THE FUNGI

• YEASTS AND MOLDS

• THE STUDY OF FUNGI IS CALLED MYCOLOGY

• DISTRIBUTION – 20O-30OC

• ECONOMIC IMPORTANCE

Nutrition and Growth

– VAST MAJORITY ARE SAPROBES– ALL ARE CHEMOHETEROTROPHS– PREFER AN ACID pH– MOST ARE OSMOTOLERANT– MOST ARE EITHER AEROBIC OR

FACULTATIVE– NUTRITIONAL NEEDS ARE MINIMAL

Basic Structure of the Fungi

– TYPICALLY EUCARYOTIC– UNICELLULAR AND

MULTICELLULAR(HYPHA)– CELL WALL - CHITIN, CELLULOSE AND

OR GLUCANS– SEPTA - SEPTATE OR NON-SEPTATE

HYPHAE

Classification of the Fungi (Phyla)

• GROUPINGS BASED ON HABITAT, MORPHOLOGY AND SEXUAL COMPLEXITY

1. ZYGOMYCOTA

2. ASCOMYCOTA

3. BASIDIOMYCOTA

4. DEUTEROMYCOTA

Classification of the Fungi (continue)

1. ZYGOMYCOTA– TERRESTRIAL /MAINLY MOLDS– REPRODUCES ASEXUALLY BY THE

PRODUCTION OF A NON-MOTILE SPORE CALLED A SPORANGIOSPORE

– REPRODUCE SEXUALLY BY THE PRODUCTION OF A THICK - WALLED ZYGOSPORE

– RHIZOPUS sp. - NON SEPTATE

Classification of the Fungi (continue)

2. ASCOMYCOTA– TERRESTRIAL / YEASTS AND MOLDS– REPRODUCES ASEXUALLY BY THE

PRODUCTION OF A NON-MOTILE SPORE CALLED A CONIDIOSPORE (CONIDIUM)

– REPRODUCE SEXUALY BY THE PORDUCTION OF SEXUAL SPORES CALLED ASCOSPORES FORMED WITHIN A SAC CALLED AN ASCUS

– PENICILLIUM sp. - MOLD - SEPTATE

Classification

– ASPERGILLUS sp - MOLD - SEPTATE– SACCHAROMYCES CEREVISIAE - YEAST

• REPRODUCE ASEXUALLY BY BUDDING OR BINARY FISSION

• REPRODUCE SEXUALLY BY THE PRODUCTION OF ASCOSPORES IN AN ASCUS

– PLANT DISEASES CAUSED BY MEMBERS OF THE ASCOMYCOTA

• POWDERY MILDEW OF ROSES

• APPLE SCAB

• PEACH LEAF CURL

Classification of the Fungi (continue)

• ERGOT OF RYE - POTENT ALKALOIDS(ERGOTAMINE) – SMOOTH MUSCLE CONTRACTIONS– CONSTRICTION OF ARTERIES– HALLUCINATIONS

• MYCOTOXINS – AFLATOXINS– BRAZILIAN PEANUT MEAL EXPORTED TO

ENGLAND IN 1960– GRAINS STORED IN SILOS MONITORED

Classification of the Fungi (continue)

3. BASIDIOMYCOTA - MOSTLY MUSHROOMS

4. DEUTEROMYCOTA– YEASTS AND MOLDS/SEPTATE– TERRESTRIAL– NONE EXHIBIT A SEXUAL CYCLE– YEASTS REPORDUCE ASEXUALLY BY

BUDDING ONLY– MOLDS REPRODUCE ASEXUALLY BY THE

PRODUCTION OF CONIDIA – MORPHOLOGICALLY IDENTICAL TO

MEMBERS OF THE ASCOMYCOTA

HUMAN FUNGAL INFECTIONS

• MOST FUNGI ARE OPPORTUNISTIC PATHOGENS• INFECTION IS RARE UNLESS SPECIAL

SITUATIONS EXIST– WET WARM SPOT FOR EXTENDED TIME– IMMUNOCOMPROMISED PERSON– MASSIVE SPORE EXPOSURE

• TWO GROUPS OF FUNGAL INFECTIONS– DERMATOMYCOSES

• CAUSED BY MOLDS CALLED

DERMATOPHYTES

Human Fungal Infection (continue)

• SUPERFICIAL INFECTIONS OF HAIR, NAILS AND SKIN

– PRODUCE ENZYMES THAT DIGEST KERATIN

• ALL MEMBERS OF THE DEUTEROMYCOTA• MEDICAL NAMES USE TWO WORDS -

TINEA FOLLOWED BY THE AFFECTED REGION

– TINEA PEDIS, TINEA CRURIS, TINEA CAPITUS

• DERMATOPHYTES BELONG TO THREE GENERA OF FUNGI

– TRICHOPHYTON, MICROSPORIUM, AND EPIDERMOPHYTON

• TREATMENT-GRISEOFULVIN, NYSTATIN– SYSTEMIC MYCOSES

• FOUND TROUGHOUT PHYLA (YEASTS AND MOLDS)

• CAN INFECT DEEPER TISSUES THAN DERMATOPHYTES; KILL

• INITIAL INFECTION THROUGH RESPIRATORY SYSTEM OR BREAK IN SKIN

• MOST ARE DIMORPHIC1. 37o C YEAST STAGE IN BODY2. RT FILAMENTOUS STAGE ON LAB MEDIA AND IN

ENVIRONMENT

• MOST ARE GEOGRAPHICALLY DISTRIBUTED

• DISEASES – MOLDS(6)

1. PNEUMOCYSTIS PNEUMONIA CAUSED BY PNEUMOCYSTIS CARINII (JIROVECI)

2. SAN JOAQUIN VALLEY FEVER CAUSED BY COCCIDIOIDES IMITIS

3. HISTOPLASMOSIS CAUSED BY HISTOPLASMA CAPSULATUM

PNEUMOCYSTIS PNEUMONIA

SAN JOAQUIN VALLEY FEVER (COCCI)

HISTOPLASMOSIS

4. BLASTOMYCOSIS CAUSED BY BLASTOMYCES DERMATITIDIS

5. MUCORMYCOSIS CAUSED BY MUCOR sp

6. ASPERGILLOSIS CAUSED BY ASPERGILLUS sp

• DISEASES - YEASTS1. CANDIDIASIS CAUSED BY

CANDIDA sp

2. CRYPTOCOCCOSIS CAUSED BY CRYPTOCOCCUS NEOFORMANS

• TREATMENT - AMPHOTERICIN B, KETOCONAZOLE, OR FLUCONAZOLE

THE LICHENS

• MUTUALISTIC RELATIONSHIP BETWEEN A FUNGUS AND A PHOTOTROPHIC ORGANISM USUALLY CYANOBACTERIA OR AN ALGA