Pneumocystis Jirovecii

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Introduction Pneumocystis jirovecii is a genus of unicellular fungi found in the respiratory tracts of many mammals and humans. Causal Agents Pneumocystis jirovecii taxonomic classification has been a debate since it was discovered in 1909. It was originally labeled incorrectly as a trypanosome and again later for a protozoan (Bennett, 2013). In 1988, it was proven wrong when Edman and Stringer showed that the ribosomal RNA sequences of P carinii correlated to those of fungus and entirely dissimilar to those of other parasites (Catherinot, 2010). Since then, P. jirovecii has been placed in the fungal kingdom. P. jirovecii can be seen in 3 different morphologic forms: trophozite, sporozite and as a cyst. In the tropohozoite from, the organism is pleomorphic, non-motile and is in a vegetative state. The sporozoites, which amount up to 8 within a cyst, is crescent shaped. One question remains whether the bodies escape from the cyst by active motility or whether they are forced out passively as a result of the cyst collapsing (Remington 2011). P. jirovecii cannot be cultivated by standard methods. Instead, it is detected through other staining methods. “Because clinical and radiologic findings are not specific for PCP and because P jirovecii cannot be grown in vitro, histopathologic demonstration is necessary before a definitive diagnosis is established (Bennett, 2013).” Although some tests are not as effective or sensitive, there are still other histochemical stains such as the Diff-Quik, Grocott-Gomori methenamine silver (GMS), and Calcofluor white stains to view fungus in its three forms (Procop, 2004). Pneumocystis organisms are commonly found in the lungs of healthy individuals and are inhaled and spread throughout the resp... ... middle of paper ... ...rnal Article, Review DOI: 10.1016/j.idc.2009.10.010 3) James Stringer, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, 45267-0524 USA; fax: 513-558-8474; 4) http://www.danmedbul.dk/DMB_2004/0304/0304-disputatser/DMB3677.pdf 5) http://www.aafp.org/afp/1999/1015/p1699.html Website 1)http://emedicine.medscape.com/article/225976-overview#showall 2)http://www.antimicrobe.org/f11.asp - top 3) http://www.cdc.gov/dpdx/pneumocystis/index.html 4) https://www.mdguidelines.com/pneumocystis-carinii-pneumonia 5) http://www.medicinenet.com/sulfamethoxazole_and_trimethoprim/article.htm Book 1)https://www.inkling.com/read/infectious-diseases-fetus-newborn-remington-7th/chapter-34/pneumocystis-jiroveci-formerly 2)http://hab.hrsa.gov/deliverhivaidscare/clinicalguide11/cg-625_pcp.html

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