medical mycology intro

Flashcards about Medical Mycology

Fungi

Eukaryotic cells; Living body is a mycelium made of hyphae; Grow as saprophytes and decompose dead organic matter.

Mycelium

The living body of a fungus, made up of a branching network of filaments.

Hyphae

Filaments that make up the mycelium of a fungus.

Saprophytes

Organisms that obtain nutrients from dead organic matter.

Saccharomyces cerevisiae

Used to ferment sugar to alcohol and carbon dioxide in the production of beer, wine, and bread.

Aspergillus oryzae and Aspergillus sojae

Used in the production of soy sauce and miso.

Mycoses

Diseases caused by fungi.

Superficial Mycoses

Affects only the outermost layers of skin and hair with little or no pathology.

Cutaneous Mycoses

Destruction of the keratin of skin, hair, and nails.

Subcutaneous Mycoses

Involves skin, muscle & connective tissue immediately below the skin

Systemic Mycoses

Involves the deep tissues and organs of the body.

Polyene Macrolides

Act by binding to the fungal cell membrane and causing the fungus to leak electrolytes.

Azoles

Inhibit the synthesis of ergosterol by blocking a specific enzymatic action.

Antimetabolites (5-Fluorocytosine)

A DNA substrate analog that leads to incorrect DNA synthesis.

Allylamines

Inhibit another enzyme in the pathway that leads to synthesis of ergosterol.

Glucan Synthesis Inhibitors

Inhibit glucan synthesis, a key component of the fungal cell wall.

Griseofulvin

Acts by disrupting the mitotic spindle.

Yeast

Single round to oval cells that usually bud to form daughter cells

Pseudohyphae

Chains of cells formed by budding that, when elongated, resemble true hyphae but are constricted at the septa

Mold

Composed of filaments that generally form a colony that may either be fuzzy, powdery, woolly, velvety, or relatively smooth

Hyphae

Tubular, thread-like structures of fungus

Mycelium

Many hyphae intertwined to form a thick mat

Aerial Hyphae

Above the agar surface; Usually support reproductive structures

Vegetative Hyphae

Food-absorbing portion that grows into the agar like roots

Aseptate Hyphae

No cross walls, wide and ribbon-like

Septate Hyphae

Cross walls very evident

Dimorphism

Quality of possessing two different appearances, or phases

Asexual Reproduction

Nuclear and cytoplasmic division, or mitosis, to produce two more identical cells; results in the formation of conidia (conidiogenesis)

Sexual reproduction

Fusion of two compatible haploid nuclei to form a zygote

Dueteromycetes

fungal imperfecti have asexual name and sexual name

Conidiogenesis

Asexual formation of conidia

Blastic Conidiogenesis

Parent cell enlarges, then a septum separates the enlarged portion into a daughter cell

Thallic Conidiogenesis

A septum forms first, and the growing point ahead of it becomes the daughter cell

Arthric Conidiogenesis

Daughter cells fragment within the hyphal strand (thallic)

Holo

All wall layers of the parent cell are involved in daughter conidium development

Entero-

Only inner cell wall layers are included

Blastoconidia

Holoblastic condia formed by budding along hyphae, pseudohyphae, or a single cell, as in yeasts

Poroconidia

Holoblastic conidia produced through a pore in the parent cell wall

Phialoconidia

Conidia arising from a phialide, which is a vase-shaped cell that may be ringed at the top by a cup-shaped collarette

Annelloconidia

Conidia arising from an annellide, which is a vase-shaped cell that exhibits a new ring of material as each conidium passes through

Chlamydoconidia

Thick-walled hyphal survival conidium formed during poor environmental conditions, which will germinate and produce conidia when a better climate occurs

Chlamydospore

thick wall vessicle of C. albians and some other yeast, which neither germinates nor produces conida when mature

Arthroconidia

Conidia produced by fragmentation of the hyphal strand through the septation points

Sporangia

Asexual sac-like structures at the tip of support stalk; contains sporangiospores

Microconidia

Smaller conidia in fungi that produce both large and small conidia

Macroconidia

Larger conidia in fungi that produce both may be single celled, but usually multicelled

Antheridium

male cell

Ascogonium

female cell

Ascus

zygote

Ascospores

formed by nuclear division within the ascus

Ascocarp

protective sac which houses the asci & ascospores

Cleistothecium

completely enclosed ascocarp

Basidium

club-shaped mother cell from which basidiospores arise

Basidiospores

sexual spore formed by the fusion of 2 compatible nuclei and cells into a zygote

Basidiocarp

protective structure which houses basidia and basidiospores

Zygophore

arm of hyphae that extends towards another compatible arm to produce a zygospore

Zygospore

sexual spore formed by fusion of 2 compatible hyphal arms

Zygosporangium

thick outer layer covering a zygospore

Mycelia Sterilia

No reproductive structures, just lots of hyphae

Cottony or Wooly Texture

Very high, dense aerial mycelium

Velvety Texture

Low aerial mycelium

Granular or Powdery Texture

Dense production of conidia

Glabrous Texture

Waxy, smooth, no aerial mycelium

Rugose Topography

Deep furrows irregularly radiating from center

Umbonate Topography

Button-like central elevation

Verrucose Topography

Wrinkled, convoluted surface

Dematiaceous

Darkly colored conidia and hyphae

Hyaline

Lightly colored conidia and hyphae

darkly colored condia and hyphae