Difference between revisions of "Microorganisms"
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==Histoplasmosis== | ==Histoplasmosis== | ||
*''Histoplasma capulatum'' - primative fungus, typical location: lung. | *''Histoplasma capulatum'' - primative fungus, typical location: lung. | ||
** Often in yeast form in tissue 2-5 micrometres.<ref>WMSP | ** Often in yeast form in tissue 2-5 micrometres.<ref name=Ref_WMSP103>{{Ref WMSP|103}}</ref> | ||
** Nice bright red on PAS-D - [http://en.wikipedia.org/wiki/File:Histoplasma_pas-d.jpg histoplasmosis (wikipedia.org)]. | ** Nice bright red on PAS-D - [http://en.wikipedia.org/wiki/File:Histoplasma_pas-d.jpg histoplasmosis (wikipedia.org)]. | ||
==Coccidiomycosis== | ==Coccidiomycosis== | ||
*''Coccidioides immitis'' - fungus, from soil, typical locations: lung, oral cavity.<ref>WMSP | *''Coccidioides immitis'' - fungus, from soil, typical locations: lung, oral cavity.<ref name=Ref_WMSP3>{{Ref WMSP|3}}</ref> | ||
** Forms spherules 60-80 micrometres in size.<ref>WMSP | ** Forms spherules 60-80 micrometres in size.<ref name=Ref_WMSP103>{{Ref WMSP|103}}</ref> | ||
** [http://commons.wikimedia.org/wiki/File:Mature_spherule_with_endospores_of_Coccidioides_immitis_PHIL_480_lores.jpg Coccidioides (commons.wikimedia.org)]. | ** [http://commons.wikimedia.org/wiki/File:Mature_spherule_with_endospores_of_Coccidioides_immitis_PHIL_480_lores.jpg Coccidioides (commons.wikimedia.org)]. | ||
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*''Pneumocystis jirovecii'' (used to be called ''Pneumocystis carinii'') - fungus (that used to be considered a parasite), typical location: lung. | *''Pneumocystis jirovecii'' (used to be called ''Pneumocystis carinii'') - fungus (that used to be considered a parasite), typical location: lung. | ||
**Clinical: Opportunistic infection. May have subtle finding on chest x-ray. | **Clinical: Opportunistic infection. May have subtle finding on chest x-ray. | ||
**"Dented ping-pong ball" appearance;<ref>WMSP | **"Dented ping-pong ball" appearance;<ref name=Ref_WMSP103>{{Ref WMSP|103}}</ref> - remember '''P'''C'''P''' = '''p'''ing-'''p'''ong. | ||
**Approximately 7-8 micrometres in size - [http://commons.wikimedia.org/wiki/File:Pneumocystosis_carinii_of_lung_in_AIDS_959_lores.jpg PCP (WP)]. [http://commons.wikimedia.org/w/index.php?title=Special%3ASearch&search=Pneumocystis+carinii&go=Go Several images are here (WC)]. | **Approximately 7-8 micrometres in size - [http://commons.wikimedia.org/wiki/File:Pneumocystosis_carinii_of_lung_in_AIDS_959_lores.jpg PCP (WP)]. [http://commons.wikimedia.org/w/index.php?title=Special%3ASearch&search=Pneumocystis+carinii&go=Go Several images are here (WC)]. | ||
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*Commonly ''Candida albicans'' - yeast (fungus), locations: oral cavity, vagina. | *Commonly ''Candida albicans'' - yeast (fungus), locations: oral cavity, vagina. | ||
*''Dimorphic'' - seen in two forms: | *''Dimorphic'' - seen in two forms: | ||
**Pseudohyphae<ref>WMSP | **Pseudohyphae<ref name=Ref_WMSP3>{{Ref WMSP|3}}</ref> - collections of many ''C. albicans'' cells in a branching pattern. | ||
**Yeast form - single cells, 10 to 12 micrometres in diameter, gram positive.<ref>[http://pathmicro.med.sc.edu/mycology/mycology-3.htm http://pathmicro.med.sc.edu/mycology/mycology-3.htm]</ref> | **Yeast form - single cells, 10 to 12 micrometres in diameter, gram positive.<ref>[http://pathmicro.med.sc.edu/mycology/mycology-3.htm http://pathmicro.med.sc.edu/mycology/mycology-3.htm]</ref> | ||
*Stains: PAS, methenamine silver. | *Stains: PAS, methenamine silver. | ||
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==Blastomycosis== | ==Blastomycosis== | ||
*Usually ''Blastomyces dermatitidis'' - fungus. | *Usually ''Blastomyces dermatitidis'' - fungus. | ||
*May be in the oral cavity.<ref>WMSP | *May be in the oral cavity.<ref name=Ref_WMSP3>{{Ref WMSP|3}}</ref> | ||
*Histology = '''B'''road-based budding yeast -- is '''B'''lastomyces.<ref name=pmid12375640>PMID 12375640</ref> | *Histology = '''B'''road-based budding yeast -- is '''B'''lastomyces.<ref name=pmid12375640>PMID 12375640</ref> | ||
**The interface between two separating fungi, i.e. fungi in the process of reproducing, is very large. | **The interface between two separating fungi, i.e. fungi in the process of reproducing, is very large. | ||
Revision as of 21:20, 8 July 2010
Microorganisms show-up every once in a while. It is essential to know 'em.
