Chapter 6 Flashcards
Fungi includes
Yeasts, molds, and fleshy fungi
Fungi
Eukaryotic
May be unicellular -yeast or multicellular -molds
Have a rigid cell wall made of chitin
Non-motile
Are NOT photosynthetic
Obtain nutrients as saprohytes or as parasites
Superficial Mycoses
Times vesicolor
Caused by yeast Malassezia furfur
Fungal growth is on outer surface of skin and hair (epidermis)
No inflammation involved
It is associated with psoriasis and dermatitis
Cutaneous Mycoses
Dermatomycoses
Tinea (worm) infections:
Jock itch- Tinea Cruris
Athletes foot - tinea pedis
Ringworm - tinea capitis
Subcutaneous Mycoses
(Sporotrichosis)
Rose-Gardener’s disease
Caused sporothrix schenckii
Subcutaneous tissue at the point of skin puncture
Leads to open skin lesions at point of entry and along associated lymphatic channels
Mycoses
- Superficial
- Cutaneous (through skin)
- Subcutaneous
- Systemic
- Opportunistic
Deep Mycoses
Systemic Mycoses
Caused by pathogenic fungi
Dimorphic
Change due to temperature
Infects lower respiratory tract with TB symptoms
Asymptomatic or clinically mild infections may occur
Infection could spread to other systems too
All diseases result in immunity
Histoplasma capsulatum
Ohio Valley Fever or Summer Flu
Caused by Histoplasmosis
It is lung disease
It is a soul fungus in areas of bird/bat droppings
Rich in nitrogen
Infection by inhalation of sports found in the dust
Coccidioides immis
Valley Fever
Caused by coccidiosomycosis
Lives in alkaline soils in semiarid, hot climates
Infection is by inhalation of spores
Blastomyces dermatitidis
Chicago’s disease
Caused by blastomycosis
Common to Great Lakes
Associated with dusty soils, decaying wood, and wood droppings
Lung inhalation of spores
Opportunistic Mycoses
Most fungi are saprophytic and not pathogenic (parasitize fungi)
Require a compromised host in order to establish infection
Conditions that predispose a person to fungal disease
- pregnancy
- immunosuppressant drugs
- surgery
- drug/alcohol addiction
- occupation
- climate
- stress
- health -diabetes, obesity, allergies, AIDS, STDs
Candida albicans
Caused candidiasis
Most common opportunistic final infection
C. Albicans
- most common cause of candidiasis
- occurs as normal flora
- yeast
Candida albicans
Causes Thrush
Infection of mucous membranes of the mouth, gums, cheeks, or throat
Symptoms creamy white growth
Common in new norms and elderly patients
Candida albicans
Causes vulvovaginitis
STD
Cause of infection may be due to
- birth control pills may change pH of vagina
- antibiotic use that may eliminate lactobacilli
Itching, burning, internal pain
White to yellow milky discharge
Reddening (inflammation) and swelling of vaginal tissue
Candida albicans (Causes Gastrointestinal Tract Candidiasis)
Esophagus and anus most affected
Frequently a complication of AIDS
Closely tied to use of antibiotics
Yogurt helps replace lost flora
Candida albicans
Causes Systemic Candidiasis
Major ports of entry are
- Alimentary tract
- Intravascular catheters
Involves kidney, liver, spleen, brain, eyes, and heart infections.
Considered the major nosocomial fungal infection
Pneumocystis carinii
Caused by Pneumocytosis
Most common cause of non-bacterial pneumonia in immuno-suppressed individuals
Cryptococcus neoformans
Caused by Cryptococcosis
Involves the encapsulated yeast form
It causes pneumonia and/or meningitis
Infection is by inhalation of dried infected pigeon droppings
Aspergillosis fumigatus
Caused by Aspergillosis
Common airborne soil fungus
Serious opportunistic threat to AIDS, leukemia, and transplant patients
Able to infect brain, heart, and other organs
A round ball of mycelium called Aspergilloma forms in the lung
Conidia in the ear wax leads to Otomycosis
-painful ear infection
Rhizopus and Mucor
Common caused my rare diseases Zygomycosis or Mucormycosis
Seen in severely immunocompromised patients
Fungal toxins and allergies
Mold, mildew, and fungi can grow big indoor and outdoors
Mostly present in moist, dark areas
Spores (allergens) produced may cause allergies
Mycotoxins
Produced by some mushrooms
Some mycotoxins are carcinogenic
Some cause central nervous system damage
Ergot
Produced by a clavicle ps purpurea
Grows on grains
Can cause hallucinations
Also constricts capillaries and can cause gangrene of extremities
Commercial derivatives are used to cause contractions of smooth muscle
Beneficial aspects of fungi
- mold
- antibiotic
- cheese manufacture
- decomposers
- rice to sake (Rhizopus)
Hyphae
Mass of hypha called mycelium
Mycelium is the vegetative structure
Hyphae be separate or coenoxyic (aseptate)
