MAJOR FUNGI
Assist Prof Dr.
Syed Yousaf Kazmi
OBJECTIVES
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Classify Fungi
Clinical significance of fungal infections
List common diseases caused by fungi
Importance of opportunistic fungal infections
in human
INTRODUCTION TO FUNGI
• 80,000 species of fungi- less
than 400 are medically
important
• Beneficial to humankind
• Breaking down and recycling
organic matter
• Production of food and
spirits, including cheese,
bread, and beer
• Antibiotics (eg, penicillin) and
immunosuppressive drugs
e.g. Cyclosporine
INTRODUCTION TO FUNGI
• Eukaryotic Organisms
• Yeast Form (Unicellular), Mold Form
(Multicellular)
• Obligate or facultative aerobes
• Natural habitats being water, soil, and organic
debris
• Human are gen resistant to fungal infections
• Some form of immune deficiency in patients with
fungal infections
• Normal flora e.g. Candida albicans
Classification of the fungi
1. True yeast
Cryptococcus
neoformans
2. Yeast like fungi
Candida albicans
3. Dimorphic fungi
Histoplasma
capsulatum,
Blastomyces dermatidis
4. Moulds
Aspergillus fumigatus
CLASSIFICATION OF FUNGI
Category
Mycosis
Causative Fungal Agents
SUPERFICIAL
Pityriasis versicolor
Malassezia species
CUTANEOUS
Dermatophytosis
SUBCUTANEOUS
Candidiasis of skin, mucosa,
or nails
Sporotrichosis
Microsporum species, Trichophyton species, and
Epidermophyton floccosum
Candida albicans and other Candida species
Mycetoma
ENDEMIC
(PRIMARY,
SYSTEMIC)
OPPORTUNISTIC
Sporothrix schenckii
Coccidioidomycosis
Pseudallescheria boydii, Madurella
mycetomatis, and others
Coccidioides posadasii and Coccidioides immitis
Histoplasmosis
Histoplasma capsulatum
Systemic candidiasis
Candida albicans and other Candida species
Cryptococcosis
Cryptococcus neoformans and Cryptococcus
gattii
Aspergillus fumigatus etc
Aspergillosis
Mucormycosis (zygomycosis) Species of Rhizopus, Absidia, Cunninghamella,
FUNGAL DISEASES IN HUMANS
Allergic reaction
Result from inhaling fungal spores
React to fungal toxin
Many have hallucinogenic
properties
Certain species produces toxins
implicated in cancer. e.g. Aflatoxin
Mycoses
Fungi grows on or in the body
Can be superficial, intermediate,
systemic
Economic impact
Destroy human food supply
causing starvation
FUNGAL ALLERGIES & MYCOTOXICOSES
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Fungal spores -common sources of
Atopic allergies
Asthma, Farmer’s lung,
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Fungal toxins lead to
mycotoxicoses
Ergot poisoning -ingestion of
moldy grain
Fungal Aflatoxin related to human
cancer
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FUNGAL DISEASES-MYCOSIS
Mycoses are classified into
A. Superficial mycoses:
Infections of hair shafts and
superficial epidermal cells.
Prevalent in tropical climates
B. Cutaneous mycoses:
keratinized epidermis (skin, hair,
nails)
Trichophyton, Microsporum,
Epidermophyton
Examples:
– Ringworm (Tinea capitis and T.
corporis)
– Athlete’s foot (Tinea pedis)
– Jock itch (Tinea cruris)
FUNGAL DISEASES-MYCOSIS
C. Subcutaneous mycoses:
Invade traumatized beneath skin
Destructive local lesions
–Lymphocutaneous sporotrichosis
–Chromoblastomycosis
–Mycetomal
D. -Systemic mycoses:
Fungal infections deep within the body
Usually caused by fungi that live in the soil and are inhaled.
Examples:
–Histoplasmosis (Histoplasma capsulatum):
–Coccidiomycosis (Coccidioides immites):
FUNGAL DISEASES
Opportunistic mycoses:
 Caused by organisms that are
generally harmless unless individual
has weakened defenses:
- AIDS and
cancer patients
- Individuals treated with broad
spectrum antibiotics
-Very old or very young individuals
(newborns).
e.g. Inhalation of Aspergillus spores.
Yeast Infections by Candida albicans.
CUTANEOUS FUNGAL
INFECTIONS:
Thrush
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Cutaneous Mycosis
MYCETOMA
1. When Soil Microbes Are Accidentally
Implanted Into The Skin
2. Progressive, Tumor-like Disease Of The Hand
Or Foot Due To Chronic Fungal Infection;
May Lead To Loss Of Body Part
3. Caused By Pseudallescheria or Madurella
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Tinea Capitis
Gray Patch
Tinea corporis – body ringworm
Tinea Unguium – Nail Infection
Tinea Pedis – Athlete’s Foot Infection
Superficial mycoses
1. Tinea versicolor causes mild scaling, mottling
of skin
2. White piedra is whitish or colored masses on
the long hairs of the body
3. Black piedra causes dark, hard concretions on
scalp hairs
1. White & black piedra
1. Transmission is often mediated by shared hair brushes or combs
2. Several members of a family are usually infected at the same time
3. Infected areas must often be shaved to remove the fungi
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Cryptococcus neoformans
1. A widespread encapsulated
yeast that inhabits soils
around pigeon roosts
2. Common infection of AIDS,
cancer or diabetes patients
3. Infection of lungs leads to
cough, fever, & lung nodules
4. Dissemination to meninges &
brain can cause severe
neurological disturbance &
death
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Pneumocystis jerovecii
1. A small, unicellular fungus
that causes pneumonia
(PCP), the most prominent
opportunistic infection in
AIDS patients
2. This pneumonia forms
secretions in the lungs that
block breathing & can be
rapidly fatal if not controlled
with medication
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MUCORMYCOSIS
1. Genera most often
involved are Rhizopus,
Absidia, & Mucor
2. Destructive invade the
membranes of the nose,
eyes, heart, & brain
3. Strong association with
diabetes mellitus
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LIST OF IMPORTANT FUNGAL
INFECTIONS
 Candidiasis
 Cryptococcosis
 Pneumocystis jerovecii
 Aspergillosis
 Tinea +
 Maduromycosis
Blastomycosis
 Histoplasmosis
 Coccidioidomycosis
 Paracoccidioidomycosis
 Mucormycosis