END - Micro

Question 1

1. Which statement is correct regarding fungal hypersensitivity reaction?
   a. Non-viable fungi are capable of eliciting severe allergic reactions
   b. Patients are highly infectious
   c. Regardless of the site of deposition of the antigen the clinical manifestations are the same
   d. Atopic as well as healthy individuals have the same degree of response to the potent surface antigens of these fungal particles

Answer 1

a. Non-viable fungi are capable of eliciting severe allergic reactions.
Rationale: Allergic reactions to fungal particles, including those from non-viable fungi, can be significant. Non-viable fungi contain allergens that can trigger severe hypersensitivity reactions in sensitized individuals.

Question 2

3 Tests that distinguish C. albicans from other species of Candida
a. Germ tube test
b. Sugar fermentation and assimilation tests
c. Using a nutritionally deficient media produces chlamydospores
d. All are correct

Answer 2

d. All are correct.
Rationale: All listed tests are commonly used to distinguish Candida albicans from other Candida species. The germ tube test, sugar fermentation and assimilation tests, and the production of chlamydospores on specific media are diagnostic methods used for this purpose.

Question 2

2. The characteristics of fungi include all, EXCEPT:
   a. Fungal cytoplasmic membranes contain glycerol
   b. Fungal spores are all sexually produced
   c. Fungal nuclei have nuclear membranes
   d. Fungi are eukaryotes

Answer 2

b. Fungal spores are all sexually produced.
Rationale: Fungal spores can be produced both sexually and asexually, depending on the species and environmental conditions. This statement is incorrect because it ignores the presence of asexual spores (conidia, sporangiospores, etc.).

Question 3

4 One of the following grows primarily within cells of the reticuloendothelial system
a. Histoplasma capsulatum
b. Coccidioides immitis
c. Blastomyces dermatitides
d. Cryptococcus neoformans

Answer 3

a. Histoplasma capsulatum.
Rationale: Histoplasma capsulatum primarily grows within cells of the reticuloendothelial system, particularly within macrophages. This intracellular lifestyle is a key characteristic of its pathogenicity.

Question 4

5 Which of the following cause subcutaneous mycoses
a. Trichophyton
b. Histoplasma capsulatum
c. Microsporum
d. Sporothrix shenckii

Answer 4

d. Sporothrix schenckii.
Rationale: Sporothrix schenckii causes sporotrichosis, a subcutaneous mycosis that typically follows inoculation of the fungus through the skin. It is known for causing lymphocutaneous infections.

Question 5

6. Most pathogenic fungi are exogenous. Which of the following is not a natural habitat for fungi
   a. Canals where the water is contaminated with КОН
   b. Organic debris
   c. Soil
   d. Water

Answer 5

a. Canals where the water is contaminated with KOH.
Rationale: KOH (potassium hydroxide) is used in laboratories to help dissolve keratin in skin samples to detect fungal elements. It is not a natural habitat for fungi; rather, it is detrimental to fungal survival due to its high pH.

Question 6

7. Which one of the following pathogenic yeasts is not a common member of the normal flora or microbiota?
   a. Cryptococcus neoformans
   b. Candida tropicalis
   c. Candida glabrata
   d. Malassezia globose

Answer 6

a. Cryptococcus neoformans.
Rationale: Cryptococcus neoformans is not typically a part of the normal human flora. It is an environmental yeast that can cause opportunistic infections, particularly in immunocompromised individuals.

Question 7

8. Blastomyces
   A. Encapsulated
   B. Multiple Budding
   C. Spherule
   D. Broad based bud

Answer 7

D. Broad-based bud.
Rationale: Blastomyces dermatitidis, the causative agent of blastomycosis, is characterized by its broad-based budding where the bud and the parent cell are nearly the same size at the base.

Question 8

9. A 42-year-old HIV-positive male, originally from Vietnam but now residing in Thailand. Presents with a painful ulcerative lesion on his upper lip (Cheilitis). A biopsy was done. Histopathologic slide revealed spherical structures (20-50 um in diameter) that divide by fission.
   What is likely the disease consistent with this finding?
   a. Infection with Penicillium marneffei
   b. Blastomycosis
   c. Coccidioidomycosis
   d. Cryptococcosis

Answer 8

a. Infection with Penicillium marneffei.
Rationale: Penicillium marneffei (now known as Talaromyces marneffei) is an important pathogen in HIV-infected individuals in Southeast Asia and produces characteristic yeast-like cells that divide by fission. The description matches the typical microscopic appearance of this fungus.

Question 9

10. A 6-year-old was taken to a physician for evaluation of a slowly growing bump on the back of her head. The bump was a raised, scaling lesion 4 cm in diameter. Lesion was positive with numerous conidia. The girl’s disease was:
    a. Dermatomycosis
    b. candidiasis
    c. rubella
    d. seborrheic dermatitis

Answer 9

a. Dermatomycosis.
Rationale: The description of a slowly growing, raised, scaling lesion with numerous conidia is consistent with a fungal infection of the skin, also known as dermatomycosis. This is typically caused by dermatophytes like Trichophyton or Microsporum species.

Question 10

11. Mycotoxins are secondary metabolites of some fungi. Which of the statements below is an inaccurate description?
    a. Ingestion results in a dose-related mycetismus
    b. Can cause fatal damage to the liver
    c. Effects of mycotoxin are dependent on fungal infection and viability
    d. Cooking does not reduce its potency

Answer 10

c. Effects of mycotoxin are dependent on fungal infection and viability.
Rationale: Mycotoxins are toxic chemical products produced by fungi that are harmful to humans and animals. These toxins can cause disease and death even when the fungus is not present or is no longer viable, as they are stable compounds not dependent on the presence of living fungi.

Question 11

12 Which of these diagnostic tools is an ineffective mode of identification of Pityriasis versicolor?
a. Wood’s light
b. Direct microscopy using Calcofluor white staining
c. Gram stain
d. KOH treatment of skin scrapings and microscopy

Answer 11

c. Gram stain.
Rationale: Gram staining is not effective for identifying fungi, including those causing Pityriasis versicolor, due to the distinctive characteristics of fungal cell walls that do not retain the Gram stain well. Other methods like Wood’s light, KOH treatment, and Calcofluor white staining are more appropriate for visualizing fungal elements.

Question 12

13. Visualization of fungi in a clinical specimen is best accomplished by treatment with
    a. Potassium hydroxide
    b. Para aminobenzoic acid
    c. Silver nitrate
    d. Hydrochloric acid

Answer 12

a. Potassium hydroxide.
Rationale: Potassium hydroxide (KOH) preparation is commonly used to dissolve keratin in skin, hair, and nail samples to make fungal elements more visible under a microscope, facilitating the identification of fungal infections.

