THE TRUE FUNGAL PATHOGENS

Portals of Entry for Fungi

• Primary mycoses: Respiratory portal via inhaled spores
• Subcutaneous: Inoculated skin through trauma
• Cutaneous and superficial: Contamination of the skin surface

Virulence Factors of Fungi

• Thermal dimorphism
• Toxin-like substances
• Capsules and adhesion factors
• Hydrolytic enzymes
• Inflammatory stimulants

Control of Mycotic Infections

• Immunization is not usually effective.
• Control involves intravenous antibiotics.
• In some cases, surgical removal of damaged tissues is necessary.
• Prevention is limited to masks and protective clothing to reduce contact with spores.

What is a Mycoses?

Infections are presented according to type, level of infection, and degree of pathogenicity

What are True Pathogens?

Systemic, cutaneous, and superficial mycoses

What is Opportunistic mycoses?

Fungal infections that occur in individuals with weakened immune systems

What are Systemic mycoses?

Fungal infections that affect internal organs

What are Cutaneous mycoses?

Fungal infections that affect the skin, hair, and nails

What does endemic region mean in the context of systemic fungal infections?

Regions where these systemic fungal infections are commonly found.

How do spores usually enter the body in systemic fungal infections?

Spores are typically inhaled into the lungs or inoculated into the skin.

What does it mean for a fungal infection to become systemic?

The infection spreads throughout the body, affecting multiple organs and systems.

What is Histoplasmosis?

Also known as Ohio Valley Fever, it is caused by Histoplasma capsulatum, a common true pathogen.

What type of organism is Histoplasma capsulatum?

It is typically dimorphic, meaning it can exist in both mold and yeast forms depending on environmental conditions.

Where is Histoplasma capsulatum most prevalent in the U.S.?

It is most prevalent in the eastern and central regions of the United States.

Where does Histoplasma capsulatum grow?

It grows in moist soil with high nitrogen content, often associated with bird and bat droppings.

How does primary pulmonary infection occur with Histoplasma capsulatum?

Infection occurs when conidia (spores) are inhaled, leading to a primary pulmonary infection.

What are the potential complications of Histoplasma capsulatum infection?

The primary pulmonary infection may progress to systemic involvement of various organs and chronic lung disease.

What is the treatment for Histoplasmosis?

The recommended treatment is antibiotic therapy.

What is Coccidioidomycosis?

Also known as Valley Fever, it is caused by Coccidioides immitis.

Where does Coccidioides immitis live?

Coccidioides immitis lives in alkaline soils in semiarid, hot climates and is endemic to the southwestern U.S.

How does infection of Coccidioides immitis occur?

Infection occurs when Arthrospores are inhaled from dust, creates spherules, and can form nodules in the lungs.

What is the treatment for Coccidioidomycosis?

The recommended treatment is antibiotic therapy.

What is Blastomyces Dermatitidis?

It causes North American Blastomycosis.

What are characteristics of Blastomyces dermatitidis?

It is a dimorphic fungus.

Where is Blastomyces dermatitidis found?

It is a free-living species distributed in the soil of a large section of the midwestern and southeastern U.S.

How does Blastomyces dermatitidis infection occur?

Conidia convert to yeasts and multiply in the lungs.

What are the symptoms of Blastomyces dermatitidis infection?

Symptoms include cough and fever.

What are the potential complications of Blastomyces dermatitidis infection?

Chronic cutaneous, bone, and nervous system complications may occur.

What is the treatment for Blastomyces dermatitidis infection?

The recommended treatment is antibiotic therapy.