Difference between revisions of "Systemic Mycoses"

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==Histoplasmosis==
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[[Histoplasmosis]]
{| align="right"
 
|<gallery>Image:Histoplasmosis canine spleen.jpg|<center><p>'''Histoplasmosis in a canine spleen'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center></gallery>
 
|}
 
 
 
*''Histoplasma capsulatum''
 
 
 
*Non-contageous, systemic mycosis
 
 
 
*Commonly pulmonary infections occur
 
**Other organs can be involved
 
**Involves the reticuloendothelial system
 
**Intestinal form can also occur
 
 
 
*Acute and chronic disease can occur
 
 
 
*Endemic to the USA
 
**Isolated cases have been reported in Europe
 
 
 
*Respiratory infection
 
**Infection via ingestion can also occur
 
 
 
*Affects dogs, cats, cattle, horses and humans
 
 
 
*Found in soil contaminated by bird droppings, decaying vegetation and in caves inhabited by bats
 
{| align="right"
 
|<gallery>Image:Histoplasmosis lung.jpg|<center><p>'''Histoplasmosis lesions in lungs'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center></gallery>
 
|}
 
*Fine, branching, septate hyphae with smooth-walled pyriform to spherical microconidia and large, thick-walled tuberculate macroconidia on simple conidiophores
 
 
 
*Dimorphic fungi
 
 
 
*Hard to demonstrate in smears as the organisms is very small
 
**Stain with Giemsa or Wright and examine under oil immersion lens
 
 
 
*Present intracellularly in [[Macrophages - WikiBlood|macrophages]] as oval yeast cells with few buds
 
**Clear halo is seen around the darker staining central material
 
 
 
*Grows on Sabouraud's Dextrose agar
 
**Creamy white colonies, turning tan coloured and then brown
 
 
 
*Also grows on Blood agar
 
**Small, white yeast-like colonies
 
 
 
*Test using immunodiffusion, complement fixation and counterimmunoelectrophoresis
 
**Skin test of little value as it only indicates exposure
 
 
 
*Treatment with [[Antifungal Drugs#Polyene Antifungals|Amphotericin B]]
 
**If [[Antifungal Drugs#Polyene Antifungals|Amphotericin B]] is contra-indicated, [[Antifungal Drugs#Imidazoles|imidazoles]] can be given orally
 
 
 
*The prognosis is poor in acute and disseminated cases
 
 
 
 
 
{| align="center"
 
|<gallery>Image:Histoplasmosis canine spleen silver stain.jpg|<center><p>'''Histoplasmosis in a canine spleen using silver stain'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center>
 
Image:Histoplasmosis phagocyte.jpg|<center><p>'''Histoplasmosis phagocyte'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center>
 
Image:Histoplasmosis tuberculate chlamydospores.jpg|<center><p>'''Histoplasmosis tuberculate chlamydospores'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center></gallery>
 
|}
 
  
 
==Zygomycosis==
 
==Zygomycosis==

Revision as of 13:45, 29 April 2010



Infectious agents and parasitesWikiBugs Banner.png
FUNGI



Adiaspiromycosis


Aspergillosis


Blastomycosis


Coccidioidomycosis

Entomophthoromycisus


Histoplasmosis

Zygomycosis

  • Also known as mucormycosis, hyphomycosis and phycomycosis
  • Caused by strains of Mucor, Absidia, Rhizopus and Mortierella
    • Mucor circinelloides(rare), Rhizomucor pusillus and R. meihi
    • Absidia corymbifera often causes zygomycosis in cattle and pigs
    • Rhizopus arrhizus, R. microsporus and R. rhizopodormis
    • Mortierella wolfi implicated in bovine abortion (mycotic placentitis), M. hygrophila in fowl and M.polycephala in cattle
  • Occurs widely in nature
  • Infection is by inhalation and ingestion


  • Granulomatous lesions which can ulcerate
  • Mostly localised lesions but can be generalised
  • Pigs
    • Mediastinal and submandibular lymph nodes lesions
    • Embolic tumours in the liver and lungs
    • Can also be present in gastric ulcers
  • Horses, dogs, cats, sheep, mink, guinea-pigs and mice can also be infected
  • Microscopically:
    • Fragments of non-septate hyphae which are branched and coarse
    • Rhizomucor produce a thick, grey mycelium and have short, black, spherical sporangia
    • Mucor produce thick, colourless mycelium with no rhizoids. Globose spoangia with small spores are present and sporagiospores are simple or branched.
    • Absidia resemble Rhizopus grossly
    • Mortierella produce white, velvet colonies on Sabouraud's Dextrose and Blood agar
  • Grows on Sabauraud's Dextrose agar
    • Common contaminants
  • Treatment is with Amphotericin B
    • Surgery is also an option in treatment

Further Links