Difference between revisions of "Microorganisms"
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'''Microorganisms''' show-up every once in a while. It is essential to know 'em. | '''Microorganisms''' show-up every once in a while. It is essential to know 'em. | ||
== | =Microorganisms= | ||
==Fungi== | |||
{| class="wikitable" | {| class="wikitable" | ||
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*'''Bold''' text = key features. | *'''Bold''' text = key features. | ||
=Fungi= | |||
{{Main|Fungi}} | {{Main|Fungi}} | ||
*There are lots of 'em. Below are a few of 'em. | *There are lots of 'em. Below are a few of 'em. | ||
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*[[Mucormycosis]]. | *[[Mucormycosis]]. | ||
=Worms & stuff= | |||
==Schistosoma== | ==Schistosoma== | ||
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*May cause [[epilepsy]]; most common parasitic CNS infection.<ref name=pmid19208982>{{cite journal |author=Prasad KN, Prasad A, Verma A, Singh AK |title=Human cysticercosis and Indian scenario: a review |journal=J. Biosci. |volume=33 |issue=4 |pages=571–82 |year=2008 |month=November |pmid=19208982 |doi= |url=}}</ref> | *May cause [[epilepsy]]; most common parasitic CNS infection.<ref name=pmid19208982>{{cite journal |author=Prasad KN, Prasad A, Verma A, Singh AK |title=Human cysticercosis and Indian scenario: a review |journal=J. Biosci. |volume=33 |issue=4 |pages=571–82 |year=2008 |month=November |pmid=19208982 |doi= |url=}}</ref> | ||
=Viruses= | |||
{{Main|Viruses}} | {{Main|Viruses}} | ||
This is a fairly big topic. There are about half a dozen viral inclusions (e.g. [[CMV]], [[HSV]], [[VZV]], [[adenovirus]]) a decent pathologist ought to be able to identify. The ''virus'' article covers 'em. | This is a fairly big topic. There are about half a dozen viral inclusions (e.g. [[CMV]], [[HSV]], [[VZV]], [[adenovirus]]) a decent pathologist ought to be able to identify. The ''virus'' article covers 'em. | ||
=Bacteria= | |||
{{Main|Bacteria}} | {{Main|Bacteria}} | ||
This is a small topic when considered from the perspective of an anatomical pathologist. Most stuff is sorted-out by microbiology. | This is a small topic when considered from the perspective of an anatomical pathologist. Most stuff is sorted-out by microbiology. | ||
=See also= | |||
*[[Staining]]. | *[[Staining]]. | ||
*[[Immunohistochemistry]]. | *[[Immunohistochemistry]]. | ||
*[[Viruses]]. | *[[Viruses]]. | ||
=References= | |||
{{reflist|2}} | {{reflist|2}} | ||
Revision as of 04:31, 15 November 2011
Microorganisms show-up every once in a while. It is essential to know 'em.
Microorganisms
Fungi
| 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 | [1] | Mucormycosis (homestead.com), Zygomycosis (WC) |
| Coccidioides, usually C. immitis (coccidioidomycosis) |
Fungi | Large - 20-60 micrometers, endospores 1-5 micrometers |
Spherules | Stains? | Other? | Immunodeficient | [1] | Coccidioidomycosis (med.sc.edu) C. immitis (WC) (webpathology.com) |
| Histoplasma (histoplasmosis) | Fungi | 2-5 micrometers | Spherical | GMS | Intracellular (unlike candida), granulomata | Source: soil with bird droppings | [1] | Histoplasmosis (WC) |
| Blastomyces (Blastomycosis) | Fungi | 5-15 micrometres | Spherical (yeast) | Stains? | Granulomas, broad-based budding yeast | Habitat: Northeast America, Africa | [1][2] | Blastomyces |
| Paracoccidioides (Paracoccidioidomycosis) | Fungi | 6-60 micrometres | Spherical (yeast) | Stains? | Multiple budding "steering wheel" appearance | Clinical??? | [1] | 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 | [3] | PCP (WC) |
| Cryptococcosis | Fungi | 5-15 micrometres | Yeast | GMS | Prominent (i.e. thick polysaccharide) capsule | HIV/AIDS associated, most common CNS fungus | [1] | Crytococcosis - methenamine silver (WC), Crytococcosis - mucicarmine (WC). |
Notes:
- Bold text = key features.
Fungi
Main article: Fungi
- There are lots of 'em. Below are a few of 'em.
Terminology:[4]
- 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.[5]
Tissue invasive fungi
Typically:[6]
- Mucor.
- Aspergillus.
List
- Histoplasmosis.
- Coccidioidmycosis.
- Pneumocystis pneumonia.
- Cryptococcus.
- Cryptosporidiosis.
- Candidiasis.
- Blastomycosis.
- Mucormycosis.
Worms & stuff
Schistosoma
- See Urine cytopathology.
- Associated with squamous cell carcinoma of the bladder.
Microscopic
Features of ova:
- Elliptical ~80 micrometres max dimension.
- S. haematobium has a "spike" approx. the size of a PMN.
Image:
Toxoplasma
General
- Common CNS infection.
- Toxoplasma gondii - pathogenic; causes toxoplasmosis.
- Protozoa.
Microscopic
General:
- Dependent on location in body.
