ATI RN
openstax microbiology test bank Questions
Question 1 of 5
A patient with diarrhea had stool microscopy revealing flagellated protozoa with two nuclei. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Giardia lamblia. Giardia lamblia is a flagellated protozoan with two nuclei, known as the "falling leaf" appearance. It causes diarrhea in humans through ingestion of contaminated water or food. Entamoeba histolytica causes amoebic dysentery, characterized by bloody diarrhea and colitis. Trichomonas vaginalis is a sexually transmitted protozoan causing vaginal discharge but is not found in stool. Balantidium coli is a ciliated protozoan causing diarrhea but does not have flagellated forms.
Question 2 of 5
Which one is an example of an immunomodulator
Correct Answer: C
Rationale:
Step-by-step rationale for why C is correct:
1. Immunomodulators regulate the immune response.
2. Gamma-interferon is a cytokine that enhances immune function.
3. It helps fight infections and regulate inflammation.
4. Pentaxim and Hexacima are combination vaccines.
5. Rifampin is an antibiotic, not an immunomodulator.
Summary:
- A and B are combination vaccines.
- D is an antibiotic.
- C is the correct answer as gamma-interferon is an immunomodulator that regulates the immune response.
Question 3 of 5
A female patient consulted a doctor about a sense of epigastric discomfort, nausea and anorexia. A duodenal content analysis revealed lamblia. What drug should be prescribed?
Correct Answer: A
Rationale: The correct answer is A: Metronidazole. Metronidazole is the drug of choice for treating Giardiasis caused by Giardia lamblia, which presents with symptoms such as epigastric discomfort, nausea, and anorexia. Metronidazole effectively targets and eliminates the parasite. Chingamin, Rifampicin, Isoniazid, and Acyclovir are not effective against Giardia lamblia and are used to treat other infections caused by different pathogens.
Therefore, Metronidazole is the most appropriate choice in this scenario.
Question 4 of 5
Which of the following is a type of acute infection generally caused by group A Streptococcus?
Correct Answer: C
Rationale: The correct answer is C: Erysipelas. Erysipelas is a type of acute infection caused by group A Streptococcus bacteria. This bacteria infects the upper dermis and superficial lymphatics, leading to a distinct raised, well-demarcated, erythematous skin lesion. The other choices are incorrect because: A Carbuncle is a deep skin infection involving hair follicles, B Impetigo is a superficial skin infection caused by Staphylococcus or Streptococcus bacteria, and D Acne is a chronic inflammatory skin condition not typically caused by group A Streptococcus.
Question 5 of 5
A patient presents with a history of diarrhea of several weeks' duration. Which of the following may be the cause?
Correct Answer: B
Rationale: The correct answer is B: Yersinia enterocolitica. Y. enterocolitica is known to cause gastroenteritis and diarrhea in humans. It is often associated with contaminated food or water. Bordetella pertussis causes whooping cough, not diarrhea. Corynebacterium diphtheria causes respiratory diphtheria. Neisseria meningitidis is associated with meningitis and septicemia, not diarrhea.
Therefore, based on the patient's symptoms and history, Y. enterocolitica is the most likely cause of the diarrhea in this case.