Mycosis II Flashcards
What is the most common fungus found in bone marrow transplant patients?
Aspergillus (mold)
What is the most common fungus found in solid organ transplants?
Candida (Yeast)
T/F Candida is a human commensal organism?
TRUE
what is considered the leading cause of opportunistic fungal infections?
Candida
what 3 general areas are usually attacked by candida?
1) skin and nails
2) mucosa (vagina, esophagus)
3) blood
What is thrush?
A common HIV disease that is a mucosal candida infection mainly affecting the esophagus.
what is candidiasis?
blood stream infection of candida
T/F candida is the 3rd most common cause of central line associated infections?
TRUE
How does candida usually get into the blood stream?
usually catheter related.
what is hepatosplenic candidaisis?
microabscesses in liver/spleen from candida that is unique to cancer patients with prolonged neutopenia.
what are the 6 major risk factors for candida infection?
immunocompromized with:
1) antibiotic use
2) catheter
3) abdominal surgery
4) TPN
5) In the hospital
6) Neutopenia
what are the two most common types of candida?
1) candida albicans
2) candida glabrata
What is this describing? budding yeast that can form pseudohyphae and rarely may form true septate hyphae?
All candida species
what is chromogenic media? why is it used?
It is media that turns different colors depending on the type of candida grown. Great for identification.
why is early diagnosis of candida difficult?
1) lack of inflammatory response
2) Diagnostic procedures are risky
3) lack of sensitive assays
How do you treat skin and mucosal candida disease?
topical medications such as “-azoles”
How do you treat invasive candida disease?
Oral therapy such as “-azoles”, and amphotericin B.
Also, pull any indwelling catheters.
what is considered to be the most common cause of invasive mold infection?
Aspergillus
Over 95% of human disease caused by a mold is caused by which 3 organisms?
1) A. fumigatus
2) A. flavus
3) A. niger
T/F Aspergillus routinely colonize healthy individuals?
False, but candida does
what is allergic aspergillosis?
Airway colonization of aspergillus with allergic reaction. Associated with bronchospasm and scarring.
what is Aspergilloma in pre-existing cavity?
Secondary colonization of the lung with a fungus ball. Frequently associated with hemoptysis
what is semi-invasive aspergillosis?
Chronic cavitary, chronic fibrosing, chronic invasive
what is invasive aspergillosis?
Life threatening and rapid spreading mold that is angioinvasive causing infaction.
Risk factors: neutropenia, immunosuppression, transplant
What do you see with an MRI when looking at the lungs of someone with allergic bronchopulmonary aspergillosis?
thickening of the airways (bronchiectasis) and pleura
where does invasive aspergillosis usually begin?
in the lungs
T/F Mortality associated with Aspergillosis in increasing as we advance in modern medicine?
False. The mortality rate is slowly declining.
Which type of organism has septate hyphae that branch at 45 degrees?
Aspergillis
How do you diagnose aspergillis?
1) 45 degree branching hyphae that are septated
2) Antigen detection (Galactomannan in the blood)
Which 3 underlying diseases make you have the highest risk of invasive aspergillosis?
1) Bone marrow transplant
2) Neutropenia
3) Hemotologic cancer
what is Galactomann?
a polysaccaride cell wall component of aspergillus. It serves as an antigen for monitoring hematologic malignancy in patients. (NOTE: it is not helpful with patients receiving antifungal therapy or certain antibiotics because it gives a false negative)
How do you treat allergic bronchopulmonary aspergillosus?
corticosteroids
How do you treat an aspergilloma?
combined surgical and medical therapy
how do you treat semi-invasive and invasive aspergillosus?
1) Voriconazole is first line therapy
2) Amphoteracin B would follow
Which group of organisms are characteristically classified by broad hyphae without septate?
Zygomycosis
Rhizopus, Mucor, and Rhizomucor all belong to which group?
Zygomycosis
What diseases does zygomycosis usually cause?
1) Rhinocerebral DZ
2) pulmonary DZ
3) Disseminated DZ in immunocompromized
What are the 3 main risk factors for zygomycosis infections?
1) Diabetes with hyperglycemia
2) acidosis
3) Hematologic malignancies
what is the treatment for zygomycosis?
Amphoteracin B and surgical debridment
T/F If you have a coinfection of zygomycosis and aspergillus and you knock out aspergillus with treatment, zygomycosis infection will increase?
TRUE
When tying to identify zygomycosis, you should mince rather than crush of ground the hyphae. Why?
This is to minimize the damage done to the hyphae. Recall identification of zygomycosis is by identifying broad non-septate hyphae.
T/F you can detect zygomycosis by D-glucan or galactomannan assays?
False. Both of these will not help detect zygomycosis
what type of fungus is known as lid lifters?
zygomycosis grows so quickly that if you leave it, it will overgrow its container.
T/F Pneumocytis jeroveci = P. carinii?
TRUE
In which patients do you generally see P. Jeroveci?
AIDS patients with <200 CD4 level
why has the incidence of P. Jeroveci decreased in AIDS patients over the last decade?
Introduction of the HAART therapy
What has a ground glass infiltrate appearance on CXR?
Interstitial pneumonia from Pneumocystis Jeroveci
what is the most common clinical syndrome for pneumocystis?
interstitial pneumonia
What is the best way to diagnose pneumocystosis?
It is almost entirely through microscopic examination of sputum of bronchial samples.
what is the best treatment for Pneumocystosis (jeroveci)?
1 bactram (Trimethoprim-sulfamethoxazole)
T/F Patient receiving treatment for pneumocystosis using bactram get worse before they get better?
True. This is because with treatment a large antigen load is released from the lysing organisms.