Question 13

14. Cryptococcus neoformans has tropism for the:
    a. Skin
    b. lungs
    c. kidney
    d. meninges

Answer 13

d. meninges.
Rationale: Cryptococcus neoformans has a particular tropism for the central nervous system, specifically the meninges, where it can cause life-threatening meningitis, especially in immunocompromised individuals.

Question 14

15. Microscopic examination of a lung biopsy shows ovoid cells in macrophages. You suspect these are the cause of the patient’s symptoms but your culture grows a filament. which of the following is the possible etiologic agent?
    a. Coccidioides
    b. Mycobacteria
    c. Histoplasma
    d. Chlamydophila

Answer 14

c. Histoplasma.
Rationale: Histoplasma capsulatum often appears as ovoid cells within macrophages in tissue samples and can convert to a filamentous form in culture, which matches the description provided.

Question 15

16. Conidial Formation through a budding process
    a. Phialoconidia
    b. blastoconidia
    c. arthroconidia

Answer 15

b. blastoconidia.
Rationale: Blastoconidia are a type of conidia formed by budding off from the parent cell, which is characteristic of certain yeast forms like Candida species.

Question 16

17. Which statement regarding aspergillosis is correct?
    a. The diagnosis of pulmonary aspergillosis is frequently established by culturing Aspergillosis from the sputum and blood.
    b. Patients receiving parenteral corticosteroids are not at risk for invasive aspergillosis
    c. The clinical manifestation of aspergillosis includes local infections of the ear, cornea, nails and sinuses
    d. Patients with allergic bronchopulmonary aspergillosis rarely have eosinophilia

Answer 16

c. The clinical manifestation of aspergillosis includes local infections of the ear, cornea, nails, and sinuses.
Rationale: Aspergillosis can manifest as local infections in various body sites, including the ear, cornea, nails, and sinuses. Other options include incorrect statements or misconceptions about the risk factors and diagnostics associated with aspergillosis.

Question 17

18. A 50-year-old man with poorly controlled DM developed bloody nasal discharge, facial edema, and necrosis of his nasal septum.
    Culture of his cloudy nasal discharge showed Rhizopus species.
    What is the most important implication of this finding?
    a. Strongly suggestive of HIV infection
    b. Strongly suggestive of ketoacidosis
    c. Consider treatment for rhinocerebral mucormycosis (zygomycosis)
    d. No diagnostic value because mold is an airborne contaminant

Answer 17

c. Consider treatment for rhinocerebral mucormycosis (zygomycosis).
Rationale: The presence of Rhizopus species in a diabetic patient with these symptoms is highly suggestive of rhinocerebral mucormycosis, a severe fungal infection that requires urgent treatment.

Question 18

19. Candida albicans can be identified by the
    A. production of true hyphae
    B. demonstration of thermal dimorphism
    C. production of yeasts and pseufohyphae
    D. AOTA

Answer 18

D. AOTA (All of the Above).
Rationale: Candida albicans can be identified by the production of true hyphae, pseudohyphae, and yeasts, and it demonstrates thermal dimorphism (yeast form at 37°C and filamentous form at lower temperatures).

Question 19

20. Each of the following statements concerning fungi is correct
    EXCEPT:
    a. Yeasts are fungi that reproduce by budding
    b. thermally dimorphic fungi exist as yeasts at 37 degrees celsius and as a mold at 25 degrees celsius
    c. Both yeasts and molds have a cell wall made of peptidoglycan
    d. molds are fungi that have elongated filaments

Answer 19

c. Both yeasts and molds have a cell wall made of peptidoglycan.
Rationale: Fungi, including yeasts and molds, have cell walls made of chitin and glucans, not peptidoglycan, which is a characteristic of bacterial cell walls.

Question 20

21. Which statement regarding the laboratory identification of fungi is correct?
    A. Mold is routinely speciated by a battery of physiologic tests, such as the ability to assimilate various sugars
    B. Since many saprobic (nonpathogenic) molds resemble dimorphic mycotic agents in culture at 30°C, the identification of putative dimorphic pathogenic fungi must be confirmed by conversion to the tissue form in vitro or by the detection of species-specific antigens or DNA sequence analysis.
    C. A positive germ tube test provides a rapid presumptive identification of Candida glabrata
    E. Budding yeast cell and abundant pseudohyphae are typical Pneumocystis jiroveci

Answer 20

B. Since many saprobic (nonpathogenic) molds resemble dimorphic mycotic agents in culture at 30°C, the identification of putative dimorphic pathogenic fungi must be confirmed by conversion to the tissue form in vitro or by the detection of species-specific antigens or DNA sequence analysis.
Rationale: This statement is accurate because it addresses the challenge of differentiating between saprobic and pathogenic fungi, which can appear similar in culture. Confirmatory tests such as conversion to the tissue form or molecular methods are essential for accurate identification.

Question 21

22. Nails thickened or crumbling distally, discolored, associated with Tinea pedis
    a. Tinea pedis
    b. onychomycosis
    c. tinea capitis
    d. tinea barbae

Answer 21

b. onychomycosis.
Rationale: Onychomycosis refers to a fungal infection of the nails, which commonly presents with thickened, crumbling, and discolored nails. It is often associated with tinea pedis (athlete’s foot) as both are caused by dermatophytes.

Question 22

23 Which statement regarding the epidemiology of candidiasis is correct?
a. Patients with AIDS frequently develop mucocutaneous candidiasis, such as thrush
b. Patients receiving bone marrow transplants are not at risk for systemic candidiasis
c. Pregnancy lowers the risk of candidal vaginitis
d. Patients with any form of diabetes have enhanced resistance to candidiasis

Answer 22

a. Patients with AIDS frequently develop mucocutaneous candidiasis, such as thrush.
Rationale: This statement is correct. Individuals with compromised immune systems, such as those with AIDS, are at increased risk of developing mucocutaneous candidiasis.

Question 23

24. Caused by saprophytic species of fungi
    a. Eumycetoma
    b. Eumycetoma and Actinomycetoma
    c. Actinomycetoma

Answer 23

b. Eumycetoma and Actinomycetoma

Question 24

25. From the following features which does not describe a “fungus ball”?
    a. Very invasive
    b. caused by aspergillus
    c. occupies an abnormal pulmonary space
    d. Also called aspergilloma

Answer 24

a. Very invasive.
Rationale: A “fungus ball” or aspergilloma is typically non-invasive. It is a mass composed of fungal hyphae growing in a pre-existing cavity in the lung, not invading surrounding tissues.

Question 25

26. Generally, dermatophyte infections are treated with topical agents. One drug administered orally is effective and appears to be deposited in the stratum corneum.
    a. Tolnaftate
    b. Undecylenic acid
    c. griseofulvin
    d. amphotericin В

Answer 25

c. griseofulvin.
Rationale: Griseofulvin is an oral antifungal medication that accumulates in the stratum corneum of the skin. It is particularly used for treating infections of the skin, hair, and nails caused by dermatophytes.

