| Histoplasma | |
|---|---|
) | |
| Histoplasma (bright red, small, circular). PAS diastase stain | |
| Scientific classification | |
| Kingdom: | |
| Division: | |
| Class: | |
| Order: | |
| Family: | Ajellomycetaceae |
| Genus: | Histoplasma Darling (1906) |
| Type species | |
| Histoplasma capsulatum Darling (1906) | |
| Species | |
| Histoplasma capsulatum | |
Histoplasma is a genus of dimorphic fungi commonly found in bird and bat fecal material.[1] Histoplasma contains a few species, including—Histoplasma capsulatum—the causative agent of histoplasmosis;[2] and Histoplasma capsulatum var. farciminosum (old term, Histoplasma farciminosum), causing epizootic lymphangitis in horses.[3]
This fungus is mainly found in the Ohio and Mississippi River Valleys in the United States as well as Central/South America, Africa, Asia and Australia.[4]
Forms / Stages
Histoplasma capsulatum has two forms: its environmental form is hyphae with microconidia and tuberculate macroconidia while its tissue form is a small intracellular yeast with a narrow neck and no bud with no capsule[5] and can be detected in aerobic blood culture bottle.[6] In the saprophytic stage, it bears features of both microconidia and macroconidia. Infection occurs through inhalation of the small microconidia or small mycelia fragments. The dimorphic mold-yeast transforms and enters host macrophages and proliferates within them most often seen in immunodeficient individuals.[7]
References
- ^ Giannella RA (1996). Salmonella. In: Baron's Medical Microbiology (Baron S et al, eds.) (4th ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
- ^ Ryan KJ; Ray CG, eds. (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. ISBN 0-8385-8529-9.
- ^ OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals 2004 Chapter 2.5.13, "Archived copy". Archived from the original on 2007-08-04. Retrieved 2007-06-14.
- ^ "Histoplasmosis". Centers for Disease Control and Prevention. 28 October 2020. Retrieved 27 January 2021.
- ^ Hutton, JP (April 1985). "Hyphal forms of Histoplasma capsulatum. A common manifestation of intravascular infections". Archives of Pathology and Laboratory Medicine. 109: 330–332 – via Pubmed.
- ^ Salimnia, Hossein (August 2021). "Hyphal and yeast forms of Histoplasma capsulatum growing within 5 days in an automated bacterial blood culture system". Journal of Clinical Microbiology. 50: 2833–2834 – via Pubmed.
- ^ Lopez, CE (Oct 2006). "Dimorphism and Pathogenesis of Histoplasma capsulatum". Revista Argentina de Microbiologia. 38: 235–242 – via Pubmed.
External links
- Histoplasma information from doctorfungus.org