(3) Chapter 12: Mycology Pt.3

What fungal disease is caused by Cryptococcus neoformans?

Cryptococcosis (cryptococcal meningitis).

What type of mycosis is Cryptococcosis?

Opportunistic systemic mycosis.

Which patients are at greatest risk for Cryptococcosis?

AIDS patients and other immunocompromised individuals.

What body system is primarily affected by Cryptococcosis?

Central nervous system (meninges).

How is Cryptococcus neoformans transmitted?

By inhalation of fungal spores.

Where are Cryptococcus spores commonly found?

Soil contaminated with pigeon droppings.

What virulence factor makes Cryptococcus difficult for the immune system to destroy?

A thick polysaccharide capsule.

Why is the capsule of Cryptococcus important?

It inhibits phagocytosis by white blood cells.

What are early symptoms of Cryptococcal meningitis?

Headache, fever, stiff neck, vomiting, and confusion.

What severe neurological symptoms may develop in Cryptococcosis?

Paralysis, loss of coordination, brain swelling, and death.

What recently emerging Cryptococcus species was discussed in lecture?

Cryptococcus grubii.

Which states were mentioned as having increased Cryptococcus grubii infections?

California and Arizona.

According to the lecture, what environmental condition may contribute to increased Cryptococcus infections?

Severe drought.

Without treatment, what is the mortality rate of Cryptococcal meningitis in AIDS patients?

Approximately 90% within one year.

What fungal disease is caused by Histoplasma capsulatum?

Histoplasmosis.

What type of mycosis is Histoplasmosis?

Systemic mycosis.

How is Histoplasmosis acquired?

Inhalation of fungal spores.

Where are Histoplasma spores commonly found?

Soil contaminated with bird or bat droppings.

What occupations or activities increase the risk of Histoplasmosis?

Cleaning chicken coops, exploring caves, disturbing contaminated soil.

What organ is infected first in Histoplasmosis?

Lungs.

What symptoms resemble tuberculosis in Histoplasmosis?

Lung lesions.

What common symptoms occur with Histoplasmosis?

Fever, headache, flu-like symptoms, cough, and fatigue.

Which patients are most likely to develop severe Histoplasmosis?

Immunocompromised individuals.

What does disseminated Histoplasmosis mean?

The infection spreads beyond the lungs to other organs.

Which body area commonly becomes involved in disseminated Histoplasmosis?

Skin.

Where is Histoplasmosis most common in the United States?

Ohio and Mississippi River Valleys.

What fungal disease is caused by Blastomyces dermatitidis?

Blastomycosis.

How is Blastomycosis transmitted?

Inhalation of spores.

Besides inhalation, how else can Blastomyces enter the body?

Through traumatic implantation beneath the skin.

What type of lesions are characteristic of Blastomycosis?

Cutaneous ulcers.

Which organ is infected first after inhalation?

Lungs.

Where is Blastomycosis commonly found geographically?

Eastern and Midwestern United States.

What body system is affected if Blastomycosis disseminates?

Skin and other organs.

What fungal disease is caused by Coccidioides immitis?

Coccidioidomycosis.

What is another name for Coccidioidomycosis?

San Joaquin Valley Fever.

How is Coccidioidomycosis transmitted?

Inhalation of arthroconidia (fungal spores).

Where is Coccidioides commonly found?

Desert soils of the southwestern United States.

Which states have the highest incidence of Coccidioidomycosis?

California and Arizona.

What structure develops inside the body during Coccidioides infection?

Spherules filled with endospores.

What happens when a spherule ruptures?

It releases endospores that infect nearby tissue.

What symptoms occur with Valley Fever?

Fever, cough, chest pain, fatigue, and flu-like illness.

What fungi cause Dermatophytosis (cutaneous mycoses)?

Trichophyton, Microsporum, and Epidermophyton.

Which dermatophyte infects hair, skin, and nails?

Trichophyton.

Which dermatophyte infects hair and skin only?

Microsporum.

Which dermatophyte infects skin and nails only?

Epidermophyton.

What is Tinea capitis?

Ringworm of the scalp.

What is Tinea pedis?

Athlete's foot (ringworm of the feet).

What is Tinea unguium?

Fungal infection of the fingernails or toenails.

What is another name for Tinea unguium?

Onychomycosis.

What is Tinea cruris?

Jock itch (ringworm of the groin).

Do dermatophytes invade living tissue?

No. They remain in keratinized tissues such as skin, hair, and nails.

What protein do dermatophytes digest?

Keratin.

What fungal disease is caused by Mucor and Rhizopus species?

Mucormycosis.

What type of mycosis is Mucormycosis?

Opportunistic mycosis.

Who is at highest risk for Mucormycosis?

Diabetics and severely immunocompromised patients.

Which genera commonly cause Mucormycosis?

Mucor and Rhizopus.

Which fungus causes candidiasis?

Candida albicans.

Is Candida albicans normally part of the human microbiota?

Yes.

When does Candida become pathogenic?

When normal microbiota are disrupted or immunity is weakened.

What type of pathogen is Candida albicans?

Opportunistic pathogen.

Which fungus causes Pneumocystis pneumonia (PCP)?

Pneumocystis jirovecii.

Which patients are at greatest risk for PCP?

AIDS patients and severely immunocompromised individuals.

Which organ is primarily affected by Pneumocystis jirovecii?

Lungs.

Which fungus most commonly causes Aspergillosis?

Aspergillus fumigatus.

What type of pathogen is Aspergillus fumigatus?

Opportunistic fungus.

How are Aspergillus infections acquired?

By inhalation of airborne conidia.

Which patients are most susceptible to Aspergillosis?

Immunocompromised individuals.

What fungus is commonly called "black mold"?

Stachybotrys.

Why is Stachybotrys medically important?

It produces toxic mold that may cause respiratory illness.

What fungal disease is caused by Sporothrix schenckii?

Sporotrichosis.

What is the common nickname for Sporotrichosis?

Rose gardener's disease.

How is Sporothrix schenckii transmitted?

Traumatic implantation through puncture wounds.

What body part is most commonly infected first in Sporotrichosis?

Hands or fingers.

Where does Sporothrix spread after entering the skin?

Lymphatic vessels.

What type of lesions develop in Sporotrichosis?

Ulcers or nodules that spread along lymphatic vessels.

What are the five major categories of mycoses?

Systemic, subcutaneous, cutaneous, superficial, and opportunistic.

Which mycoses are the most severe?

Systemic mycoses.

Which mycoses involve only the outer dead layer of skin, hair, or nails?

Cutaneous mycoses.

Which mycoses occur beneath the skin after traumatic implantation?

Subcutaneous mycoses.

Which mycoses primarily affect immunocompromised individuals?

Opportunistic mycoses.

What is the most common route of transmission for systemic fungal pathogens?

Inhalation of spores.

What environmental source was repeatedly emphasized by the professor for systemic fungi?

Soil contaminated with bird or bat droppings.

What is the most important virulence factor discussed for Cryptococcus neoformans?

Its thick capsule.

Which systemic fungal disease resembles tuberculosis?

Histoplasmosis.

Which systemic fungal disease is also called Valley Fever?

Coccidioidomycosis.

Which fungal disease is nicknamed Rose Gardener's Disease?

Sporotrichosis.

Which dermatophyte infects all three: hair, skin, and nails?

Trichophyton.

Which dermatophyte infects hair and skin but not nails?

Microsporum.

Which dermatophyte infects skin and nails but not hair?

Epidermophyton.