FILAMENTOUS FILAMENTOUS ASCOMYCETES IASCOMYCETES I

IB 371 - General Mycology

Lecture 21

Thursday, November 6, 2003

FILAMENTOUS ASCOMYCETESFILAMENTOUS ASCOMYCETES

Mycelium septateMycelium septate Septa with single pore or many small Septa with single pore or many small

porespores Woronin bodies present at poresWoronin bodies present at pores Nuclei haploid, except during meiosisNuclei haploid, except during meiosis Antheridia & ascogonia may or may Antheridia & ascogonia may or may

not be formed prior to meiosisnot be formed prior to meiosis Ascogenous hyphae formedAscogenous hyphae formed

SEPTAL PORESEPTAL PORE

Woronin Bodies

NUCLEUS PASSING NUCLEUS PASSING THROUGH PORETHROUGH PORE

GENERAL LIFE CYCLE

MEIOSIS & ASCOSPOROGENESIS

In-class activity

How is a crozier like a clamp connection?

ASCOGONIAASCOGONIA

TEM of crosier by Charles Mims

Crosiers & Developing Asci

TEM of developing ascus by Charles Mims

TEM of ascospores developing within an ascus by Charles Mims

TEM of maturing ascospores within an ascus by Charles Mims

TYPES OF ASC0MATATYPES OF ASC0MATA CleistotheciumCleistothecium - round & completely

closed ApotheciumApothecium - open & saucer shaped PeritheciumPerithecium - flask shaped with an

opening at the top PseudotheciumPseudothecium - may look like a

perithecium but it is stromatic & is formed prior to the ascogenous hyphae

TYPES OF ASCITYPES OF ASCI

Prototunicate Prototunicate - one functional wall that - one functional wall that deliquesces earlydeliquesces early

UnitunicateUnitunicate - one functional wall that - one functional wall that remains as one wall when ascospores remains as one wall when ascospores are dischargedare discharged

Bitunicate (fissitunicate)Bitunicate (fissitunicate) - two - two functional walls that separate when functional walls that separate when ascospores are dischargedascospores are discharged

HamatheciumHamathecium

None Paraphyses Apical paraphyses Pseudoparaphyses Catenophyses

ONYGENALESONYGENALES Sexual apparatus - Sexual apparatus - antheridiumantheridium

surrounded by a coiled surrounded by a coiled ascogoniumascogonium

Homothallic or heterothallicHomothallic or heterothallic

Asci Asci unitunicateunitunicate, globose to subglobose, globose to subglobose

Ascus wall breaks down to release Ascus wall breaks down to release ascospores (ascospores (deliquescentdeliquescent))

Ascospores usually non-septate Ascospores usually non-septate (amerospores)(amerospores)

ONYGENALESONYGENALES

Ascoma is a cleistotheciumcleistothecium of thin cottony hyphae or very thin layer of pseudoparenchymapseudoparenchyma tissue

Peridial hyphae Peridial hyphae (peridiumperidium = wall of cleistothecium) similar to vegetative hyphae, colored and/or rough walled

ONYGENALESONYGENALES

AnamorphsAnamorphs are solitary holoblastic are solitary holoblastic (determinate) or arthric (thallospores)(determinate) or arthric (thallospores)

Taxonomic characters Taxonomic characters - peridial wall - peridial wall ornamentation, ascospore charactersornamentation, ascospore characters

EcologyEcology - - keratinophilickeratinophilic, , cellulolytic cellulolytic - - saprophytes and parasites of animalssaprophytes and parasites of animals

HabitatHabitat - soil, plant debris, faecal pellets of - soil, plant debris, faecal pellets of carnivores, birds’ nests and droppings, hoofs carnivores, birds’ nests and droppings, hoofs and hornsand horns

