[2] Microbiology of Fungi and Opportunistic Pathogens Flashcards Preview

[OS 217] Infectious Diseases > [2] Microbiology of Fungi and Opportunistic Pathogens > Flashcards

Flashcards in [2] Microbiology of Fungi and Opportunistic Pathogens Deck (40):
1

Distribution of Candida spp.

Saprophytes in Humans nad Animals

2

Candida exists in what form in body tissue?

Yeast and Mold Form (Pseudohyphae)

3

What is the typical agar used to culture Candida?

Sabaroud Dextrose Agar

4

Color of Candida colonies?

White to Cream Colored with a smooth, waxy surface

5

[Treatment]

Candida: Superficial Infections

Topical nystatin and Azoles

6

[Treatment]

Candida albicans

Oral Fluconazole

7

[Treatment]

Candida: other groups

Amphotericin B

8

Important feature to distinguish Cryptocococcus gattii from C. neoformans

Formation of Cryptococcomas
Higher mortality
Longer treatment period

9

Cryptocococcus neoformans is usually found in?

Pigeon droppings

10

Cryptocococcus gattii is usually found in?

Eucalyptus trees (but is found worldwide, go figure)

11

Pathway of Pathogenesis of Cryptococcus

Inhaled Yeast -> Primary Pulmonary Infection -> Asymptomatic Dormant -> Brain (Most common site of dissemination)

12

[Characteristics]

Cryptococcus

Encapsulated, yeast-like
Reproduce by budding

13

[Laboratory Diagnosis: Microscopic Examination]

Cryptococcus

India Ink Mount

14

[Laboratory Diagnosis: Culture]

Cryptococcus

Sabouraud Agar without Cyclohexidine (it can kill the organism and prevent growth)

15

[Laboratory Diagnosis: Definitive Test]

Cryptococcus

(+) CSF Culture

16

[Treatment]

Cryptococcus: Mild to Moderate CNS Infections

Fluconazole

17

[Treatment]

Cryptococcus: Meningitis

Amphotericin B in combination with Flucytosine or Fluconazole

18

Most common species of Aspergillus causing invasive disease

Aspergillus fumigates
Aspergillus flavus

19

Most common species of Aspergillus causing allergic disease

Aspergillus fumigates
Aspergillus clavatus

20

Most common route of infection of Aspergillus

Respiratory Tract (Paranasal Sinus and Lungs)

21

Species of Aspergillus linked to production of aflatoxin

Aspergillus flavus (Commonly found in peanuts)

22

[Identify]

Septate hyphae
Dichotomous hyphae
Spores
Acute angle branching

Aspergillus

23

[Laboratory Diagnosis: Microscopic Examination]

Aspergillus

10% KOH and Parker Ink

24

[Laboratory Diagnosis: Culture]

Aspergillus

Sabouraud Agar

25

[Laboratory Diagnosis: Serology]

Aspergillus: Allergy

Detection of specific IgE in Serum: RAST

26

[Laboratory Diagnosis: Serology]

Aspergillus: Invasive Infection

Detection of Galactomannan Antigen in Serum: ELISA

27

Etiologic Agents of Systemic Zygomycosis (Mucormycosis)

Zygomycetes

28

[Laboratory Diagnosis: Microscopic Examination]

Zygomycetes

10% KOH

29

[Identify]

Broad, irregularly shaped, non-septated Hyphae
Right angle branching

Zygomycetes

30

[Laboratory Diagnosis: Culture]

Zygomycetes

Sabouraud's Agar without Cyclohexamide

31

[Treatment]

Zygomycetes

Surgery + Antifungals

1. Drainage and debridement
2. Amphotericin B

32

Most common opportunistic mycoses in HIV

Pneumocystis carinii

33

Most common fungal meningitis in HIV

Cryptococcosis

34

[Laboratory Diagnosis: Culture]

Pneumocystis carinii

Has not yet been cultured in labs

35

3 Distinct Morphologic Stages of Pneumocystis carinii

Trophozoite
Sporozoite
Cyst

36

[Pathogenesis]

Pneumocystis carinii

Inhaled spores are deposited in alveoli -> Increase in number -> Pneumocystis carinii Pneumonia -> Acute Respiratory Distress Syndrome

37

[Treatment]

Pneumocystis carinii

Trimethoprim

38

[Identification]

Dichotomous septate hyphae
Asexual fruiting structure

Aspergillosis

39

[Identification]

India Ink: Encapsulated Yeast

Cryptococcus

40

[Identification]

Budding yeast
Septate hyphae
Pseudohyphae

Candida