CHAPTER EIGHT

MEDICAL MYCOLOGY GLOSSARY   

Dr Art DiSalvo
Emeritus Director, Nevada State Laboratory, Reno
Emeritus Director of Laboratories, South Carolina Department of Health and Environmental Control, Columbia

A

ACTIDIONE - Trademark name for cycloheximide, a selective antifungal agent.

AERIAL - mycelium: Hyphal units above the colony agar interface.

ANAMORPH - A somatic or reproductive structure that originates without nuclear recombination (asexual reproduction). Cf. Teleomorph.

ANTHROPOPHILIC - A fungus (dermatophyte) that preferentially grows on man rather than other animals or the soil.

ARTHROCONIDIUM - (pl. arthroconidia)  A thallic conidium released by the fragmentation or lysis of hypha.  It is not notably larger than the hypha from which it    was produced, and separation occurs at a septum.

ARTHROSPORE - See arthroconidium.

ASTEROID BODY -(Splendore-Hoeppli phenomenon) An eosinophilic substance which forms a covering of approximately 10 microns thick around a basophilic yeast especially in sporotrichosis.

B

BASE - The junction of a bud and the mother cell of a yeast.

BIOFILM – Microcolonies of organisms which adhere to a surface (catheter, implant, waterpipe, blood vessel) and which resist removal by fluid movement and have a decreased susceptibility to anti-microbials.

BUD - A type of asexual reproduction commonly found in yeasts.

C

CAPSULE - A hyaline mucopolysaccharide covering around the cell body of certain yeasts (Cryptococcus, Rhodotorula) and some spores and conidia.

CHLAMYDOSPORE - Thick-walled resistant resting spore, especially in Histoplasma capsulatum. See macroconidium. 

COENOCYTIC - Without septa.

COLONIZATION - growth of an organism in a host without tissue invasion.

COLUMELLA - A sterile invagination of a sporangium, as in the Zygomycetes.

COMMENSALISM - A symbiotic relationship in which there is no damage to either participant.

COMPLEMENT FIXATION - A serologic procedure to determine antibody to fungus infections.  Cross reacts  with other systemic fungi but is a quantitative test.

CONIDIOGENOUS CELL - The cell that gives rise to a conidium.

CONIDIUM (pl. conidia) - A reproductive propagule produced in the absence of nuclear recombination, thus representing anamorphic or asexual reproduction.

CONIDIOPHORE - A specialized hypha that gives rise to, or bears a conidium.

CYCLOHEXIMIDE - See Actidione.

D

DERMATOMYCOSIS - An infection of hair, skin and nails caused by the keratinophilic fungi of the genera Trichophyton, Microsporum and Epidermophyton which infect hair, skin and nails.

DERMATOPHYTE - Infection of hair, skin and nails caused by fungi other than dermatophytes.

DEMATIACEOUS - A fungus having brown or black melanotic pigment in the cell wall.

DICHOTOMOUS - A type of branching of hyphae that is repetitious without pattern; the branches are approximately equal in size and equal the stem from which they originated.

DIMORPHIC - Having two forms.  

E

ECHINULATE - Covered with delicate spines.

ECOLOGY - The science of organisms as affected by the factors of their environment.

ECTOENDOTHRIX - Arthroconidia formed on the outside and inside of a hair shaft.

ECTOTHRIX - Forming a sheath of arthroconidia on the outside of a hair shaft.  The cuticle of the hair is destroyed.

EDENTULOUS - The absence of teeth.

ENDOGENOUS - From within.

ENDEMIC - A disease which occurs in a limited geographic area.

ENDOSPORE - A spore formed within some other unit, such as in a spherule. (Typical of Coccidioidomycosis).

ENDOTHRIX - Arthroconidia formed inside a hair shaft.  The cuticle of the hair remains intact.

EXOGENOUS - From without. The source of most mycotic infections is exogenous, i.e. outside the body (the environment)

F

FLOCCOSE - Cottony  or wooly. 

FOMITE - A substance other than food that may harbor and transmit infections organisms. 

FRUITING BODY - Reproductive structures of fungi. (Spores).

FUNGEMIA - Presence of fungi in the blood.  

G

GMS - Gomori methenamine-silver. An excellent stain for visualizing fungi.  The cell wall stains black and the background is green.  Advantage: stains all fungi.  Disadvantage: the tissue reaction is not visible.

GEOPHILIC - Soil-seeking, having a soil reservoir.

GERM TUBE - Initial hypha from a sprouting conidia, spore or yeast.

GLABROUS - Smooth.