PATHOGENS OF HUMANSPATHOGENS OF HUMANS

ringworm (tinea), athletes foot, jock itchringworm (tinea), athletes foot, jock itch Trichophyton (A)/ Arthroderma (T)Trichophyton (A)/ Arthroderma (T) Microsporum (A)/ Nannizzia (T)Microsporum (A)/ Nannizzia (T) Geophilic - soil inhabiting species that are only Geophilic - soil inhabiting species that are only

occasionally pathogenic to humansoccasionally pathogenic to humans Zoophilic - live on animals but occasionally Zoophilic - live on animals but occasionally

infect humansinfect humans anthropophilic - species that live only on anthropophilic - species that live only on

humanshumans

DERMATOPHYTESDERMATOPHYTES

KeratinophylicKeratinophylic - - live on hair, nails, dead skin live on hair, nails, dead skin cells (protein keratin)cells (protein keratin)

Symptoms caused by enzymes that irritate Symptoms caused by enzymes that irritate epidermal cellsepidermal cells

Treatment may be systemic (griseofulvum) or Treatment may be systemic (griseofulvum) or topical (azole antifungals, ciclopirox, others)topical (azole antifungals, ciclopirox, others)

NORTH AMERICAN NORTH AMERICAN BLASTOMYCOSISBLASTOMYCOSIS

Blastomyces dermatitidis (A) / Blastomyces dermatitidis (A) / Ajellomyces dermatitidis (T)Ajellomyces dermatitidis (T)

Thought to occur in soil in midwest, Thought to occur in soil in midwest, US-Canadian border from the Great US-Canadian border from the Great Lakes to the east coast.Lakes to the east coast.

Infection through inhalation of conidia Infection through inhalation of conidia into the lungsinto the lungs

NORTH AMERICAN NORTH AMERICAN BLASTOMYCOSISBLASTOMYCOSIS

fever, chills, cough, chest pain, fever, chills, cough, chest pain, pneumonia (sometimes fatal), skin pneumonia (sometimes fatal), skin lesionslesions

fungus is dimorphic - filamentous in fungus is dimorphic - filamentous in nature, yeast-like in body (or above nature, yeast-like in body (or above 30C)30C)

Itraconazole daily for six months or if Itraconazole daily for six months or if life threatening, amphotericin Blife threatening, amphotericin B

dimorphic - yeast dimorphic - yeast stagestage

HISTOPLASMOSISHISTOPLASMOSIS Histoplasma capsulatum Histoplasma capsulatum (A) / (A) / EmmonsiellaEmmonsiella

(Ajellomyces) (Ajellomyces) capsulatumcapsulatum Grows as hyphae in soil enriched with bird Grows as hyphae in soil enriched with bird

droppingsdroppings Ohio and Mississippi river valleys, Great Ohio and Mississippi river valleys, Great

Lakes to east coast, Florida, TexasLakes to east coast, Florida, Texas Infection by breathing in conidiaInfection by breathing in conidia

HISTOPLASMOSISHISTOPLASMOSIS most people remain asymptomaticmost people remain asymptomatic

fever, chills, headache, chest pain, malaise, fever, chills, headache, chest pain, malaise, nodules in the lungnodules in the lung

chronic pulmonary histoplasmosis mimics TB chronic pulmonary histoplasmosis mimics TB (diagnosis is very important)(diagnosis is very important)

acute disease requires treatment with acute disease requires treatment with amphotericin B, followed by itraconazoleamphotericin B, followed by itraconazole

immunocompromised patients require lifelong immunocompromised patients require lifelong treatment if infectedtreatment if infected

Conidium of H. capsulatum

Yeast stage of H. capsulatum

VALLEY FEVERVALLEY FEVER

aka desert rheumatism, California disease - aka desert rheumatism, California disease - occurs in desert SW, Mexico, SAoccurs in desert SW, Mexico, SA

Coccidioides immitis Coccidioides immitis (only imperfect state (only imperfect state known, connected to Onygenales by 18S r-known, connected to Onygenales by 18S r-DNA sequences)DNA sequences)

Inhalation of conidia (arthrospores), Inhalation of conidia (arthrospores), symptoms somewhat similar to symptoms somewhat similar to histoplasmosishistoplasmosis

