Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology > Mycology > Flashcards

Mycology Flashcards

(97 cards)

Start Studying
1
Q

How do Mucor and Rhizopus enter the body?

A

Via inhalation of spores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the clinical name for dermatophyte (cutaneous fungal) infections?

A

Tinea (dermatophytes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does Pneumocystis pneumonia appear on methanamine-stained samples?

A

Disc-shaped yeasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What 2 stains are used to diagnose Cryptococcus neoformans?

A

India ink (shows clear halo) and mucicarmine (shows inner red capsule)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What disease is caused by Pneumocystis jirovecii?

A

Pneumocystis pneumonia (PCP), which is a diffuse interstitial pneumonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What structure must Mucor and Rhizopus penetrate to invade the brain?

A

Cribriform plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A man with diabetes mellitus has a headache, facial pain, a black necrotic facial eschar, and cranial nerve palsies. What is the likely diagnosis?

A

Cavernous sinus thromboses leading to cranial nerve involvement, a complication of Mucor and Rhizopus infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

An athlete has hypopigmented and hyperpigmented macules on her back after intensive summer training. What is the most likely diagnosis?

A

Tinea (pityriasis) versicolor (Malassezia spp, Pityrosporum spp)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

An immunocompromised patient presents with “soap bubble” lesions in his brain on imaging. How does an infection with Cryptococcus neoformans lead to this?

A

Through hematogenous dissemination after inhalation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 3 different manifestations of tinea pedis?

A

Moccasin distribution, vesicular type, and interdigital (most common)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A male patient, positive for HIV, has an infection with a heavily encapsulated, nondimorphic yeast. What is the likely diagnosis?

A

Cryptococcus infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the various prophylaxis options for Pneumocystis pneumonia?

A

Trimethoprim-sulfamethoxazole (TMP-SMX), dapsone, pentamidine, or atovaquone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How can tinea corporis be acquired?

A

From contact with infected pets or farm animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does Sporothrix schenckii exist in the human body and in the soil?

A

Cigar-shaped yeast in the human body at 37°C; hyphae with spores in soil (conidia); S schenckii is dimorphic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where are the abscesses in Mucor and Rhizopus infections most commonly found?

A

Rhinocerebral and frontal lobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

You culture Cryptococcus neoformans at 25°C and then at 37°C. What morphology do you note?

A

C neoformans grows as a yeast at both temperatures (it is not dimorphic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is observed when Candida albicans is grown at 20°C and then at 37°C?

A

Forms pseudohyphae and budding yeast at 20°C; germ tube formation at 37°C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do you treat disseminated candidiasis?

A

Amphotericin B, fluconazole, or echinocandins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is Pneumocystis pneumonia diagnosed?

A

From a bronchoalveolar lavage or lung biopsy; sample stained with methenamine silver or identified with a fluorescent antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

At what CD4+ count should patients who are HIV+ begin to receive prophylaxis against Pneumocystis pneumonia?

A

< 200 cells/mm3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What populations are more likely to develop invasive aspergillosis?

A

Patients who are immunocompromised and those with disorders of neutrophil dysfunction (ie, chronic granulomatous disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the first-line treatment for oral thrush alone?

A

Treatment for superficial Candida infections is nystatin, fluconazole, or echinocandins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What class of organisms causes tinea pedis, cruris, corporis, capitis, and unguium?

A

Dermatophytes (representative geni include Microsporum, Trichophyton, Epidermophyton)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which population is at an increased risk of developing vulvovaginitis due to Candida albicans?

