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Flashcards in Mycology Deck (15):
1

Systemic mycoses

  • Define the disease assoc
  • All are caused by dimorphic fungi (def?)
    • exception?
  • Treatment for local & systemic infection?
  • Systemic mycoses can mimic what?

  • Histoplasmosis, Blastomycosis, Coccidioidomycosis, Paracoccidioidomycosis
  • dimorphic= cold (20oC)= mold | warm (37oC)=yeast 'mold in the cold, yeast in the beast'
    • coccidioidomycosis= is spherule (not yeast) in tissue
  • Treatment
    • local= fluconazole or itraconazole
    • systemic= amphotericin B
  • systemic:  mimics TB (granuloma formation) except unlike TB have NO person-person transmission.

2

  • Endemic location and pathologic features
    • Mississippi, Ohio River valleys, Causes pneumonia
  • What is the disease?
  • what is the call that it targets?
  • Where can it be transmitted from?

  • Histoplasmosis
  • Macrophage filled with histoplasma (orgnaism is smaller than RBC)
  • Bird or Bat droppings

Histo hides within macrophages 

3

  • Endemic location and pathologic features
    • States east of Mississipis River, and Central America
    • Causes inflmmatory lung disease, and can disseminate to skin and bone.
    • Forms granulomatous nodules
  • What is the disease?
  • what its its histological feature?

  • Blastomycosis
  • Broad-based budding (same size as RBC)

4

  • Endemic location and pathologic features
    • Southwestern US, California
    • Causes pneumonia and meningitis,
    • can disseminate to bone and skin
    • case rate inc after earthquakes
    • (spores in dust are thrown up in the air and become spherules in lungs)
  • What is the disease?
  • what its its histological feature?

  • Coccidiodiomycosis
  • Spherule (much larger than RBC) filled with endospores.
  • Coccidio crowds 
  • 'San Joaquin Vally fever'
  • "Desert bumps" = eryhtema nodosum
  • "Desert rheumatism" = arthralgias

5

  • Endemic location and pathologic features
    • Latin America
  • What is the disease?
  • what its its histological feature?

  • Paracoccidoidomycosis
  • Budding yeast with 'captian wheel' formation (much larger than RBC)

Paracoccidio parasails w/the captian's wheel all the way to Latin America.

6

Define the cutaneous mycoses

  • Tinea versicolor
  • Other tineae

7

Pt presents with cutaneous mycoses that has an organism that casues:

  • Degradation of lipids produces acids that damage melanocytes and hypopigmented &/or hyperpigmented patches.
  • Occurs in hot humid weather.
  • Appearance is 'Spaghettis and meatball' like on histology

 

  • What is the disease
  • What is the name of the organism
  • what is the treatment?

  • Tinea versicolor
  • Malassezia furfur
  • Topical miconazole or Selenium sulfide (Selsun= dandruff shampoo).

8

Name of cutaneous mycoses in the 

  • head or scalp
  • body
  • groin
  • foot
  • onychomycois on fingernalis

  • Tinea capitis
  • Tinea corporis
  • Tinea cruris
  • Tinea pedis
  • Tinea unguinium

9

  • Describe the ring worm in cutaneous mycoses
  • What is it caused by>
  • what is seen on KOH prep.

  • Pruritic lesions with central clearing resembling a ring
  • Caused by dermatophytes (Microsporum, Trichophyton, Epidermophyton)
  • See mold hyphae on KOH prep, Not dimorphic.

10

systemic or superifical fungal infection

  • In immunocompromised (neonates, steroids, diabetse, AIDS)
    • oral and esophageal thrush
  • In diabetes, use of antiboitics
    • Vulvoginitis
  • Iv drug users
    • endocarditis
  • other
    • diaper rash, CMC (chronic mucocutaneous candidiasis)
  • What is the organism
  • treatment for: vaginal, oral/esophageal, systemic

  • Candidiasis albicans
    • alba= white
  • Treatment
    • Vaginal= topical azole
    • Oral/esophageal= fluconazole or caspofungin
    • systemic= fluconazole, amphotericin B, caspofungin

11

  • What acute angle fungi is seen in immunocompromised and those with chronic granulomatous disease?
  • What fungi is associated with asthma and CF
    • may cause bronchiectasis and eosinophilia
  • What fungi is seen in lung cavities, especially after TB infection
  • What is produces by a fungi that is assoc with hepatocellular carcinoma?

Aspergillus fumigatus

  • Invasive aspergillosis
  • Allergic bronchopulmonary aspergillus (ABPA)
  • Aspergillomas
  • Aflatoxins

Think A for Acute Angles in Aspergillus, Not dimorphic

12

Define the mycologic organism

  • Heavily encapsulated yeast, not dimorphic.
  • Found in soil, pigeon droppings. Acquired through inhalation with hematogenous dissemination to meninges.

 

  • Define the organism
  • What is this organism cultured on?
  • Stains with what (2)?
  • Latex agglutination detects what?
  • what is seen in the brain

  • Cryptococcus neoformans
  • Sabouraud agar
  • India ink & mucicarmine
  • Latex agg detects polysaccharide capsular antigen
  • brain lessions 'soapy bubbles'

13

Presentation

  • Rhinocerebral, frontal lobe abscesses, headache, facial pain, black necrotic eschar on face, may have cranial nerve involvement
  • disease is mostly seen in ketoacidic diabeteis and leukemic patients
    • define organism
  • Fungi proliferate in blood vessel walls when there is excess of what?
    • how does it enter the brain?
  • What is the treatment?

  • Mucor and Rhizopus spp
  • ketone and glucose
    • thus after it leaves the blood vessel wall due to ketone and glucose being in excess
    • penetrates the cribiform plate and enters the patin.
  • Treatment:  Amphotericin B

14

  • What organism causes PCP (pneumocystis pneumoina) a diffuse interstitial pneumonia
    • ​yeast (orgnially classified as protozoan)
    • Inhaled, most infections are asymptomatic.
    • Diffuse bilateral CXR appearance
  • What group of pt is predisposed to the disease?
  • How is it diagnosed
  • how does it appear on methenamine silver stain of lung tissue?
  • Treatment?
  • Prophylaxis? (when do you start)

  • Pneumocystis jirovecii (carnii)
  • Pt with immunosuppression are predisposed (AIDS)
  • Disc shaped yeast appears on MSS
  • Treatment:
    • TMP-SMX
    • Pentamidine
  • Prophyalxis (when CD4 drops <200 cells/mm3) in HIV pt.
    • Dapsone
    • Atovaquone

15

Pt presentation

Yeast is dimorphic cigar shaped budding yeast that lives on vegetation.  When spores are traumatically introduced into the skin, typically by a thorn (rose gardener's disease) causes local pustule or ulcer with nodules along drainig lymphatics (ascending lymphagitis).  Little systemic illness.

  • What is the organism?
  • What is the treatment?

  • Sporothrix schenckii
  • Treatment: itraconazole or potassium iodide.