Fungal Infections

Question 1

Opportunistic blooms of Candida can occur, which results in _____________ - usually results from _________ in normal host __________ and or lack of _______ normal flora

Answer 1

Candidiasis
defects
defenses
competitive

Question 2

2 situations where you will see lack of competitive normal flora

Answer 2

1. antibiotics treatment, some estrogen treatments

2. immunosuppressive therapies or immunosuppressive diseases

Question 3

Organisms that live on dead or decaying organic matter

Answer 3

saprobes

Question 4

Fungi are eukaryotic organisms. T/F

Answer 4

True

Question 5

What makes our cells different from fungi cells?

Answer 5

Fungi cell membranes have an addition of ergosterol and zymosterol instead of cholesterol which is in humans

Question 6

Antifungal medication attacks fungi where?

Examples of these medications?

Answer 6

cell membrane
azoles inhibit ergosterol synthesis and polyenes form pores
The glucan cell wall is also a target

Question 7

What is the fungi cell wall made up of?

Answer 7

a multilayer rigid cell wall made up of mainly cross-linked glucans

Question 8

Why are there few effective antifungal treatments?

Answer 8

mainly bc fungal cells like mammalian cells are eukaryotic so it is difficult to make medications that wont harm human cells but will harm fungal cells

Question 9

What are the 2 morphologies of fungi?

Answer 9

1. yeasts ( single cells)

2. hyphae or filamentous (multinucleated branched, mold like)

Question 10

The collective term for a mass of hyphae?

Answer 10

mycelium ( aka mold)

Question 11

What is the term for the morphology of fungi that means they can exist in both a filamentous (hyphae) or yeast morphology depending on conditions?

Answer 11

dimorphic

since candida can be in 3 forms, yeast, hyphae, and pseudohyphae = polymorphic

Question 12

What is the morphology of fungi (specifically Candida) where the cells are elongated and linked like sausages?

Answer 12

pseudohyphae

Question 13

______ cannot fight a fungal infection, but these 2 forms of defense can__________ and _________

Answer 13

Antibodies
Innate defenses (functioning epithelium is primary barrier)
cellular Immunity

Question 14

What is the fungi cell wall made up of? ( and type of linkages)
Is the Cell wall thin or thick?

Answer 14

Beta-1,4 N-AGM (Chitin)

Very thick -> 90% of dry weight

Question 15

What is the fungi binding structure?

Answer 15

Lectin

Question 16

how does the fungi get “food”?

Answer 16

Fungi contain enzymes that degrade extracellular organic material into small substrate for fungal growth.

Question 17

The fungal plasma membrane is made up of phospholipids, which ones specifically? (5)

Answer 17

1. Phosphatidyl - choline
2. Phosphatidyl - ethanolamine
3. Phosphatidyl - serine
4. Phosphatidyl - inositol
5. Phosphatidyl - glycerol

Question 18

Fluconazole is what?

Answer 18

An antifungal medication that targets ergosterol

Question 19

What 4 things contribule to host (human) resistance to a fungal infection?

Answer 19

1. Fatty acids
2. pH
3. epithelial cell turnover
4. normal bacteria flora

Question 20

What is a rare fungal pathology that releases various toxins?

Answer 20

Mycotoxicoses

Question 21

Commmon fungal pathology that causes hay fever, asthma, and contact dermatitis?

Answer 21

Hypersensitivities
Type 1 (IgE) -> hayfever/asthma
Type 4 - (cell mediate) -> contact dermatitis

Question 22

Which fungal pathology is common and causes no immune response?

Answer 22

Superficial Mycoses - found on the outermost skin layers/hair

Question 23

Which fungal pathology refers to tinea… of the skin & nails? Give 5 examples using tinea

Answer 23

Cutaneous Mycoses

1. Tinea pedis (athlete’s foot)
2. Tinea capitis ( scalp ringworm)
3. Tinea corporis ( body ringworm)
4. Tinea cruris (jock itch)
5. Tinea unguium (nail fungus)

Question 24

3 species of cutaneous mycoses caused by dermatophytes

Answer 24

1. Trichophyton
2. Micosporum
3. Epidermophyton

Question 25

A very rare fungal pathology that deals with fungi/spores into dirty wounds (think joplin tornado)

Answer 25

Subcutaneous Mycoses - serious!

