps in adhesion of bacterIa – Capsule • Enzymes – Streptokinases- fibrinolysin – Deoxyribonucleases – Hyaluronidase – NADase • Pyrogenic exotoxin/ Erythrogenic exotoxin • Hemolysins – Streptolysin O- Oxygen labile, antigenic – Streptolysin S- serum soluble Pathogenesis & Virulence Factors
- 7. Streptococcus Oxygen requirement Aerobes &facultative anaerobes Hemolysis Alpha HS Beta HS Gama HS/NHS Obligate anaerobes e.g. Peptostreptococci GREEN Partial H’lysis Small zone Viridans Group Pneumococci Clear, Complete, 2 – 4mm Streptolysin O O2 labile, Seen in deep subsurface colonies, Antigenic in nature Streptolysin – S O2 stable, surface h’lysis, non-antigenic 20 Lancefiled groups , based on carbohydrate “C” antigen , A-V without I & J Group – A ( S. pyogenes ) Group B ( S Agalactiae) Enterocococcus Non- enterococcus group
- 8. -hemolysis -hemolysis -hemolysis Hemolysis on Bloodagar • This classification according hemolysis is given by Brown et al.
- 9. Serological Lancefield Classification: •Streptococci classified into many groups from A to V except I &J • One or more species per group • Classification based on C- carbohydrate antigen of cell wall – Groupable streptococci • A, B and D (more frequent) • C, G and F (Less frequent) – Non-groupable streptococci • S. pneumoniae (pneumonia) • viridans streptococci – e.g. S. mutans – Causing dental carries Streptococci Group A S. pyogenes Group B S. agalactiae Group C S. equisimitis Group D Enterococcus Lanciefield classification Other groups (E-U)
- 10. Group A Streptococci(GAS) S. pyogenes: Cultural characteristics • Aerobes and facultative anaerobes • Optimum temperature: 37C • For growth - needs enrichment media with blood or serum . 1.On Blood agar: Small(0.5-1.0mm),circular,semi-transparent colonies Produce wide zone of β- hemolysis Growth and hemolysis are promoted by 5-10% CO2 Virulent strains, on fresh isolation form lesions, produce a ‘matt’ (finely granular) colony while non virulent strains form ‘glossy’ colonies 2.On Liquid media: Glucose or serum broth Growth occurs as a granular turbidity with a powdery deposit No pellicle is formed
- 11. Resistance S.pyogenes isa delicate organism,easily destroyed by heat (54C for 30 min) Sensitive to bacitracin Has developed less resistance to drugs Dies in a few days in culture, unless stored at a low temperature (4C) preferably in Robertson’s cooked meat medium Rapidly inactivated by antiseptics and many antibiotics Fig. Zone of inhibition shown by S. pyogenes
- 12. Antigenic structure Capsular hyaluronicacid: • Non antigenic as hyaluronic acid is identical to that found in human connective tissue and hence bacteria can disguise themselves with an immunological self substance • Has weak anti-phagocytic activity but protects streptococci against immunological attacks
- 13. Antigenic structure A,Cell wall: 1.Outer layer: Protein and lipoteichoic acid 2. Middle layer: Group specific carbohydrate 3. Inner layer: Peptidoglycan (mucoprotein) Responsible for cell wall rigidity Enhances non-specific resistance (pyrogenic and thrombolytic activity) B. Group specific C-carbohydrates Serological grouping of streptococci is done on its basis Divided into 20 Lancefield groups (A to V) except I and J on the basis of group specific carbohydrates. All streptococci except viridans (α-hemolytic) group have a layer of carbohydrate
- 14. C. Proteins Presentin outermost layer Produces surface protein antigens (F, M, T and R) Useful in serological typing of S. pyogenes M protein: Most virulent; heat and acid stable, but susceptible to tryptic digestion. 80 types identified. Griffith typing. T protein: Not virulent, acid labile, trypsin resistant. R protein: Not virulent Antigenic structure
- 15. Antigenic structure F-protein Recognizeshost fibronectin, a matrix protein that is present in eukaryotic cells. Hence helps in attachment together with lipoteichoic acid and M protein M protein Most antigenic Covered with lipoteichoic acid that enable the organism to attach to epithelial cell M protein is heat and acid stable but susceptible to tryptic digestion On the basis of antigenic difference in M protein, S. pyogenes can be divided into about 100 types The most distal part of M protein shows extensive variability among strains hence individual may suffer from recurrent S. pyogenes infections with strains expressing different versions of M protein. Acts as a virulence factor by inhibiting phagocytosis T-Protein • Common to many M- types • Not associated with virulence and is not a protective antigen • It is strongly antigenic R protein • Non-type-specific and is associated with M- proteins of types 2,3 28 and 48 known as M- associated protein (MAP) • Not associated to virulence and not a protective antigen • Strongly antigenic
