Fungi Flashcards

1
Q

What are the mycoses that are systemic infections?

A

Histoplasmosis
Blastomycosis
Coccidioidomycosis
Paracoccidioidomycosis

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2
Q

What fungi is common among farmers in the Ohio River Valley and causes granulomas in the lungs?

A

Histoplasmosis

- respiratory route from fucking caves, bat/bird droppings, and farmers

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3
Q

If an immunocompetent patient is infected with Histoplasmosis, what might be found on microscopy and x-ray?

A
  • Chronic Cough, granuloma w/ fibrosis in the lung
  • Yeast form
  • Multiple ovul bodies within Macrophages, lungs/liver
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4
Q

What are symptoms a patient might expect from histoplasmosis?

A
  • Resp Symptoms
  • Hepatosplenomegaly
  • Erythema Nodosum – from immune response
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5
Q

How do you differentiate a granuloma of histoplasmosis from TB?

A

Both have granulomas in the lungs and have similar respiratory symptoms

  • TB would have night sweats
  • Histo - hilar calcification, antigen in urine/serus
  • *Need to biopsy**
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6
Q

If you are looking at a respiratory biopsy with KOH and notice broad budding yeast, what is the likely infection?

A

Blastomycosis

  • blasto buds broadly
  • yeast in heat, mold in cold
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7
Q

What are the typical manifestations of blastomyocosis?

A

Typically asymptomatic in competent hosts with a hazy infiltrate in the lungs
Immunocompromised = systemic spreading to bones (osteomyelitis) and skin

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8
Q

Where is Coccidioidomycosis usually located and why?

A

Southwest US

  • spreads in the air from dust of soil
  • earthquakes, dust storms, construction
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9
Q

What is the most concerning manifestiation of Coccidioidomycosis in immunocompromised individuals?

A

Can spread to the Meninges causing meningitis

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10
Q

How does coccidioidomycosis look under microscopy?

A
  • Spherule filled with Endospores
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11
Q

What fungi would you be suspicious of if you saw a “Captain’s Wheel” formation on KOH stain?

A

Paracoccidiodomycosis

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12
Q

How do the symptoms of Coccidio compared to Paracoccidio?

A

Coccidio – pneumonia, meningitis, bone spread

Paracoccidio – granulomatous lungs, cervical LAD, Musosal ulcers in the mouth and upper resp

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13
Q

What has Spaghetti and Meatball appearance on KOH stain?

A

Malassezia furfur / Pityriasis Versicolor

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14
Q

Hot / Humid near the equator with scattered hyper and hypopigmentation on the torso?

A

Malassezia furfur / Pityriasis Versicolor

  • only affects the top layer of skin without any itching or irritation, changes pigmentation
  • Selenium Sulfate
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15
Q

Who are at risk for systemic Malassezia furfur?

A

Infants who are getting TPN and Lipid infusions, because M. Furfur love lipids and thrive in blood.

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16
Q

How can you diagnosis a tinea infection?

A
  • KOH with hyphae present

- Woods Lamp will illuminate

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17
Q

What are common oral drugs to treat tinea infections, especially onychomycosis (of the nail)?

A

Terbinafine

- if needed Griseofuvum

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18
Q

What fungi can commonly infect gardeners and has a “cigar-like yeast” form in the infected wounds?

A

Sporothrix Schenckii – “Rose Gardeners Disease”

– getting cuts by thorn bush or other plants

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19
Q

What is a unique characteristic of Sporothrix Schenckii?

A

Ascending Lymphadenitis from the inoculation site

- Red raised bumps

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20
Q

If you find a person who has oral candida and candida esophagitis, what could that indicate?

A

They are immunocompromised and with the esophagitis must have CD4 count below 100. AIDS defining illness.

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21
Q

How can you compare bacterial vaginosis vs vaginal candida?

A

Vaginal candida does not change the pH

Bacterial Vaginosis / Trichomoniasis increases the pH to become more basic

22
Q

What might you find if a patient has had several bouts of Aspergillus Fumigatus who is not immunocompromised?

A

Chronic Granulomatous Disease

    • Defective NADPH Oxidase (Resp Burst)
    • Increased infections by CATALASE POSITIVE
23
Q

What is unique about Aspergillus microscopic characteristics?

A

Not Dimorphic, branched 45 Degree Hyphae

    • “Acute Angle Branching”
    • Catalase Positive
    • Conconidia stalks
24
Q

Why does Aspergillus Fumigatus cause a person to have increased risk of heptatocellular carcinoma?

A

Produces Aflatoxin – associated with liver cancer

25
Q

What are common clinical manifestations of Aspergillus in competent vs compromised patients?

A

Only affects Immunocompromised patients.

