Bio 220: Systemic Mycoses

Front 1

What are systemic mycoses?

Back 1

These are rare but very serious infections that can invade deeper tissues.
Most are dimorphic displaying yeast-like characteristics at 37 degrees C and mold-like characteristics at 25 degrees C.

Front 2

Coccidioidomycosis (San Joaquin Valley Fever)

Back 2

Etiologic agent – Coccidioides immitis
• fungus is found in the soil of the California central valley.Arthrospores are inhaled. Symptoms include mild fever, chest pain, coughing and weight loss. Most recover in a few weeks. However, sometimes the disease persists as a progressive
tuberculosis-like illness. The organisms can invade tissues where thick-walled bag-like
structures known as spherules can be found. Spherules are filled with spores. Most individuals
living in endemic areas (SW U.S.) possess antibodies made in response to exposure to the
fungus. Amphotericin B and imidazoles can be used for treatment purposes.

Front 3

Histoplasmosis

Back 3

Etiologic agent – Histoplasma capsulatum
• upon initial examination this can resemble
tuberculosis as X-rays can reveal a similar type lung involvement. This can spread systemically
to include the blood, lymph, lymph nodes, spleen and organs. Within the U.S. the disease is
most commonly found in areas around the Mississippi and Ohio rivers. Spores can be inhaled by
coming into close contact with bat guano and chicken manure droppings, as they can be a
source of the fungus.

Front 4

Blastomycosis

Back 4

Etiologic agent – Blastomyces dermatitidis
• the disease begins in the lungs and can initially
mimic the symptoms of bacterial pneumonia. The infection can spread rapidly and cause skin
ulceration and generalized tissue destruction. The fungus is concentrated in the U.S. around the
Mississippi and Ohio river valleys as is the etiologic agent which causes histoplasmosis.

Front 5

Cryptococcosis

Back 5

Etiologic agent – Cryptococcus neoformans • the fungus is free living in the soil and can
oftentimes be transmitted by inhaling contaminated dried pigeon feces. In tissues, the yeastlike
cells can be observed in polysaccharide capsules. As is typical of these systemic fungal
organisms, Cryptococcus, is usually nonpathogenic. However, in compromised individuals such
as in AIDS patients, the organism can proliferate in CNS fluids and cause severe chronic and
sometimes fatal meningitis.

Front 6

Mucormycosis

Back 6

Etiologic agent – Rhizopus spp. or Mucor spp.
• these opportunistic fungi oftentimes are seen in
compromised individuals who suffer from diseases such as diabetes or leukemia. Those using
immunosuppressant drugs are also susceptible. Infection can involve the sinuses, brain or lungs.

Front 7

Aspergillosis

Back 7

Etiologic agent – Aspergillus niger or Aspergillus nodulans
• compromised individuals who sufferfrom lung diseases or cancer can suffer from infections following the inhalation of spores. Lung complications can include the coughing up of blood. This can lead to severe or fatal
hemorrhaging. Other organs including the kidneys or liver may become involved. Aspergillus
can also infect the outer ear canal and cause an otomycosis. This can be acquired by swimming
in contaminated water.

Front 8

Aspergillus flavus

Back 8

found in moldy hay and peanuts, produces Aflatoxin. Aflatoxin is a
natural mutagen and carcinogen which can cause hepatomas and liver damage.