Difference between revisions of "Bacteria"

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==Actinomycetes==
==Actinomycetes==
===General===
===General===
*IUD needs to be removed if found on a pap test<ref name=Ref_WMSP446>{{Ref WMSP|446}}</ref> - see ''[[Gynecologic cytopathology#Actinomycetes|gynecologic cytopathology]]''.
*[[IUD]] needs to be removed if found on a pap test<ref name=Ref_WMSP446>{{Ref WMSP|446}}</ref> - see ''[[Gynecologic cytopathology#Actinomycetes|gynecologic cytopathology]]''.
*Gram-positive branching rods.
*[[Gram]]-positive branching rods.
*Common in the tonsils.
*Common in the tonsils.
*Part of the large [[Actinobacteria]] group.<ref name=pmid17804669>{{Cite journal  | last1 = Ventura | first1 = M. | last2 = Canchaya | first2 = C. | last3 = Tauch | first3 = A. | last4 = Chandra | first4 = G. | last5 = Fitzgerald | first5 = GF. | last6 = Chater | first6 = KF. | last7 = van Sinderen | first7 = D. | title = Genomics of Actinobacteria: tracing the evolutionary history of an ancient phylum. | journal = Microbiol Mol Biol Rev | volume = 71 | issue = 3 | pages = 495-548 | month = Sep | year = 2007 | doi = 10.1128/MMBR.00005-07 | PMID = 17804669 | PMC = 2168647}}</ref>
*Part of the large [[Actinobacteria]] group.<ref name=pmid17804669>{{Cite journal  | last1 = Ventura | first1 = M. | last2 = Canchaya | first2 = C. | last3 = Tauch | first3 = A. | last4 = Chandra | first4 = G. | last5 = Fitzgerald | first5 = GF. | last6 = Chater | first6 = KF. | last7 = van Sinderen | first7 = D. | title = Genomics of Actinobacteria: tracing the evolutionary history of an ancient phylum. | journal = Microbiol Mol Biol Rev | volume = 71 | issue = 3 | pages = 495-548 | month = Sep | year = 2007 | doi = 10.1128/MMBR.00005-07 | PMID = 17804669 | PMC = 2168647}}</ref>
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Notes:
Notes:
*''Mycete'' = fungus; these organisms have a fungus-like appearance.
*''Mycete'' = fungus; these organisms have a fungus-like appearance.
** Also called ''pseudomycosis''.


===Gross===
===Gross===
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*Sulfur granule may be seen grossly - yellow.<ref name=medsc>URL: [http://pathmicro.med.sc.edu/mycology/mycology-2.htm http://pathmicro.med.sc.edu/mycology/mycology-2.htm]. Accessed on: 14 September 2011.</ref>
*Sulfur granule may be seen grossly - yellow.<ref name=medsc>URL: [http://pathmicro.med.sc.edu/mycology/mycology-2.htm http://pathmicro.med.sc.edu/mycology/mycology-2.htm]. Accessed on: 14 September 2011.</ref>


Images:
====Images====
*[http://commons.wikimedia.org/wiki/File:Actinomyces_-_high_mag.jpg Actinomyces - high mag. (WC)].
<gallery>
*[http://commons.wikimedia.org/wiki/File:Actinomyces_-_very_high_mag.jpg Actinomyces - very high mag. (WC)].
Image:Actinomyces_-_high_mag.jpg | Actinomyces - high mag. (WC)
Image:Actinomyces_-_very_high_mag.jpg | Actinomyces - very high mag. (WC)
File:Actinomycetes_CNS_HE.jpg | Purulent encephalitis with actinomyces in HE. (WC/jensflorian)
File:Actinomycetes_CNS_grocott.jpg | Purulent encephalitis with actinomyces in Grocott. (WC/jensflorian)
</gallery>
*[http://pathology.class.kmu.edu.tw/ch05/Slide42.htm Actinobacteria (kmu.edu.tw)].
*[http://pathology.class.kmu.edu.tw/ch05/Slide42.htm Actinobacteria (kmu.edu.tw)].


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*PAS +ve.  
*PAS +ve.  
**May be confused with a fungus!
**May be confused with a fungus!
*Grocott +ve.


==Helicobacter pylori==
==Helicobacter pylori==
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==Clostridium difficile==
==Clostridium difficile==
*Commonly ''C. difficile''.
*Commonly ''C. difficile''.
*Classic cause of [[pseudomembranous colitis]].


