Transcript Streptococcus pneumoniae

Streptococcus
pneumoniae
Adele Ricciardi
Pneumonia-inflammatory condition of the lung
PNEUMONIA CAN BE CAUSED BY:
VIRUSES
FUNGI
BACTERIA
Symptoms
Diagnosis
cough (often produces
rust colored mucus)
Chest x-ray (in hospitals
and clinics)
fever and chills
Blood test
shortness of breath
Sputum culture
chest pain
physical examination
fatigue
CT scan
CHEST X-RAY
Streptococcus
pneumoniae
nasopharynx of healthy
people
Gram-positive bacteria
Paired (diplococci) or
appear in chains
May also infect brain
(pneumococcal
meningitis) and blood
stream (pneumococcus
septicemia)
Scanning Electron Micrograph of Streptococcus pneumoniae. Source: CDC/ R. Facklam, J. Carr
S. pneumoniae was first isolated in 1881,
but it still remains the number 1 killer of
children under 5 today.
The Toll
4 million deaths every year
half of these deaths - children under age 5
5,500 children die from pneumonia every day
98% of children who die of pneumonia live in
developing countries
contributes to the cycle of poverty
S. Pneumoniae -Virulence
•
Polysaccharide capsule, > 90 serotypes
•
Resistance to phagocytosis and antibiotics
Different serotypes
Different serotypes
Pneumococci in intimate contact
with lung cells show reduced
capsular polysaccharide
Virulence- Pneumolysin
Toxin
Cholesterol-dependent
cytolysin
Cytokine synthesis
Inflammatory response
Pneumococcal
conjugate vaccine
•
Elicits antibodies against the seven most common
capsular types
•
Sero-specific
Results:
Decrease nasopharyngeal
colonization
Reduce disease of included
serotypes
Problems:
Expensive
Alter serotype distribution
Use of pneumococcal conjugate
vaccine is limited to parts of the
developing world
Pneumonia will continue to kill
Unless we do something about it…
Treatment
•
•
Antibiotics, <$1/dose
•
Amoxicillin – inhibit cell wall formation
•
Erythromycin- inhibit protein synthesis
1 out of 5 children with pneumonia receives
antibiotics
We can protect from
pneumonia
Pneumonia suffers
from scientific neglect
They may not be excited
now...
but they will be. This vaccine
deal could save 900,000
lives by 2015.
•
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•
World Health Organization: The top 10 causes of death. October 2008.
http://www.who.int/mediacentre/factsheets/fs310/en/index.html [2] Rudan I, Boschi-Pinto C, Biloglav Z, Mulholland K,
Campbell H. Epidemiology and etiology of childhood pneumonia. Bull World Health Organ. 2008;86:408–16.
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http://www.who.int/whosis/whostat/EN_WHS09_Full.pdf
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Rudan I, Boschi-Pinto C, Biloglav Z, Mulholland K, Campbell H. Epidemiology and etiology of childhood pneumonia. Bull
World Health Organ. 2008;86:408–16.
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World Health Organization. World health statistics 2006. Geneva: World Health Organization; 2006.
http://www.who.int/whosis/whostat2006.pdf.
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World Health Organization. World health statistics 2006. Geneva: World Health Organization; 2006.
http://www.who.int/whosis/whostat2006.pdf..
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Rudan I, Boschi-Pinto C, Biloglav Z, Mulholland K, Campbell H. Epidemiology and etiology of childhood pneumonia. Bull
World Health Organ. 2008;86:408–16.
•
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children under five years of age. Bull World Health Organ. 2004;82:895–903.
References