ATI RN
microbiology a systems approach test bank Questions
Question 1 of 5
When doctors of a sanitary and epidemiologic institution examine employees of public catering establishments they often reveal asymptomatic parasitosis, that is when a healthy person is a carrier of cysts that infect other people. What causative agent can parasitize in such a way?
Correct Answer: A
Rationale: The correct answer is A: Dysenteric amoeba. This is because dysenteric amoebas can cause asymptomatic parasitosis, where a healthy person carries cysts that can infect others. Dysenteric amoebas are known to infect the intestines and can be transmitted through contaminated food or water.
Choice B, Malarial plasmodium, causes malaria transmitted through mosquitoes.
Choice C, Enteral trichomonad, causes diarrhea and is transmitted through contaminated water.
Choice D, Dermatotropic leishmania, causes skin lesions and is transmitted through sandfly bites. These choices do not fit the scenario of asymptomatic parasitosis in public catering establishments.
Question 2 of 5
Acute febrile pharyngitis and pharyngoconjunctival fever are often the clinical presentation of which viral infection:
Correct Answer: D
Rationale: The correct answer is D: Adenovirus. Adenovirus commonly causes acute febrile pharyngitis and pharyngoconjunctival fever. Adenovirus is known to cause respiratory infections and can present with symptoms such as sore throat, fever, and conjunctivitis. VZV (Varicella-Zoster Virus) causes chickenpox and shingles, not these specific symptoms. Measles virus causes a systemic illness with characteristic rash, not typically pharyngitis. Rubella virus causes a mild febrile illness with rash, but not pharyngitis.
Therefore, based on the clinical presentation described, adenovirus is the most likely cause.
Question 3 of 5
The function of beta-lactamase in bacteria is to:
Correct Answer: A
Rationale: The correct answer is A: Break down antibiotics like penicillin. Beta-lactamase is an enzyme produced by bacteria to inactivate beta-lactam antibiotics like penicillin by breaking the beta-lactam ring. This mechanism helps bacteria resist the antibiotic's effects. The other choices are incorrect because beta-lactamase does not enhance protein synthesis, facilitate DNA replication, or transport nutrients. It specifically targets and deactivates beta-lactam antibiotics, making choice A the most appropriate answer.
Question 4 of 5
The following spore-forming bacteria can be preserved in soil over a long period of time: clostridia of tetanus, botulism, anaerobic gas infection. Name the way with which these microorganisms get into soil.
Correct Answer: A
Rationale:
Step 1: Clostridia of tetanus, botulism, anaerobic gas infection are spore-forming bacteria.
Step 2: Spores are resistant structures that allow bacteria to survive in harsh conditions.
Step 3: Feces contain these spore-forming bacteria due to contamination.
Step 4: When feces are deposited on soil, the spores of these bacteria enter the soil.
Step 5: Spores can remain dormant in soil for long periods.
Summary:
Choice A is correct as spore-forming bacteria enter soil through feces, which act as a source of contamination.
Choices B, C, and D are incorrect as they do not involve the direct introduction of spores into soil like feces do.
Question 5 of 5
A fecal smear from a patient with chronic diarrhea revealed cysts with four nuclei. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Entamoeba histolytica. This protozoan parasite causes amoebic dysentery and is characterized by cysts with four nuclei in fecal smears. It is commonly associated with chronic diarrhea. Balantidium coli (
B) presents with large ciliated trophozoites, not cysts. Giardia lamblia (
C) has trophozoites with flagella and causes giardiasis, not cysts with four nuclei. Trichomonas hominis (
D) typically has a pear-shaped trophozoite and is not associated with cysts with four nuclei.