A young woman recently returned from a camping trip in Death Valley National Park, California. She developed a cough, chest pain, headache, general malaise and myalgia with fever, and has slight monocytosis. A chest x-ray showed pneumonic infiltrates with one well defined nodule. Antibiotic therapy failed to relieve her symptoms. Biopsy of the nodule showed this structure. What organism is causing this disease?
A) Coccidiodes imitis
The term dematiaceous is used to describe
D) the presence of pigmentation within the hyphae or the spores.
Pertaining to this fungus, the conidia are produced from structures called
D) Phialides
The genus Microsporum is characterized by all the following characteristics except:
A) has a bright red reverse surface
The photo shows a large, round yeast with multiple budding cells, often referred to as a mariner's wheel. Which yeast is associated with this morphology?
A) Paracoccidioides brasiliensis.
Match the following characteristics of fungi with the appropriate definition.
+Hyphae fragmentation through the points of septation
+The rounding up and enlargement of the terminal cells of the hyphae
+The fungal element that is produced when buds elongate and fail to dissociate
+A slender tubular outgrowth from a spore in germination
+Budding yeast
Hyphae fragmentation through the points of septation: Arthroconidia
The rounding up and enlargement of the terminal cells of the hyphae: Chlamydoconidia
The fungal element that is produced when buds elongate and fail to dissociate: Pseudohyphae
A slender tubular outgrowth from a spore in germination: Germ tube
Budding yeast: Blastoconidia
An isolate from a corneal infection grows white cottony colonies on Sabouraud dextrose agar at 4 days. The reverse colony morphology is a light off-white. Microscopic examination shows the microscopic morphology shown below. What is the organism?
D) Fusarium spp.
Which fungal media is preferred for the recovery of organisms such as Microsporum and Trichophyton because it contains antibacterials and antifungals?
C) Cornmeal agar with Tween 80
Match the following fungal disease to the appropriate description.
+usually on hands and feet, chronic infection characterized by swollen tumor-like lesions that yield granular pus through draining sinuses
+subcutaneous mycoses in which there is a localized cutaneous and subcutaneous infection where the tissue turns into rounded sclerotic bodies, called copper pennies
+term to describe any infection caused by a dematiacious organism, can be subcutaneous, localized, or systemic infections
+infections of the skin or nails caused by dermatophyte fungi, outer ring is active, progressing infection, with central healing within the ring
usually on hands and feet, chronic infection characterized by swollen tumor-like lesions that yield granular pus through draining sinuses: Mycetoma
subcutaneous mycoses in which there is a localized cutaneous and subcutaneous infection where the tissue turns into rounded sclerotic bodies, called copper pennies: Chromoblastomycosis
term to describe any infection caused by a dematiacious organism, can be subcutaneous, localized, or systemic infections: Phaeohyphomycosis
infections of the skin or nails caused by dermatophyte fungi, outer ring is active, progressing infection, with central healing within the ring: Tinea
This photograph shows the macroconidia of Epidermophyton floccosum. Which of the following characteristics is also particular to this fungi?
B) no microconidia are produced.
The term hyaline is used to describe
B) the absence of pigmentation within the hyphae.
This organism shows a "spaghetti and meatballs" appearance and is most commonly associated with:
D) Tinea versicolor
The most definitive means for identification of superficial, subcutaneous, or opportunistic molds is
A) microscopic morphologic features such as shape and arrangement of conidia, and appearance of hyphae
A patient relocated to the US 10 years ago from The Sudan. They now present with a mycetoma of the foot which developed over the last 20 years. Sinus tracts release pus which contains dark granules. The organism is cultivated at 25°C and yields macroconidia with the morphology shown below. What is this organism?
A) Curvularia spp.
A superficial skin infection, caused by Hortaea werneckii, manifested by blackish brown macular patches on the palm of the hand or sole of the foot is called
C) Tinea nigra.
A child with a small wound on their hand develops secondary sores along the lymphatic tracts of the arm. Cigar-shaped blastoconidia are observed in tissue but in culture, you see the morphology in this picture. What is this organism?
