Streptococcus pneumoniae

Adele Ricciardi

Pneumonia-inflammatory condition of the lung

PNEUMONIA CAN BE CAUSED BY:VIRUSESFUNGI

BACTERIA

Symptoms Diagnosis

cough (often produces rust colored mucus)

fever and chills

shortness of breath

chest pain

fatigue

Chest x-ray (in hospitals and clinics)

Blood test

Sputum culture

physical examination

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,

S. pneumoniae was first isolated in 1881,

but it still remains the number 1 killer of children under 5 today.

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

Problems:Expensive

Alter serotype distribution

Results:Decrease nasopharyngeal

colonizationReduce disease of included

serotypes

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.

References• Bruyn, G.W, Zegers, B. M, R. van Furth. Mechanisms of Host Defense against Infection with

Streptococcus pneumoniae. Clinical Infections Diseases 1992;14;251-62.

• Daniels, Briles, Mirza, Hakasson, Briles. Capsule does not block antibody binding to PspA, a surface virulence protein of Streptococcus pneumoniae. Microbial Pathogenesis. 40;2006;228-233.

• Alonsodevelasco, Verhuel, Verhoef, Snipe. Atreptococcus pneumoniae: Virulence Factors, Pathogenesis and Vaccines. Microbiological Reviews. Dec. 1995, 591-603.

• Hsieh, Lee, Shao, Chang, Huang. The Transforming Streptococcus Pneumoniae in the 21st century. Chang Gung Med J Vo. 30 No. 2 2008;31:117-24

• Hammerschmidt, Wolff, Hocke, Rosseau, Muller, Rohde. Illustration of Pneumonococcal Polysacharide Capsule during adherence and invasion of epithelial cells. Infection and Immunity. 2005; 4653-4667.

• Kadioglu, Weiser, Paton, Andrew. The role of streptococcus pneumoniae virulence factors in host respiratory colonization and disease. Nature. 2008;6.

• 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.

• World Health Organization. World health statistics 2009. Geneva: World Health Organization; 2008. http://www.who.int/whosis/whostat/EN_WHS09_Full.pdf

• 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.

• World Health Organization. World health statistics 2006. Geneva: World Health Organization; 2006. http://www.who.int/whosis/whostat2006.pdf.

• World Health Organization. World health statistics 2006. Geneva: World Health Organization; 2006. http://www.who.int/whosis/whostat2006.pdf..

• 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.

• Rudan I, Tomaskovic L, Boschi-Pinto C, Campbell H. Global estimate of the incidence of clinical pneumonia among children under five years of age. Bull World Health Organ. 2004;82:895–903.