Most people recover but sometimes the Most people recover but sometimes the disease is fatal disease is fatal

EUROTIALESEUROTIALES

Asci free on mycelium or in ascomataAsci free on mycelium or in ascomata Ascomal wall thin, mesh-like or solid Ascomal wall thin, mesh-like or solid

layerlayer Sexual fusion usually by a trichogyne Sexual fusion usually by a trichogyne

and undifferentiated hyphaand undifferentiated hypha Asci spherical to ovoid, evanescentAsci spherical to ovoid, evanescent

EUROTIALESEUROTIALES

Ascospores 1-celled, oblate, Ascospores 1-celled, oblate, spherical, globosespherical, globose

Ascospores smooth or with Ascospores smooth or with reticulations, spines or thickened ringsreticulations, spines or thickened rings

Conidial states phialidic, conidia Conidial states phialidic, conidia seceding schizolytically, in dry chainsseceding schizolytically, in dry chains

EUROTIALESEUROTIALES

Ubiquitous in distributionUbiquitous in distribution Found commonly in soils and on Found commonly in soils and on

plant litterplant litter Associated with cellulosic, starchy Associated with cellulosic, starchy

or oily substratesor oily substrates

EUROTIALESEUROTIALES

DecomposersDecomposers

Agents of biodeteriorationAgents of biodeterioration

Human pathogens (aspergillosis, Human pathogens (aspergillosis, penicilliosis)penicilliosis)

Aflatoxin & ochratoxin production Aflatoxin & ochratoxin production

EUROTIALESEUROTIALES

Important in cheese industryImportant in cheese industry Production of industrially important Production of industrially important

acids (citric, gallic, fumaric, oxalic, acids (citric, gallic, fumaric, oxalic, gluconic), and enzymes (alpha-gluconic), and enzymes (alpha-galactosidase)galactosidase)

Production of antibiotics (penicillin, Production of antibiotics (penicillin, cephalosporin, griseofulvum cephalosporin, griseofulvum

PENICILLIUMPENICILLIUM

Teleomorph genera – Eupenicillum Talaromyces

Discovery of penicillin Changed the world. In 1928, Alexander Fleming found P. notatum

growing on a Petri dish (dish is still preserved). In 1939, Howard Florey & Ernest Chain began

work on how to use and identify the antibiotic produced by P. notatum.

In 1941, work began in Peoria, IL, to increase production of the antibiotic. “Moldy Mary” brought in a moldy melon colonized by the high yielding species, P. chrysogenum.

Discovery of penicillin

In 1942, the first patient was treated successfully in New Haven, Connecticut (Anne Miller).

In 1945, Fleming, Florey & Chain received the Nobel Prize for their work.

PENICILLIUMPENICILLIUM

From Hanlin, 1998. Illustrated Genera of Ascomycetes Vol II

From Hanlin, 1998. Illustrated Genera of Ascomycetes Vol II

ASPERGILLUSASPERGILLUS

Teleomorph genera - Eurotium Neosartorya Emericella

Eurotium/AspergillusEurotium/Aspergillus

ASPERGILLUSASPERGILLUS

http://www.bsu.edu/classes/ruch/msa/geiser/1.jpg

Conidial state of Aspergillus (Picture from David Geiser)

Hülle cells (picture from David Geiser)

http://www.bsu.edu/classes/ruch/msa/mims/1-51.jpg

Young conidiophores of Aspergillus (SEM from Charles Mims)

Mature conidiophores of Aspergillus (SEM from Charles Mims)

SEM of conidiogenesis in Aspergillus (from Charles Mims)

SEM of conidiogenesis in Aspergillus (from Charles Mims)

EUROTIUM ASCIEUROTIUM ASCI

ASCOSPORES OF ASCOSPORES OF EUROTIUMEUROTIUM

From Hanlin, 1998. Illustrated Genera of Ascomycetes Vol II