Case

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Case 1

• 34 year old male with AML status-post allo-BMT
  complicated by severe GVHD
• Admitted with lower fevers, GI bleed and
  diarrhea.
• Nodule noted in right lower lobe of lung and a
  bronchoscopy was performed.
• Modified acid fast stain requested.

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BAL-Modified Acid Fast Stain
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Case 1
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Identification of Fungi
lt1um Branching Filaments (actinomycetes)
Filamentous fungi
Yeast
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Actinomycetes

• Resemble fungi in that they form filaments but
  their lack of mitochondria/membrane bound nucleus
  and susceptibility to anti-bacterial agents
  define them as bacteria.
• Includes Nocardia, Nocardiopsis, Actinomadura,
  Streptomyces.
• Initial distinction made on basis of partial
  acid-fast stain followed by chemical tests.
• Nocardia are acid-fast positive.

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Modified Acid Fast
Gram Stain
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Nocardia

• Can cause pulmonary, systemic or cutaneous
  disease.
• Special request for modified acid-fast stain.
• Special request for Nocardia culture.
• Grow on Sab agar and LJ agar
• White, orange chalky colonies
• Will grow on blood, chocolate but can take over a
  week and normal sputum culture plates only held
  48 hours.
• After suspect an actinomycetes will do further
  tests to determine genus/species (e.g., lysozyme
  sensitivity, casein decomposition)

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Case 2

• 23 year old woman presents with worsening left
  groin pain.
• At age 15 developed cough and fever while living
  in Arizona which cleared on its own.
• CT scan shows retroperitoneal abscess from which
  fluid was aspirated and sent for cytology and
  fungal culture.

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Case 2
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Case 2
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Case 2 Abscess Fluid
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Csae 2 Abscess Fluid
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Identification of Fungi
lt1mm Branching Filaments (actinomycetes)
Filamentous fungi
Yeast
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Filamentous Fungi
Hyaline monomorphic
Septate hyphae
Aseptate hyphae
Saprophytes -Aspergillus -Penicillium -Fusarium -S
copulariopsis -Others
Dermatophytes -Microsporum -Trichophyton -Epidermo
phyton
Hyaline Dimorphic -Histoplasma -Coccidioides -Othe
rs
Zygomycetes -Rhizopus -Mucor -Absidia -Cunninghame
lla -Others
Dematiaceous (dark mold) -Exophiala -Clodosporiu
m -Others
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Dimorphic Fungi

• Grow as filamentous molds in the environment or
  when cultured on routine mycology agar at 25-30
  degrees C
• Yeast-like in vivo or when grown on enriched
  media at 35-37 degrees C
• Includes Histoplasma, Coccidioides,
  Paracoccidioides, Blastomycoces, and Sporothrix

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Coccidioides immitis

• Endemic in Southwestern US, Central and South
  America
• Typically asymptomatic or self-limiting
  respiratory infection although can infect almost
  any tissue.
• Growth typically in 3-5 days although
  characteristic arthroconidia (barrel-shaped
  alternated with empty cells) may take 1-2 weeks
  to grow. White cottony colony.
• Appears as spherule filled with endospores in
  tissue. Can produce spherules in vitro but need
  special conditions and not typically done.
• Infection can be confirmed by exoantigen testing
  or nucleic acid probes.

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Coccidioides-fungal form
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Spherules and Endospores