FUNGI

Question 1

Each of the following fungal genera cause dermatophytosis except one:

a. blastomyces
b. Microsporum
c. trichophyton
d. Epidermophyton

Answer 1

blastomyces

Question 2

What is a dermatophyte?

Answer 2

pathogenic members of the keratinophilic (keratin digesting) soil fungi.

Question 3

T/F The dermatophytes Microsporum and Trichophyton are human and animal pathogens

Answer 3

True

Question 4

T/F The dermatophyte Epidermophyton is a animal pathogen

Answer 4

False, is human pathogen

Question 5

What are arthrospores

Answer 5

asexual spores formed in the hyphae of the parasitic stage

Question 6

what are conidia

Answer 6

sexual or asexual spores formed in the “free living” environmental stage

Question 7

in regards to dermatophytes; infections occur by contact with ______ or _________

Answer 7

arthrospores or Conidia

Question 8

Describe the process of infection of dermatophytes

Answer 8

Infection usually begins in a growing hair or the stratum corner of the skin. Dermatophytes do not generally invade resting hairs, since the essential nutrients they need for growth are absent and limited. Hyphae spread in the hairs and keratinized skin, eventually developing infectious arthrospores

Question 9

in humans, dermatophytoses are referred to as:

Answer 9

tinea infections; are named with reference to the area of the body involved.

Question 10

Tinea corporis in children is

Answer 10

often the result of tinea capitis infection that has spread to the face; represents how infections can spread

Question 11

Tinea capitis:

Answer 11

most often seen in children, is a dermatophyte infection of the hair and scalp

Question 12

tinea corporals (ring worm)

Answer 12

occurs on the trunk, extremities, and face

Question 13

Tinea barber is

Answer 13

an infection of the hairs and skin in the beard and mustache area, and is usually seen in men

Question 14

Tinea faciei

Answer 14

is seen on the nonbearded parts of the face

Question 15

Tinea cruris

Answer 15

is an infection of the groin. commonly called jock itch

Question 16

Tinea pedis (athlete foot)

Answer 16

is an infection of the foot

Question 17

Tinea Manuum

Answer 17

Dermatophyte infection of one or occasionally both hands

Question 18

Tinea unguium

Answer 18

dermatophyte infection of the nail

Question 19

The most effective antimycotic (anti fungal agent is

Answer 19

griseofulvin (although griseofulvin is prescribed to treat infections of the skin, it cannot be applied as a cream and must be taken in pill form

Question 20

Describe Fungi

Answer 20

are eukaryotic, have a complex cell wall, are all gram positive, grow in sabouraud medium and contain both DNA and RNA

Question 21

What are the two types of Fungi:

Answer 21

yeasts and molds

Question 22

describe yeasts:

Answer 22

grow as single cells that reproduce by asexual budding

Question 23

describe molds:

Answer 23

Long filaments (hyphae) which form mat-like structure that is referred to as mycelium

Question 24

what is dimorphism?

Answer 24

characteristic of some fungi, meaning they form different structures at different temperatures (i.e exist as molds in saprophytic, free-living state at ambient temperatures and as yeasts in host tissues at body temperature)

Question 25

What are the major dimorphic fungi?

Answer 25

Blastomyces, histoplasma, coccidioides, and sporothrix schenckii

Question 26

Must fungi reproduce asexually by forming _____ from the sides or ends of specialized structures called ________.

Answer 26

Conidia (asexual spores); conidiophores

*different conidia help identification of fungi

Question 27

Examples of asexual spores (conidia);

Answer 27

arthrospores, chlamydospores, blastospores, and sporangiospores

Question 28

Some fungi reproduce sexually by mating and forming:

Answer 28

sexual spores (examples zygospores, ascospores, and basidiospore)

Question 29

All fungi, except for those belonging to the class zygomycetes are ___

Answer 29

septated

Question 30

the cell walls of most fungi contain

Answer 30

chitin and beta-1:3-linked gluten

Question 31

sterols (ergosterol) are in ____. most anti fungal agents target this component of fungal cell membranes

Answer 31

cell membranes

Question 32

Fungal infections generally initiate a _______ delayed hypersensitivity reaction

Answer 32

type IV

Question 33

The formation of ______ in response to fungal infection is common

Answer 33

granulomas (seen in coccidioidomycosis, histoplasmosis, blastomycosis, etc)