Lymph node
LN features:[7]
- Reactive germinal centers (pale areas - larger than usual).
- Often poorly demarcated - due to loose epithelioid cell clusters at germinal center edge - key feature.
- Epithelioid cells - perifollicular & intrafollicular.
- Loose aggregates of histiocytes (do not form round granulomas):
- Abundant pale cytoplasm.
- Nucleoli.
- Loose aggregates of histiocytes (do not form round granulomas):
- Monocytoid cells (monocyte-like cells) - in cortex & paracortex.
- Large cells in islands/sheets key feature with:
- Abundant pale cytoplasm - important.
- Well-defined cell border - important.
- Singular nucleus.
- Cell clusters usually have interspersed neutrophils.
- Large cells in islands/sheets key feature with:
Images (lymph node):
CNS
CNS features:[8]
- Granular appearing ball ~ 2x the size of resting lymphocyte.
Images (CNS):
- CNS toxoplasmosis - very high mag. (WC).
- CNS toxoplasmosis - IHC - very high mag. (WC).
- CNS toxoplasmosis (ouhsc.edu).
- CNS toxoplasmosis (ouhsc.edu).
IHC
- IHC for toxoplasma.[9]
Strongyloidiasis
General
- Causes by worm Strongyloides stercoralis.
- High case mortality rate ~ 70%.[10]
- May present after years of latency due to immune suppression.[11]
Location:
- Lung. (???)
Microscopic
Features:
- Long worms.
- ~10-15 micrometers wide.
Images:
Echinococcus
- Several species - most common: Echinococcus granulosus.
- Causes hydatid disease in the liver.
Microscopic
Features:
- Laminated wall +/- calcification.[12]
- Organisms:
- Hooklets.
- Scoleces - knoblike anterior end of a tapeworm.[13]
Enterobius vermicularis
- AKA pinworm.
Features:[14]
- Ovoid eggs - double walled shells, one side flat.
Images:
Trichinella
General
- Causes Trichinosis.
- Classically associated with uncooked pork.[15]
- Several types; most due to T. spiralis.[15]
Microscopic
Features:
- Worm.
Image:
Cysticercosis
General
- Caused by Taenia solium; pork tapeworm.
- May cause epilepsy; most common parasitic CNS infection.[17]
Viruses
Main article: Viruses
This is a fairly big topic. There are about half a dozen viral inclusions (e.g. CMV, HSV, VZV, adenovirus) a decent pathologist ought to be able to identify. The virus article covers 'em.
Bacteria
Main article: Bacteria
This is a small topic when considered from the perspective of an anatomical pathologist. Most stuff is sorted-out by microbiology.
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Lefkowitch, Jay H. (2006). Anatomic Pathology Board Review (1st ed.). Saunders. pp. 682. ISBN 978-1416025887.
- ↑ http://pathmicro.med.sc.edu/mycology/mycology-6.htm
- ↑ Lefkowitch, Jay H. (2006). Anatomic Pathology Board Review (1st ed.). Saunders. pp. 684. ISBN 978-1416025887.
- ↑ http://www.fungionline.org.uk/1intro/3growth_forms.html
- ↑ http://pathmicro.med.sc.edu/mycology/mycology-3.htm
- ↑ CM 17 Apr 2009.
- ↑ Ioachim, Harry L; Medeiros, L. Jeffrey (2008). Ioachim's Lymph Node Pathology (4th ed.). Lippincott Williams & Wilkins. pp. 113. ISBN 978-0781775960.
- ↑ URL: http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/N0I001-PQ01-M.htm. Accessed on: 19 October 2010.
- ↑ URL: http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/N0I001-PQ01-M.htm. Accessed on: 19 October 2010.
- ↑ Lim, S.; Katz, K.; Krajden, S.; Fuksa, M.; Keystone, JS.; Kain, KC. (Aug 2004). "Complicated and fatal Strongyloides infection in Canadians: risk factors, diagnosis and management.". CMAJ 171 (5): 479-84. doi:10.1503/cmaj.1031698. PMID 15337730.
- ↑ Siddiqui, AA.; Berk, SL. (Oct 2001). "Diagnosis of Strongyloides stercoralis infection.". Clin Infect Dis 33 (7): 1040-7. doi:10.1086/322707. PMID 11528578.
- ↑ Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 448. ISBN 978-1416054542.
- ↑ http://www.thefreedictionary.com/scoleces. Accessed on: 10 January 2010.
- ↑ Lefkowitch, Jay H. (2006). Anatomic Pathology Board Review (1st ed.). Saunders. pp. 685. ISBN 978-1416025887.
- ↑ 15.0 15.1 Kaewpitoon N, Kaewpitoon SJ, Philasri C, et al. (October 2006). "Trichinosis: epidemiology in Thailand". World J. Gastroenterol. 12 (40): 6440–5. PMID 17072975. http://www.wjgnet.com/1007-9327/12/6440.asp.
- ↑ URL: http://library.med.utah.edu/WebPath/EXAM/IMGQUIZ/msfrm.html. Accessed on: 5 December 2010.
- ↑ Prasad KN, Prasad A, Verma A, Singh AK (November 2008). "Human cysticercosis and Indian scenario: a review". J. Biosci. 33 (4): 571–82. PMID 19208982.