Question 26

27. Infects skin and hair
    a. Trichophyton
    b. Microsporum
    c. None of the choices

Answer 26

b. Microsporum

Question 27

28. Generally, dermatophyte infections are treated with topical agents. One drug administered orally is effective and appears to be deposited in the stratum corneum.
    A. Tolnaftate
    B. Undecylenic acid
    C. griseofulvin
    D. amphotericin B

Answer 27

c. griseofulvin.
Rationale: Griseofulvin is an oral antifungal medication that accumulates in the stratum corneum of the skin. It is particularly used for treating infections of the skin, hair, and nails caused by dermatophytes.

Question 28

29. Histoplasma
    a. Broad-based bud
    b. spherule
    c. intracellular
    d. encapsulated

Answer 28

c. intracellular.
Rationale: Histoplasma capsulatum is primarily intracellular, residing within macrophages after infection. It does not form broad-based buds or spherules and is not encapsulated.

Question 29

30 Which is not a predisposing factor for Candidiasis vaginitis?
a. Diabetes
b. Menopause
c. Broad spectrum antibacterial chemotherapy
d. Pregnancy

Answer 29

b. Menopause.
Rationale: Menopause is generally not considered a predisposing factor for candidiasis vaginitis. The other options, including diabetes, broad-spectrum antibacterial chemotherapy, and pregnancy, are known to predispose women to this infection due to altered local immune defense and changes in the vaginal pH and flora.

Question 30

31. Aflatoxin poisoning is caused by a toxin produced by Aspergillus flavus. Which of the following commodities is most affected or contaminated?
    a. Rice
    b. peanuts
    c. corn
    d. wheat

Answer 30

b. peanuts.
Rationale: Aflatoxin, produced by Aspergillus flavus (and also Aspergillus parasiticus), most notably contaminates peanuts, as well as corn and other nuts. However, peanuts are particularly prone to contamination under conditions of high humidity and temperature, which are conducive to the growth of these fungi.

Question 31

32. An 8-year-old boy develops a circular dry, scaly, and pruritic lesion on his leg. What is the diagnostic significance of observing branching, septate, nonpigmented hyphae….. hydroxide/calcofluor white preparation of a scraping from this skin lesion?
    a. Chromomycosis
    b. Dermatophytosis
    c. Sporotrichosis
    d. Phaeohyphomycosis

Answer 31

b. Dermatophytosis.
Rationale: The presence of branching, septate, nonpigmented hyphae in a skin scraping is indicative of a dermatophyte infection, or dermatophytosis. These fungi affect keratinized tissues (such as skin, hair, and nails) and typically present with circular, dry, scaly, and itchy lesions.

Question 32

33. Evidence suggests that Cryptococcus neoformans infections in the Philippines are strongly associated with:
    a. Eucalyptus trees
    b. Pigeon droppings
    c. Chicken manure
    d. guano

Answer 32

b. Pigeon droppings.
Rationale: Cryptococcus neoformans is commonly associated with pigeon droppings, which provide a rich environment for the fungus to thrive. The birds themselves are not affected by the fungus but can carry large amounts of it in their droppings, increasing the risk of human exposure, especially in urban areas.

Question 33

34. Penicilliosis is an opportunistic endemic fungal pathogen found in several regions of southeast asia. Penicillium marniffei has been isolated in soil especially soil … and their habitat. Choose the correct statement about penicilliosis.
    A. Penicillium marneffei is a dimorphic fungus
    B. Tuberculosis is the highest risk factor
    C. The number of cases of penicilliosis in the endemic areas parallels that of leptospirosis
    D. Clinical picture does not include skin lesions

Answer 33

A. Penicillium marneffei is a dimorphic fungus.
Rationale: Penicillium marneffei (now known as Talaromyces marneffei) is indeed a dimorphic fungus, meaning it can exist in both yeast and mold forms, depending on the temperature and environment. This characteristic is crucial for its identification and understanding its pathogenic mechanism.

Question 34

35 Chief of “black dot” tinea capitis
a. Trichophyton tonsurans
b. Microsporum and Trichophyton tonsurans
c. Microsporum

Answer 34

a. Trichophyton tonsurans.
Rationale: Trichophyton tonsurans is a common cause of “black dot” tinea capitis, which is characterized by the presence of dark spots within hair shafts on the scalp due to the hair breaking off at the scalp surface.

Question 35

36. Treatment includes nystatin, ketoconazole, etc.:
    a. Eumycetoma
    b. Eumycetoma and Actinomycetoma
    c. Actinomycetoma

Answer 35

b. Eumycetoma and Actinomycetoma.

Rationale: This question seems to focus on the appropriate treatments for both fungal and bacterial forms of mycetoma. Eumycetoma is caused by fungi and can be treated with antifungal medications like ketoconazole, itraconazole, and amphotericin B. Actinomycetoma, on the other hand, is caused by actinomycetes (a type of filamentous bacteria), and while traditionally treated with antibacterial agents, some of the treatments for fungal infections (like ketoconazole for secondary fungal infections or mixed infections) might be considered in certain cases.

Question 36

37. Which statement regarding fungi is correct?
    a. Fungi are photosynthetic
    b. Although fungi are eukaryotes, they lack mitochondria
    c. Fungi have one or more nuclei and chromosomes
    d. All fungi are anaerobic

Answer 36

c. Fungi have one or more nuclei and chromosomes.
Rationale: Fungi are eukaryotic organisms, meaning they have a complex cellular structure with a nucleus containing chromosomes. They are not photosynthetic, they contain mitochondria, and not all fungi are anaerobic.

Question 37

38. A 32-year-old man with AIDS, currently living in the Bronx, presented with osteomyelitis of the left hip. A needle biopsy of the bone marrow was obtained, and the calco… a variety of myelogenous cells, monocytes, and macrophages containing numerous intracellular yeast cells that were elliptical and approx. 2x4 um.
    a. Candidiasis
    b. Cryptococcosis
    c. Histoplasmosis
    d. Blastomycosis

Answer 37

c. Histoplasmosis.
Rationale: The description of intracellular yeast cells within macrophages and other myelogenous cells is characteristic of Histoplasma capsulatum, the causative agent of histoplasmosis. This fungus can cause systemic infections and is known to affect the bone marrow among other organs.

Question 38

39. Coccidioides
    a. Broad-based bud
    b. Intracellular
    c. Multiple budding
    d. Cigar-shaped

Answer 38

c. Multiple budding

Question 39

40. What does the fungal characteristic “achlorophyllous” imply? Implies that the fungus is:
    a. Plant pathogen
    b. aerobic
    c. opportunistic
    d. saprophytic

Answer 39

d. saprophytic.
Rationale: “Achlorophyllous” implies that the fungus lacks chlorophyll, the pigment necessary for photosynthesis. This means the fungus does not derive its energy from light but rather from decomposing organic material, classifying it as saprophytic.