A

Patients with diabetes and those using antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What treatment options are available for Aspergillus infections?
Voriconazole, echinocandins (2nd line)
26
How does tinea versicolor cause hypopigmentation on skin?
Lipid degradation by Malassezia spp (Pityrosporum spp) produces acids → inhibit tyrosinase (melanin synthesis) → hypopigmentation
27
What opportunistic fungus is a cause of endocarditis in IV drug users?
Candida albicans
28
Name 3 infections caused by Cryptococcus neoformans typically found in immunocompromised patients.
Cryptococcosis, cryptococcal encephalitis ("soap bubble" lesions in the brain), and cryptococcal meningitis
29
A gardener presents with a pustule on her forearm and multiple nodules tracing upward toward her axilla. What is the most likely diagnosis?
Sporotrichosis (rose gardener's disease)
30
How does Aspergillus fumigatus appear on culture media at 37°C?
45° branching septate hyphae (broom-like appearance)
31
Which group of hosts would be symptomatic if infected with Pneumocystis?
Immunocompromised patients (eg, those with AIDS); otherwise, most are asymptomatic
32
What part of the body is affected in a tinea unguium infection?
Nails (fungal nail infection is also termed onychomycosis)
33
What is the appearance of Pneumocystis pneumonia on chest imaging?
Diffuse, bilateral ground-glass opacities with pneumatoceles
34
What is the treatment of tinea (pityriasis) versicolor?
Selenium sulfide, topical and/or oral antifungal medications
35
A man has multiple erythematous scaling rings with central clearing. What is the most likely diagnosis?
Tinea corporis infection (ringworm)
36
What populations are at high risk for oral/esophageal thrush?
Immunocompromised: neonates, patients with diabetes and AIDS, chronic steroid users
37
How is sporotrichosis transmitted?
Introduction of fungal spores into the skin after an injury, often caused by thorns (hence, rose gardener's disease)
38
What is the treatment for vaginal candidiasis?
Oral fluconazole/topical azoles
39
Where are ringworms commonly found on the body?
Torso
40
How are Mucor and Rhizopus infections with brain involvement treated?
Surgical debridement and amphotericin B or isavuconazole
41
A woman has a fungal infection that produces aflatoxins. For what condition should this patient periodically be monitored?
Hepatocellular carcinoma (Aflatoxins, produced by some Aspergillus species, are associated with this malignancy)
42
How do Mucor and Rhizopus proliferate in the body and cause infection?
The fungi are inhaled as spores and then grow in the blood vessels and enter the brain via the cribriform plate
43
Which 2 groups of patients are most likely to develop ABPA (allergic bronchopulmonary aspergillosis)?
Patients with asthma and cystic fibrosis
44
How do Mucor and Rhizopus spp appear on culture media?
Broad, irregular, nonseptate hyphae that branch at wide angles
45
What causes the hyperpigmentation and/or pink patches seen in tinea versicolor?
The inflammatory response
46
What is the most specific test to confirm an infection with Cryptococcus neoformans?
Latex agglutination test to detect the polysaccharide capsular antigen
47
What fungal infection are patients with TB at risk for due to their cavitary lesions?
Aspergillus fumigatus, which may cause aspergillomas in preexisting lung cavities (especially those from TB)
48
How is sporotrichosis treated?
Itraconazole or potassium iodide (for cutaneous/lymphocutaneous disease)
49
An immunosuppressed pigeon keeper has meningitis. Mucicarmine stains of the CSF culture results are shown (image). What might brain imaging show?
"Soap bubble" lesions on brain imaging from concomitant encephalitis (diagnosis: Crytococcus neoformans; note the red inner capsule on mucicarmine)
50
A patient has had frequent outbreaks of white plaques in his mouth (image) for his entire life. What is a possible diagnosis?
Chronic mucocutaneous candidiasis as the underlying cause of Candida albicansoral thrush
51
A patient with asthma presents with the CT findings (image), and a diagnosis of allergic bronchopulmonary aspergillosis is made. What is the pathophysiology of this condition?
Patients with asthma or cystic fibrosis have a hypersensitivity response to aspergillus colonization
52
What organism is shown in this image?
Malassezia spp (Pityrosporum spp); shows "spaghetti and meatball" appearance on microscopy
53
Which patient populations are most susceptible to disease with the fungal organism pictured (image)?
Mucor and Rhizopus are most worrisome in patients with diabetic ketoacidosis or neutropenia (eg, leukemia)
54
A patient presents with lymphadenopathy and the findings in the image below. What is the likely diagnosis?
Tinea capitis (note alopecia and scaling in the image)
55
A patient presents with foot discoloration (image) and is thought to have a fungal skin infection. What is the most likely diagnosis?
This is tinea pedis, with a moccasin distribution (dermatophyte infection)
56
The cerebrospinal fluid of a male with meningitis who is positive for HIV shows a fungus (image). At what temperature has this fluid specimen likely been analyzed?
This is Candida albicans, a white ("alba") dimorphic yeast that exhibits pseudohyphae and budding yeasts at 20°C, as shown in the image (germ tubes would be seen at 37°C)
57
A transplant patient develops fever and dyspnea. Bronchoalveolar lavage with methenamine staining of the sample is shown (image). What findings would be seen on a chest CT?
Diffuse, bilateral ground-glass opacities with pneumatoceles (air-filled cysts); this is Pneumocystis pneumonia
58
A patient with cystic fibrosis has a fungal culture that shows the following. What is the diagnosis?
Infection with Aspergillus fumigatus, causing allergic bronchopulmonary aspergillosis (ABPA); note conidia in radiating chains at the ends of conidiophores
