L21/22

Question 1

sporebearing, lack chlorophyl, have absorptive nutrition and reproduce both sexually and asexually

Answer 1

eukaryotic organism

Question 2

Fungi range from____ forms (yeasts) to____ moulds and mushrooms

Answer 2

unicellular
multicellular

Question 3

Yeasts and moulds

Answer 3

microscopic fungi consisting of solitary cells that reproduce by budding. Moulds, in contrast, occur in long filaments known as hyphae, which grow by apical extension

Question 4

Moulds

Answer 4

occur in long filaments known as hyphae, which grow by apical extension

Question 5

Yeasts

Answer 5

are microscopic fungi consisting of solitary cells that reproduce by budding

Question 6

Heterotrophic fungi

Answer 6

• use reduced, preformed organic molecules as carbon source

Question 7

Osmotrophic fungi

Answer 7

soluble nutrients are absorbed through the cytoplasmic membrane

Question 8

Saprophytic - fungi

Answer 8

derive nutrition from degradation of dead organic matter

Question 9

Dimorphic – fungi

Answer 9

have two different morphological form

Question 10

Thermally dimorphic fungus exists in the environment in its hyphal/_____form. In the host, the change in temperature induces changes and switch to____-phase

Answer 10

mycelial
yeast

Question 11

Dimorphic fungal pathogens are a significant cause of human disease worldwide and are known as primary_____ pathogens that cause disease in immunocompetent individuals with over 650 000 new infections occurring each year in the United States.

Answer 11

pulmonary

Question 12

Human fungal infections

Answer 12

• 300 known for humans
• Superficial, cutaneous and subcutaneous mycosis are direct contact infections of the skin, hair and nails.
• Systemic mycosis - disseminate to visceral tissue
• Opportunistic mycosis - fungi with low virulence affect immunosuppressed
• Cause hypersensitivities and poisoning.

Question 13

Superficial, cutaneous and subcutaneous mycoses are transmitted by___ contact

Answer 13

direct

Question 14

dermatophytes and ringworm

Answer 14

The fungi involved in superficial and cutaneous mycosis are also known as this.
* disease known as tinea or ringworm

Question 15

• Category for mycoses
  *Scalp, beard, nack, face and arms
• Piedras and tineas

Answer 15

Superficial mycoses

Question 16

• Category for mycoses
• Hair of beard, scalp, skin, buttocks, feet, nails
• Dermatomycoses (ringworm and tineas)

Answer 16

Cutaneous mycoses

Question 17

• Category for mycoses
• legs, feet, puncture wounds
• Sporotrichosis

Answer 17

Subcutaneous mycoses

Question 18

The skin is composed of two distinct layers: the

Answer 18

epidermis - outermost
and dermis.

Question 19

The outermost layer (the epidermis) is composed of layers of differentiated____. The top layer, or ______ ____, is composed of terminally differentiated, enucleated keratinocytes that are chemically crosslinked to fortify the_____ of the skin

Answer 19

keratinocytes
stratum corneum
barrier

Question 20

Superficial mycoses

Answer 20

▪ invade only the stratum corneum and the superficial layers of the skin
▪ Dead tissue is invaded and there is no cellular response from the host
▪ Malassezia furfur cause tinea versicolor brownish-red scales on skin of trunk, neck, face, arms
▪ Trichosporon ssp. cause white Piedra, a superficial cosmetic fungal infection of the hair shaft

Question 21

Malassezia furfur

Answer 21

cause tinea versicolor brownish-red scales on skin of trunk, neck, face, arms
superficial mycoses

Question 22

Trichosporon ssp.

Answer 22

cause white Piedra, a superficial cosmetic fungal infection of the hair shaft
superficial mycoses

Question 23

Cutaneous mycoses

Answer 23

▪ Infections of skin cells - require keratin as carbon source for growth
▪ Most com fungal diseases- humans
▪ Common genera of dermatophytes are **Microsporum and Trichophyton **
▪ Tinea corporis

Question 24

ringworm of the body - circular red itchy lesions

Answer 24

▪ Tinea pedis
Cutaneous mycoses

Question 25

athlete’s foot - scaling, fissuring, itchy lesions

Answer 25

▪ Tinea unguinum
Cutaneous mycoses

Question 26

nail infection - nail discoloured, separates from nail bed

Answer 26

▪ Tinea cruris
Cutaneous mycoses

Question 27

Jock itch - proximal medial thighs, genital, pubic, perineal, and
perianal skin

Answer 27

Cutaneous mycoses

Question 28

Tinea is transmitted via the

Answer 28

• feet by desquamated skin scales in substrates like carpet and matting.
• Desquamated skin scales may remain infectious in the environment for months or years

Question 29

Subcutaneous mycoses

Answer 29

▪ Caused by dermatophytes that infect under the skin
▪ Fungi normally saprophytic inhabitants of soil and decaying vegetation
▪ Introduced via puncture wound
▪ Disease develops slowly, often over years

Question 30

Osmotrophic microorganisms feed by secreting extracellular ____into the environment to degrade complex polymers, such as cellulose, lignin and proteins and by transporting the resulting simple, monomeric sugars and amino acids into their own cells.

Answer 30

depolymerizing enzymes

Question 31

Subcutaneous mycoses - Sporotrichosis caused by

Answer 31

Sporothrix schenckii, a dimorphic fungus (filamentous form in environment, yeast form in host)

Question 32

Subcutaneous mycoses - Sporotrichosis information

Answer 32

▪ Caused by Sporothrix schenckii
▪ Occurs worldwide, most common in USA
▪ Found on plants – roses, hay, pine bark mulch etc.
▪ Disease is occupational hazard for florists, forestry workers
▪ Secondary spread to articular surfaces, bone and muscle is not infrequent,. Infection occasionally involve the central nervous system, lungs or genitourinary tract.

Question 33

Systemic mycosis

Answer 33

▪ acquired by an air-borne route when spores are inhaled from the soil where the free-living fungi are found
▪ Caused by thermally dimorphic fungi: Coccidioides, Histoplasma, Blastomyces, Paracoccidioides, Emmonsia, and Emergomyces

Question 34

Systemic mycosis caused by thermally dimorphic fungi:

Answer 34

• Coccidioides,
• Histoplasma,
• Blastomyces,
• Paracoccidioides,
• Emmonsia, and
• Emergomyces

Question 35

Coccidioidomycosis

Answer 35

▪ Valley fever, San Joaquin fever, desert rheumatism
▪ Coccidioides (C.) immitis and Coccidioides posadasii
▪ C. immitis, primarily endemic in California, and C. posadasii, endemic elsewhere throughout the Western Hemisphere.