MV Prelims Flashcards

*Question: What is the diagnostic feature of Pityriasis versicolor under KOH microscopy?

A) Copper pennies

B) Spaghetti and meatballs appearance

C) Cigar-shaped yeast

D) Asteroid bodies

*Answer: B) Spaghetti and meatballs appearance

*Question: Which antifungal drug targets ergosterol by binding to it and creating pores in the fungal cell membrane?

A) Fluconazole

B) Flucytosine

C) Amphotericin B

D) Caspofungin

*Answer: C) Amphotericin B

*Question: What is the causative agent of Rose Gardener's Disease?

A) Fonsecaea pedrosoi

B) Madurella mycetomatis

C) Sporothrix schenckii

D) Hortaea werneckii

*Answer: C) Sporothrix schenckii

*Question: Which fungal class produces ascospores as its sexual spore?

A) Zygomycetes

B) Basidiomycetes

C) Deuteromycetes

D) Ascomycetes

*Answer: D) Ascomycetes

*Question: What is the hallmark finding in Chromoblastomycosis tissue sections?

A) Asteroid bodies

B) Sclerotic (Medlar) bodies

C) Draining sinuses with granules

D) Cigar-shaped yeast

*Answer: B) Sclerotic (Medlar) bodies

*Question: Which Candida species is the exception that cannot form chlamydospores and pseudohyphae on Corn Meal Agar?

A) C. tropicalis

B) C. krusei

C) C. glabrata

D) C. albicans

*Answer: C) C. glabrata

*Question: The germ tube test is used to identify which organism?

A) Cryptococcus neoformans

B) Candida albicans

C) Aspergillus fumigatus

D) Trichophyton rubrum

*Answer: B) Candida albicans

*Question: What is the main sterol found in fungal cell membranes that serves as the primary target of antifungal drugs?

A) Cholesterol

B) Zymosterol

C) Ergosterol

D) Lanosterol

*Answer: C) Ergosterol

*Question: Which dimorphic fungus shows a mariner's wheel appearance?

A) Histoplasma capsulatum

B) Coccidioides immitis

C) Blastomyces dermatitidis

D) Paracoccidioides brasiliensis

*Answer: D) Paracoccidioides brasiliensis

*Question: What stain is used for the negative staining of Cryptococcus neoformans capsule?

A) Lactophenol cotton blue

B) India ink

C) Calcofluor white

D) Gomori's methenamine silver

*Answer: B) India ink

*Question: Which dermatophyte genus does NOT produce microconidia?

A) Trichophyton

B) Microsporum

C) Epidermophyton

D) All produce microconidia

*Answer: C) Epidermophyton

*Question: What is the mode of transmission for subcutaneous mycoses?

A) Inhalation of spores

B) Ingestion of contaminated food

C) Traumatic inoculation

D) Sexual contact

*Answer: C) Traumatic inoculation

*Question: Which culture medium is specifically used for the identification of Cryptococcus neoformans based on phenoloxidase production?

A) CHROMagar Candida

B) Corn Meal Agar

C) Niger Seed Agar

D) Dermatophyte Test Medium

*Answer: C) Niger Seed Agar

*Question: What is the most common cause of eumycetoma worldwide?

A) Scedosporium boydii

B) Exophiala jeanselmei

C) Madurella mycetomatis

D) Fusarium solani

*Answer: C) Madurella mycetomatis

*Question: Dimorphic fungi grow in what form at 25-30°C?

A) Yeast form

B) Mold form

C) Spore form

D) Pseudohyphal form

*Answer: B) Mold form

*Question: Which toxin produced by Amanita phalloides binds to actin in cell membranes causing vacuolization and membrane leakage?

A) Aflatoxin

B) Alpha-amanitin

C) Phalloidin

D) Ochratoxin

*Answer: C) Phalloidin

*Question: What is the most common fungal infection in humans?

A) Candidiasis

B) Aspergillosis

C) Ringworm infection (Dermatophytosis)

D) Cryptococcosis

*Answer: C) Ringworm infection (Dermatophytosis)

*Question: Which sexual reproduction process involves the fusion of two nuclei to form a diploid nucleus?

A) Plasmogamy

B) Meiosis

C) Karyogamy

D) Mitosis

*Answer: C) Karyogamy

*Question: What is the current accepted name of the organism formerly known as Penicillium notatum that produces penicillin?