- 16. Antigenic Structure D. Pili(Fimbriae) Hair like and project from capsule Consist partly of M-protein Covered with lipoteichoic acid Important in the attachment of streptococci to epithelial cells
- 17. Hemolysins (Streptolysins) Producecomplete disruption of RBC Contribute to tissue invasion and destruction There are two types of Streptolysins Streptolysin O: sensitive to oxygen Streptolysin S: insensitive to oxygen
- 18. Erythrogenic toxin • Alsoknown as pyrogenic exotoxin/ Dick/ Scarlatinal toxin • Primary effect of the toxin is production of fever hence also called Streptococcal pyrogenic exotoxin (SPE) • Known as erythrogenic because its intradermal injection into susceptible individuals produced an erythematous reaction (Dick test) • DICK TEST- Used to identify susceptibility to scarlet fever • Mediate production of rash e.g. (scarlet fever) • SUPERANTIGENS hence massive release of cytokines occur that leads to variety of clinical signs including inflammation, shock and organ failure Rash in scarlet fever
- 19. Streptokinase (Fibrinolysin) Twotypes of streptokinase (A and B) Antigenic protein Fibrinolysin facilitates spread of infection by breaking down the fibrin barrier around the lesions also known as spreading factor Promotes the lysis of human blood clot by converting plasminogen to plasmin It is given intravenously for the treatment of early myocardial infarction and other thromboembolic disorders
- 20. Deoxyribonucleases (Streptodornase, DNAase) •Degrades DNA • Four antigenically distinct DNAases: A,B,C,D; B most antigenic • Capable of liquefying DNA accumulated in thick pus derived from nuclei of necrotic cells, hence the exudate is thin in streptococcal infections • Important therapeutically in liquefying localised collections of thick exudates (Empyema) • Demonstration of anti-DNAase B antibody in the diagnosis of S. pyogenes infections when ASO titres is low
- 21. Hyaluronidase • Breaks downhyaluronic acid of connective tissue and favors spread of infection • Antigenic and specific antibodies are formed • Degrades capsule • Others are proteinase, phosphatase, amylase, esterases, NADase, C5a peptidase, lipase, Serum opacity factor (SOP) etc.
- 22. Pathogenicity Produces pyrogenicinfection with a tendency to spread locally, along lymphatics and through blood stream Disease caused can be: 1. Suppurative diseases: a. Respiratory infections b. Skin and soft tissue infections c. Genital infections 2. Non suppurative sequelae: a. Acute rheumatic fever b. Acute glomerulonephritis
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- 24. Group A StreptococcalDiseases Suppurative: 1 Pharyngitis (“strep throat”) • inflammation of the pharynx 2 Pyoderma/Impetigo • confined, pus-producing lesion that usually occurs on the face, arms, or legs 3 cellulitis and Necrotizing fasciitis • toxin production destroys tissues and eventually muscle and fat tissue 4 Toxic shock syndrome • S. pyogenes is also known as ‘FLESH EATING BACTERIA’ - extensive necrosis of subcutaneous and muscular tissue and adjacent fascia – causes Toxic shock like syndrome
- 25. Non suppurative: 1 Scarletfever – • Rash that begins on the chest and spreads across the body. • Complication of S. pyogenes pharyngitis due to specific M protein types • Characterized by aschoff nodules (sub cutaneous nodule) • Aschoff bodies are nodules found in the hearts of individuals with rheumatic fever. They result from inflammation in the heart muscle and are characteristic of rheumatic heart disease 2 acute glomerulonephritis- • Caused by specific nephritogenic strains of group A streptococcus • Characterized by acute inflammation of renal glomeruli with edema, hypertension, hematuria and proteinuria • Sequela of both pharyngeal and pyodermal streptococcal infection