Microorganisms
| Name (disease) | Kingdom | Size | Shape | Stains | Other (microscopic) | Clinical | References | Image |
|---|---|---|---|---|---|---|---|---|
| Aspergillus (aspergillosis) | Fungi | ? | Hyphae that branching with 45 degrees angle |
PAS-D | Fruiting heads when aerobic | ? Immunosuppression | [1] | Aspergillus (WC), Aspergillus cytology (WC) |
| Zygomycota (zygomycosis); more specific Mucorales (mucormycosis) |
Fungi | ? | Branching hyphae with variable width | ? | Granulomata assoc. | Diabetes, immunodeficient | [2] | Mucormycosis (homestead.com), Zygomycosis (WC) |
| Coccidioides, usually C. immitis (coccidioidomycosis) |
Fungi | Large - 20-60 micrometers, endospores 1-5 micrometers |
Spherules | Stains? | Other? | Immunodeficient | [3] | Coccidioidomycosis (med.sc.edu) C. immitis (WC) |
| Histoplasma (histoplasmosis) | Fungi | 2-5 micrometers | Spherical | GMS | Intracellular (unlike candida), granulomata | Source: soil with bird droppings | [4] | Histoplasmosis (WC) |
| Blastomyces (Blastomycosis) | Fungi | 5-15 micrometres | Spherical (yeast) | Stains? | Granulomas, broad-based budding yeast | Habitat: Northeast America, Africa | [5][6] | Blastomyces |
| Paracoccidioides (Paracoccidioidomycosis) | Fungi | 6-60 micrometres | Spherical (yeast) | Stains? | Multiple budding "steering wheel" appearance | Clinical??? | [7] | P. brasiliensis (WC). |
| Pneumocystis jirovecii (Pneumocystis carinii pneumonia; abbrev. PCP) | Fungi (previously thought to be a protozoan) | 7-8 micrometres | "Dented ping-pong ball" | GMS | Usually in clusters of alveolar casts with a honeycomb appearance | HIV/AIDS associated | [8] | PCP (WC) |
| Cryptococcosis | Fungi | 5-15 micrometres | Yeast | GMS | Prominent (i.e. thick polysaccharide) capsule | HIV/AIDS associated, most common CNS fungus | [9] | Crytococcosis - methenamine silver (WC), Crytococcosis - mucicarmine (WC). |
Notes:
- Bold text = key features.
Fungi
- There are lots of 'em. Below are a few of 'em.
Terminology:[10]
- Hyphae = microscopic filamentous growth (of fungi) -- single cell.
- Mycelial = filamentous network of hyphae.
- Septae/septation = hyphae may be subdivided by septae -- if they aren't they are one mass of protoplasm. (?)
- Dimorphism = exist in two forms; e.g. single cell (yeast) and mycelial growth.
- Pseudohyphae = looks like hyphae --but branching pattern is created by separate cells.[11]
Tissue invasive fungi
Typically:[12]
- Mucor
- Aspergillus
Histoplasmosis
- Histoplasma capulatum - primative fungus, typical location: lung.
- Often in yeast form in tissue 2-5 micrometres.[13]
- Nice bright red on PAS-D - histoplasmosis (wikipedia.org).
Coccidiomycosis
- Coccidioides immitis - fungus, from soil, typical locations: lung, oral cavity.[14]
- Forms spherules 60-80 micrometres in size.[13]
- Coccidioides (commons.wikimedia.org).
Pneumocystis pneumonia (PCP)
- Pneumocystis jirovecii (used to be called Pneumocystis carinii) - fungus (that used to be considered a parasite), typical location: lung.
- Clinical: Opportunistic infection. May have subtle finding on chest x-ray.
- "Dented ping-pong ball" appearance;[13] - remember PCP = ping-pong.
- Approximately 7-8 micrometres in size - PCP (WP). Several images are here (WC).
Cryptococcus
- Usually C. neoformans, fungus - opportunistic infection, typical location: lung.
- Most common fungus seen in CSF specimens.[15]
Appearance:
- Yeast:
Images:
- Micrograph of crytococcosis - mucicarmine stain (WC).
- Micrograph of crytococcosis - methenamine silver stain (WC).