H

H & E - Hemotoxylin and Eosin.  A stain used routinely for general pathology.  Most fungi are visible, but not distinctive. Fungal walls usually stain blue or purple. Other cells stain pink.  Advantage: the tissue reaction is visible.

HYALO - Colorless; also hyaline.

HYPHA (pl. hyphae) - A vegetative filament of a fungus.

HYPHOMYCETE - An fungus that produces mycelium with or without discernible dark pigment in the cell walls.  If the hypha is pigmented, it is called dematiaceous; if colorless, hyaline.

I

IMMUNODIFFUSION - A serologic test to determine the presence of antibody by double diffusion precipitation in auger.

INCIDENCE - The number of new cases of a disease occurring during a specific period.

INCUBATION PERIOD - The time between an infectious agent entering the body and the onset of clinical symptoms.

INDURATED - Hard.

INTERCALARY - Formed within a hyphal unit.

INVASIVE - The entrance and growth of an organism in tissue.  

L

LATEX AGGLUTINATION - A simple serologic procedure to detect antibody by the clumping of antigen coated particles.

M

MACROCONIDIUM - The larger of two types of conidia produced in the same manner by the same fungus.

MICROCONIDIUM (pl. microconidia) - The smaller of two types of conidia produced in the same manner by the same fungus.

MOLD - See Mycelium.

MURIFORM - Like a wall; multicellular, with transverse and longitudinal septations.

MYCELIUM - The mass of hyphae making up a fungus colony.

MYCOLOGY -  The study of fungi.

O

ORGANOTROPISM - The predilection of a fungus to invade a particular organ.

P

PHAEO - Darkly pigmented.

PREVALENCE - The total number of cases of a disease in existence at a certain time in a designated area.

PROBE – A specific nucleic acid sequence (known) used to detect a complimentary sequence in an unknown fungus.

PSEUDOHYPHA (pl. pseudohyphae) -  A fragile string of cells that result from the budding of blastoconidia that have remained attached to each other.  The septa separating the cells are complete and there is no cytoplasmic connection, as is found in most true septate hypha.  

R

RHIZOID - A root like structure.  Used in the identification of some Zygomycetes.

RESERVOIR - A permanent host or carrier from which infection is spread.

S

SAPROBE - An organism which requires organic material as a source of energy.

SAPROPHYTE - See Saprobe.

SCLEROTIC BODY - (sclerotic cell).  The tissue form (yeast-like) of most agents of chromomycosis. Dark brown, single or in short chains, occasionally septate, 5 - 15 microns in diameter.

SENSITIVITY - The ability to detect all patients with a specific disease.

SEPTUM (pl. septa) - A cross wall. 

SEROLOGY - The study of antigens or antibodies in peripheral blood to support, confirm or rule out certain diseases.

SOURCE -  The clinical specimen most likely to yield the etiologic agent. ALSO  The ecologic niche or natural nidus of the etiolgic agent.

SPECIFICITY - The capacity to identify a disease correctly.

SPINOSE - Covered with small spines.

SPORANGIOPHORE - A specialized hypha that gives rise to a sporangium.

SPORANGIOSPORE - A reproductive unit formed in a sporangium.

SPORANGIUM -  A cell within which spores are borne by progressive cleavage.

SPORE - A reproductive propagule produced internally by "free cell" formation, as in the ascomycete, i.e., complete spores formed all at once around the nuclei available or by "progressive cleavage," as in a sporangium.

STOLON - Hypha from which rhizoids and sporangiophores are produced, as in the genus Rhizopus.

SYNONYM - Another (especially a later or illegitimate) name for a species or taxonomic group.  

T

TELEOMORPH - The sexual state of a fungus. 

TERMINAL - Formed at the end of a structure. 

TINEA - Literally "moth". A clinical term meaning "ringworm".

THERMOTOLERANT - Ability to grow at high temperatures (usually above 42 C).

TUBERCULATE - Spines or finger-like projections on macroconidia, characteristic of Histoplasma capsulatum. 

V

VESICLE - A swollen or bladder-like cell.

VIRULENCE - Degree of pathogenicity; the disease producing capacity of an organism.

Y

YEAST - A unicellular fungus, usually round or ovoid, that reproduces by budding.

Z

ZOOPHILIC - Infecting lower animals rather than man.  

The glossary was derived from several sources including: Rippon, Medical Mycology, Third Edition; Emmons, Binford, Utz, and Kwon-Chung, Medical Mycology, third Edition; Ainsworth & Bisby's Dictionary of the Fungi, Seventh Edition; and other keen authorities.  

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