- 26. Treatment, prevention andcontrol DRUGS USED: • For streptococcal pharyngitis: Oral penicillin V or amoxicillin • Oral cephalosporin or macrolides can be used for penicillin sensitive patients • For severe, systemic infection: Combined use of intravenous penicillin with protein synthesis inhibiting antibiotics (clindamycin) is recommended • Streptococcal pyogenes have developed resistance over tetracyclines and sulfonamides, newer macrolides • Antimicrobial drugs has no effect on glomerulonephritis and rheumatic fever
- 27. Prophylaxis • Rheumatic feverrequires long term antibiotic prophylaxis to prevent recurrence of disease • Penicillin is used in patients who have developed early signs of rheumatic fever • For acute glomerulonephritis no need of antibiotic therapy and prophylactic therapy (no re-infection) • For patients with serious soft tissue infection, drainage and aggressive surgical debridement must be initiated
- 28. Group B betahemolytic Streptococci Streptococcus agalactiae • Infect newborns - Neonatal infection • Source – Infection acquired through maternal vagina during birth • Group B Streptococci (GBS) – puerperal sepsis, pneumonia • Presents as meningitis, pneumonia or septicemia • Most common cause of neonatal meningitis • Diagnostic markers – Hippurate hydrolysis, CAMP test
- 29. CAMP test • Christie,Atkins and Munch-Peterson • When S. agalactiae is inoculated perpendicular to a streak of S. aureus grown on blood agar an accentuated zone of hemolysis occurs S. aureus (Spingomyelinase C) Group A Streptococcus Group B Streptococcus (CAMP Factor) Enhanced Zone of Hemolysis
- 30. Group C betahemolytic Streptococci Streptococci equisimilis • Upper respiratory infections • Endocarditis, osteomyelitis, brain abscess • Treat with penicillin and gentamicin • Source of streptokinase used for thrombolytic therapy in patients
- 31. Classified into 2groups: 1. Non enterococcal group: containing S. suis, S. bovis and S. equinus. 2.The enterococcus group: which have been reclassified as a separate genus called Enterococcus, containing- E. faecalis, E. faecium and E. durans. Group D Streptococci:
- 32. • E. faecalisand E. faecium – Previously classified as group D streptococci but reclassified as a separate genus – Normal microbiota of the human colon • Opportunistic disease: – Urinary Tact Infection – Endocarditis – Common cause of nosocomial infections • Treatment: Difficult to treat due to resistance – Ampicillin and ceftriaxone Enterococcus
- 33. Alpha-Hemolytic Streptococci: The ViridansGroup • Alpha-hemolytic (“viridans = green”) • No Lancefield group – Lack group-specific carbohydrates • Normal microbiota – mouth, pharynx, GI tract, GU tract • Opportunistic Disease: – One of the causes of dental caries and dental plaques; produces dextran; leads to biofilm formation – Can cause meningitis and endocarditis Types: 1. S. mitis 2. S. mutans 3. S. salivarius 4. S. sanguis
- 34. Alpha-Hemolytic Streptococci: Streptococcus pneumoniae •Gram-positive diplococcus • Alpha-hemolytic • Normally colonizes the mouths and pharynx • Can cause disease if travels to the lungs • Disease is highest in children and the elderly
- 35. Streptococcus pneumoniae Morphology: • Lancetshaped (one end broad, other pointed) • Capsulated • Diplococci S. pneumoniae: lancet-shaped diplococcus
- 36. 36 Disease caused: • Middleear – otitis media • Para nasal sinuses – sinusitis • Respiratory tract – pneumonia, bronchitis, empyema • Meningitis is secondary to otitis media, penumonia, sinusitis and conjunctivitis Treatment: o Penicillin o Amoxycillin o ceftriaxone/ceftazidime o Vancomycin For prophylaxis: Pneumococcal conjugate vaccine is available
- 37. Lab Diagnosis ofStreptococci: Sample:Throat swab, pus / swab, Joint fluid (arthritis), Blood (septicemia) etc, Gram Stain- Gram Positive in chains Culture on Blood agar- hemolytic colonies, catalase negative
- 42. Bacitracin sensitivity • Principle: –for presumptive identification of group A – distinguish between S. pyogenes from other beta hemolytic streptococci – Strep. Pyogenes sensitive to Bacitracin giving zone of inhibition around disk
- 43. Our Adviser Mr. Alexander Lee Loremipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
- 44. Agenda Page Agenda 01 Loremipsum dolor sit amet, consectetur adipiscing elit. Agenda 02 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Agenda 03 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Agenda 04 Lorem ipsum dolor sit amet, consectetur adipiscing elit.