A) Penicillium chrysogenum

B) Penicillium rubens

C) Penicillium marneffei

D) Penicillium notatum

*Answer: B) Penicillium rubens

*Question: Which echinocandin antifungal targets the fungal cell wall by inhibiting 1,3-beta-D-glucan synthase?

A) Flucytosine

B) Amphotericin B

C) Caspofungin

D) Voriconazole

*Answer: C) Caspofungin

*Question: What is the hallmark finding of Sporotrichosis in H&E stained tissue sections?

A) Medlar bodies

B) Asteroid bodies (Splendore-Hoeppli phenomenon)

C) Sclerotia

D) Copper pennies

*Answer: B) Asteroid bodies (Splendore-Hoeppli phenomenon)

*Question: Which type of hyphae lacks septa and forms a continuous multinucleate structure?

A) Septate hyphae

B) Dematiaceous hyphae

C) Coenocytic hyphae

D) Hyaline hyphae

*Answer: C) Coenocytic hyphae

*Question: The lysis centrifugation technique (Isolator) is optimal for the isolation of which organism?

A) Candida albicans

B) Cryptococcus neoformans

C) Histoplasma capsulatum

D) Aspergillus fumigatus

*Answer: C) Histoplasma capsulatum

*Question: Trichophyton rubrum is identified by which characteristic reverse pigmentation on culture?

A) Deep yellow

B) Reddish-brown

C) Deep red (non-diffusible)

D) Tan to olive green

*Answer: C) Deep red (non-diffusible)

*Question: Which aflatoxin-producing Aspergillus species is most commonly found in peanut skin?

A) Aspergillus fumigatus

B) Aspergillus flavus

C) Aspergillus niger

D) Aspergillus terreus

*Answer: B) Aspergillus flavus

*Question: What type of conidiogenesis involves the septum appearing FIRST before a cell develops into a spore?

A) Blastic conidiogenesis

B) Thallic conidiogenesis

C) Holoblastic conidiogenesis

D) Enteroblastic conidiogenesis

*Answer: B) Thallic conidiogenesis

*Question: Which specimen CANNOT be refrigerated in mycology?

A) Urine

B) Blood

C) Sputum

D) Skin, hair, and nails

*Answer: D) Skin, hair, and nails

*Question: What is the most accurate method to preserve and observe fungi in their original living state?

A) Basic tease mount

B) KOH wet mount

C) Slide culture

D) Cellophane tape mount

*Answer: C) Slide culture

*Question: Which Trichophyton species requires both thiamine AND inositol for growth (Trichophyton Agar 3)?

A) T. rubrum

B) T. tonsurans

C) T. violaceum

D) T. verrucosum

*Answer: D) T. verrucosum

*Question: Endothrix hair invasion is characterized by which of the following?

A) Hyphae covering the outside of hair; destroys cuticle; fluoresces

B) Hyphae inside the hair shaft; cuticle intact; does NOT fluoresce

C) Hyphae inside and outside the hair shaft

D) Only arthroconidia on the hair surface

*Answer: B) Hyphae inside the hair shaft; cuticle intact; does NOT fluoresce

*Question: Which culture medium is a combination of Sabouraud Dextrose Agar and Brain Heart Infusion used for fastidious dimorphic fungi?

A) IMA

B) SABHI Agar

C) Czapek Agar

D) V-8 Agar

*Answer: B) SABHI Agar

*Question: The Rapid Urease Test showing a color change from peach to magenta is used for preliminary identification of which organism?

A) Candida albicans

B) Trichophyton mentagrophytes

C) Cryptococcus neoformans

D) Histoplasma capsulatum

*Answer: C) Cryptococcus neoformans

*Question: Which subcutaneous mycosis is also known as Madura foot?

A) Sporotrichosis

B) Chromoblastomycosis

C) Mycetoma

D) Phaeohyphomycosis

*Answer: C) Mycetoma

*Question: What is the primary monomer of chitin found in fungal cell walls?

A) D-Glucose

B) D-Mannose

C) D-Glucosamine

D) N-acetyl glucosamine (NAG)

*Answer: D) N-acetyl glucosamine (NAG)

*Question: Which azole antifungal is used topically for mild dermatophytosis including Tinea versicolor?

A) Voriconazole

B) Itraconazole

C) Miconazole

D) Fluconazole

*Answer: C) Miconazole

*Question: What is the causative agent of Tinea nigra?

A) Malassezia furfur

B) Piedraia hortae

C) Hortaea werneckii

D) Trichosporon inkin

*Answer: C) Hortaea werneckii

*Question: Which mycosis classification is caused by normal flora with uncontrolled fungal growth, such as Candidiasis?

A) Superficial mycosis

B) Subcutaneous mycosis

C) True systemic mycosis

D) Opportunistic mycosis

*Answer: D) Opportunistic mycosis

*Question: Calcofluor white produces what color result when fungi are present under UV light?

A) Reddish-orange

B) Yellow-green

C) Apple-green or bluish-white

D) Dark brown

*Answer: C) Apple-green or bluish-white

*Question: What is the virulence factor of lymphocutaneous Sporotrichosis that allows it to spread to lymph nodes?

A) Aflatoxin

B) Glucuronoxylomannan

C) Neuraminidase

D) Phenoloxidase

*Answer: C) Neuraminidase

*Question: Which serological test is the easiest and cheapest, similar to a pregnancy test format?

A) ELISA

B) Complement Fixation Test

C) Immunodiffusion

D) Lateral Flow Assay

*Answer: D) Lateral Flow Assay

*Question: Microsporum canis shows what appearance on culture?

A) White cottony surface with deep yellow reverse

B) Tan powdery colony with orange-brown reverse

C) White cottony surface with deep red reverse

D) Flat velvety surface with tan to olive green

*Answer: A) White cottony surface with deep yellow reverse

*Question: Which antifungal is the FIRST successful antifungal drug developed and is used mainly for oral and vulvovaginal candidiasis?

A) Amphotericin B

B) Griseofulvin

C) Nystatin

D) Flucytosine

*Answer: C) Nystatin

*Question: What is the characteristic microscopic appearance of Sporothrix schenckii in its yeast form?

A) Fusiform macroconidia with hooked tips

B) Small elliptoid budding cigar-shaped yeasts

C) Chains of arthroconidia

D) Large thick-walled spherules with endospores

*Answer: B) Small elliptoid budding cigar-shaped yeasts

*Question: Which organism is the most common cause of mycetoma in the United States?

A) Madurella mycetomatis

B) Exophiala jeanselmei

C) Scedosporium boydii

D) Acremonium spp.

*Answer: C) Scedosporium boydii

*Question: What pH range favors the natural growth of fungi?

A) 7-8 (alkaline)

B) 5-6 (acidic)

C) 3-4 (very acidic)

D) 6.5-7.5 (neutral)

*Answer: B) 5-6 (acidic)

*Question: Which Candida species produces BLUE colonies on CHROMagar?

A) C. albicans

B) C. krusei

C) C. glabrata

D) C. tropicalis

*Answer: D) C. tropicalis

*Question: Which test is used to differentiate Trichophyton mentagrophytes from Trichophyton rubrum using epilated hair?

A) Germ tube test

B) Hair baiting/perforation test

C) Urea hydrolysis test

D) Rapid urease test

*Answer: B) Hair baiting/perforation test

*Question: What is the hallmark of Mycetoma that differentiates it from other subcutaneous mycoses?

A) Medlar bodies

B) Cigar-shaped yeast

C) Draining sinuses and sclerotia (granules)

D) Polypoid nasal masses

*Answer: C) Draining sinuses and sclerotia (granules)

*Question: In the Latex Agglutination Test (LAT) grading, a Grade +4 result is interpreted as?

A) Small clumping with cloudy background

B) No agglutination

C) Moderate to large clumps with clear background

D) Large sized clumps with clear background

*Answer: D) Large sized clumps with clear background

*Question: Which Aspergillus species produces aflatoxin, acting as a mutagen, carcinogen, and teratogen?

A) A. fumigatus

B) A. flavus and A. parasiticus

C) A. niger

D) A. terreus

*Answer: B) A. flavus and A. parasiticus

*Question: Griseofulvin inhibits fungal growth by binding to which cellular target?

A) Ergosterol in cell membrane

B) 1,3-beta-D-glucan synthase

C) Microtubular protein (mitosis)

D) 14-alpha-demethylase

*Answer: C) Microtubular protein (mitosis)

*Question: Which dermatophyte genus primarily infects hair and skin only, NEVER nails?

A) Trichophyton

B) Epidermophyton

C) Microsporum

D) Candida

*Answer: C) Microsporum

*Question: What is the incubation temperature and duration for dermatophyte cultures before reporting as negative?

A) 37°C for 3 weeks

B) 30°C for 21 days

C) Room temperature for 6 weeks

D) 25°C for 2 weeks

*Answer: C) Room temperature for 6 weeks

*Question: Tinea capitis is most prevalent in which age group?

A) Infants (0-2 years)

B) Children (3-7 years old)

C) Adolescents (13-17 years)

D) Elderly (>65 years)

*Answer: B) Children (3-7 years old)

*Question: Which fungal infection does NOT involve living tissue invasion and produces essentially no pathologic changes in the host?

A) Cutaneous mycosis

B) Subcutaneous mycosis

C) Superficial mycosis

D) Opportunistic mycosis

*Answer: C) Superficial mycosis

*Question: What is the yeast-like cigar body of Sporothrix schenckii compared to morphologically in laboratory notes?

A) Thick-walled round budding yeast

B) Fat Escherichia coli

C) Spaghetti and meatballs

D) Copper pennies

*Answer: B) Fat Escherichia coli

*Question: Which Trichophyton species is the most common agent of athlete's foot (Tinea pedis)?

A) T. verrucosum

B) T. tonsurans

C) T. rubrum

D) T. violaceum

*Answer: C) T. rubrum

*Question: Flucytosine (5-FC) is converted inside the fungal cell into which active compound that inhibits DNA synthesis?

A) 5-fluorouridine

B) 5-FdUMP

C) Deoxyuracil monophosphate

D) Deoxythymidine monophosphate

*Answer: B) 5-FdUMP

*Question: Which stain has affinity for melanin and is used to identify dematiaceous hyphae in pigmented tissue?

A) Periodic Acid Schiff

B) Gridley's stain

C) Fontana-Masson stain

D) Gomori's Methenamine Silver

*Answer: C) Fontana-Masson stain

*Question: What type of Tinea infection is characterized by extensive concentric rings forming polycyclic plaques with thick scales, common near equatorial regions?

A) Tinea gladiatorum

B) Tinea incognita

C) Tinea imbricata

D) Majocchi's granuloma

*Answer: C) Tinea imbricata

*Question: What is the recommended minimum volume of blood for fungal culture?

A) 1 mL

B) 3 mL

C) 5 mL

D) 10 mL

*Answer: C) 5 mL

*Question: Which mycosis is associated with coal miners, mimics tuberculosis, and involves the inhalation of Sporothrix conidia?

A) Fixed cutaneous sporotrichosis

B) Pulmonary sporotrichosis

C) Lymphocutaneous sporotrichosis

D) Osteoarticular sporotrichosis

*Answer: B) Pulmonary sporotrichosis

*Question: The polysaccharide antigen detected by Latex Agglutination in Cryptococcosis is?

A) Mannan

B) Galactomannan

C) Glucuronoxylomannan

D) Beta-D-glucan

*Answer: C) Glucuronoxylomannan

*Question: Which agar plate disadvantage requires using 40 mL of agar instead of the usual 25-30 mL to prevent dehydration?

A) Screw-capped tubes

B) Agar plates

C) Biphasic broth systems

D) Petri dishes with Parafilm

*Answer: B) Agar plates

*Question: Which causative agent of White Piedra is most commonly isolated?

A) Trichosporon asahii

B) Trichosporon ovoides

C) Trichosporon inkin

D) Trichosporon cutaneum

*Answer: C) Trichosporon inkin

*Question: What is the Biosafety Level required for handling dimorphic fungi such as Histoplasma capsulatum?

A) BSL1

B) BSL2

C) BSL3

D) BSL4

*Answer: C) BSL3

*Question: Which Phialophora microscopic feature distinguishes it from other chromoblastomycosis agents?

A) Chains of blastoconidia acropetally arranged

B) Short flask-shaped phialides with collarette

C) Sympodial conidiation like malunggay

D) Lateral and terminal conidia from conidiogenous cell

*Answer: B) Short flask-shaped phialides with collarette

*Question: The 1,3 beta-D-glucan assay (Fungitell) is described as a pan-fungal marker. Which organism is NOT detected by this assay?

A) Candida spp.

B) Cryptococcus neoformans

C) Aspergillus spp.

D) Fusarium spp.

*Answer: B) Cryptococcus neoformans

*Question: Tinea pedis of the moccasin type is most commonly associated with which causative agent?

