FILAMENTOUS ASCOMYCETES I IB 371 - General Mycology Lecture 21 Thursday, November 6, 2003.
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Transcript of FILAMENTOUS ASCOMYCETES I IB 371 - General Mycology Lecture 21 Thursday, November 6, 2003.
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
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
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
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
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
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.
http://www.bsu.edu/classes/ruch/msa/geiser/1.jpg
Conidial state of Aspergillus (Picture from David Geiser)
http://www.bsu.edu/classes/ruch/msa/mims/1-51.jpg
Young conidiophores of Aspergillus (SEM from Charles Mims)