- 45. Reminders for this Class Loremipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing . Title Here Title Here Title Here Lorem ipsum dolor sit amet, consectetur adipiscing. Lorem ipsum dolor sit amet, consectetur adipiscing.
- 46. Lesson 01: Classifying Viruses Loremipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
- 47. What is aVirus? A virus is an infectious organism made of genetic material surrounded by a protein coat. Viruses are commonly classified using two key characteristics: Type of Genetic Material and Shape.
- 48. Genetic Material Viruses can beclassified based on the type of genetic material they contain, either DNA (deoxyribonucleic acid) or RNA (ribonucliec acid). DNA (deoxyribonucleic acid) Double Stranded RNA (ribonucliec acid) Single Stranded
- 49. dsDNA: Adenovirus causes respiratory infections ssDNA: Parvovirus causes parvo indogs dsRNA: Reovirus causes gastroenteritis ssRNA: Coronavirus causes SARS & Covid-19 Genetic Material Examples for each virus type are given above.
- 50. Virus Shape Viruses can beclassified based on their general shape. Common virus shapes include spherical, helical, polyhedral or complex. Spherical The genetic material in a spherical virus is protected inside a sphere-shaped outer envelope. Complex The genetic material in a complex virus sits inside a complex structure made up of a head, body and legs (tail fibers). Polyhedral The genetic material in a polyhedral virus is protected inside an outer envelope with many flat-sided faces. Helical The genetic material in a helical virus is twisted into a coil-like shape, similar to a metal spring.
- 51. Lesson 02: Bacteria Reproduction Loremipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
- 52. Bacteria Reproduction Bacteria reproduce asexually. Bacteriacan reproduce through three main processes: binary fission, budding and fragmentation.
- 53. Binary Fission Most bacteriareproduce through binary fission. This process involves a 'parent' bacteria cell dividing into two identical 'daughter' cells. Binary fission allows bacteria to rapidly increase in number, which is important for their survival. It is also a simple and efficient way to reproduce that allows bacteria to adapt quickly to changes in their environment. Stage 01 DNA begins to replicate in the parent cell in preparation for segregation. Stage 02 Cells start to elongate. The cell wall, cytoplasm and DNA begin to separate. Stage 03 Cell walls fully separate to form two identical daughter cells.
- 54. Add topic here Loremipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Title here Title here
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- 56. Education is the passportto the future, for tomorrow belongs to those who prepare for it today. Malcolm X
- 57. Lesson 03: Activity Time! Loremipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
- 58. Research Activity Task: Completeeach of the questions by conducting research online. Make sure to keep a list of your references in the space provided. Question 1: What is the basic structure of a virus and how does it allow the virus to infect cells? Question 2: How do viruses replicate and reproduce themselves once they have infected a cell? Question 3: What are some common illnesses caused by viruses, and how do they affect the human body? Question 4: How do viruses 'hide' from our immune system?
- 59. Introduce yourself! Name 01 Loremipsum dolor sit amet, consectetur adipiscing elit. Name 02 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Name 03 Lorem ipsum dolor sit amet, consectetur adipiscing elit.
- 60. Goodbye for now, students! Loremipsum dolor sit amet, consectetur adipiscing elit.
- 61. Resource Page Use these designresources in your Canva Presentation. This presentation template uses the following free fonts: Titles: Fredoka One Bold Headers: Roboto Bold Body Copy: Roboto Regular You can find these fonts online too. Happy designing! Don't forget to delete this page before presenting.
- 62. Credits This presentation templateis free for everyone to use thanks to the following: SlidesCarnival for the presentation template Pexels and Pixabay for the photos Happy designing!