59
A patient complains of itching in her inguinal area (image). No central clearing is present. Diagnosis?
Tinea cruris
60
A man presents with pruritic lesions (see image) on his extremities. What is the likely diagnosis?
Tinea corporis (note the patches with central clearing in image)
61
A gardener has an arm pustule with ascending lymphangitis (image). What is the diagnosis?
Sporotrichosis
62
A chest x-ray (image) is shown of a patient with AIDS who is short of breath. A lung biopsy and methenamine silver staining of tissue reveals disc-shaped yeast. Diagnosis?
Pneumocystis pneumonia
63
A fungal organism is stained with India ink (image). What additional stain, targeting an inner capsule, could help to confirm the diagnosis?
A mucicarmine stain, which highlights the inner capsule as red (diagnosis: Cryptococcus neoformans; note the "clear halo" appearance)
64
Light microscopy of a KOH prep with blue fungal stain reveals the following (image). What is the organism?
Dermatophytes (tinea infection)
65
A patient presents with the itchy lesion shown in the image. What would a KOH preparation of a sample taken from the lesion demonstrate?
Branching septate hyphae; this is tinea pedis (with interdigital presentation, which is most common)
66
A CT of the chest in a patient with AIDS, acute-onset dyspnea, and hypoxia is shown (image). What diagnostic testing can identify the causative organism?
Bronchoalveolar lavage or lung biopsy; this is Pneumocystis pneumonia (note the presence of pneumatoceles with interstitial pneumonia)
67
A patient with chronic granulomatous disease is superinfected with the organism shown in the image. Name 3 presentations of this infection.
Allergic bronchopulmonary aspergillosis (ABPA), lung cavity aspergillomas, and invasive aspergillosis (note Acute Angles in Aspergillosis)
68
Light microscopic findings of a fungal culture grown at 37°C are shown (image). What is the organism?
Candida albicans
69
A patient develops recurrent fungal infections every summer with the rash shown (image). What characteristic pattern of this lesion would be seen on microscopy?
Spaghetti and meatball pattern (diagnosis: tinea versicolor)
70
How do TB and the systemic mycoses differ in transmission?
Only TB can be transmitted from person to person
71
What physical exam findings are evident in coccidioidomycosis?
Erythema nodosum (desert bumps) and multiforme, arthralgias (desert rheumatism), may see meningeal signs if meningitis is present
72
A 70-year-old patient who is diagnosed with coccidioidomycosis pneumonia subsequently develops persistent headache and blurry vision. What condition should he be evaluated for?
Meningitis; as coccidioidomycosis can result in meningitis
73
All systemic mycoses can primarily cause what type of illness?
Pneumonia; all can disseminate
74
A 40-year-old immunocompromised man presents with pneumonia and verrucous skin lesions shortly after traveling to Wisconsin. What is the most likely diagnosis?
Blastomycosis
75
If blastomycosis disseminates to the skin, which other disease may it mimic?
Squamous cell carcinoma
76
How is histoplasmosis generally acquired?
Inhalation from bird (eg, starling) or bat droppings
77
Where is paracoccidioidomycosis endemic?
Latin America (Paracoccidioparasails with the captain’s wheel all the way to Latin America)
78
How do Histoplasma, Blastomyces, Coccidioides, and Paracoccidioides organisms compare in terms of size to an RBC?
Histoplasma organisms are smaller; Blastomyces organisms are the same size; Coccidioides and Paracoccidioides organisms are larger
79
Which 3 systemic fungi are dimorphic?
Histoplasma, Blastomyces, Paracoccidiodes (dimorphic: metamorphosing into mold in cold [20°C] and into yeast in heat [37°C])
80
How is Coccidioides distinguished from all other dimorphic fungi?
It is a spherule in tissue (37°C), not a yeast
81
What region is blastomycosis endemic to?
Eastern or central United States, Great Lakes
82
What test diagnoses histoplasmosis?
Urine/serum antigen
83
Paracoccidioidomycosis presents most similarly to which other systemic fungal disease?
Blastomycosis
84
What signs/symptoms can be seen in a patient with blastomycosis?
Inflammatory lung disease, forms granulomatous nodules, disseminates to bone/skin (can mimic squamous cell carcinoma)
85
How do you treat disseminated systemic mycoses?
Amphotericin B
86
How do you treat local infections of systemic mycoses?
With azoles (eg, itraconazole, fluconazole)
87
Pathologically, how are systemic mycoses and tuberculosis similar?
Both can form granulomas
88
What region is Coccidioidomycosis endemic to?
Southwestern United States and California
89
Where is histoplasmosis endemic?
The Ohio and Mississippi River valleys
90
Is paracoccidiodomycosis more common in females or males?
Males \> females
91
What signs/symptoms can be seen in a patient with histoplasmosis?
Palatal or tongue ulcers, pancytopenia, splenomegaly
92
What exposure is most strongly associated with coccidioidomycosis infection?
Dust exposure in endemic areas (eg, after earthquakes or during excavations)
93
A patient presents with pancytopenia, splenomegaly, and palatal ulcers. A bone marrow biopsy is done and the image below shows the results. What is the likely diagnosis?
Histoplasmosis
94
What is the size of this organism relative to that of an RBC (image)?
Larger than an RBC (this is the characteristic “captain's wheel" of paracoccidioidomycosis)
95
What systemic mycoses has the following histopathology (image)?
Histoplasma; this is a macrophage filled with Histoplasma organisms
96
What systemic mycoses is characterized by the following histopathology (image)?
Blastomycosis ("Broad-based budding: Blasto buds broadly")
97
What systemic mycosis (histopathology below) can present with meningitis and pneumonia?
Coccidioidomycosis

Microbiology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions