Primer 4 - Mycology Flashcards
What are 3 medically important yeasts?
- Candida albicans
- Cryptococcus neoformans
- Pnemocystis jirovecii
How can you differentiate from oral leukoplakia from Epstein-Barr virus from oral thrush from Candida Albicans?
Oral leukoplakia are white patches on the side of the tongue that cannot be removed. Oral thrush can be scrapped off, leaving a raw bleeding mucosa. Thrush covers the top of the tongue and back of the mouth.
What are three symptoms of candida esophagitis?
- Painful swallowing
- Substernal chest pain
- Feeling of obstruction when swallowing.
What is special about candida infection compared to other mycotic infection in terms of what it does to the vaginal environment?
Candida lowers pH while other vaginal infections raise the pH.
What is an important clinical finding in diaper rash caused by candidiasis?
Satelite lesions.
What is intertrigo?
Rash on the folds of the body.
What is one of the most prevalent mycotic agents that causes meningitis in AIDS patients?
Cryptococcus Neoformans.
What is a widely used medium to culture fungi?
Sabourd agar
What is a famous lesion seen in meningitis that is caused by cryptococcus neoformans?
Soap-bubble lesions.
What is the treatment for crytococcus meningitis?
Begins with Amphoteracin B + flucytocin and then followed by single therapy fluconazole.
What does Pneumocystis jirovecii cause?
Diffuse interstitial pneumonia that can develop into a deadly pneumonia. Causes walking pneumonia.
When do you start Pneumocystis jirovecii prophylaxis in AIDS patients?
When CD4 count falls below 200.
What does Aspergillus fumigatus cause in the lungs?
Allergic bronchopulmonary aspergilosis or be a colonizer and great a fungus ball in the lung cavity.
What is the characteristic finding in culture of Aspergillus fumigatus?
Hyphae that is narrow sceptate that branches at acute angles (less than 45 degrees).
What is the characteristic finding in culture of Mucor and Rhizopus?
With broad irregular nonseptate hyphae that branch at wide angles (> 90 degrees).
What is onychomycosis?
Tinea unguium - mycotic infection on the nails.
What causes tinea versicolor?
Malassezia furfur
What is the clinical presentation of tinea versicolor?
Hipopigmented patches and sometimes hyperpigmented patches of skin in the back.
What do we find in a KOH preparation of a skin scrapping of malassezia furfur?
Spaghetti and meatballs.
What is a dymorphic fungi?
A fungi that can be grown as a mold form or a yeast form: 20 degrees you get mold and 37 degrees you get yeast.
What are 5 agents of disease associated with Birds?
- Histoplasma capsulatum.
- Cryptococcus neoformans.
- Chlamydophila psittaci
- H5N1 influenza
- West Nile Virus
What is the pathophysiology of histoplasma capsulatum?
The fungus hides inside macrophages.
What is the geological range of blastomyces dermatitidis?
States bordering the Mississippi river and Ohio River all the way up to Canada and down to Mexico.
What histological finding do we find with blastomyces dermatitidis?
Broad-based budding. Blasto yeast forms are about the same size of RBC.
What is arthroconidia and in which type of fungus is it seen?
Arthroconidia is a type of fungal spore typically produced by segmentation of pre-existing fungal hyphae. These spores are asexual. They are seen in Coccidioides immitis.
What is a histological finding of paracoccidioides braseliensis?
Captain’s wheel appearance.
What are two clinical presentations that Paracoccidioides brasiliensis cause?
Severe pneumonia and granulomatous changes in the mucus and skin.
What is the usual route of infection of Sporothrix schenckii?
Gets inside the skin through trauma; “rose-gardener’s disease”.
What is the clinical presentation of Sporothrix schenckii?
Small ulcer or pustule at the site of infection, and then nodules appear along the draining lymphatics, nodules are usually painless, even when ulcerate.
What is a simple remedy for cutaneous Sporothrix schenckii?
Potassium iodide. [Plant erodes in a Pot (for potassium)].
Which yeast is responsible for causing meningitis in AIDS patients?
Cryptococcus neoformans.
Which fungus is found in SW USA including Texas and California?
Coccidiodies immitis.
Which fungus is found in the Mississippi and Ohio River basins?
Histoplasma capsulatum.
Which fungus causes San Joaquin Valley fever?
Coccidioides immitis.
What fungus is found in states east of the Mississippi River?
Blastomyces dermatitidis.
What fungus has broad-based budding of yeast?
Blastomyces dermatitidis.
What fungus has multiple budding of yeast form?
Paracoccidioides brasiliensis.
