(Q4) Diseases of Fungi and Protozoa/Mycology and Protozoology (Ch. 28) Flashcards
Fungi
- A group of often filamentous unicellular and multicellular organisms lacking chlorophyll and usually bearing spores
- eukaryotic: has a nucleus
- Most fungi are saprophytes
- Can reproduce either sexually or asexually through budding or reproductive spore formation.
Three Fundamental Categories of Fungi
- Yeasts
- Molds
- Dimorphic Fungi
Yeasts
- eukaryotic, unicellular, encapsulated fungi
Molds
- A fungal growth that forms and spreads on various kinds of damp or decaying organic matter.
- filamentous and multicellular
Dimorphic Fungi
- Fungi that have a yeast (or yeast-like) phase and a mold (filamentous) phase.
- Alternate between unicellular and multicellular forms
Dermatophytes
- A group of fungi that infect keratinized tissues, such as the skin, hair, and nails.
- Cause ringworms (tineas)
- Tinea capitis
- Tinea cruris
- Tinea pedis
Dermatomycoses
- infections caused by dermatophytes
- Fungal infections of the skin and skin appendages
Trichophyton, Microsporum, and Epidermophyton
- Cause tineas (ringworms): Tinea capitis, Tinea cruris, Tinea pedis
Tinea capitis
Ringworm of the scalp
Tinea cruris
Ringworm of the groin/ “jock itch”
Tinea pedis
Ringworm of the foot/ “athlete’s foot”
Candida albicans
- Candidiasis: yeast infection
- Causative agent of superficial yeast infections or candidiasis (thrush, vaginitis)
- Fourth most common cause of nosocomial blood-stream infections in the US
Cryptococcus neoformans
- Cryptococcosis: rare form of fungal meningitis (cryptococcal meningitis)
- Birds carry the fungus on their beeks and disperse it through their feces
Cryptococcus neoformans Portal of Entry and Mode of Transmission
- Respiratory Tract
- Inhalation of spores
Histoplasma capsulatum
- Histoplasmosis/Darling’s Disease/ Cave sickness
- Soil fungus endemic to the Mississippi and Ohio River Valley regions
- Found in bird and bat feces
- Causes flu-like symptoms in healthy individuals
- Can be a secondary infection for compromised individuals
Histoplasma capsulatum Portal of Entry and Mode of Transmission
- Respiratory Tract
- Inhalation of contaminated particles
Coccidioides immitis
- Coccidioidomycosis/ Valley Fever/ Desert Rheumatism
- Soil fungus endemic to arid regions
- Causes flu-like symptoms in healthy individuals
- Can be a secondary infection for compromised individuals
Coccidioides immitis Portal of Entry and Mode of Transmission
- Respiratory Tract
- Inhalation of contaminated particles
Pneumocystis jirivecii (carinii)
- Pneumocystis pneumonia (PCP)
- Fungus found in normal flora of lungs
- Opportunistic infection for compromised individuals
Aspergillus fumigatus
- Aspergillosis
- Found in decaying vegetation: compost, manure, soil
- pneumonia-like symptoms
- Other symptoms can develop if the infection spreads from the lungs to other body parts.
Aspergillus fumigatus Portal of Entry and Mode of Transmission
- Respiratory or GI Tract
- Ingestion or Inhalation
Protozoa
- Unicellular eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris
- Majority do not have disease-causing potential in humans
- Cryptosporidium parvum
- Entamoeba histolytica
- Giardia lamblia
- Plasmodium malariae
- Toxoplasma gondii
- Trypanosoma brucei
- Trypanosoma cruzi
Cryptosporidium parvum
- Cryptosporidiosis
- a diarrheal disease
Cryptosporidium parvum Portal of Entry and Mode of Transmission
- GI Tract
- Ingestion of contaminated food or water, or fecal-oral route