A) Sporothrix schenckii
Yeast recovered from the urine of a catheterized patient receiving chemotherapy for cancer gave the following results:
Germ tube positive
Pseudohyphae positive
Arthrospores negative
Chlamydospores positive
Green on CHROMagar
What further testing is necessary for positive identification?
C) no further testing is needed for identification.
A 24-year-old woman presents with fever, dry cough, and shortness of breath for 10 days, and is getting worse. Nothing in the medical history or physical exam indicates a potential pathogen. She was given antibiotics for atypical pneumonia, but was much worse five days later. Further investigation showed her boyfriend of 2 years is HIV positive, and that she had been loosing weight and suffering night sweats. A Giemsa stain of sputum showed the following. What is indicated by the arrow?
D) Pneumocystis jiroveci cyst
Immunocompromised patients, particularly those who have uncontrolled diabetes mellitus and those who are receiving prolonged corticosteroid, antibiotic, or cytotoxic therapy, are at greatest risk of developing infection with
D) Zygomycetes.
The following is an India ink prep of a tissue section from a liver abscess. What is the infective organism?
C) Cryptococcus neoformans
This photo is of a dermatophyte that perforates the hair. The image illustrates the microconidia which typically show as powdery clusters of round to pyriform shape on branched conidiophores. The hyphae often spiral or coil at the ends. Finally, this fungi does not fluoresce under UV light. What is the name of this fungus?
B) Trychophyton mentagrophytes
Match the following fungi with their diagnostic characteristic.
+pectinate hyphae
+4 possible conidial forms
+cigar-shaped blastoconidia
+spiral hyphae
+intracystic bodies
A 38-year-old Tennessean, who worked clearing brush and pruning trees for a power company, reported to the doctor with a low-grade fever, myalgias, and nonproductive cough. After 2 weeks of therapy his condition had not improved. A chest radiograph demonstrated right middle lobe air space disease and a different oral antibiotic was given. Over the next month his condition worsened, with daily fevers, chills, night sweats and weight loss. He was admitted to the hospital, where a skin examination now showed a tender, raised, erythematous papule on the bridge of the nose. A bronchoscopy was performed, but KOH examination , acid-fast, modified acid-fast and Gram stains gave negative results. Examination of exudate from the skin lesions using a silver stain is shown below. What is the differential diagnosis for the patient?
B) Blastomycosis
What is the mechanism of action associated with amphotericin B?
A) binds to ergosterol in the cell membrane
Indicate the appropriate characteristics for fungi in the Ascomycetes and Zygomycetes groups
A 50-year-old woman noticed a burning sensation in her palate after an 8-month bout with allergic rhinitis. A rapidly progressing ulceration developed with perforation of the hard palate into the floor of the nose in just 7 days. A biopsy of the palatal lesion demonstrated inflammation and the hyphal elements shown below. What caused this form of phaeohyphomycosis?
C) Alternaria spp.
A bone marrow transplant patient develops an abrupt fever with respiratory distress. Despite treatment with antifungal medications, the patient dies on the fifth day. The following organism was isolated from both sputum and blood cultures. Identify the organism shown below.
A) Aspergillus spp.
Which organism produces mostly shades of green or blue-green colonies? Microscopically, hyphae are hyaline and septate and produce brushlike/broomlike conidiophores.
C) Penicillium
A scientist returned from a field trip charting the habitat of bat species in western West Virginia. He reports suffering from mild flu-like symptoms but his x-ray shows no infiltrates. A sputum culture from this patient grows the organism shown below. Identify the organism.
A) Paracoccidiodes brasiliensis
Sporangiophores that are singularly produced or branched and have at their tip a round sporangium filled with sporangiospores and the absence of rhizoids or stolons would usually indicate infection with
B) Mucor
You have isolated a dematiacious mold that produces oblong thick-walled multicelled conidia with a zig-zag pattern on the conidiophore where the conidia were attached. The identification of this mold is