===General===
===General===
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*May mimic a malignancy.
*May mimic a malignancy.
*Strong association with [[HIV]].
*Strong association with [[HIV]].
*TB has characteristics of Gram positive and Gram negative bacteria.<ref name=pmid12356459>{{Cite journal  | last1 = Fu | first1 = LM. | last2 = Fu-Liu | first2 = CS. | title = Is Mycobacterium tuberculosis a closer relative to Gram-positive or Gram-negative bacterial pathogens? | journal = Tuberculosis (Edinb) | volume = 82 | issue = 2-3 | pages = 85-90 | month =  | year = 2002 | doi =  | PMID = 12356459 }}</ref>
**Gram stain: subtle positive,<ref name=pmid22476652>{{Cite journal  | last1 = Kawakami | first1 = S. | last2 = Kawamura | first2 = Y. | last3 = Nishiyama | first3 = K. | last4 = Hatanaka | first4 = H. | last5 = Fujisaki | first5 = R. | last6 = Ono | first6 = Y. | last7 = Miyazawa | first7 = Y. | last8 = Nishiya | first8 = H. | title = Case of Mycobacterium tuberculosis meningitis: Gram staining as a useful initial diagnostic clue for tuberculous meningitis. | journal = J Infect Chemother | volume = 18 | issue = 6 | pages = 931-6 | month = Dec | year = 2012 | doi = 10.1007/s10156-012-0382-y | PMID = 22476652 }}</ref> often weak positive/little staining.<ref name=pmid21327691>{{Cite journal  | last1 = Atsukawa | first1 = Y. | last2 = Kawakami | first2 = S. | last3 = Asahara | first3 = M. | last4 = Ishigaki | first4 = S. | last5 = Tanaka | first5 = T. | last6 = Ono | first6 = Y. | last7 = Nishiya | first7 = H. | last8 = Fujisaki | first8 = R. | last9 = Koga | first9 = I. | title = The usefulness of changing focus during examination using Gram staining as initial diagnostic clue for infective tuberculosis. | journal = J Infect Chemother | volume = 17 | issue = 4 | pages = 571-4 | month = Aug | year = 2011 | doi = 10.1007/s10156-011-0216-3 | PMID = 21327691 }}</ref>
**Genetically closer to Gram negative microorganism than Gram positive organisms - when the whole genome is considered.<ref name=pmid12143965>{{Cite journal  | last1 = Fu | first1 = LM. | last2 = Fu-Liu | first2 = CS. | title = Genome comparison of Mycobacterium tuberculosis and other bacteria. | journal = OMICS | volume = 6 | issue = 2 | pages = 199-206 | month =  | year = 2002 | doi = 10.1089/153623102760092797 | PMID = 12143965 }}</ref>


====Clinical====
====Clinical====
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Treatment:
Treatment:
*Multiple drugs for a long time (months).
*Multiple drugs for a long time (months).
**Commonly used drugs: isoniazid, rifampin, pyrazinamide, and ethambutol.  
**Commonly used drugs: isoniazid, rifampin, pyrazinamide, and ethambutol.


===Gross===
===Gross===
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*Similar to pyogenic granuloma - ''see [[pyogenic granuloma]]''.
*Similar to pyogenic granuloma - ''see [[pyogenic granuloma]]''.


Features - ''cat-scratch disease'':
Features - ''[[cat-scratch disease]]'':
*Stellate granulomas.
*Stellate granulomas.


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Image:
Image:
*[http://commons.wikimedia.org/wiki/File:Blood_culture_negative_endocarditis.jpg Bartonella henselae (WC)].
*[http://commons.wikimedia.org/wiki/File:Blood_culture_negative_endocarditis.jpg Bartonella henselae (WC)].
==Lactobacillus==
===General===
*Gram positive bacilli.
*Normal vaginal flora.
===Microscopic===
Features:
*Slender bacilli.
<gallery>
Image:Lactobacillus_sp_01.png | Lactobacilli. (WC)
</gallery>
==Pseudomonas==
===General===
*Gram-negative bacteria.
*Common pathogenic ''Pseudomonas aeruginosa''.
*Community-acquired [[bronchopneumonia]].
**May be seen under nail - causes green nails.<ref name=pmid23064921>{{Cite journal  | last1 = Barankin | first1 = B. | last2 = Levy | first2 = J. | title = Dermacase. Can you identify this condition? Pseudomonas aeruginosa infection. | journal = Can Fam Physician | volume = 58 | issue = 10 | pages = 1103-4 | month = Oct | year = 2012 | doi =  | PMID = 23064921 }}</ref><ref>{{Cite journal  | last1 = Hengge | first1 = UR. | last2 = Bardeli | first2 = V. | title = Images in clinical medicine. Green nails. | journal = N Engl J Med | volume = 360 | issue = 11 | pages = 1125 | month = Mar | year = 2009 | doi = 10.1056/NEJMicm0706497 | PMID = 19279344 }}</ref>
===Gross===
*Green [[nail]].
Images:
*[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3470509/figure/f1-0581103/ Green nail (nih.gov)].<ref name=pmid23064921/>
==Sarcina==
{{Main|Sarcina}}


