Survey of Eukaryotes 3

Fungi

cell wall made of chitin and cellulose

cell membrane uses ergosterol

acquire nutrients from their environment

most fungal pathogens are opportunists 

Difference between primary and opportunistic fungal pathogens

primary pathogens infect healthy individuals; opportunistic pathogens mainly infect immunocompromised individuals

2 basic forms of fungi

yeast and hyphae

Fungal form: yeast

unicellular organisms that are circular or oval in shape

reproduced by budding or cell fission

Fungal form: Hyphae

multicellular

comprised of hyphal mats

mycelium can be used for nutrient acquisition or reproduction (sexual or asexual)

Levels of invasion in fungal infections (mycoses)

superficial, cutaneous, subcutaneous, and deep

Superficial mycosis

surface infections like thrush, tineas, cosmetic tissue, treated with topical antifungals

Cutaneous mycosis

infections of superficial skin, scalp, nails; treated with topical or oral antifungals

Subcutaneous mycosis 

infections of dermis/subcutaneous tissue from soil fungi; often enter through breaks in skin

Deep mycosis

severe systemic infections from inhaled spores; affect multiple organ systems; often life threatening

Examples of anti fungal drugs

azoles, echinocandins, polyenes

Antifungal drug target: Azoles

ergosterol (cell membrane)

Antifungal drug target: polyene

erosterol (cell membrane)

Antifungal drug target: echinocandins

1-3 Beta-D Glucan synthase (cell wall)