A) T. mentagrophytes

B) T. tonsurans

C) E. floccosum

D) M. canis

*Answer: C) E. floccosum

*Question: What is the characteristic colony appearance of Wangiella dermatitidis that distinguishes it as neurotropic?

A) White fluffy colonies with brownish gray reverse

B) Moist shiny yeast-like colonies becoming velvety; surface and reverse olive black

C) Tan powdery colonies with orange-brown reverse

D) Rapid growing gray-green to dark brown powdery colonies

*Answer: B) Moist shiny yeast-like colonies becoming velvety; surface and reverse olive black

*Question: Which process in sexual reproduction of fungi involves the mating of two genetically different strains to produce the dikaryon?

A) Karyogamy

B) Plasmogamy

C) Meiosis

D) Mitosis

*Answer: B) Plasmogamy

*Question: What is the recommended treatment for cutaneous and lymphatic sporotrichosis?

A) Intravenous Amphotericin B

B) Saturated solution of potassium iodide (KI)

C) Topical selenium sulfide

D) Griseofulvin oral tablets

*Answer: B) Saturated solution of potassium iodide (KI)

*Question: Histoplasma capsulatum produces what distinctive microscopic appearance at its yeast form in tissue?

A) Belt appearance

B) Mariner's wheel appearance

C) Flower appearance with buds

D) Cigar-shaped yeast

*Answer: C) Flower appearance with buds

*Question: Which causative agent of Rhinosporidiosis cannot be grown on artificial culture media?

A) Loboa loboi only

B) Rhinosporidium seeberi only

C) Both Rhinosporidium seeberi and Loboa loboi

D) Basidiobolus haptosporus

*Answer: C) Both Rhinosporidium seeberi and Loboa loboi

*Question: In Immunodiffusion for Histoplasmosis, what does a positive M band ONLY indicate?

A) Active infection

B) Early or chronic infection

C) Past resolved infection

D) No clinical significance

*Answer: B) Early or chronic infection

*Question: What is the dermoscopic finding with the highest predictive value for Tinea capitis involving short hairs that bend and go back into the scalp?

A) Barcode hairs

B) Zigzag hairs

C) Corkscrew hairs

D) Comma hairs

*Answer: D) Comma hairs

*Question: Which antifungal drug is used as oral treatment for dermatophytes that are non-responsive to azoles, sourced from Penicillium?

A) Nystatin

B) Griseofulvin

C) Amphotericin B

D) Terbinafine

*Answer: B) Griseofulvin

*Question: What does the Dermatophytid (Id) reaction represent clinically?

A) Direct fungal infection at a secondary site

B) Allergic response to fungal antigens; culture and microscopy are negative

C) Superimposed bacterial infection over fungal infection

D) Drug reaction to antifungal medication

*Answer: B) Allergic response to fungal antigens; culture and microscopy are negative

*Question: Which rapid-growing dematiaceous fungi are associated with paranasal sinus phaeohyphomycosis, remembered by the mnemonic ABC?

A) Aspergillus, Bipolaris, Curvularia

B) Alternaria, Bipolaris, Curvularia

C) Alternaria, Basidiobolus, Curvularia

D) Aspergillus, Blastomyces, Cladosporium

*Answer: B) Alternaria, Bipolaris, Curvularia

*Question: Which culture medium uses tartaric acid to lower pH to 3.5 to inhibit contaminating bacteria in food mycology?

A) Czapek Agar

B) V-8 Agar

C) Potato Dextrose Agar (PDA)

D) SABHI Agar

*Answer: C) Potato Dextrose Agar (PDA)

*Question: Which Fonsecaea species involved in Chromoblastomycosis shows sympodial conidiation resembling a malunggay plant?

A) F. compacta

B) F. pedrosoi

C) F. monophora

D) F. nubica

*Answer: B) F. pedrosoi

*Question: The Cottonseed Conversion Agar is specifically used for the conversion of which organism from mold to yeast form?

A) Histoplasma capsulatum

B) Sporothrix schenckii

C) Blastomyces dermatitidis

D) Coccidioides immitis

*Answer: C) Blastomyces dermatitidis

*Question: What is the macroscopic appearance of yeast colonies that differentiates them from bacterial colonies on culture media?

A) Pinpoint, translucent, watery colonies

B) Pasty, opaque, cream-colored colonies much larger than bacterial colonies

C) Flat, spreading colonies with metallic sheen

D) Small, black, powdery colonies

*Answer: B) Pasty, opaque, cream-colored colonies much larger than bacterial colonies