Question 26

Which fungal infection primary involves inhaled spores? What does this cause?

Answer 26

Systemic Mycoses "rarish" | Causes lung infections similar to TB ( Geographically dependant like AZ has valley fever)

Question 27

What fungal pathology affects the immunocompromised? | List 4 examples and what they cause, in order of most common to most rare

Answer 27

Opportunistic Mycoses 1. Candidiasis - oral(thrush) and vaginal (yeast infections) 2. Cryptococcus - from bird droppings -> lung infections 3. Aspergillosis -soil -> lung infections 4. Pneumocystis - yeast like fungus -> lung infection (AIDS patients)

Question 28

When are opportunistic mycoses a concern? 8 reasons

Answer 28

Only cause serious disease under unusual circumstances -> mostly involving host debilitation. 1. AIDS 2. immunosuppressive therapies ( for cancer/ transplantations) 3. frequent use of broad-spectrum antibiotics 4. Endocrine imbalance (birth control, diabetes) 5. Oral devices / catheters 6. Defects in T cells and or phagocytic cells 7. Infants 8. Elderly

Question 29

Most common Candida involved in candidiasis?

Answer 29

C. albicans - In 80% of individuals -> part of normal flora

Question 30

The development of oral _______ in previously healthy adults not receiving _________ therapy or ________ therapy should strongly alert the clinician to consider serious ___________ conditions such as _______

Answer 30

``` Candidiasis corticosteroid broad-spectrum antibiotic immuno-compromising HIV ```

Question 31

If Candida is usually part of our normal flora, what protects us from fungal infections? (5)

Answer 31

1. our high level of innate immunity to fungal disease -> but if it fails... candida = classic opportunist 2. fatty acid content 3. pH 4. epithelial turnover 5. normal competitive bacteria flora

Question 32

Steps of adaptive immunity response to candidiasis (5)

Answer 32

1. Ags presented on epithelial APCs to Th 2. Th produce cytokines 3. Cytokines signal epithelium to hyperproligerate 4. Capillaries respond to inflammation signal and open 5. PMNs arrive and attack

Question 33

As a result of a fungal infection, what is made up of PMNs, dead PMNs, fibrin, and fungal cells. It can be easily wiped off but reveals a raw erythematous sometimes bleeding base

Answer 33

loosely adherent pseudomembrane

Question 34

What type of APCs are used in fungal infections?

Answer 34

Langerhans Cells

Question 35

Primary oral candidiasis that is white, cottage cheese like in appearance, is seen more in the elderly then in infants, and is associated with terminal illness, diabetes, and Leukemia.

Answer 35

Acute Pseudomemranous

Question 36

What is the difference between primary and secondary oral candidiasis?

Answer 36

Primary -> localized infection present only on the oral and surrounding tissues. Secondary -> infection of oral tissues that are associated with other candidial infections at other mucosal and cutaneous sites

Question 37

What are the 2 types of Erythematous (primary oral candidiasis)?

Answer 37

1. Acute Atrophic - post antibiotic sore mouth | 2. Chronic Atrophic - "denture mouth"

Question 38

When are secondary oral candidiasis infections seen?

Answer 38

with rare disorders, generalized immunosuppression (AIDS) | Systemic mucocutaneous candidal infections

Question 39

Type of primary oral candidiasis which increases keratin (which can increase malignant transformation) and can cause leukoplakia

Answer 39

Chronic Hyperplastic "new bioniche"

Question 40

Which primary oral candidiasis is due to a immune defect ( localized, familial, syndrome)?

Answer 40

Chronic Mucocutaneous