Fungi Flashcards
Fungi with geographic location in Mississippi and Ohio River Valleys
Histoplasmosis
Macrophages filled with intracellular oval bodies and transmitted via bird or bat droppings after cave exploring. What is organism?
Histoplasmosis
How is Histoplasmosis diagnosed?
Urine or Serum antigen test
Fungus that is smaller than RBC inside macrophage and is cold in mold and yeast in the heat
Histoplasma
Systemic infection that causes palatal/tongue ulcers, erythema nodosum and hepatosplenomegaly
Histoplasmosis
Treatment of choice for Blastomyces, Coccidioides, and Histoplasma local infections
Itraconazole
Treatment of choice for Blastomyces, Coccidioides, Histoplasma, Candida and Cryptococcus infections
Amphotericin B
Amphotericin B mechanism of action
Binds ergosterol forming membrane pores allowing leakage of electrolytes
Azoles mechanism of action
Blocks cytochrome P450 that converts lanosterol to ergosterol
Azole of choice for Aspergillus and some Candida infections
Voriconazole
Azole of choice for serious Aspergillus and Mucorales infections
Isavuconazole
Treatment of choice for topical fungal infections
Clotrimazole and miconazole
Adjuvant that may be added to Cryptococcus infection in addition to amphotericin B
Flucytosine
Gynecomastia is seen with treatment of what antifungal?
Ketoconazole
Fungus geographically found in Great Lakes and Ohio River Valley (Eastern and Central US)
Blastomyces
Broad-based budding organism forming patchy infiltrate with cavitary lesions in lungs near Great Lakes area
Blastomyces
Blastomyces inflammatory lung disease can disseminate where?
Skin and bones
Local Blastomyces infection presents how?
Local pneumonia
Fungus that appears as spherules filled with endospores in the lung
Coccidioidomycosis
Fungal infection that is strongly associated with erythema nodosum
Coccidioidomycosis
Disseminated Coccidioidomycosis infection can cause what
Skin and bone infections and meningitis in immunocompromised
Fungus geographically found in South America and looks like budding yeast with “captain’s wheel” formation
Paracoccidioidomycosis
Mode of transmission of Paracoccidioidomycosis
Respiratory droplets
Fungus that presents with cervical lymphadenopathy, Mucocutaneous lesions, and progresses to granulomas in lungs
Paracoccidioidomycosis
Fungus with spaghetti and meatball appearance that causes hypo/hyperpigmented skin patches
Malassezia furfur
Tinea versicolor is caused by what organism?
Malassezia
Malassezia mechanism of action
Lipids degradation produces acids damaging melanocytes causing hyper/hypopigmented skin patches
Epithelial layer damaged by Malassezia
Stratum corneum of epithelium
Treatment for Malassezia furfur
Selenium sulfide
Fungus best visualized under Wood’s lamp
Microsporum
Onychomycosis
Fungal infection of nails caused by Tinea unguium
Treatment for Onychomycosis
Oral turbinafine
Treatment for severe infections of Onychomycosis
Griseofulvin
Turbinafine mechanism of action
Inhibits fungal enzyme squalene epoxidase
Griseofulvin mechanism of action
Interferes with microtubule function
Antifungal that disrupts mitosis
Griseofulvin
Cigar-shaped budding yeast that grows in branching hyphae with rosettes of conidia
Sporothrix schenckii
Best treatment for patient working in garden who developed ulcers with nodules in an ascending pattern of draining lymphatics
Itraconazole or potassium iodide
Fungus that forms germ tubes at 37 degrees
Candida albicans
Fungus that forms pseudo hyphae and budding yeast at 20 degrees
Candida albicans
Fungus that is catalase positive and is normal flora of GI tract and oropharynx
Candida albicans
Common cause of diaper rash
Candidiasis
Oral thrush is caused by what and seen in what population group
Caused by Candida in immunocompromised
Difference between leukoplakia and oral thrush
Oral thrush can be scraped off
Patients on oral/inhaled steroids who fail to rinse mouth are at risk for what
Oral Candidiasis (oral thrush)
Candidal esophagitis in HIV patients develops at what CD4 count?
CD4 count < 100
Candidal vulvovaginitis is common in what population group?
Diabetics and women who use antibiotics or OCPs
IV drug user is at risk for what from which fungal infection
Candidal endocarditis more commonly tricuspid valve
Common treatment for oral candidiasis
Nystatin swish and swallow
Treatment for disseminated/resistant Candidiasis
Caspofungin
What drugs are Echinocandins?
Micafungin, Anidulafungin, Caspofungin
Echinocandins mechanism of action
Block cell wall synthesis by inhibiting beta-glucan
Nystatin mechanism of action
Binds ergosterol forming membrane pores allowing leakage of electrolytes
Antifungals that bind ergosterol and form membrane pores
Amphotericin B and Nystatin
Flucytosine mechanism of action
Blocks DNA and RNA biosynthesis by conversion to 5-fluorouracil
Enzyme involved in converting Flucytosine to 5-fluorouracil
Cytosine deaminase
Catalase positive organism associated with hepatocellular carcinoma and forms septate hyphae with acute angle branching
Aspergillus fumigatus
Fungus that forms conidia in radiating chains at end of conidiophore
Aspergillus
Fungus that can cause a hypersensitivity response associated with asthma and cystic fibrosis
Aspergillus
Bronchiectasis visualized on chest x-ray with eosinophilia in an asthmatic is associated with what organism
Aspergillus fumigatus
Catalase positive fungi
Candida and Aspergillus
Condition that causes wheezing, fever, and migratory pulmonary infiltrate in an asthmatic with eosinophilia
Allergic Bronchopulmonary Aspergillosis (ABPA)
Allergic Bronchopulmonary Aspergillosis is associated with what type of hypersensitivity reaction
Type I
Gravity dependent fungus balls that appear after TB infection
Aspergillomas
Disease in patient with ring enhancing brain lesion, kidney failure, and endocarditis with hemoptysis and acute angle hyphae seen in blood vessels
Angioinvasive aspergillosis
Necrosis around nose with acute angle branching hyphae
Aspergillosis
Angioinvasive aspergillosis treatment
Amphotericin B
Aspergillosis treatment of choice
Voriconazole
Encapsulated, urease positive organism with repeating polysaccharide capsular antigens found in pigeon droppings
Cryptococcus
Most common cause of fungal meningitis and presents with fever and pneumonia
Cryptococcus
Latex agglutination test detects polysaccharide capsular antigen, clear halo on India ink and “soap bubble lesions” in brain gray matter. What is organism
Cryptococcus
Order of treatment for Cryptococcal meningitis
Amphotericin B + flucytosine followed by fluconazole
Most common predisposing risk factor for Mucormycosis
Diabetic Ketoacidosis (DKA)
Organism with non-septate, wide-angle branching hyphae causing necrosis of the nose
Mucormycosis
Mucormycosis mechanism of infection
Invades blood vessel walls then enters cribriform plate
Black eschar in nasal cavity in patient with DKA
Mucormycosis
Treatment for Mucormycosis infection
Surgical debridement of necrotic tissue and amphotericin B
Patient with CD4 count < 200, and diffuse interstitial ground-glass appearance on x-ray
Pneumocystis pneumonia
How do you confirm diagnosis in patient with CD4 count < 200, and diffuse interstitial ground-glass appearance on x-ray
Bronchoalveolar lavage (BAL) stained with methamine silver
Disc-shaped yeast on methamine silver stain
Pneumocystis jirovecii
Drug used for treatment and prophylaxis of Pneumocystis infection
TMP-SMX
When do you start prophylaxis treatment for Pneumocystis infection
CD4 count < 200 cells
Drug used for Pneumocystis infection in someone with sulfa allergy
Pentamidine