==See also==
==See also==

Revision as of 09:20, 7 March 2016

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

Notes:

  • Mycete = fungus; these organisms have a fungus-like appearance.
    • Also called pseudomycosis.

Gross

  • Yellow granules.[3]

Microscopic

Features:[4][3]

  • 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!
  • Grocott +ve.

Helicobacter pylori

  • Commonly abbreviated H. pylori or HP.

General

Microscopy

See Helicobacter gastritis.

Clostridium difficile

General

  • Gram positive bacillus.

One virulent strain is:[6][7] BI/NAP1.

  • Deletion of tcdC locus.
  • Resistant to fluoroquinolones (gatifloxacin and moxifloxacin).

Chlamydia trachomatis

  • May be referred to as Chlamydia.

General

Note:

  • Often co-exists with gonorrhea.

Microscopic

  • Variable.

Lymphogranuloma venereum:

Mycobacterium tuberculosis

  • Abbreviated TB.

General

  • Causes tuberculosis.
  • May mimic a malignancy.
  • Strong association with HIV.
  • TB has characteristics of Gram positive and Gram negative bacteria.[8]
    • Gram stain: subtle positive,[9] often weak positive/little staining.[10]
    • Genetically closer to Gram negative microorganism than Gram positive organisms - when the whole genome is considered.[11]

Clinical

Classic features - pulmonary/systemic:

  • Cough.
  • Fever.
  • Weight loss.

CNS manifestations:

  • Tuberculoma (mass).
  • Meningitis.
  • Abscess.

Tests:

  • PPD test, AKA Mantoux test, AKA TB skin test.

Treatment:

  • Multiple drugs for a long time (months).
    • Commonly used drugs: isoniazid, rifampin, pyrazinamide, and ethambutol.

Gross

Ghon complex

Consists of two components:[12][13]

  1. Peripheral focus - subpleural, calcified.
  2. Central focus - the hilar lymph node that drains the peripheral focus.

Image:

Microscopic

Features:

Note:

  • May be non-necrotizing.

DDx:

Images:

Stains

  • Ziehl-Neelsen stain - red rod-shaped bacteria - key feature.
    • Very small - must use 40x objective.

Image:

Molecular

  • Can be diagnosed with PCR.

Mycobacterium leprae

General

  • Causes leprosy.

Clinical:

  • Nerve damage -> injuries -> disability.

Microscopic

Features:

Stains

  • Fite stain - red rod-shaped bacteria - key feature.
    • Very small - must use 40x objective.

Images:

Mycobacterium avium complex

  • Abbreviated MAC.
  • Previously referred to as Mycobacterium avium-intracellulare, abbreviated MAI.

General

  • Refers to an infection with both:[16]
    • Mycobacterium avium
    • Mycobacterium intracellulare.

Microscopic

Features:

  • Small rod-shaped organisms - within histocytes.
  • +/-Granulomas.

DDx:

Stains

  • AFB +ve.

Coxiella burnetii

General

  • Causes: Q fever.

Features:

  • Intracellular bacterium.
  • Gram negative.

Clinical:

  • Flu-like symptoms.

Microscopic

Features:

  • Fibrin ring granuloma.
    • Epithelioid macrophages (i.e. a granuloma) surrounding a thin pink (fibrin) ring.

DDx:[17]

  • Infections (Coxiella burnetii, CMV, EBV + others).
  • Drug reaction.
  • Malignancy (e.g. Hodgkin lymphoma[18]).

Images:

Bartonella henselae

General

Causative agent in:

Microscopic

Features - bacillary angiomatosis:

Features - cat-scratch disease:

  • Stellate granulomas.