Question 40

41. Which statement regarding fungal growth and morphology is correct?
    a. Molds produce hyphae that may or may not be partitioned with cross-walls or septa
    b. Yeasts lack cell walls
    c. Pseudohyphae are produced by all yeasts
    d. Conidia are produced by sexual reproduction

Answer 40

a. Molds produce hyphae that may or may not be partitioned with cross-walls or septa.
Rationale: This statement is correct as molds can produce both septate (with cross-walls) and aseptate (without cross-walls) hyphae, depending on the species. The other options contain inaccuracies: yeasts do have cell walls, not all yeasts produce pseudohyphae, and conidia are typically products of asexual reproduction.

Question 41

42. Infects skin and nails
    a. Trichophyton
    b. Epidermophyton
    c. None are correct

Answer 41

b. Epidermophyton

Question 42

43. Cryptococcus neoformans in order to infect and colonize should be inhaled
    A. With its entire capsule intact
    B. In a form that is minimally encapsulated
    C. Size of infective particle has no bearing to its transmissibility
    D. Inhalation of the whole capsule enhances its virulence

Answer 42

B. In a form that is minimally encapsulated.
Rationale: For Cryptococcus neoformans, being minimally encapsulated when inhaled facilitates entry into the lungs and establishment of infection, as the minimal capsule allows for better evasion of immune detection during initial colonization.

Question 43

44 Which of the following conditions will saprophytic aspergillus least likely cause infection?
a. cancer
b. impaired immune system
c. individual with calcified TB lesion
d. diabetes

Answer 43

d. diabetes.
Rationale: While Aspergillus infections can occur in individuals with diabetes, it is less likely compared to those with cancer or impaired immune systems, or those with calcified TB lesions, where the fungus finds an easier niche to colonize or immunocompromised conditions that allow for invasive infection.

Question 44

45 Contents of granules are large hyphal fragments
a. Eumycetoma
b. Eumycetoma and Actinomycetoma
C. Actinomycetoma

Answer 44

a. Eumycetoma.
Rationale: Eumycetoma is characterized by the presence of granules containing large hyphal fragments within the discharge or infected tissues. Actinomycetoma, caused by bacterial agents, typically shows granules with filamentous bacteria.

Question 45

46. Pneumocystis pneumonia in HIV/AIDS is caused by
    a. Penicillium marneffei
    b. An intracellular obligate member of the normal flora
    c. pneumocystis carinii
    d. Pneumocystis jiroveci

Answer 45

d. Pneumocystis jiroveci.
Rationale: Pneumocystis jiroveci is the causative agent of Pneumocystis pneumonia in HIV/AIDS patients, not Penicillium marneffei, which causes penicilliosis.

Question 46

47. Presence of a thick gelatinous capsule is characteristic of
    a. Histoplasma capsulatum
    b. Cryptococcus neoformans
    c. Rhizopus species
    d. Sporothrix schenckii

Answer 46

b. Cryptococcus neoformans.
Rationale: Cryptococcus neoformans is known for its thick gelatinous capsule, which is a major virulence factor and diagnostic feature, particularly visible using India ink staining.

Question 47

48. Aspergillus fumigatus is least likely to cause
    A. Tissue invasion in immunocompromised host
    B. Aspergilloma
    C. thrush
    D. Allergy following inhalation of airborne fungal particles

Answer 47

C. thrush.
Rationale: Thrush is caused by Candida spp., not Aspergillus fumigatus. Aspergillus can cause tissue invasion, aspergilloma, and allergic reactions but not thrush.

Question 48

49. Dermatophytes are classified based on their usual habitat and one of the following is excluded. Which one?
    a. Humans
    b. Plants
    c. Animals
    d. Soil

Answer 48

b. Plants.
Rationale: Dermatophytes are fungi specialized in infecting keratinized tissues of humans, animals, and soil but are not typically associated with plants.

Question 49

50. Mycoses with the highest incidence and are part of the normal human biota are:
    a. Dermatophytosis and aspergillosis
    b. Candidiasis and histoplasmosis
    c. Candidiasis and dermatophytosis
    d. Candidiasis and cryptococcosis

Answer 49

c. Candidiasis and dermatophytosis.
Rationale: Candidiasis and dermatophytosis are among the most common fungal infections and part of normal human biota. Candidiasis involves yeast from the Candida genus, and dermatophytosis involves skin infections by dermatophytes. These conditions are prevalent and often involve organisms that are common in the human environment.

Question 50

51. Contents of granules are fine filaments
    a. Both eumycetoma and actinomycetoma
    b. Actinomycetoma
    c. Eumycetoma

Answer 50

b. Actinomycetoma
Rationale: Actinomycetoma is characterized by granules containing fine filaments typical of the actinomycetes (bacterial origin), while eumycetoma (fungal origin) granules contain larger fungal hyphae.

Question 51

52. Most common media used to culture fungi
    a. Tellurite medium
    b. Saboraid’s agar
    c. Lowenstein jensen
    d. SS agar

Answer 51

b. Sabouraud’s agar
Rationale: Sabouraud’s agar is the most common medium used for culturing fungi due to its low pH which inhibits bacterial growth, allowing for better fungal isolation and growth.

Question 52

53 Etiologic agent of tinea capitis
a. Microsporum only
b. Microsporum and Trichophyton tonsurans
c. Trichophyton tonsurans only
d. None of the choices

Answer 52

b. Microsporum and Trichophyton tonsurans
Rationale: Both Microsporum and Trichophyton species are common etiologic agents of tinea capitis, affecting the scalp and hair of primarily children.

Question 53

54 The potassium hydroxide examination of sputum from a heart transplant patient with fever and pulmonary infiltrates contains dichotomous branching. What is the significance?
a. Phaeohyphomycosis
b. Candidiasis
c. Aspergillosis
d. Hyalohyphomycosis

Answer 53

c. Aspergillosis
Rationale: The presence of dichotomous branching hyphae in sputum is a hallmark of Aspergillus species. This finding in a heart transplant patient suggests a probable infection with Aspergillosis, particularly in the setting of immunosuppression.

Question 54

55. sporothrix
    a. Spherule
    b. Cigar-shaped
    c. Intracellular
    d. Broad-based bud

Answer 54

b. Cigar-shaped

Question 55

56. Which statement regarding fungal cell wall is correct
    a. Fungi cell wall components rarely stimulate an immune response
    b. Fungal cell walls undergo frequent mutations
    c. The cell wall is not essential for fungal viability or survival
    d. Fungal cell wall components are targets for major classes of antifungal antibiotics, such as polyenes and azoles

Answer 55

d. Fungal cell wall components are targets for major classes of antifungal antibiotics, such as polyenes and azoles
Rationale: The fungal cell wall is a crucial target for many antifungal drugs. Polyenes, like amphotericin B, bind to ergosterol in the cell wall, disrupting membrane integrity, while azoles inhibit ergosterol synthesis.