Cryptosporidiosis
- Uniform spherical nodules 2-4 micrometres in diameter, typical location - GI tract brush border.
- Tip-off -- key feature -- bluish staining of brush border
- Images:
Notes:
- Cryptosporidium parvum?[18]
Candidiasis
- Commonly Candida albicans - yeast (fungus), locations: oral cavity, vagina.
- Dimorphic - seen in two forms:
- Stains: PAS, methenamine silver.
- Images:
Blastomycosis
- Usually Blastomyces dermatitidis - fungus.
- May be in the oral cavity.[14]
- Histology = Broad-based budding yeast -- is Blastomyces.[20]
- The interface between two separating fungi, i.e. fungi in the process of reproducing, is very large.
- Images:
Mucormycosis
General
- Causative organism: Mucorales.
- Kingdom: Fungi.
- AKA Zygomycota (zygomycosis).
- Assoc. with diabetes, immunodeficiency.
Histology
Features:[21]
- Branching hyphae variable width.
- Granulomata associated.
Image:
Worms
Strongyloides
- Lung?
Features:
- Long worms.
- ~10-15 micrometers wide.
Echinococcus
- Echinococcus granulosus.
- Causes hydatid disease in the liver.
Features:
- Hooklets.
- Scoleces - knoblike anterior end of a tapeworm.[22]
Enterobius vermicularis
- AKA pinworm.
Features:[23]
- Ovoid eggs - double walled shells, one side flat.
Viruses
Many virus afflicit humans. Only a few of them can be diagnosed histologically.
Viral inclusions
Cowdry types:[24]
- Cowdry type A inclusion:[25]
- Round eosinophilic material surrounded by a clear halo.
- Cowdry type B inclusion:[26]
- Neuropathology thingy. (???)
Images:
Herpes simplex virus (HSV)
- Canker sores - usually HSV-1.
- Genital herpes - usually HSV-2.
Histology/cytology
Features:[27]
- Clear "ground glass" nuclei.
- Rim of peripheral chromatin.
- Nuclear inclusions.
- Multinucleation with nuclear molding, i.e. multiple nuclei that touch over a large surface area.
Image:
Cytomegalovirus (CMV)
Features:
- Very large nucleus (as the name implies) with clearing.
- Granular cytoplasmic inclusions (red on H&E sections).
Images:
Adenovirus
Features:
- "Smudge" cells[28] - black/blue blob ~ 15 micrometers. (???)
- Affects endothelial cells. (???)
Images:
Parvo B19
Features:
- Big red nuclear inclusion.[30]
See also
References
- ↑ APBR P.682.
- ↑ APBR P.682.
- ↑ APBR P.682.
- ↑ APBR P.682.
- ↑ APBR P.682.
- ↑ http://pathmicro.med.sc.edu/mycology/mycology-6.htm
- ↑ APBR P.682.
- ↑ APBR P.684.
- ↑ APBR P.682.
- ↑ http://www.fungionline.org.uk/1intro/3growth_forms.html
- ↑ http://pathmicro.med.sc.edu/mycology/mycology-3.htm
- ↑ CM 17 Apr 2009.
- ↑ 13.0 13.1 13.2 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 103. ISBN 978-0781765275.
- ↑ 14.0 14.1 14.2 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 3. ISBN 978-0781765275.
- ↑ APBR P.682.
- ↑ APBR P.682.
- ↑ APBR P.682.
- ↑ http://www.dpd.cdc.gov/dpdx/HTML/Cryptosporidiosis.htm
- ↑ http://pathmicro.med.sc.edu/mycology/mycology-3.htm
- ↑ PMID 12375640
- ↑ Lefkowitch, Jay H. (2006). Anatomic Pathology Board Review (1st ed.). Saunders. pp. 682. ISBN 978-1416025887.
- ↑ http://www.thefreedictionary.com/scoleces. Accessed on: 10 January 2010.
- ↑ APBR P.685.
- ↑ URL: http://www.pathconsultddx.com/pathCon/largeImage?pii=S1559-8675%2806%2970864-6&figureId=fig3&ecomponentId=mmc3. Accessed: 12 January 2010.
- ↑ URL: http://www.whonamedit.com/synd.cfm/3495.html. Accessed on: 22 January 2010.
- ↑ http://www.whonamedit.com/synd.cfm/3496.html. Accessed on: 22 January 2010.
- ↑ SM. 11 January 2010.
- ↑ URL: http://www.pathguy.com/lectures/infect.htm. Accessed on: 8 July 2010.
- ↑ URL:http://www.medscape.com/viewarticle/438534_2. Accessed on: 8 July 2010.
- ↑ URL: http://www.pathguy.com/lectures/infect.htm. Accessed on: 8 July 2010.