Lecture 1 Principles of Mycology

bacteria

fungi are eukaryotes that are more complex than ________

anamorph

which fungal form is most likely seen in tissue

16S

what is the subunit rRNA that is in the 30S

23S and 5S

what is the subunit rRNA that is in the 50S

18S

what is the subunit that is in the 40S rRNA

28S, 5.8S, and 5S

what is the subunit that is in the 60S rRNA

eukaryotes with an ergosterol biosynthetic pathway

hu

branching filaments

fungi are unicellular or may differentiate and become multicellular by the development of:

asexually or sexually

how do fungi reproduce?

subacute to chronic with indolent, relapsing features

Fungal infections (= mycoses) vary greatly in their manifestations but tend to be:

uncommon with fungal infections

Acute diseases, such as those produced by many viruses and bacteria, are:

about 200

about how many fungi are considered pathogenic (low number due to temperature)

mycoses

what are fungal infections called?

slower

growth of fungi compared to bacteria?

chemoheterotrophic

fungus are classified as

ethanol

primary fungal metabolite example

penicillin

secondary fungal metabolite

teleomorph

form that produces sexual spores

anamorphic

form that produces asexual spores

mitosis only

asexual spore formation

involving meiosis

sexual spore formation

fungi imperfecti

there are no known teleomorph

classic fungal taxonomy

based on cellular morphology and spore production

modern taxonomy

ultrastructure, biochemical, and molecular characteristics

anamorph

clinically what is more relevant

ajellomyces

what is an example of a telomorph

histoplasmosis capsulatum

what is an example of an anamorph

chitin and glucan

fungi cell wall is rigid composed of:

ergosterol

fungal plasma membrane has what as the major sterol?

calcofluor-white

what can chitin be stained with?

anti-fungals

ergosterol is a target for:

budding or fission

how do yeasts reproduce?

Pseudohyphae

yeasts may form:

unicellular

yeast are usually:

round, pasty or mucoid

structure of yeast colonies

multicellular -- hyphae

molds are:

apical extension

Molds elongate at their tips by:

coenocytic or septate

hyphae of molds

mycelium (colonies filamentous, hairy, woolly)

what do molds produce?

vegetative hyphae

grow into agar

aerial hyphae

stick out of agar and are usually colored because they contain spores

septate hyphae

clear septum between cells

ascomycetes

septae hyphae have many

coenocytic hyphae

have few septae - cell with many nuclei in it

mucormycetes

coenocytic hyphae

septate hyphae with clamp connections

basidiomycetes - fungus on pizza

hyphae with arthroconidia and disjunction cells

coccodiodes spp.

sporangiophore

produces sporangium that contains spores - spores break easily and spill out

aspergillus

produce conidiophore and produce naked conidia - spores that fly away

conidia

this is born naked on a specialized structure

mucormycetes, basidiomycetes, ascomycetes, microsporidia

major phyla causing disease in humans

zygomycetes

another name for mucormycetes

mucormycetes

Molds with sparsely septate, coenocytichyphae

asexual sporangiospores

what do mucormycetes produce?

rhizoids

Root-like structures, present in some genera of mucormycetes

irregular width, broad angle of branching

mucormycetes are hyphae with

rhizopus and mucor

what are some examples of mucormycetes

yeasts

basidiomycetes are typically filamentous, some are:

clamp connections

basidiomycetes have hyphae with:

sexual reproduction

basidiomycetes undergo:

cryptococcus and malassezia

what are some examples of basidiomycetes

ascomycetes

Septate hyphae, with fairly regular width (tube-like)

Pneumocystidomycetes

Trophic forms and cystlike structures - Pneumocystis jirovecii

Saccharomycetes

Budding yeasts and hyphae, pseudohyphae Candida and Saccharomyces

Eurotiomycetes

Budding yeasts, septate hyphae, asexual conidia borne on specialized structures Dermatophytes, Blastomyces, Histoplasma, Aspergillus, Fusarium,Scedosporium spp

colonization

transient or chronic association with the host

disease (mycosis)

fungus-host association (infection) results in pathological process with deleterious effects on physiological functions of the host due to one or more of the following: fungal growth, production of toxins, immunological response to pathogen

strict (primary) pathogen and opportunistic (secondary) pathogen

fungal pathogenesis can include:

mycotoxicoses

poisoning with mycotoxins - neurotoxins, hepatotoxins

mycetism

mushroom poisoning

infections and allergies

mycoses can include:

superficial mycoses

limited to surfaces of skin and hair

pityriasis versicolor

what is an example of superficial mycoses

malassezia furfur

what is the causitive agent of pityriasis versicolor

cutaneous mycoses

Infections of the keratinized layers of skin, hair, and nails - Itching, scaling, broken hairs, ring-like patches on skin, thickened, discolored nails

dermatophytes

what is an example of a cutaneous mycoses

subcutaneous mycoses

Deeper layers of skin, cornea, muscle, connective tissue - Traumatic inoculation, localized infection, abscess, ulcers, draining sinus tracts

sporothrix schenckii

what is an example of a subcutaneous mycoses

endemic mycoses

caused by dimorphic fungi which exist in both yeast and mold form

geographic regions

endemic mycoses are usually confined to:

systemic mycoses

primary infection in the lung with subsequent dissemination to other organs/tissues

true pathogens

endemic mycoses deals with:

opportunistic mycoses

environmental or commensal fungi - low or limited virulence

debilitated, immunosuppressed individuals

opportunistic mycoses really cause disease in:

implants and catheters

where can opportunistic mycoses be?