Question 56

57. Mycotoxins are toxxins produce by some fungi. which of the following organs is least affected
    A. Nervous systems
    B. Genital organs
    C. Kidneys
    D. Liver

Answer 56

B. Genital organs
Rationale: Mycotoxins generally affect the liver, kidneys, and nervous system due to their roles in detoxification and susceptibility to toxin accumulation. The genital organs are typically less affected by mycotoxins compared to these other organ systems.

Question 57

58 One of the following statements describing dematiaceous years and mols is inaccurate. Which one?
a. They are melanized
b. The melanin protects the fungi from host defenses
c. The pigments impart a brown or black pigment to the colony
d. The pigments are not associated with virulence

Answer 57

d. The pigments are not associated with virulence
Rationale: This statement is inaccurate. In dematiaceous fungi, which are melanized fungi, the melanin within the cell wall is indeed associated with increased virulence, protecting the fungi from environmental stresses and immune responses.

Question 58

59. Cryptococcus
    a. Multiple budding
    b. Intracellular
    c. Encapsulated
    d. Cigar-shaped

Answer 58

c. Encapsulated
Rationale: Cryptococcus neoformans is well-known for its thick polysaccharide capsule, which is a major virulence factor, helping the fungus evade immune detection.

Question 59

60. Which statement regarding fungal cell wall is correct
    a. Fungi cell wall components rarely stimulate an immune response
    b. Fungal cell walls undergo frequent mutations
    c. The cell wall is not essential for fungal viability or survival
    d. Fungal cell wall components are targets for major classes of antifungal antibiotics, such as polyenes and azoles

Answer 59

d. Fungal cell wall components are targets for major classes of antifungal antibiotics, such as polyenes and azoles
Rationale: As previously stated, the fungal cell wall is a critical target for antifungal therapies. Polyenes disrupt the fungal membrane by binding to ergosterol, while azoles inhibit ergosterol synthesis, thereby compromising the integrity and function of the fungal cell wall.

Question 60

61 Infected hairs fluoresce
a. Microsporum
b. Microsporum and Trichophyton tonsurans
c. Trichophyton tonsurans

Answer 60

a. Microsporum
Rationale: Infections caused by Microsporum species are known to cause hair fluorescence under Wood’s lamp examination. This is a diagnostic feature not typically associated with Trichophyton tonsurans.

Question 61

62. Which is an incorrect statement regarding anthropophilic dermatophytes?
    a. Elicit acute infections
    b. Produce few conidia in culture
    c. Difficult to eradicate
    d. Cause the greatest number of human infections

Answer 61

a. Elicit acute infections
Rationale: Anthropophilic dermatophytes, which are adapted to humans, generally cause chronic, not acute, infections that are typically less inflammatory compared to those caused by zoophilic or geophilic dermatophytes.

Question 62

63. Circular bald patches of short hair stubs, broken hair within hair follicles
    a. Tinea capitis
    b. Onychomycosiss
    c. Tinea barbae
    d. Tinea pedis

Answer 62

a. Tinea capitis
Rationale: Tinea capitis, or scalp ringworm, presents with circular bald patches and short broken hair stubs within the hair follicles, consistent with the description given.

Question 63

64. Which of the following causes a subcutaneous fungal disease characterized by swelling of sinus tracts with presence of granules?
    a. Aspergillus
    b. Cladosporium
    c. Mycetoma
    d. Sporothrix

Answer 63

c. Mycetoma
Rationale: Mycetoma is a chronic subcutaneous infection characterized by swelling, sinus tracts, and the presence of granules in discharge, which can be caused by a variety of fungi and bacteria.

Question 64

65. Infects blood vessels of the skin
    a. Epidermophyton
    b. None of the choices
    c. Microsporum

Answer 64

b. None of the choices
Rationale: Neither Epidermophyton nor Microsporum infects blood vessels of the skin. These fungi are dermatophytes that infect keratinized tissues like the skin, hair, and nails but do not invade blood vessels.

Question 65

66. In patients with HIV/AIDS, the susceptibility and incidence of opportunistic mycoses:
    a. Are high regardless of whether the source is exogenous or endogenous
    b. Are conversely correlated with CD4 lymphocyte count
    c. CD4 counts less than 200 cells/u: are highly susceptible to infections with opportunistic fungi
    d. Are inversely correlated with the CD4 lymphocyte count

Answer 65

d. Are inversely correlated with the CD4 lymphocyte count
Rationale: In HIV/AIDS patients, the susceptibility to opportunistic fungal infections increases as the CD4 lymphocyte count decreases. This inverse relationship highlights the increased risk as the immune system becomes more compromised.

Question 66

67. Subcutaneous mycoses are found worldwide and the microorganisms are soil saprophytes, How are these fungi introduced into the host?
    a. Inhalation of conidia
    b. Traumatic implantation
    c. Droplet inhalation
    d. Ingestion

Answer 66

b. Traumatic implantation
Rationale: Subcutaneous mycoses typically occur when fungi, which are often soil saprophytes, are introduced into the skin through traumatic implantation, such as through a puncture wound or other forms of direct inoculation.

Question 67

68. An inhibitory mold agar facilitates the recovery of fungi from clinical and non-sterile specimens. Which of the ff. is not a component of this culture medium?
    A. Cycloheximide
    B. Selenium sulfide
    C. Gentamicin
    D. Chloramphenicol

Answer 67

B. Selenium sulfide
Rationale: Inhibitory mold agar generally contains antimicrobial agents like cycloheximide, gentamicin, and chloramphenicol to suppress bacterial growth and select for fungi. Selenium sulfide is not commonly used in these media.

Question 68

69. Which statement is correct regarding infections caused by dermatophytes?
    a. Easily treated using penicillin
    b. Characterized by aflatoxin-induced hallucinations
    c. Confined to keratinized tissues
    d. Rarely associated with chronic lesions

Answer 68

c. Confined to keratinized tissues
Rationale: Infections caused by dermatophytes are confined to keratinized tissues such as the skin, hair, and nails because these fungi utilize keratin as a nutrient source. These infections are not easily treated with penicillin (which targets bacterial cell walls), are not associated with aflatoxin production or effects, and can indeed be associated with chronic lesions.

