Difference between revisions of "Bacteria"
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(→Mycobacterium tuberculosis: +Leprosy) |
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===Microscopic=== | ===Microscopic=== | ||
Features: | Features: | ||
*Necrotizing [[granuloma]]s | *Necrotizing [[granuloma]]s with rod-shaped bacteria. | ||
Note: | Note: | ||
| Line 98: | Line 97: | ||
Image: | Image: | ||
*[http://commons.wikimedia.org/wiki/File:Mycobacterium_tuberculosis_Ziehl-Neelsen_stain_640.jpg Tuberculosis (CDC/WC)]. | *[http://commons.wikimedia.org/wiki/File:Mycobacterium_tuberculosis_Ziehl-Neelsen_stain_640.jpg Tuberculosis (CDC/WC)]. | ||
==Mycobacterium leprae== | |||
===General=== | |||
*Causes ''leprosy''. | |||
===Microscopic=== | |||
Features: | |||
*[[Granuloma]]s with rod-shaped bacteria. | |||
===Stains=== | |||
*[[Fite stain]] - red rod-shaped bacteria - '''key feature'''. | |||
**Very small - must use 40x objective. | |||
Image: | |||
*[http://img.medscape.com/fullsize/migrated/576/467/smj576467.fig2.gif Leprosy (medscape.com)].<ref>URL: [http://www.medscape.com/viewarticle/576467_2 http://www.medscape.com/viewarticle/576467_2]. Accessed on: 2 January 2012.</ref> | |||
==See also== | ==See also== | ||
Revision as of 01:35, 3 January 2012
Bacteria are single celled microorganisms, without a nucleus (prokaryotes), that can cause lots of morbidity and mortality. They are not infrequently seen by pathologists.
Actinobacteria
General
- A very large group of bacteria.
It includes:[1]
- Actinomycetes.
- Corynebacterium.
- Mycobacterium.
- Nocardia.
- Streptomyces.
Actinomycetes
General
- IUD needs to be removed if found on a pap test[2] - see gynecologic cytopathology.
- Gram-positive branching rods.
- Common in the tonsils.
- Part of the large Actinobacteria group.[1]
Notes:
- Mycete = fungus; these organisms have a fungus-like appearance.
Gross
- Yellow granules.[3]
Microscopic
- Branching rods.
- Typically form pink/purple granules ("sulfur granule") that is surrounded by inflammatory cells (lymphocytes or neutrophils).
DDx:
- Nocardia.
Notes:
- Sulfur granule may be seen grossly - yellow.[3]
Images:
Stains
- Gram +ve.
- AFB -ve.
- Nocardia +ve.
- PAS +ve.
- May be confused with a fungus!
Helicobacter pylori
- See Stomach.
Clostridium difficile
- Commonly C. difficile.
General
- Gram positive bacillus.
One virulent strain is:[5][6] BI/NAP1.
- Deletion of tcdC locus.
- Resistant to fluoroquinolones (gatifloxacin and moxifloxacin).
Chlamydia trachomatis
General
- Common.
- May cause lymphogranuloma venereum.
Note:
- Often co-exists with gonorrhea.
Microscopic
- Variable.
Lymphogranuloma venereum:
- See: Cat-scratch disease.
Mycobacterium tuberculosis
General
- Causes tuberculosis, abbreviated TB.
- May mimic a malignancy.
- Strong association with HIV.
Clinical features:
- Cough.
- Fever.
- Weight loss.
Microscopic
Features:
- Necrotizing granulomas with rod-shaped bacteria.
Note:
- May be non-necrotizing.
Stains
- Ziehl-Neelsen stain - red rod-shaped bacteria - key feature.
- Very small - must use 40x objective.
Image:
Mycobacterium leprae
General
- Causes leprosy.
Microscopic
Features:
- Granulomas with rod-shaped bacteria.
Stains
- Fite stain - red rod-shaped bacteria - key feature.
- Very small - must use 40x objective.
Image:
See also
References
- ↑ 1.0 1.1 Ventura, M.; Canchaya, C.; Tauch, A.; Chandra, G.; Fitzgerald, GF.; Chater, KF.; van Sinderen, D. (Sep 2007). "Genomics of Actinobacteria: tracing the evolutionary history of an ancient phylum.". Microbiol Mol Biol Rev 71 (3): 495-548. doi:10.1128/MMBR.00005-07. PMC 2168647. PMID 17804669. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2168647/.
- ↑ Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 446. ISBN 978-0781765275.
- ↑ 3.0 3.1 3.2 URL: http://pathmicro.med.sc.edu/mycology/mycology-2.htm. Accessed on: 14 September 2011.
- ↑ URL: http://pathology.class.kmu.edu.tw/ch05/Slide42.htm . Accessed on: 14 September 2011.
- ↑ URL: http://www.medpagetoday.com/InfectiousDisease/PublicHealth/2254. Accessed on: 15 August 2011.
- ↑ McDonald, LC.; Killgore, GE.; Thompson, A.; Owens, RC.; Kazakova, SV.; Sambol, SP.; Johnson, S.; Gerding, DN. (Dec 2005). "An epidemic, toxin gene-variant strain of Clostridium difficile.". N Engl J Med 353 (23): 2433-41. doi:10.1056/NEJMoa051590. PMID 16322603.
- ↑ URL: http://www.medscape.com/viewarticle/576467_2. Accessed on: 2 January 2012.