8. PNEUMOCOCCI
• Culture media
• Blood agar and chocolate agar
• Colonies
• Small rounded colconies at first dome shaped later
develop a central plateau with elevated rim
• Alpha hemolysis on blood agar
• Transformation
• When uncapsulated pnemococci are cultured in the
presence of DNA extracted from a capsulated
pneumococcus encapsulated puneumococci of later
type are formed this is called transformation.
10. PNEUMOCOCCI
• Lysis of colonies
• Pneumococcal colonies are sensitive to lysis by
an autolytic enzymes L alanine muramyl
amidase that cleaves bond linking L alanine
peptide to muramic acid of peptidoglycan
wall.
11. PNEUMOCOCCI
• Growth characteristics
• Oxygen requirements: aerobic and facultative
anaerobes.
• Peptostreptococci are obligate anaerobes
• Energy source is ferment sugar produces lactic
acid but not gas. Lactic acid limits the growth.
• Temperature 37degree c
• 5-10% co2 promotes growth.
12. PNEUMOCOCCI
• Antigen
• Capsular polysaccharide
• A distinct for each of more than 80 serologic types.
• B virulence is due to capsule which protect it from
phagocytosis.
• B cells response which provide type specific immunity.
• M protein
• Characteristics for each type.
• C CHO
• It is group specific common to all pnemococci.
14. PNEUMOCOCCI
• Enzymes
• IgA protease
• It enhances organism ability to colonizes mucosa
of upper respiratory tract.
• Toxin
• Pnemolysin
• Binds to cholestrol in host cell membrane.
• Inhibit antimicrobial properties of neutrophils
and opsonic activity of serum.
15. PNEUMOCOCCI
• Habitat and transmission
• Habitat
• Normal inhabitant of u.respiratory tract.
• Transmission
• Via respiratory droplets
16. PNEUMOCOCCI
• Pathogenes and clinical finding
• pnemococcal lobar pneumonia:
• It is characterized by exudation of fibrinous edema fluid
into alveoli following by RBC and leukocytes many
pnemococci are also present in alveoli. This causes
consloidation of portion of lung.
• Clinical finding
• A sudden onset of high fever with violent , shaking chills
• B sharp pleutal pain and friction rub.
• C cough at first dry or productive of thin watery sputum :
later bloody or rusty sputum.
20. PNEUMOCOCCI
• Bacteremia with its complication
• From alveolar exudates organism reach bloodstream
via lymphatics and causes bacteremia which have a
traid of serious complication
• Meningitis
• Endocarditis
• Septic arthritis
• Sinusitis
• Pericardiditis
• Empyema
• Otitis media
21. PNEUMOCOCCI
• Meningitis
• Pneumococcus is the second common bacterial pathogen
that causes meningitis in adults.
• Pathogenesis:
• It may arises as a complication of pnemonia in which
pneumococci reach the meninges by way of blood stream.
• It results from a skull fracture ,permitting pnemococci from
nasopharynx to enter the meninges.
• Otitis media
• Pnemococci is the etilogic agent of about 50% cases of
otitis media in chidren.
25. PNEUMOCOCCI
• Diagnostic laboratory test
• Specimen blood pus sputum CSF
• Microscopy gram +ve diplococci
• Culture blood agar chocolate agar
• Capsule swelling test quelling test
• Omni antisera test
• opotochin disk test
• Animal inoculation test
26. PNEUMOCOCCI
• Immunity
• Type specific immunity to reinfection with
pnemococci develops. It is due to type specfic
anticapsular antibodies.
27. PNEUMOCOCCI
• Treatment
• Penicillin
• Erythromycin
• Cephaothin
• Chloramphenical
• Prevention and control
• Immunization with polyvalent ( ploysaccharide
vaccine)
• Vaccine provides protection for 5 years.
28. PNEUMOCOCCI
• Difference b/w lobar pneumonia and
bronchopneumonia
• Lobar pneumonia
• Cased 90% by pneumococci few cases by klebsiella
pnemoniae, staph aureus.
• Occurs in otherwise healthy individual b/w 30-50 years
• Onset is sudden with high grade fever, shaking chills
and bloody or rust sputum
• Conslidation of whole lobe.
• Complication bacteremia, meningitis,endocarditis,
septic arthritis.
29. PNEUMOCOCCI
• Bronchopneumonia
• Caused by staphylococci streptococci, H
influenzae proteus and pseudomonas.
• Occurs infants ,old and those suffering chronic
debiliating illness or immunosuppression.
• Onset is insiduous with low grade fever and
cough productive of purulent sputum.
• Patchy pneumonic consolidation.
• Complications: fibrosis, bronchiectasis,lung
abscess.
