Bacterial pneumonia (Streptococcus pneumoniae) Zachary Rushton
Dec 14, 2015
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.jpg
http://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.