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Flashcards in Fungi Deck (29):
1

Fungal characteristics

eukaryotic, heterotrophs

possess a chitinous cell wall with beta(1,3) and (1,6) glucans, mannose modified proteins and GPI- anchored proteins

ergosterol in cell membrane

produce filamentous structures and spores

2

Dimorphic fungi

exist as 2 different forms depending on temp

heat (35-40)-yeast, cold (<30)-mold

includes blastomyces dermatidis, coccidiodes immitis, histoplasma capsulatum and paracoccidioides brasiliensis

3

Virulence factors

thermal dimorphism, toxin production, capsules and adhesion factors, hydrolytic enzymes, inflamm stimulants

4

fungal disease classification

hypersensitivity
mycotoxicoses
mycetismus
infections

5

systemic classification

ascomycota
basidiomycota
zygomycota
mitosporic fungi

6

Ascomycetes

form sexual spores in an ascus, largest fungal phylum

septate fungi

candida albicans, pneumocystis jirovecii, trichophyton rubrum/mentagrophytes

7

basidiomycetes

form sexual spores on surface of a pedestal- basidium

cryptococcus neoformans

8

Zygomycetes

most primitive fungal phylum forming spores as zygosporangium

Aseptate fungi with right angle branching

Mucor spp, rhizopus spp, absidia app

9

Superficial mycoses

colonization of outer layers of skin, hair, nails

malazzezia furfur- pityriasis Versicolor
Hortae werneckii- Tinea Nigra
Piedra Hortae- Black Piedra
Trichophyton Rubrum and Mentagrophytes (Ascomycete)- onchomycosis

10

Cutaneous Mycoses

macular, papular or pustular lesions that itch and spread from scratching; due to soil organisms introduced into extremities via trauma

Tinea barbae- beard
tinea pedis- athletes foot
tinea- crusis
tinea corporsis- trunk
tinea capitis- scalp

11

Subcutaneous mycoses

Sporothrix schenckii- asomycete- sporotrichosis, mycetoma/eumycetoma, chromoblastomycosis

12

opportunistic mycosis

cause disease in immunocompromised ppl

candida albicans- ascomycete- candidas
aspergillus- ascomycete
cryptococcus neoformans- basidiomycetes
rhizopus, absidia, mucor- zygomycete
pneumocystis jirovecii- ascomycetes

13

candida albicans

opportunistic ascomycetes with pseudohyphae

superficial skin infection, oral cavity, genitalia, LI- forms off white pasty colony with yeasty odor

causative agent of oral thrush, vulvovaginal yeast infection and cutaneous candidiasis

gram positive

14

Aspergillus

opportunistic ascomycetes with low angle branching hyphae, septate

common airborne soil fungus infecting the lungs

AIDS, leukemia, transplant pts

15

cryptococcus neoformans

opportunistic basidomycetes

inhaled, inhabits soil around pigeon roosts infecting lungs and othe rograns like brain

AIDS,cancer,diabetes

use bird seed agar

16

Rhizopus, absidia, mucor

opportunistic zygomycete

saprobic fungi found in soil, water, organic debris and food

usually harmless but can invade nose, eyes, heart, brain and ppl with diabetes or malnutrition

17

pneumocystic jirovecii

opportunistic ascomycetes

small unicellular fungus that causes PCP, can be rapidly fatal

AIDS

18

Sporotrichosis

subcutaneous ascomycete

sporothrix schenckii

subacute or chronic granulomatous infection often infecting lymphatics

rose bush penetrates skin-> lesion-> ulcerates-> spreads to lymph

19

mycetoma/eumycetoma

subcutaneous ascomycete

sporothrix schenckii

granulomatous infection- extends from subcutaneous to bone

pigmented nodules may drain through sinuses and produce grains

20

Chromoblastomycosis

subcutaneous ascomycete

sporothrix schenckii

warty pigmented lesions which grow outward from site of introduction "cauliflower lesion"- darker reddish in color

21

Malassezia furfur

superficial mycoses

pityriasis/tinea versicolor

infects and causes hypo/hyperpigmented skin

fluoresces under UV

22

hortea werneckii

superficial

tinea nigra- causes skin to darken

23

piedra hortae

superficial

black piedra- infects hair shaft- also called white piedra

24

trichophyton rubrum/mentagrophytes

superficial ascomycete

onchomycosis

infects fingernails and toenails
degenerates keratin/keratinolytic

25

10% KOH

fungal stain used only chitionous hyphae survive and visible as hyaline shadows

26

calcofluor white

binds chitin and fluoresces under UV

27

gomori methanamine silver stain

for hyphae, spores, conidiophores

28

Sabrouraud dextrose agar

ph 5.4 for acidic bacterial growth

supplement with antibiotics to inhibit saprophytic fungi

29

Histoplasma capsulatum

form tuberculate macroconidia