Streptococcus Pyogenes and Psuedomonas Aeuroginosa

by on March 7th, 2015
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Psuedomonas aeruginosa Psuedomonas aeruginosa is one of the rare rod species from the VirtualUnknown Lab. I did not know much about pseudomonas except their resilience to adverse environments. Research shows that they are similar to salmonella and shigella generas because they grow in xylose-lysine agar. It is non-discriminatory to which organ system it grows, and can often batter the GI tract and urinary tract. It is often a nosocomial infection, or hospital-acquired. It is extremely unlikely to cause infection in healthy subjects. It is difficult to treat with antibiotics because they are natively resistant to beta-lactam. The best antibiotics are only partially effective because they cannot spend enough time inside the cell. It is commonly known in food circles to be commonly found in refrigerated products that have expired.

P. aruginosa is universally motile at temperatures higher than even tested in laboratory, and has a
positive catalase test. It can perform quorum in a biofilm.
(http://textbookofbacteriology.net/pseudomonas.html)
Tests:
Lysine decarboxylase (+) indole negative, methyl red negative, Voges Proskauer test negative.
Fine et al. “Prognosis and outcomes of patients with community-acquired pneumonia. A meta-analysis.” JAMA. 1996 Jan 10;275(2):134-41.

S. Pyogenes- Pie Ah Jen Ease Streptococcus pyogenes are catalase negative and are facultative anaerobes. Facultative anaerobe means it is capable of living without oxygen via fermentation, but prefers oxygenation. The most favorable temperature for development is 37°C. It is most interesting that it can be found in healthy individuals as well as from afflicted individuals. This is the pathogen for strep throat, scarlet fever, and rheumatic fever. It is also implicated in Toxic Shock Syndrome. It can be treated with penicillin. However, if one is allergic to penicillin, various agents may be used. Resistance to other antibiotics is noted, particularly macrolides and clarithromycin. Failure to treat this pathogen allows its toxins to become septic, and allows the incidence of necrotizing fasciitis. Its place of primary concern is the respiratory tract, as this medium is about the temperature of the human body in the oral tract. The testing algorithm for this organism is as follows (all should be positive): Catalase (http://www2.austin.cc.tx.us/microbugz/html/catalase_test.html) Growth on mannitol salt agar (http://www.austincc.edu/microbugz/html/mannitol_salt_agar.html) Sugar fermentation tests, including OF glucose (http://jlindquist.net/generalmicro/dfnewgfbpage.html)


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