Question 69

70. A conidia that result from fragmentation of hyphal cells
    A. Phialoconidia
    B. Blastoconidia
    C. Arthroconidia

Answer 69

C. Arthroconidia
Rationale: Arthroconidia result from the fragmentation of hyphal cells, which then develop into thick-walled, durable spores. This is a common reproductive strategy among certain fungi, including some dermatophytes and dimorphic fungi.

Question 70

71 Which statement about phaeohyphomycosis is correct?
a. Phaeohyphomycosis may exhibit several clinical manifestations, including subcutaneous disease, brain abscess as well as sinusitis
b. The causative agents are members of the normal microbial flora and can be isolated readily from the skin and mucosa of healthy persons
c. Infected tissue reveals branching, septate non pigmented hyphae
d. The infection only occurs in immunocompetent patients

Answer 70

a. Phaeohyphomycosis may exhibit several clinical manifestations, including subcutaneous disease, brain abscess as well as sinusitis.
Rationale: Phaeohyphomycosis is caused by various dematiaceous fungi and can present with a range of clinical manifestations from superficial to deep infections, including subcutaneous cysts, sinusitis, and even brain abscesses, particularly in immunocompromised patients.

Question 71

72 A 27-year-old rock singer complained of non-pruritic, painless hypopigmented patches over the chest and back/ The macular lesions[[ear after many sweaty night rowdy crowd of fans. Physical exam revealed branny desquamation near the periphery of the lesions. Most probate diagnosis is
a. Tinea corporis
b. Piedra
c. Pityriasis versicolor
d. Mycetome

Answer 71

c. Pityriasis versicolor.
Rationale: The description of hypopigmented, non-pruritic, painless patches with branny desquamation fits the classic presentation of pityriasis versicolor, a superficial fungal infection caused by Malassezia species.

Question 72

73. No bacterial pathogens can be isolated from the sputum of a patient with pneumonia. Antibiotic therapy has not been successful. The next step should be:
    a. culturing for Mycobacterium tuberculosis
    b. A change in antibiotics
    c. Culturing for fungi.
    d. Culturing for Mycoplasma pneumoniae

Answer 72

c. Culturing for fungi.
Rationale: If bacterial pathogens are not isolated and antibiotics have failed, considering fungal causes is a logical next step, especially in cases with clinical presentations that could suggest fungal infections such as persistent pneumonia.

Question 73

74. The following are superficial mycoses EXCEPT
    a. Mycetoma
    b. Piedra
    c. Tinea nigra
    d. Pityriasis versicolor

Answer 73

a. Mycetoma.
Rationale: Mycetoma, which can be caused by both bacteria (actinomycetoma) and fungi (eumycotic mycetoma), is a deep, chronic infection typically involving the skin, subcutaneous tissue, and bones. It is not classified as a superficial mycosis.

Question 74

75. The following are superficial mycoses, EXCEPT
    a. Mycetoma
    b. Piedra
    c. Tinea nigra
    d. Pityriasis versicolor

Answer 74

a. Mycetoma.
Rationale: Mycetoma, which can be caused by both bacteria (actinomycetoma) and fungi (eumycotic mycetoma), is a deep, chronic infection typically involving the skin, subcutaneous tissue, and bones. It is not classified as a superficial mycosis.

Question 75

76.Several Candida species are endogenous to humans They can be isolated from the following sites, EXCEPT
a. Mucus membrane
b. Skin
c. GIT
d. Blood

Answer 75

d. Blood.
Rationale: Candida species are commonly isolated from mucous membranes and the skin as part of the normal flora and can colonize the gastrointestinal tract, but they are not normally found in the blood. Candidemia or the presence of Candida in the blood indicates an invasive infection, especially in immunocompromised individuals.

Question 76

77. A mass of fungal elements is called
    A. Septum
    B. Mycelium
    C. Germ tube
    D. Pseudohyphae

Answer 76

B. Mycelium.
Rationale: A mass of fungal elements, consisting of intertwined hyphae, is called a mycelium. This is a basic structural unit of a fungus.

Question 77

78. Tightly-packed masses of hyphae surrounded by a thick rough rind may be found only in:
    a. Both actinomycetoma and eumycotic mycetoma.
    b. Actinomycetoma only
    c. Eumycotic mycetoma only
    d. Neither actinomycetoma and eumycotic mycetoma

Answer 77

a. Both actinomycetoma and eumycotic mycetoma.
Rationale: Both types of mycetoma (actinomycetoma caused by bacteria and eumycotic mycetoma caused by fungi) can form tightly-packed masses of filaments (mycelium in fungi and bacterial filaments in actinomycetoma) surrounded by a granulomatous rind.

Question 78

79 A 25-year-old female sex worker from Tokyo, japan, complained of headache, dizzines, and occasional episodes of “spacing out” during the past 2 weeks. A lumbar p… sugar, elevated protein, and 450 mononuclear leukocytes per milliliter. She was seropositive for HIV, her history compatible with fungal meningitis due to Cryptococcus coccidioides posadasii, or a species of Candida. Which one of the following tests is confirmatory?
a. Meningitis due to Coccidioides posadasii would be confirmed by a positive skin test to coccidioidin
b. Meningitis due to species of Candida would be confirmed by microscopic observation of oval yeast cells and pseudohyphae in the CSF
c. Meningitis due to Cryptococcus neodomans would be confirmed by a positive test of the CSF for complement fixation antibodies to coccidioidin
d. Meningitis dir to Coccidioides posadasii would be confirmed by a positive test of the CSF from cryptococcal antigen

Answer 78

b. Meningitis due to species of Candida would be confirmed by microscopic observation of oval yeast cells and pseudohyphae in the CSF.
Rationale: The presence of yeast cells and pseudohyphae in CSF is indicative of Candida infection. Cryptococcal meningitis would be confirmed by detection of cryptococcal antigen in the CSF, not coccidioidin.

Question 79

80 Conidia that are produced by :vase-shaped” conidiogenous cell
a. Arthroconidia
b. Blastoconidia
c. Phialoconidia

Answer 79

c. Phialoconidia.
Rationale: Phialoconidia are conidia that are produced from a phialide, which is a type of conidiogenous cell that can be described as vase-shaped. This type of asexual spore production is characteristic of certain fungi, particularly in the Aspergillus genus.

Question 80

81. Which statement regarding sporotrichosis is correct?
    a. Most patients are immunocompromised
    b. Most cases are subcutaneous and nonymphangitic
    c. The etiologic agent is dimorphic fungus
    d. The ecology of the etiologic agent is unknown

Answer 80

c. The etiologic agent is dimorphic fungus
Rationale: Sporothrix schenckii, the fungus causing sporotrichosis, is a dimorphic fungus, meaning it can exist as yeast at body temperature and as mold at lower temperatures. This is a fundamental aspect of its biology.

