Bacterial pneumonia (Streptococcus

pneumoniae)Zachary Rushton

Inflammatory condition of the lung affecting the alveoli especially

Most common infectious agent leading to hospitalization in the world

What it is…

http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/19680.jpg

Gram-positive, aero tolerant anaerobe

http://textbookofbacteriology.net/PHILspbloodGram.jpghttp://pathmicro.med.sc.edu/fox/strep-pneu_small1.jpg

Structure

http://www.nature.com/nrmicro/journal/v6/n4/images/nrmicro1871-f2.jpg

Rate of pneumococcal bacteremia are about 19 per 100,000 per year

http://worldpneumoniaday.org/learn/2011-progress-report/

90 different serotypes

http://cid.oxfordjournals.org/content/51/9/1042/F1.medium.gif

Strains are differentiated by the capsular polysaccharide coat

http://www.microbiologyinpictures.com/bacteria%20photos/streptococcus%20pneumoniae%20photos/streptococcus%20pneumoniae%20027.jpg

Bacteria usually infect the lungs, causing pneumonia

http://www.thailabonline.com/bacteria6streppneumo.htm

From the blood bacteria can traverse the blood-brain barrier and infect the meninges

http://upload.wikimedia.org/wikipedia/commons/thumb/f/fd/Streptococcus_pneumoniae_meningitis%2C_gross_pathology_33_lores.jpg/402px-Streptococcus_pneumoniae_meningitis%2C_gross_pathology_33_lores.jpg

Mucosal epithelium of the nasopharynx primary site of colonization

http://practicalhospital.com/wp-content/uploads/2011/07/c7_nasopharynx-297x300.jpg

http://www.thailabonline.com/bacteria6streppneumo.htm

S. Pnumoniae does not damage by bacterial toxins but instead by this strong inflammatory response

White blood cell pneumolysin

If concentration of cell wall components exceeds 100,000/mL, rapid inflammatory response is initiated

http://funwithgovernment.blogspot.com/2011/03/killer-diseases-in-philippines.html

Diagnosis is made by isolating the bacterium from blood or urine

http://www.nlm.nih.gov/medlineplus/ency/imagepages/19680.htm

In the past treatment was straightforward due to high penicillin susceptibility

http://www.nlm.nih.gov/medlineplus/ency/imagepages/19680.htm

Penicillin resistance has led to increase in mortality rate◦ Penicillin- nonsusceptible 19.4%◦ Susceptible 15.7%

◦ Production of altered penicillin binding proteins

Β-lactam resistance should be fought with vancomycin and a third generation cephalosporin

http://science-naturalphenomena.blogspot.com/2009/04/cephalosporins.html

There currently exists a 23 valent capsular polysaccharide vaccine

Based on knowledge that antibodies formed against the capsule are very effective in preventing lethal S. pneumoniae infection

How can disease be prevented

Antibodies are type-specific (over 90 types), thus it was constructed using 23 of the most common strains

1 shot

5 years later, a booster is given

http://www.sciencephoto.com/media/283366/enlarge

Arancillo. (2010, February). Pneumonia [Video file] Retrieved from http://www.youtube.com/watch?v=Hat0_VDQACA

Hanage W, Fraser C, Tang J, Connor T, Corander J. 2009. Hyper-Recombination, Diversity, and Antibiotic Resistance in Pneumococcus. Science: 324:1454-1457.

Huang SS, Platt R, Rifas-Shiman SL, Pelton SI, Goldmann D, Finkelstein JA. 2005. Post-PCV7 Changes in Colonizing Pneumococcal Serotypes in 16 Massachusetts Communities, 2001 and 2004. Pediatrics: 117:593-594.

Magner L N. 2009. A history of infectious diseases and the microbial world. Westport, Conn.: Praeger. xxiv, 225 p.

Pneumonia Progress Report 2011. [Internet]. 2012. Baltimore, MD: IVAC. [cited 2012 Mar 29] Available from: http://worldpneumoniaday.org/wp-content/uploads/2011/11/IVAC-2011_PNEUMONIA_PROGRESS_REPORT.pdf.

"Streptococcus Pneumoniae." Thai Labonline. <http://www.thailabonline.com/bacteria6streppneumo.htm>. 2 April 2012.

Tomasz A. c2000. Streptococcus pneumoniae : Molecular biology & mechanisms of disease. Larchmont, NY: Mary Ann Liebert Inc. xxi, 501 p.

Washer P. 2010. Emerging infectious diseases and society. Houndmills, Basingstoke, Hampshire [England] ;: Palgrave Macmillan. xiv, 191 p.