Kozel: Opportunistic Mycoses Flashcards
(52 cards)
List 5 opportunistic mycoses
Candidiasis Cryptococcosis Aspergillosis Mucormycosis Pneumocystosis
Where are Candida albicans and Candida spp. normally found?
in the skin - particularly in health care workers
in the GI tract from the mouth to the rectum
in the female GU tract
What is the most common species of Candida?
C. albicans
What is the morphology of Candida albicans and Candida spp?
primarily yeasts
true hyphae
pseudohyphae
What do Candida spp form?
germ tubes *hypha emerging from a yeast-like structure
Most infections with Candida are endogenous. What does this mean?
normal commensal flora takes advantage of an opportunity to cause infection
What does Candidiasis cause at mucous membranes?
thrush
candida esophagitis *often in AIDS
vaginitis
What % of normal women have at least one episode of vaginitis causes by Candida?
75%
What organs/organ systems can Candida affect?
CNS pneumonia - lungs bones and joints endocarditis urinary tract abdominal hematogenous disseminated candidiasis - in the blood
What type of infection does candidiasis cause?
major nosocomial infection
**3rd most common blood stream infection
What are the general risk factors for invasive candidiasis?
hematologic cancer neutropenia GI surgery premature infants patients older than 70
What are some special risk factors for invasive candidiasis?
time spent in ICU
central venous catheter
colonization at multiple sites
number of antibiotics given
How would you diagnose candidiasis?
- scrape mucosal and cutaneous lesions and use KOH to see if yeast is present
- histopathology
- budding yeast-like forms and pseudohyphae
- look for germ tube formation
In all cases, look for budding yeast and pseudohyphae
What are three sources of tissue that you could culture to look for candida?
- scrapings from lesions
- blood *only 50% positive
- tissue or normally sterile body fluids
Candida can grow on standard mycologic media. What other medium might you use?
selective chromogenic medium
How can you CONFIRM a diagnosis of Candida?
germ tube formation - production of germ tubes when grown on serum
What is used to treat oral thrush caused by candida?
topical creams and lotions: nystatin or clotrimazole (azole)
oral systemic therapy: fluconazole or other azoles
prophylactic fluconazole in AIDS
What is used to treat esophagitis caused by candida?
oral systemic therapy: fluconazole
**topical therapy usu fails
What can be used to treat uncomplicated Candida vaginitis? What about recurrent Candida vaginitis?
over the counter topical azoles/oral azoles;
remove or treat causal factor - or induce course of azole followed by long-term maintenance regimen
How can you avoid cadidiasis?
avoid broad spectrum antibiotics!!
be cautious with catheter care
infection control
What are some ways in which you could remove the source of infection for candida?
remove or change the catheter
drain abscesses
List three antifungal agents used for candida
Polyene **AmB (but watch out for nephrotoxicity)
Triazole **esp fluconazole
Echinocandin
Where is Aspergillus spp. found?
everywhere! in air, soil, decaying vegetation
hospitals - air, water, potted plants
What is the morphology of Aspergillus spp? What does it look like?
branched septate hyphae;
conidial heads with spheric conidia