Question 81

82. Produce spores within the hair (endothrix)
    a. Microsporum and Trichophyton tonsurans
    b. Trichophyton tonsurans
    c. Microsporum

Answer 81

b. Trichophyton tonsurans
Rationale: Trichophyton tonsurans is known for producing spores within the hair shaft (endothrix infection), typical of its infection pattern in tinea capitis.

Question 82

83. Infects skin, hair, and nails
    A. Epidermophyton
    B. None of the choices
    C. Trichophyton

Answer 82

c. Trichophyton
Rationale: Trichophyton species infect the skin, hair, and nails, encompassing a wide range of dermatophytic infections.

Question 83

84 Management of fungal hypersensitivity reactions include all but one of the following
a. Desensitization
b. Confinement in a “sick building”
c. Corticosteroids
d. Avoidance of the offending agent

Answer 83

b. Confinement in a “sick building”
Rationale: Management of fungal hypersensitivity reactions includes avoiding the offending agent, possibly using corticosteroids to manage symptoms, and desensitization. Confinement in a “sick building” is not a management strategy and could potentially worsen symptoms if the building has mold issues.

Question 84

85. Acute: Itching red vesicular lesions, chronic: itching scalling fissures of interdigital spaces of feet
    a. Onychomycosis
    b. tinea capitis
    c. Tinea barbae
    d. Tinea pedis

Answer 84

d. Tinea pedis
Rationale: The description of acute itching, red vesicular lesions, and chronic scaling fissures in the interdigital spaces of the feet is characteristic of tinea pedis, or athlete’s foot.

Question 85

86. Criteria for administering anti-fungal prophylaxis to a patient with an underlying high risk disease (does not belong to the criteria?)
    a. Persistent cough in patient with lung CA
    b. Progressive unexplained organ failure
    c. Observation of new and unexplained pulmonary infiltrate on radiographs
    d. Neutropenia lasting for over a week

Answer 85

a. Persistent cough in patient with lung CA
Rationale: Persistent cough in a patient with lung cancer alone is not a criterion for administering antifungal prophylaxis unless accompanied by other specific risk factors or indications of fungal infection.

Question 86

87. Edematous, erythematous lesions involving beard hair
    a. Tinea capitis
    b. Tinea barbae
    c. Onychomycosis
    d. Tinea pedis

Answer 86

b. Tinea barbae
Rationale: Tinea barbae is a fungal infection involving the beard area, typically presenting with edematous, erythematous lesions.

Question 87

88. Paracoccidioides
    a. Broad-based bud
    b. Intracellular
    c. Multiple budding
    d. Cigar-shaped

Answer 87

c. Multiple budding
Rationale: Paracoccidioides brasiliensis, the causative agent of paracoccidioidomycosis, is known for its characteristic multiple budding, where a central mother cell can have several buds, giving it a “mariner’s wheel” appearance.

Question 88

89. A 24-year-old HIV-negative migrant worker from Colombia presented with a painful ulcerative lesion on the tongue. The edge of the lesion was gently scraped and a ca… hydroxide smear revealed tissue cells, debris and several large, spherical, multiply budding yeast cells. Based on this observation, what is the most likely diagnosis?
    a. Coccidioidomycosis
    b. Blastomycosis
    c. Candidiasis
    d. Paracoccidioidomycosis

Answer 88

d. Paracoccidioidomycosis
Rationale:

Clinical Presentation: The description of multiply budding yeast cells is characteristic of Paracoccidioides brasiliensis, the causative agent of paracoccidioidomycosis. This fungus typically presents with oral lesions that may be ulcerative, resembling the case described.
Geographical Context: The patient being from Colombia is a significant clue, as paracoccidioidomycosis is endemic to parts of Central and South America, including Colombia.
Morphology: Paracoccidioides brasiliensis is known for its “mariner’s wheel” appearance due to multiple buds forming from a parent yeast cell, which matches the description of “multiply budding yeast cells.”

Question 89

90. Tinea versicolor or pityriasis is a superficial skin infection characterized by hypopigmented areas The causative agent is
    a. Malassezia furfur
    b. Sporothrix
    c. candida albicans
    d. Microsporum

Answer 89

a. Malassezia furfur
Rationale: Tinea versicolor (pityriasis versicolor) is caused by Malassezia furfur, a yeast that affects the skin and alters pigment production, leading to hypopigmented or hyperpigmented areas.

Question 90

91. Infected hairs do not fluoresce
    a. Microsporum and Trichophyton tonsurans
    b. Microsporum
    c. Trichophyton tonsurans

Answer 90

c. Trichophyton tonsurans
Rationale: Trichophyton tonsurans does not cause fluorescence of infected hairs under Wood’s lamp examination. This characteristic is specific to certain species of Microsporum, which do fluoresce.

Question 91

92. Circular patches on glabrous skin with advancing red, vesiculated border and central scaling are called
    A. Ringworm
    B. Tinea corporis
    C. All of the choices are correct
    D. Dermatophyte infection

Answer 91

C. All of the choices are correct
Rationale: The description of circular patches on glabrous skin with an advancing red, vesiculated border and central scaling can refer to ringworm, tinea corporis, and generally to a dermatophyte infection. These terms are often used interchangeably in clinical settings to describe cutaneous fungal infections caused by dermatophytes.

Question 92

93 Which statement regarding dermatophytosis is correct?
a. Acute infections are associated with anthropophilic dermatophytes such as M. canis
b. Acute infections are associated with zoophilic dermatophytes, such as Microsporum canis
c. Chronic infections are associated with zoophilic dermatophytes, such as Microsporum canis
d. Chronic infections are associated with anthropophilic dermatophytes, sync ash M. canis.

Answer 92

b. Acute infections are associated with zoophilic dermatophytes, such as Microsporum canis
Rationale: Zoophilic dermatophytes, such as Microsporum canis, typically cause more inflammatory (acute) reactions due to less adaptation to the human host, compared to anthropophilic dermatophytes which tend to cause more chronic, less inflammatory infections.

Question 93

94. Which statement about Blastomycosis is correct?
    a. The disease is predominantly endemic in South America
    b. In tissue, one finds large, thick-walled, single budding yeast cell with broad connections between the parent yeast and bud
    c. Infection starts in the skin, and the organisms commonly disseminate to the lungs, bone, genitourinary tract, or other sites
    d. All cases require treatment with amphotericin B

Answer 93

b. In tissue, one finds large, thick-walled, single budding yeast cell with broad connections between the parent yeast and bud
Rationale: This is a correct description of Blastomyces dermatitidis, the causative agent of blastomycosis, which is known for this distinctive morphological feature in tissue specimens.

Question 94

95. Produce a cain off spores that form a sheath around the hair (ectothrix)
    a. None of the choices
    b. Trichophyton tonsurans only
    c. Microsporum
    d. Microsporum and Trichophyton tonsurans

Answer 94

c. Microsporum
Rationale: Microsporum species produce ectothrix infection, where spores form a sheath around the outside of the hair. This is distinct from Trichophyton tonsurans, which typically produces endothrix infections with spores inside the hair shaft.