Stains

Image:

Lactobacillus

General

  • Gram positive bacilli.
  • Normal vaginal flora.

Microscopic

Features:

  • Slender bacilli.

Pseudomonas

General

  • Gram-negative bacteria.
  • Common pathogenic Pseudomonas aeruginosa.
  • Community-acquired bronchopneumonia.
    • May be seen under nail - causes green nails.[19][20]

Gross

Images:

Sarcina

See also

References

  1. 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/.
  2. 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. 3.0 3.1 3.2 URL: http://pathmicro.med.sc.edu/mycology/mycology-2.htm. Accessed on: 14 September 2011.
  4. URL: http://pathology.class.kmu.edu.tw/ch05/Slide42.htm . Accessed on: 14 September 2011.
  5. Mobley, HLT.; Mendz, GL.; Hazell, SL.; Andersen, LP.; Wadström, T.. Basic Bacteriology and Culture. PMID 21290743. http://www.ncbi.nlm.nih.gov/books/NBK2444/.
  6. URL: http://www.medpagetoday.com/InfectiousDisease/PublicHealth/2254. Accessed on: 15 August 2011.
  7. 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.
  8. Fu, LM.; Fu-Liu, CS. (2002). "Is Mycobacterium tuberculosis a closer relative to Gram-positive or Gram-negative bacterial pathogens?". Tuberculosis (Edinb) 82 (2-3): 85-90. PMID 12356459.
  9. Kawakami, S.; Kawamura, Y.; Nishiyama, K.; Hatanaka, H.; Fujisaki, R.; Ono, Y.; Miyazawa, Y.; Nishiya, H. (Dec 2012). "Case of Mycobacterium tuberculosis meningitis: Gram staining as a useful initial diagnostic clue for tuberculous meningitis.". J Infect Chemother 18 (6): 931-6. doi:10.1007/s10156-012-0382-y. PMID 22476652.
  10. Atsukawa, Y.; Kawakami, S.; Asahara, M.; Ishigaki, S.; Tanaka, T.; Ono, Y.; Nishiya, H.; Fujisaki, R. et al. (Aug 2011). "The usefulness of changing focus during examination using Gram staining as initial diagnostic clue for infective tuberculosis.". J Infect Chemother 17 (4): 571-4. doi:10.1007/s10156-011-0216-3. PMID 21327691.
  11. Fu, LM.; Fu-Liu, CS. (2002). "Genome comparison of Mycobacterium tuberculosis and other bacteria.". OMICS 6 (2): 199-206. doi:10.1089/153623102760092797. PMID 12143965.
  12. Rose, Alan G. (2008). Atlas of Gross Pathology with Histologic Correlation (1st ed.). Cambridge University Press. pp. 112. ISBN 978-0521868792.
  13. URL: http://pathhsw5m54.ucsf.edu/case32/image324.html. Accessed on: 27 February 2012.
  14. URL: http://www.medscape.com/viewarticle/576467_2. Accessed on: 2 January 2012.
  15. URL: http://www.meddean.luc.edu/lumen/MedEd/orfpath/bfsrinf.htm. Accessed on: 1 April 2012.
  16. Turenne, CY.; Wallace, R.; Behr, MA. (Apr 2007). "Mycobacterium avium in the postgenomic era.". Clin Microbiol Rev 20 (2): 205-29. doi:10.1128/CMR.00036-06. PMC 1865596. PMID 17428883. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1865596/.
  17. Tjwa M, De Hertogh G, Neuville B, Roskams T, Nevens F, Van Steenbergen W (2001). "Hepatic fibrin-ring granulomas in granulomatous hepatitis: report of four cases and review of the literature". Acta Clin Belg 56 (6): 341–8. PMID 11881318.
  18. de Bayser L, Roblot P, Ramassamy A, Silvain C, Levillain P, Becq-Giraudon B (July 1993). "Hepatic fibrin-ring granulomas in giant cell arteritis". Gastroenterology 105 (1): 272–3. PMID 8514044.
  19. 19.0 19.1 Barankin, B.; Levy, J. (Oct 2012). "Dermacase. Can you identify this condition? Pseudomonas aeruginosa infection.". Can Fam Physician 58 (10): 1103-4. PMID 23064921.
  20. Hengge, UR.; Bardeli, V. (Mar 2009). "Images in clinical medicine. Green nails.". N Engl J Med 360 (11): 1125. doi:10.1056/NEJMicm0706497. PMID 19279344.