Fungi Flashcards
Why is treatment for fungal pathogens different from treatment for bacterial pathogens?
Fungi are eukaryotic organisms, and bacterial pathogens are prokaryotic
What are the typical targets for treatment of fungal pathogens?
Nuclear membrane - it is made of ergosterol, unlike humans
Cell wall - it is made of chitin, manna, and glucan, unlike plants
What form are most fungal pathogens most effectively pathogenic?
Yeasts are typically more pathogenic
What are the two main forms of fungi?
Yeast (unicellular)
Molds (branching filaments - hyphae)
How significant are the fungi that are pathogenic in the big picture of human health?
- People die of fungal infections in industrialized countries
- Antifungal drugs are profitable for pharmaceutical companies
- Sequencing of the genomes of most human pathogens is almost complete, and sequencing of other genomes is underway or projected
What are the two types of mycoses
Endemic
Opprotunistic
Endemic
Infections caused by fungal pathogens that are restricted geographically
True pathogens that typically result in systemic infections in healthy individuals
Opprotunistic
Infections caused by fungi that are not true pathogens
Cause systemic infections only in immunocompromised patients
Histoplasmosis Geography
Mid-southern US
Histoplasmosis Health concern
90% of population is infected - most produce no.mild symptoms
Part of normal skin flora
Blastomycosis Geography
primarily found in the Mississippi River Valley and southeastern states, but extends up into Canada
Coccidiodomycosis Geography
Lower sonoran life zone: Arizona, S. California, New Mexico, Texas
Blastomycosis Health Concern
If inhaled, they can invade mucosa, causing pneumonia and heamtogenous dissemination
Coccidiodomycosis Health Concern
Most healthy people have no/mild symptoms
Biggest concern is with dark-skinned individuals
Part of normal skin flora
Why is Candida capable of causing disease when other normal skin flora do not?
They do not cause infection unless the normal flora is dissrupted
It is in the mycelial form, not yeast form
What 2 typical skin flora are opprotunisitic pathogens?
Candida
Pneumocystis
What is a geophilic opprotunistic pathogen and why?
Cryptococcys neoformans - grows well at 37 degrees and produces a virulence factor in tissues, but not the environment
Why are zoophilic pathogens much more capable of infecting the human body?
Animals have similar environments to humans as compared to the soil
What are critical characteristics of humans that create the opprotunity for fungal infections?
37 degrees
What people/areas are viewed as oddities and may be more succeptible to fungal infection?
Immunocompromised people
Acidic areas
What are the key differences in immune response to disseminated and cutaneous infections
Cutaneous infection response is primarily innate immunity
Disseminated is cell-mediated
Why is ringworm listed as a fungal pathogen and not a parasite?
There has to be skin trauma for an infection to incur.
Ringworm cannot be systemic
Under what conditions can dermatophytes cause disease?
Skin trauma
Acute or chronic infection
