How do humans get fungal infections?
- -Usually: Inhalation, trauma, ingestion
- -Infrequently through person to person
- 1. Dermatophyte group
- 2. Candida and Pneumocystis
What are factors predisposing people to mycoses?
- -Medical procedures
- -Medical therapies
- -Disease conditions
- -Lifestyle factors
Why is it difficult to treat fungal infections?
- -Fungi can resist T cells
- -Fungi are similar to human cells-toxicity to human cells caused by fungicides
- -Both fungi and animal cells have: Nuclei and organelles, same sized ribosomes
What is in the cell wall of fungi?
-Complex structure composed of chitin- cannot be targeted by drugs
What is the cell membrane of fungi?
-Ergosterol, can be targeted by drugs
How do antifungal drugs work?
- -Inhibit ergosterol synthesis
- -Blocking ergosterol insertion into the membrane
What is Amphotericin B?
- -Fungicidal, most effective antifungal, but also most toxic to humans
- -Kills it
What is Azole drugs?
- -Ketoconazole, itraconazole and fluconazole
- -Fungistatic, less stock to humans
- -Stops growth
What is Coccidioidomycosis?
- -Coccidioides immitis
- -Semiarid places, Arizona
- -Valley Fever
- -Pulmonary, systemic, subcutaneous
What is Candidiasis?
- -Candida albicans
- -Skin and mucous membranes
- -40-80% of healthy people have in digestive tracts
- -Causes yeast infections, thrush, nail infections, ocular infection, diaper rash
- -Treat with Azoles or Nystatic
What are superficial mycoses?
- -Fungal infection confined to outer, dead layers of skin, nails or hair
- -primary food source Keratin
- -Dermatophytoses-infection caused by dermatophytes
- -Malassezia infections
What is Dermatophytoses?
- -Ringworm: Tinea corporis
- -Athletes foot- Tinea Pedis
- -Hair- Tinea Capitis
What is a woods lamp?
- -Diagnosis Dermatophytes
- -A black light will reveal yellow/green fluorscence.
- -If infection , the area will illuminating
What is a Malassezia infection?
- -Malassezia furfur
- -Disease: Tinea Versicolor
- -Usually the yeast grows lightly without causing a rash but causes pale brown flaky patches on the truck, neck, or arms
- -Mostly in teenagers in summer time (oily skin)
- -Treat with topical selenium Sulfide (selsun)
- -Diagnosis: Detection of hyphae and spherical yeast in skin scrapings
What is sporotrichosis?
- -Cutaneous Infection
- -Sporothrix schenckii
- -Rose gardeners Disease
- - S. Schenckii resides in soil and is introduced by thorn pricks, wood splinters
- -Causes ulcers on skin, do not heal