Fungal Diseases and Their Impact on Health and History

Oomycota

fungus-like organisms but differ in having cellulose in their cell walls instead of chitin, diploid nuclei, and a plant-like mitochondrial structure.

Potato Famine

caused massive starvation, emigration, and social unrest, significantly shaping Irish and global history.

Phytophthora infestans

It helped establish plant pathology by proving that ________________ caused late blight, supporting the idea that microorganisms cause disease.

'Fungi' in quotes

Because Oomycota are not true fungi but were originally classified as such due to morphological similarities.

Koch's postulates

help establish causation between pathogens and disease, proving that microorganisms are the cause.

Bordeaux mixture

(copper sulfate and lime) was invented to combat downy mildew in grapes.

Phytophthora infestans and Plasmopara viticola

____________ causes late blight in potatoes, and ___________________ causes downy mildew in grapes. Both reproduce via sporangia and zoospores.

Wheat rust life cycle

follows a complex life cycle with five distinct spore stages and requires two hosts.

Five spores of rust fungus

Spermogonia, aeciospores, urediniospores, teliospores, and basidiospores.

Transfer spores in rust life cycle

Aeciospores and basidiospores

Puccinia Pathway

A migration pathway for wheat rust spores that follows the planting cycles from Mexico to Canada.

Wheat Rust

Wheat Rust (Puccinia graminis), Coffee Rust (Hemileia vastatrix), Stinking Smut (Tilletia foetida) - affecting wheat and coffee.

Robigus

the Roman god of rust, and Romans sacrificed animals to prevent rust outbreaks.

Origin of Gingerbread

originated as a way to mask the bad taste and smell of wheat contaminated with Stinking Smut.

Teliospore to Basidospore development

Teliospores germinate into basidia, which produce basidiospores that restart the rust life cycle.

Factors contributing to introduced diseases

Global trade, lack of resistance, climate conditions, and genetic uniformity contribute to severe outbreaks.

Chestnut blight epidemic

A fungal disease that nearly wiped out American chestnut trees in the early 20th century.

Cryphonectria parasitica

The fungus responsible for the Chestnut blight epidemic.

Vegetative Compatibility

A system where fungi restrict gene flow by preventing fusion between genetically different individuals.

Introduction of fungus to the US

Introduced via imported Japanese and Chinese chestnut trees.

Hypovirulence

A virus that weakens the fungus, reducing its virulence.

Dutch elm disease epidemic

devastated American elms in the 20th century. virus that weakens the fungus, reducing its virulence.

Ophiostoma ulmi and Ophiostoma novo-ulmi

The fungi associated with Dutch Elm Disease.

European bark beetle

The vector that spreads Dutch Elm Disease.

Sudden Oak Death

A disease caused by Phytophthora ramorum affecting oaks in California, Oregon, and the UK.

Witches Broom

A disease caused by Moniliophthora perniciosa affecting cacao in Brazil and West Africa.

White Nose Syndrome

A disease caused by Pseudogymnoascus destructans affecting bats in North America.

Amphibian Decline

A decline in amphibian populations caused by Batrachochytrium dendrobatidis in Central America and Australia.

Human activity

Spreads spores through travel, trade, and improper quarantine measures.

Increased travel, climate change, immunosuppressive treatments, and antibiotic resistance

Factors contributing to the rise in fungal infections in animals and humans.

Histoplasmosis

A disease caused by Histoplasma capsulatum, which can be superficial or systemic.

Cryptococcosis

A disease caused by Cryptococcus neoformans, which can be superficial or systemic.

Candidiasis

A disease caused by Candida albicans, which can be superficial or systemic.

Human mycoses

Classified as superficial (e.g., ringworm), subcutaneous (e.g., sporotrichosis), and systemic (e.g., histoplasmosis).

Superficial infection

An infection that remains localized on the skin.

Systemic infection

An infection that spreads through the bloodstream to organs.

Fungal diseases treatment difficulty

Fungal cells are similar to human cells, making it difficult to target them without harming the host.

Antifungal drugs

Limited and often toxic, making treatment of fungal diseases challenging.

Secondary metabolite

A non-essential compound produced by an organism, often for defense or competition.

Aflatoxins

Produced by Aspergillus flavus, discovered after mass turkey deaths in England in 1960, toxic to the liver.

Fumonisins

Produced by Fusarium moniliforme, linked to esophageal cancer in China and South Africa.

Trichothecenes

Compounds like T-2 toxin that cause toxic effects in livestock and humans, leading to alimentary toxic aleukia.

Factors leading to a rise in mycotoxin-related problems

Industrialization, poor storage conditions, and climate changes have increased mycotoxin exposure.

Yellow Rain incident

The Yellow Rain incident involved allegations of mycotoxin use as biological weapons in Southeast Asia in the 1970s.

Claviceps purpurea

infects rye and produces ergot alkaloids, causing ergotism.

Ergot alkaloids

include ergotamine (causing gangrene) and lysergic acid (a precursor to LSD).

St. Anthony's Fire

refers to medieval ergotism outbreaks, leading to gangrene, hallucinations, and convulsions.

Evidence of ergot poisoning in Salem witch trials

Records suggest damp conditions in Salem could have led to ergot poisoning, potentially causing the witch trials.

Medicinal uses for ergot alkaloids

Ergot alkaloids have been used in medicine, including migraine treatments and labor induction drugs.

Discovery of Penicillin

revolutionized medicine by enabling the treatment of bacterial infections, reducing mortality rates.

Key scientists in Penicillin discovery

Key scientists: Alexander Fleming (discovery), Howard Florey and Ernst Chain (purification and production).

Mode of action of penicillin

Penicillin inhibits bacterial cell wall synthesis by preventing peptidoglycan cross-linking.

Beneficial secondary metabolites produced by fungi

Other beneficial fungal metabolites: Cephalosporins (antibiotics), Lovastatin (cholesterol-lowering), Cyclosporin (immunosuppressant).

Mode of action of Cephalosporins

work similarly to penicillin.

Mode of action of Lovastatin

inhibits cholesterol synthesis.

Mode of action of Cyclosporin

suppresses the immune system.

Common medicinal mushrooms in East Asian medicine

Ganoderma lucidum (Reishi) and Lentinula edodes (Shiitake) are widely used in traditional East Asian medicine.

Examples of black mold

Cladosporium, Penicillium, Aspergillus, Alternaria, Stachybotrys.

Stachybotrys chartarum

most concerning due to its association with Sick Building Syndrome and lawsuits.

Toxins produced by Stachybotrys

produces mycotoxins like satratoxins (immune suppression), stachylysin (hemolysis), and triprenyl phenol (coagulation issues).

Evidence for Stachybotrys in Sick Building cases

has been linked to lung bleeding in infants; animal studies show toxicity.

Evidence against Stachybotrys in Sick Building cases

CDC found no spores in affected infants' lungs.

Melinda Ballard

won a landmark lawsuit over toxic mold contamination in her Texas home.

Events in Cleveland with IPH babies

In the 1990s, 30 infants in Cleveland suffered pulmonary hemorrhaging, initially linked to mold but later questioned.

Contribution of toxic molds to Sick Building Syndrome

Mold exposure may contribute to Sick Building Syndrome, but the direct role in IPH remains debated.