Allergic Bronchopulmonary Aspergillus
Aspergillomas – after TB infections
Angioinvasive Aspergillosis – invades blood vessels

26
Q

What are the characteristics of Cryptococcus Neoformins?

A

Encapsulated – Thick walls (UNIQUE) - polysacchride
Urease (+)
– transmitted via aerosol pigeon droppings
– looks like wide capsular halos

27
Q

How can you tell if you have Cryptococcus or something else?

A
Stains
- Mucicarmine
- Methanamine
Latex-Agluttination Test, detects polysacc capsule
** "Soap Bubble lesions" in the head
28
Q

What are the most common clinical finding of cryptococcus neoformins?

A
  • Meningitis (Most common fungal meningitis)

- Pneumonia/Cough/Fever

29
Q

What is a unique medication used to treat Cryptococcus neoformins?

A

Flucytosine

+ Amphotericin B

30
Q

A patient who has DM and has poorly controlled blood sugar and has several bouts of DKA per year, what might they be more prone for infection of?

A

Mucormycosis

- Loves Ketones, then proliferates in blood vessels

31
Q

What is the most common clinical syndrome of patients infected with Mucormycosis?

A
  • black eschar on face and nose

- necrosis of the nasal passage way and frontal sinuses

32
Q

What is the unique microscopic look of Mucormycosis?

A

90 degree hyphae branching (Wide Angle, Nonseptate)

33
Q

When might you see an infection of Pneumocystis pneumonia / jirovicii?

A

When an HIV patient’s CD4 count is BELOW 200

– Must be very immunocompromised to become infected with pneumocystis

34
Q

What would the look of pneumocystis look like on exam?

A

CXR – ground glass appearance

Micro – methamine silver stain – disc shaped yeast

35
Q

What is the common appearance on microscopy of candida?

A

Yeast Buds WITH Hyphae (Blastoconidia)

36
Q

If you biopsied a specimen at 37 degrees and found “cigar-shaped” budding yeast, what clinical symptoms might you expect?

A

Sporothrix Schenchii

– Ascending ulcerative lymphadenitis from initial site of entrance.

37
Q

What respiratory fungi would you expect different morphology on biopsy vs culture?

A
  • Sporothrix Schenckii
  • Cocciioides
  • Histoplasmosis
  • Blastomycoses
  • Paracoccidioides
38
Q

If a culture is taken of a skin lesion and it is found to have spores with endospores present, but on culture it has hyphae, what might the organism be?

A

Coccidiodes immitis

39
Q

What is the smallest respiratory fungi that causes granulomas and has branching hyphae on culture?

A

Histoplasmosis

- Biopsy – Oval yeast within Macrophages

40
Q

What is a common fungi that is located near the great lakes in the soil with branching hyphae upon culture from sputum sample?

A

Blastomyces

- BIOPSY - “Broad Budding Yeast” B - B - B

41
Q

What fungi is found to have budding blastoconidia upon biopsy, that can resemble a “Ship’s Wheel” or Pilot Wheel formation?

A

Paracoccidiodes

    • South America/Central America
  • Yeast form with multiple budding from the central yeast, thus making the wheel and spokes formation
42
Q

What are common NONE DIMORPHIC fungi?

A
  • Aspergillus
  • Cryptococcus
  • Rhizopus/Mucor/Absidia
43
Q

What is the difference in morphology between Aspergillosis and Mucormycosis?

A

Aspergillosis – A–> Acute Angle Branching of septate hyphae
Mucor –“Wide Angle” branching of nonseptated hyphae
**Both infect the immunosuppressed

44
Q

What fungi has fungus balls and typically is found invading pre-existing cavitations in the lung (from TB)?

A

Aspergillus

    • Fungus Ball – likes invading cavities
    • Immunocompromised
45
Q

What fungi that commonly causes meningitis in immunocompromised patients has a thick walled spherules?

A

Cryptococcus

    • stains with india ink
    • THICK WALLED (KEY)
46
Q

What antifungal drug binds ergosterol and forms a pore on the membrane surface?

A

Amphotericin B – used for systemic infections

– Dose dependent renal toxicitiy

47
Q

What antifungal drug inhibits 2,3-squalene 2,3 epoxide?

A

Terbinafine – used for skin/nail dermatophytes

48
Q

What antifungal drug inhibits fungal microtubules inhibiting mitosis?

A

Griseofulvin

49
Q

What antifungal drug blocks the production of 1,3-beta-D-glucan synthesis?

A

Caspofungin

– blocks fungal wall synthesis

50
Q

What is the mechanism of the Azole drug class of anti-fungals?

A

Inhibit fungal cytochrome P450 activity

- prevents ergosterol production

51
Q

What metabolite analog is used to inhibit fungal DNA/RNA synthesis?

A

Flucytosine