Fungi: Identification and Classification in Mycology 1

Taxol

________ (anticancer drug) from plants= produced also by Taxomyces fungi.

Dimorphism

________ in nonpathogenic fungi may depend on other factors Ex: Carbon dioxide concentration.

Phialoconidia

________- produced by phialide (vase- shaped) in Aspergillus fumigatus 31.

Opportunistic Infection

________ by Candida albicans in an AIDS Patient disease is called oral thrush 37.

Claviceps purpurea

________: Produces ergot toxin in wheat and rye 17.

Asexual Reproduction

________: Conidiospores not enclosed in a sac.

Acervulus

________ (fruiting body) is a distinct feature of Colletotrichum Glomerella teleomorph form of fruiting body 16.

Conidiophores

________: specialized hyphae that produces conidia Macroconidia: big spores Microconidia: small spores Arthroconidia /Arthrospores: conidia from fragmentation of hypha Blastoconidia /blastospores: conidia formed thru budding Chlamydospore: Resistant spores.Thick- walled spore formed within a hyphal segment.When conditions are not favorable.

Vulvivaginal

________ or oral thrush, occurs in newborns, AIDS patients, people under broad spectrum antibiotics Vulvoginal yeast infection: painful inflammatory condition, ulceration & discharge Cutaneous candidiasis- chronically moist areas of skin & burn patients 38.

Coccidioides immitis

________ is dimorphic but temperature is not the factor for its dimorphism.

Ingestion

________ causes mushroom poisoning in Amanita 8.

Molds

________ Thallus: Body of a(n) ________ or fleshy fungus Hyphae: Long filaments of cells joined together.

Sexual Reproduction

________: Ascospores enclosed in a sac- like structure (ascus)

Nosocomial

(________: hospital acquired) Humans are resistant to fungal infection except for dimorphic fungi Provoke allergic response to host (molds growing in homes, spores on atopic allergies) Major factor for infection: alteration of immune system.

CHARACTERISTICS OF FUNGI

Spores cause fatal pulmonary hemorrhage in infants ________: DIMORPHISM 43.

Stachybotrys

________ grows on cellulose (dead plants), water damaged walls of homes.

medical diagnosis

Media for Fungi: culture remains definitive for ________ Non- selective Synthetic media for molds and yeasts: PDA (potato dextrose agar) .best recommended for plant pathogenic molds.

Molds Mycelium

________: loose network, Large, visible, filamentous mass made up of many hyphae.

Candidiasis

________: Caused mainly by Candida albicans.

Humans

________ become an accidental host by- Inhalation of spores & by trauma (wounds) Economic losses thru damage to plant crops (phytopathogens) Most fungal infections: nosocomial and /or occur in babies, immunocompromised individuals (opportunistic infections)

Candida albicans

________: normal flora of skin, mucous membranes, GIT Opportunistic C.albicans, attaches to epithelial cells but invades deeper tissues through pseudohyphae.

Zygomycota Division

No Septa: Easier Identification for ________ members Spores are inside sporangium.

Sexual spores

________= fusion of nuclei of mating cells of same species.

Cryptococcus neoformans

________: asexual stage Amanita: Mushroom produces lethal toxins to humans.

Humans become an accidental host by -Inhalation of spores & by trauma (wounds) Economic losses thru damage to plant crops ( phytopathogens) Most fungal infections

nosocomial and/or occur in babies, immunocompromised individuals (opportunistic infections)

Virulence Factors

Fungi Capsules Adhesion factors Hydrolytic Enzymes Inflammatory stimulants Toxin-like substances

Allergies & Asthma Farmers lung Teapickers lung Bark strippers disease Mycotoxicoses

ingesting or inhaling fungal toxins Aflatoxins by Aspergillus flavus

Stachybotrys chartarum

Sick building syndrome.Hematologic & neurological damage

Mycotoxins by mushroom

potent neurotoxins, result in deathPhalloidin & Amanitin by Amanita phalloides (death cap)

Basidiomycota

mushrooms 4

Zygomycota

no septa in hyphae Zygomycota hyphae

No Septa

Easier Identification for Zygomycota Division members No Septa/ coenocytic hyphae Faster growth (5 days) Grows faster in high sugar content conjugation fungi & Saprophytes Rhizopus stolonifer ( common black bread mold) Rhizopus & Mucor Opportunistic

No Septa

Easier Identification for Zygomycota Division members Spores are inside sporangium

For Basidiomycota and Ascomycota members

asexual form called anamorph sexual form called teleomorph Some identified deuteromycota members were eventually identified as the asexual forms of Basidiomycota or Ascomycota This of course bring about confusion in identifying Fungi like molds all over the world

Mushrooms are under Basidiomycota

teleomorphs

Molds in Petridish

usually anamorphs 15

Major Phyla To avoid confusion, scientists therefore mentions the scientific name of anamorph & teleomorph Example

Colletotrichum gloeosporioides is the anamorph

Asexual Reproduction

Conidiospores not enclosed in a sac

Sexual Reproduction

Ascospores enclosed in a sac-like structure (ascus)

Claviceps purpurea

Produces ergot toxin in wheat and rye 17

IMPORTANT DIVISIONS OF FUNGI Basidiomycota (Club Fungi)

Have septate hyphae

Classical Identification

Molds

Vegetative Hypha

obtains nutrients

Reproductive Hypha

Bears reproductive spores Projects above surface of medium 9/5/12

Characteristics of Fungal Hyphae

Septate versus Coenocytic 28

Molds Mycelium

loose network, Large, visible, filamentous mass made up of many hyphae

LIFECYCLE OF FUNGI Asexual spores

Formed by the aerial reproductive hyphae.genetically identical to the parent (commonly found) Clinical identification is based on microscopic examination of asexual spores/ conidia

Phialoconidia

produced by phialide (vase-shaped) in Aspergillus fumigatus 31

Fungi forms based on colony appearance 2.yeasts Moist, creamy Opaque or pasty colonies on media (48 hrs) Unicellular fungi Nonfilamentous oval or spherical cells Reproduce by mitosis Facultative anaerobes Fission yeasts

Divide evenly to produce two new cells (Schizosaccharomyces)

Candida albicans

normal flora of skin, mucous membranes,GIT Opportunistic C.albicans, attaches to epithelial cells but invades deeper tissues through pseudohyphae

Candidiasis

Caused mainly by Candida albicans

Germ tubes

hyphal-like extension of yeast cell

Rapid Urease test

Hydrolysis of urea by urease to produce ammonia.Ammonia wil change the medium from yellow to red (separates Candida from Cryptococcus)

C.albicans is Urease test negative

no color change

Dimorphism

switching forms

CHARACTERISTICS OF FUNGI

DIMORPHISM Mold Yeast 42

Dimorphism in nonpathogenic fungi may depend on other factors Ex

Carbon dioxide concentration

Spores cause fatal pulmonary hemorrhage in infants CHARACTERISTICS OF FUNGI

DIMORPHISM 43

CHARACTERISTICS OF FUNGI

DIMORPHISM

CHARACTERISTICS OF FUNGI Dimorphic Fungi Disease Histoplasma capsulatum histoplasmosis Sporothrix schenckii Sporotrichosis

ulcers in skin, lymph node Coccidioides immitis coccidioidomycosis Blastomyces dermatitidis Blastomycosis Paracoccidioides brasiliensis Paracoccidioidomycosis (mucosal lesions by eating vegetation with spores) Penicillium marneffei From bamboo rats in China Penicillium marneffei is recently added as dimorphic fungi

Coccidioides life cycle

dimorphism

Primary pathogens

dimorphic types