Question 1

A patient undergoing chemotherapy develops a severe oral infection characterized by white patches and inflammation. Laboratory analysis identifies the causative agent as a yeast present in the digestive tract of many healthy individuals. Which organism is most likely responsible for this infection?

Accepted Answer

Candida albicans

Question 2

Which of the following best explains why most mycoses are difficult to treat in humans?

Accepted Answer

Fungi are biochemically similar to humans, making selective toxicity challenging.

Question 3

A laboratory is attempting to culture a suspected fungal pathogen from a clinical sample. Which medium should be used to maximize the likelihood of fungal growth while minimizing bacterial contamination?

Accepted Answer

Sabouraud dextrose agar

Question 4

A patient presents with fever, chest pain, and hemoptysis after visiting rural New Mexico. A lung biopsy reveals large spherules. Which fungus is the most likely cause?

Accepted Answer

Coccidioides immitis

Question 5

Which of the following statements about opportunistic fungi is correct?

Accepted Answer

They are normal microbiota for many individuals.

Question 6

A patient develops a subcutaneous infection after being pricked by a rose thorn. The infection spreads along the lymphatic vessels, producing a series of lesions. Which fungus is most likely responsible?

Accepted Answer

Sporothrix schenckii

Question 7

Which of the following is a major contributor to the development of opportunistic mycoses?

Accepted Answer

Immunosuppressive therapy

Question 8

A patient presents with raised, red, scaly patches of skin. Laboratory analysis identifies Trichophyton rubrum as the causative agent. What is the name of this condition?

Accepted Answer

Dermatophytosis

Question 9

Which of the following fungi is an obligate intracellular parasite?

Accepted Answer

Microsporidium

Question 10

A patient is diagnosed with elephantiasis. Which organism is responsible for this condition, and how is it transmitted?

Accepted Answer

Wuchereria bancrofti, transmitted by mosquitoes

Question 11

Which of the following best describes the mechanism by which Trypanosoma brucei evades the host immune system?

Accepted Answer

It changes its glycoprotein surface antigens every time it replicates.

Question 12

A patient presents with severe, frothy diarrhea with a 'rotten-egg' smell, abdominal pain, and bloating after drinking untreated stream water. Which protozoan is most likely responsible?

Accepted Answer

Giardia intestinalis

Question 13

Which of the following is the most common parasitic worm in the United States?

Accepted Answer

Enterobius vermicularis

Question 14

A patient is diagnosed with malaria. Which diagnostic method is most appropriate for confirming this infection?

Accepted Answer

Microscopic examination of blood smears

Question 15

Which of the following is a ciliated protozoan pathogen of the intestinal tract?

Accepted Answer

Balantidium coli

Question 16

A patient presents with patches of hyperpigmented and depigmented skin on the trunk and arms. Which fungus is most likely responsible for this condition?

Accepted Answer

Malassezia furfur

Question 17

Which of the following statements about Toxoplasma gondii infection is FALSE?

Accepted Answer

Even though it can be transmitted across the placenta, it is harmless to the fetus.

Question 18

Which of the following is the primary vector for the transmission of Leishmania species?

Accepted Answer

Sand flies

Question 19

Which of the following fungal toxins is associated with an increased risk of liver cancer after chronic low-level ingestion?

Accepted Answer

Aflatoxin

Question 20

A patient presents with a vaginal infection characterized by active, motile, multi-flagellated trophozoites in vaginal secretions. Which organism is most likely responsible?

Accepted Answer

Trichomonas vaginalis

Microbiology Study Guide: Fungal and Parasitic Pathogens

Study Guide - Practice Questions

Study Guide - Flashcards