Uploaded on

Pneumostaph45

Pneumostaph45

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to like this
No Downloads

Views

Total Views
1,266
On Slideshare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
63
Comments
1
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Streptococcus pneumoniae Staphylococci Faculty: Dr. Alvin Fox www.freelivedoctor.com
  • 2.
    • S. pneumoniae
    • diplococci
    • Pneumococcus
    • autolysin
    • bile solubility test
    • optochin susceptibility
    • capsule
    • Quellung reaction
    • Staphylococcus aureus
    • opportunistic diseases
    • food poisoning/enterotoxins
    • toxic shock syndrome
    • toxic shock toxin
    • exfoliative toxin/scalded skin syndrome
    •  ,  ,  ,  cytotoxins
    • leucocidin
    • lipase
    • hyaluronidase
    • protein A
    • coagulase (+) or coagulase (–)
    • Staphylococcus epidermidis
    KEYWORDS www.freelivedoctor.com
  • 3. S. pneumoniae www.freelivedoctor.com
  • 4. S. pneumoniae
    • leading cause of pneumonia
      • particularly young and old
      • after damage to upper respiratory tract
        • * e.g. following viral infection
    • bacteremia
    • meningitis
    • middle ear infections (otitis media)
    www.freelivedoctor.com
  • 5. S. pneumoniae
    •  hemolytic
    • pneumolysin
      • degrades red blood cells under aerobic conditions
    • grows well on sheep blood agar
    • no group antigen
    www.freelivedoctor.com
  • 6. Diagnosis - spinal fluid
    • direct Gram staining
    • detection of capsular antigen
    www.freelivedoctor.com
  • 7. Autolysis - identification Bile peptidoglycan cell membrane lipoteichoic acid teichoic acid -choline autolysin www.freelivedoctor.com
  • 8. C polysaccharide
    • Teichoic acid
      • Precipitates in serum
      • C-reactive protein
    www.freelivedoctor.com
  • 9. Not optochin sensitive optochin sensitive Identification www.freelivedoctor.com
  • 10. Capsule
    • prominent
      • virulent strains
    • anti-phagocytic
    • carbohydrate antigens
      • vary among strains
    www.freelivedoctor.com
  • 11. Capsule
    • immunity
      • serotype specific
    • vaccine contains multiple serotypes
    • only for susceptible population
    www.freelivedoctor.com
  • 12. Quellung reaction
    • using antisera
    • capsule "fixed"
    • visible microscopically
    www.freelivedoctor.com
  • 13. Pathogenesis
    • Teichoic acid
      • complement activation
      • large numbers of inflammatory cells at infection site
    www.freelivedoctor.com
  • 14. Therapy
    • S. pneumoniae
      • most strains susceptible to penicillin
      • resistance is common
    www.freelivedoctor.com
  • 15. STAPHYLOCOCCI
    • Gram positive
    • Facultative anaerobes
    • Grape like-clusters
    • Catalase positive
    • Major components
    • of normal flora
      • skin
      • nose
    www.freelivedoctor.com
  • 16. Staphylococcus aureus www.freelivedoctor.com
  • 17. One of commonest opportunistic infections - hospital and community :
    • pneumonia
    • osteomyelitis
    • septic arthritis
    • bacteremia
    • endocarditis
    • abscesses/boils
    • other skin infections
    www.freelivedoctor.com
  • 18. Food poisoning
    • not an infection
    • food contaminated by humans
      • growth of bacteria
      • production of enterotoxin
    • onset and recovery both occur within few hours
    www.freelivedoctor.com
  • 19. Food poisoning
    • Vomiting
    • nausea
    • diarrhea
    • abdominal pain
    www.freelivedoctor.com
  • 20. Toxic shock syndrome
    • fever
    • rash
    • desquamation
    • vomiting
    • diarrhea
    www.freelivedoctor.com
  • 21. Toxic shock syndrome
    • Toxic shock toxin
      • Dissemination
    • Organism
      • no dissemination
    www.freelivedoctor.com
  • 22. S. aureus
    • babies
      • scalded skin syndrome
        • exfoliatin
    www.freelivedoctor.com
  • 23. Lytic exotoxins:
    •  toxin
    •  (sphingomyelinase C)
    •  toxin
    •  toxins
      • detergent-like
    • leucocidins
    www.freelivedoctor.com
  • 24. Protein A inhibits phagocytosis Protein A immunoglobulin Fc receptor BACTERIUM PHAGOCYTE www.freelivedoctor.com
  • 25. Spread
    • tissue-degrading enzymes
      • lipase
      • hyaluronidase
    www.freelivedoctor.com
  • 26. Identification
    •  hemolytic
    • sheep blood agar
    • yellow pigmented (aureus)
    • mannitol fermentation
    • coagulase-positive
    • reference laboratories
    • phage-typing
    www.freelivedoctor.com
  • 27. Staphylococcus epidermidis
    • major component, skin flora
    • opportunistic infection
    • - less common than S.aureus
    • nosomial infections
      • shunts, catheters
    • artificial heart valves/joints
    www.freelivedoctor.com
  • 28. Identification
    • Non-hemolytic
      • sheep blood agar
      • Non-pigmented
    • Does not ferment mannitol
    • Coagulase negative
    www.freelivedoctor.com
  • 29. Staphylococcus saprophyticus
    • urinary tract infections
    • coagulase-negative
      • not usually differentiated from S. epidermidis
    www.freelivedoctor.com
  • 30. Antibiotic therapy
    • Resistance to penicillin
      • penicillinase
    •  lactam antibiotics (including methicillin [MRSA])
      • often ineffective
      • modified penicillin binding proteins
    • Vancomycin
      • current drug of choice
      • resistance has been observed
    www.freelivedoctor.com
  • 31. GRAM POSITIVE COCCI S. aureus  hemolytic mannitol yellow + - Staphylococcus (Clusters) Streptococcus (pairs & chains) Catalase BETA: Bacitracin S. pyogenes (group A) CAMP/ Hippurate S. agalactiae (group B) Hemolysis Coagulase S. epidermidis nonhemolytic (usually) mannitol white ALPHA: Optochin /Bile Solubility S. pneumoniae GAMMA: Bile Esculin 6.5% NaCl Group D* Enterococcus Bile Esculin 6.5% NaCl Group D* Non- Enterococcus (*can also be alpha hemolytic) Note: S. viridans is Is alpha hemolytic and negative for all the tests below below + + + + + + + - - Summary Figure (Identification Scheme) www.freelivedoctor.com