Introduction to Clinical Mycology Flashcards
Are fungal cells eukaryotic or prokaryotic?
eukaryotic
Differences between fungi and human cells
fungi cells have a cell wall and their membrane is made of ergosterol instead of cholesterol
Yeast
unicellular
reproduce via budding
can form pseudohyphea under some conditions
What produces germ tubes that you can use to help diagnose?
candida albicans
Hyphae
individual strands of mold - think blue streaks in blue cheese
Mold reproduction
can be asexual or sexual
Dimorphi
can grow as both yeast and mold
Superficial mycoses
colonization of mold on outer layers of skin and hair
Cutaneous mycoses
extends deep into epidermis as well as invasive hair and nail infections
Subcutaneous mycoses
involve the dermis, subcutaneous tissues, muscles and fascia
Systemic mycoses
originate in the lung but may spread to any organ in the body
Opportunistic mycoses
also originates in lung. Associated with immunosuppressed patients
Ways the innate immune system helps fight
i. Intact skin
ii. pH
iii. normal bacterial flora
iv. epithelial turnover rate
v. desiccated nature of the stratum corneum
vi. mucous membranes
What is the role of humoral immunity
none known
Tropical therapy
good for superficial and most cutaneous infections
Systemic therapy
good for subcutaneous and systemic infections as well as some cutaneous
Polyenes
bind to membrane sterols
What types of drugs inhibit ergosterol synthesis
Azoles, Allyamines, Thiocarbamates, morpholines
Amphotericin B
a polyene
makes pores
Echinocandins
inhibit beta glucan synthesis
attacks the cell wall
useful in treating candida and aspergillus
KOH prep
used to examine hair, nails, skin scraping, fluids, exudates or biopsies
What happens to substances with fungi in KOH prep
dissolves slower
What can you see with KOH prep
hyphae, large yeast, spherules, and sporangia
Stains you can use to help see the cell wall
chlorazol black
calcofluor white
Stains to help advance detection of fungi
GMS
PAS
India Ink Stain
helps you find cryptococcus neoformans
Do fungi stain gram positive or negative
positive
