title: Parasitic polymorphism of Coccidioides spp.
abstract: BACKGROUND
  Coccidioides spp. is the ethiological agent of coccidioidomycosis, an infection that can be fatal. Its diagnosis is complicated, due to that it shares clinical and histopathological characteristics with other pulmonary mycoses. Coccidioides spp. is a dimorphic fungus and, in its saprobic phase, grows as a mycelium, forming a large amount of arthroconidia. In susceptible persons, arthroconidia induce dimorphic changes into spherules/endospores, a typical parasitic form of Coccidioides spp. In addition, the diversity of mycelial parasitic forms has been observed in clinical specimens; they are scarcely known and produce errors in diagnosis.
  
  
  METHODS
  We presented a retrospective study of images from specimens of smears with 15% potassium hydroxide, cytology, and tissue biopsies of a histopathologic collection from patients with coccidioidomycosis seen at a tertiary-care hospital in Mexico City.
  
  
  RESULTS
  The parasitic polymorphism of Coccidioides spp. observed in the clinical specimens was as follows: i) spherules/endospores in different maturation stages; ii) pleomorphic cells (septate hyphae, hyphae composed of ovoid and spherical cells, and arthroconidia), and iii) fungal ball formation (mycelia with septate hyphae and arthroconidia).
  
  
  CONCLUSIONS
  The parasitic polymorphism of Coccidioides spp. includes the following: spherules/endospores, arthroconidia, and different forms of mycelia. This knowledge is important for the accurate diagnosis of coccidioidomycosis. In earlier studies, we proposed the integration of this diversity of forms in the Coccidioides spp. parasitic cycle. The microhabitat surrounding the fungus into the host would favor the parasitic polymorphism of this fungus, and this environment may assist in the evolution toward parasitism of Coccidioides spp.
authors.forename: Bertha
authors.initials: B
authors.lastname: Muñoz-Hernández
authors.forename: Gabriel
authors.initials: G
authors.lastname: Palma-Cortés
authors.forename: Carlos
authors.initials: C
authors.lastname: Cabello-Gutiérrez
authors.affiliation: Laboratorio de Micología Médica, Depto, de Microbiología, Escuela Nacional de Ciencias Biológicas (ENCB), Instituto Politécnico Nacional (IPN), Carpio y Plan de Ayala s/n, Colonia Casco de Santo Tomás, Del, Miguel Hidalgo, México, DF 11340, México. angeles.12mar@hotmail.com.
authors.forename: María Angeles
authors.initials: MA
authors.lastname: Martínez-Rivera
mesh_terms: D003045:Coccidioides / Q000166:cytology / Q000502:physiology*; D003047:Coccidioidomycosis / Q000175:diagnosis / Q000382:microbiology*; D006801:Humans; D025282:Mycelium; D012189:Retrospective Studies; D013172:Spores, Fungal
references.citation: Ann N Y Acad Sci. 2007 Sep;1111:245-58
references.pmid: 17363432
references.citation: Methods Enzymol. 2007;422:465-87
references.pmid: 17628155
references.citation: Arch Pathol Lab Med. 1995 Jan;119(1):91-3
references.pmid: 7802564
references.citation: Ann N Y Acad Sci. 2007 Sep;1111:225-35
references.pmid: 17513466
references.citation: Genome Res. 2009 Oct;19(10):1722-31
references.pmid: 19717792
references.citation: J Bacteriol. 1960 Feb;79:308-9
references.pmid: 14418103
references.citation: Arch Pathol Lab Med. 2000 Feb;124(2):310-4
references.pmid: 10656747
references.citation: Hum Pathol. 1982 Dec;13(12):1136-8
references.pmid: 6757101
references.citation: PLoS One. 2012;7(2):e31536
references.pmid: 22363666
references.citation: Microbe Wash DC. 2008 Sep;3(9):416-423
references.pmid: 20628478
references.citation: J Natl Med Assoc. 1998 Jul;90(7):435-6
references.pmid: 9685779
references.citation: Eur J Clin Microbiol Infect Dis. 2008 Sep;27(9):813-20
references.pmid: 18512089
references.citation: Clin Infect Dis. 2000 Feb;30(2):349-53
references.pmid: 10671340
references.citation: J Med Vet Mycol. 1992;30(3):249-55
references.pmid: 1517961
references.citation: Vaccine. 2005 May 20;23(27):3535-44
references.pmid: 15855012
references.citation: Biochem J. 2003 Nov 15;376(Pt 1):1-14
references.pmid: 13678416
references.citation: Diagn Cytopathol. 2012 Feb;40(2):163-7
references.pmid: 21309010
references.citation: J Clin Microbiol. 2004 Mar;42(3):1247-9
references.pmid: 15004084
references.citation: Int J Infect Dis. 1998 Jul-Sep;3(1):32-5
references.pmid: 9831673
references.citation: Infect Immun. 2006 Jan;74(1):504-15
references.pmid: 16369007
references.citation: Eukaryot Cell. 2007 Oct;6(10):1701-14
references.pmid: 17715363
references.citation: Commun Integr Biol. 2012 Mar 1;5(2):156-9
references.pmid: 22808320
references.citation: Science. 2006 Apr 28;312(5773):583-8
references.pmid: 16645097
references.citation: J Clin Microbiol. 1977 Feb;5(2):149-53
references.pmid: 66238
references.citation: Curr Opin Microbiol. 2007 Aug;10(4):314-9
references.pmid: 17719267
references.citation: Ann N Y Acad Sci. 2007 Sep;1111:35-46
references.pmid: 17395734
references.citation: Clin Microbiol Rev. 2004 Oct;17(4):804-39, table of contents
references.pmid: 15489350
references.citation: Chest. 1994 Feb;105(2):412-6
references.pmid: 8306737