Exam 1 - Mycology

Question 1

Characteristics of Fungi

Answer 1

• Eukaryotic
• Sterols
• Chemoheterotrophs
• Aerobes
• Saprophytic
• Acquire food by absorption
• Produce sexual and asexual spores

Question 2

Saprophytic

Answer 2

Living on dead or decayed organic matter

Question 3

Molds

Answer 3

Multicellular, fliamentous form of fungi consisting of thread-like filaments to form fuzzy colonies
TEMP -

Question 4

Yeast

Answer 4

Unicellular; produce circular, restricted, pasty or mucous colonies
- sexual or asexual reproduction
TEMP -

Question 5

Asexual reproduction of yeast

Answer 5

Budding, binary fission

Question 6

Dimorphic

Answer 6

Exhibit either a yeast or mold phase; may be temperature dependent

Question 7

Hyphae

Answer 7

Microscopic filaments that can branch and form a network

Question 8

Septate (Hyphae)

Answer 8

Frequent perpendicular cross walls

Question 9

Sparsely septate (Hyphae)

Answer 9

Infrequent perpendicular cross walls

Question 10

Aseptate (Hyphae)

Answer 10

No septation (older term) 
Sparsely septate is correct

Question 11

Hyaline (Hyphae)

Answer 11

Nonpigmented hyphae

Question 12

Dematiaceous (Hyphae)

Answer 12

Dark and pigmented hyphae

- due to presence of melanin in the cell wall

Question 13

Mycelium

Answer 13

A network of hyphae (colony)

- extends over or through whatever substrate the fungus is using as a source of food

Question 14

Conidia

Answer 14

Fungal spores

Question 15

role of Conidia

Answer 15

• means of dispersal

- means of survival (low metabolic state, dormant state)

Question 16

Superficial (spectrum of disease)

Answer 16

Confined to the outermost “dead” layer of the skin or hair

Question 17

Cutaneous (spectrum of disease)

Answer 17

Affects the keratinized layer of the skin, hair, or nails

Question 18

Mucosal (spectrum of disease)

Answer 18

Typically local infection

Question 19

Systemic (spectrum of disease)

Answer 19

Highly invasive infection

- affects the internal organs or deep tissues of the body

Question 20

Opportunistic (spectrum of disease)

Answer 20

Found primarily in immunocompromised persons; infections of a great variety of tissues

Question 21

Innate Resistance

Answer 21

Natural resistance of an immune system, can keep spores/fungi populations under control
(Healthy immunocompetent individuals - high innate resistance to fungal infections)

Question 22

Diagnostic challenge of opportunistic mycoses

Answer 22

An immunocompromised person at risk for fungal infections

• creates a complexity of the patient population at risk
• increasing array of fungi that can infect these individuals

Question 23

Superficial/cutaneous (Mode of Transmission)

Answer 23

Person to person or form animal to human contact

Question 24

Subcutaneous (Mode of Transmission)

Answer 24

Through the skin (trauma to the skin)

Question 25

Deep mycoses (Mode of Transmission)

Answer 25

Opportunistic growth in immunocompromised; inhalation of spores; or presence of intravenous devices

Question 26

Lab values to support Bacterial pathogen

Answer 26

↑ WBC, Neutrophils, ↑ total protein, ↓glucose, CSF Lactate > 35 mg/dl

Question 27

Lab Values to support Viral Pathogen

Answer 27

↑ WBC, Lymphocytes, ↑ total protein (moderate), normal glucose, Normal lactate

Question 28

Lab Values to support Fungal Pathogen

Answer 28

↑ WBC, Lymphocytes and monocytes, ↑ total protein (moderate), normal to low glucose, lactate > 25 mg/dl

Question 29

Specimen Collection (general)

Answer 29

• collect aseptically/proper cleaning/decontamination of the site to be sampled
• collect an adequate amount of clinical material
• submitted in a sterile leak-proof container and should be accompanied by a relevant clinical history
• transport promptly or if delay store at 4oC

Question 30

Methods of Identifying pathogens

Answer 30

◦ conventional methods (direct microscopy, culture, susceptibility testing)
◦ histopathological methods
◦ immunologic methods
◦ molecular methods