Question 95

96. Which statement regarding paracoccidioidomycosis is not correct?
    a. The etiologic agent is a dimorphic fungus
    b. The etiologic agents in inherently resistant to amphotericin B
    c. Although the infection is acquired by inhalation and is initiated in the lungs, many patients develop cutaneous and mucocutaneous lesions
    d. The vast majority of patents with active disease are males

Answer 95

b. The etiologic agents in inherently resistant to amphotericin B
Rationale: This statement is incorrect. Paracoccidioides brasiliensis, the etiologic agent of paracoccidioidomycosis, is not inherently resistant to amphotericin B, which can be used effectively in severe cases.

Question 96

97. Vesicular lesions, indistinguishable from primary infections, which arise in other parts of the body of an allergic individual infected with the fungus Trichohyton and
    A. Eschar
    B. Carbuncles
    C. Furuncles
    D. Dermatophytes

Answer 96

D. Dermatophytes
Rationale: Vesicular lesions related to dermatophyte infections (e.g., due to Trichophyton species) that appear in other parts of the body are indicative of an id reaction (dermatophytid or fungus id reaction), which is an allergic reaction to the fungus.
Correct answer: c. Candida albicans

Question 97

98 Which of the following causes this genitourinary infection characterized by severe itching, thick yellow cheesy vaginal discharge?
a. Gardnerella
b. Trichomonas vaginalis
c. Candida albicans
d. Neisseria gonorrhoeae

Answer 97

c. Candida albicans
Rationale: Candida albicans often causes vaginal infections characterized by severe itching and a thick, yellow, cheesy discharge. This is typical of candidiasis (yeast infection), distinguishing it from bacterial and other protozoal infections.

Question 98

99. Thick-walled conidia, spherical, produced from terminal or intercalary hyphal cells
    a. Arthroconidia
    b. Phialoconidia
    c. Blastoconidia

Answer 98

a. Arthroconidia

Rationale:
- Definition of Arthroconidia: Arthroconidia are a type of fungal spore that forms by the fragmentation of septate hyphae, where segments of the hyphae develop thick walls and separate into individual cells. These are typically dry, thick-walled, and can be quite resilient.
- Morphological Fit: The description specifies that these conidia are thick-walled and spherical, produced from terminal or intercalary hyphal cells. Arthroconidia can indeed be spherical and are produced as segments of existing hyphae, which corresponds to being formed from terminal or intercalary cells.

This type of conidia is distinguished from:
- Blastoconidia, which typically bud off from a parent yeast cell rather than forming through segmentation of hyphae.
- Phialoconidia, which are produced in a vase-like phialide and are typically not described as thick-walled or spherical.

Thus, arthroconidia best matches the description given, aligning with their formation process and structural characteristics.

Question 99

100. Systemic mycoses portal of entry
     a. Parenteral
     b. Skin
     c. Oral-fecal
     d. Lungs

Answer 99

d. Lungs
Rationale: For systemic mycoses, such as histoplasmosis, coccidioidomycosis, blastomycosis, and others, the primary portal of entry is the lungs, where the fungal spores are inhaled and initially colonize before potentially disseminating to other parts of the body.

Question 100

7. The characteristics of fungi include all except
   a. Fungi are eukaryotes
   b. Fungal spores are all sexually produced
   c. Fungal nuclei have nuclear membranes
   d. Fungal cytoplasmic membranes contain glycerol

Answer 100

b. Fungal spores are all sexually produced

Rationale: Not all fungal spores are sexually produced; many fungi also produce spores asexually. Fungi are indeed eukaryotic organisms, their nuclei do have nuclear membranes, and their cytoplasmic membranes contain ergosterol, not glycerol, which is characteristic of bacterial membranes.

Question 101

8. Each of the following statements concerning fungi is correct except
   a. Molds are fungi that have elongated filaments
   b. Yeasts are fungi that reproduce by budding
   c. Both yeasts and molds have a cell wall made of peptidoglycan
   d. Thermally dimorphic fungi exist as yeast at 37 degrees celsius and as a mold at 25 degrees celsius

Answer 101

c. Both yeasts and molds have a cell wall made of peptidoglycan

Rationale: The cell walls of fungi are made of chitin, not peptidoglycan, which is found in bacterial cell walls. Molds form elongated filaments (hyphae), yeasts reproduce by budding, and thermally dimorphic fungi change form based on temperature.

Question 102

20. Which statement regarding fungal growth and morphology is correct?
    a. Molds produce hyphae that may or may not
    be partitioned with cross-walls or septa
    b. Yeasts lack cell walls
    c. Pseudohyphae are produced by all yeasts
    d. Conidia are produced by sexual reproduction

Answer 102

a. Molds produce hyphae that may or may not be partitioned with cross-walls or septa

Rationale: This statement is correct. Molds can have hyphae that are septate (with cross-walls) or coenocytic (without septa). The other statements are incorrect: yeasts do have cell walls, not all yeasts produce pseudohyphae, and conidia are generally produced via asexual reproduction.

Question 103

30. Species of dermatophytes found in pigs
    a. Microsporum gallinae
    b. Microsporum nanum
    c. Trichophyton equinum
    d. Trichophyton verrucosum

Answer 103

b. Microsporum nanum

Rationale: Microsporum nanum is known for infecting pigs.

Microsporum canis (dogs)
Microsporum gallinae (fowl)
Microsporum nanum (pigs)
Trichophyton equinum (horses)
Trichophyton verrucosum (cattle)

Question 104

Species of dermatophytes found in cattles
a. Microsporum gallinae
b. Microsporum nanum
c. Trichophyton equinum
d. Trichophyton verrucosum

Answer 104

d. Trichophyton verrucosum

Rationale: Trichophyton verrucosum is commonly associated with cattle, causing ringworm in these animals.

Question 105

33. Risk factors for Oral thrush caused by Candida spp except:
    a. Use of steroids
    b. Use of antibiotics
    c. Intake of glucose
    d. None of the above

Answer 105

d. None of the above

Rationale: All listed options (use of steroids, use of antibiotics, intake of glucose) are known risk factors for oral thrush caused by Candida spp., as they can disrupt normal microbial balance or affect immune function.

Question 106

34. Systemic Treatment for candidiasis except:
    a. amphotericin B
    b. nystatin
    c. caspofungin
    d. fluconazole

Answer 106

b. nystatin

Rationale: Nystatin is typically used for topical or local treatment of candidiasis, particularly for oral or intestinal infections, not systemic treatment. Amphotericin B, caspofungin, and fluconazole are used for systemic treatment of candidiasis, which can involve more severe or disseminated infections.