mycroorganisms causing pneumonia they are alot and vary depending on the way that they affect on the lung tissue.

1. ‫الرحي‬ ‫الرحمن‬ ‫هللا‬ ‫بسم‬
‫م‬
Resp
PROBLEM 3
Micro organisms causing pneumonia

2. Pneumonia
 DEF: it is an infection and inflammation of the lungs.
 Types:
Atypical
Pneumonia
Typical
pneumonia
onset
Fever
cough
Most
common
cause

3. Bacterial pneumonia
Streptococcus pneumoniae
Haemophilus influenza
Klebsiella pneumoniae
Mycoplasma pneumoniae

4. 1-Streptococcus pneumoniae
 Gram-positive, lancet-shaped,
Diplococci.

5. Virulence factors
1. Capsule: Anti-phagocytic& facilitates invasion.
2. IgA1 protease: enhances colonization of the respiratory mucosa.
3. Pneumolysin: a toxin that lyses and interferes with the function of cells
and soluble molecules of the immune system.
4.Lipoteichoic acid:a cell wall component that activates the complement,
induces cytokine production and contributes to septic shock occurring in immunocompromised patients.

8. 2-Haemophilus influenza
 Gram-negative, small cocco-
bacilli.
 Many strains are capsulated.
 Capsulated strains are of 6
types (a-f) the most
pathogenic is HIb

9. Virulence factors
1. The capsule →anti-phagocytic, facilitates invasion.
2. IgA1 protease → degrades IgA → favors mucosal colonization.
3. Fimbria →facilitates attachment to the respiratory mucosa.
4. Outer membrane lipopolysaccharides and proteins → invasion.

10. Pathogenicity
Capsulated strains (mainly Hib):Cause
invasive diseases in children below 5 years as meningitis, pneumonia,
cellulitis, septic arthritis, epiglottitis and bacteremia.
Non-capsulated strains:Cause non-invasive diseases;
otitis media and upper respiratory tract infections.
 • They may cause pneumonia and bacteremia in adults in the presence of
predisposing factors e.g. viral infections, obstructive lung disease.

11. 3-Klebsiella
pneumoniae
Klebsiella pneumoniae is
a Gram negative, capsulated,
rod-shape bacterium

12. Pathogenicity
1. Lobar pneumonia.
2. Urinary tract infection.
3. Septicemia.
4. Neonatal meningitis.

13. 4-Mycoplasma pneumoniae
 The smallest free living organisms →30 - 500 nm.
 Pleomorphic →because they lack a cell wall.
 Contain sterol in their cell membranes.
 Poorly stained with Gram stain →stained by Giemsa stain.

14. Cultural characters:
• Grow on special media enriched with serum and other ingredients
that provide sterols and nucleic acid precursors.
• Facultative anaerobes.
• Better growth at 10% Co2.
• Grow slowly and require at least one week to form visible colonies
with a characteristic “fried egg” appearance.

16. 
‫قال‬
‫المتنبى‬
:
‫المعالى‬ ‫تكسب‬ ‫الكد‬ ‫بقدر‬
...
‫سهر‬ ‫العال‬ ‫طلب‬ ‫ومن‬
‫الليالى‬
‫كد‬ ‫بغير‬ ‫العال‬ ‫طلب‬ ‫ومن‬
...
‫المحال‬ ‫طلب‬ ‫في‬ ‫العمر‬ ‫أضاع‬

17. Thanks