ATI RN
microbiology an introduction 13th edition test bank Questions
Question 1 of 5
Infections that may result from the use of catheters are classified as:
Correct Answer: A
Rationale: The correct answer is A: iatrogenic infections. Iatrogenic infections are those caused by medical interventions like catheter use. Catheters can introduce pathogens into the body, leading to infections. Local infections (B) refer to infections confined to a specific area, not necessarily caused by catheters. Exogenous infections (C) come from an external source, not specifically related to medical interventions. Endogenous infections (D) arise from the body's own flora and are not directly related to catheter use.
Question 2 of 5
A 32-year-old patient who lives in the countryside consulted a doctor about a painful swelling and a fistula in the submandibular region. Examination revealed an infiltration with a fistula discharging thick pus and containing white granules. On dissection the infiltration tissues turned out to be dense, yellow-green and had honeycomb structure because of multiple abscesses. What is the most likely diagnosis?
Correct Answer: A
Rationale: The most likely diagnosis is Actinomycosis. This is because the patient's presentation of a painful swelling with a fistula containing white granules and yellow-green honeycomb-like tissue is classic for Actinomycosis. Actinomyces is a gram-positive anaerobic bacterium that forms sulfur granules in tissues. Tuberculosis (B) typically presents with caseating granulomas, not sulfur granules. Leprosy (C) presents with skin lesions and nerve damage, not characteristic of this case. Syphilis (D) usually presents with painless ulcers and rash, not the painful swelling and fistula seen in this patient.
Question 3 of 5
Which bacteria produce a toxin that causes the disease botulism?
Correct Answer: A
Rationale: The correct answer is A: Clostridium botulinum. This bacterium produces the neurotoxin responsible for botulism. Clostridium perfringens causes gas gangrene, not botulism. Escherichia coli and Salmonella enterica are not associated with botulism. Clostridium botulinum is the only bacterium known to produce the toxin causing botulism.
Question 4 of 5
Poxviruses are largest viruses, almost visible on light microscope
Correct Answer: A
Rationale: The correct answer is A: TRUE. Poxviruses are indeed the largest viruses known, ranging from 200-450 nm in size, which is close to the resolution limit of a light microscope. This makes them almost visible under a light microscope. Explanation: 1. Poxviruses have complex structures and are among the largest viruses. 2. Light microscopes have a resolution limit of around 200 nm. 3. Poxviruses fall within the size range that is close to the resolution limit of a light microscope. 4. Therefore, poxviruses are almost visible under a light microscope. Summary: Choice B is incorrect because poxviruses are indeed large enough to be almost visible under a light microscope. Choice C is incorrect as it implies uncertainty, but poxviruses are consistently close to the resolution limit of a light microscope. Choice D is incorrect as the size of poxviruses being almost visible under a light microscope is a factual statement, not dependent
Question 5 of 5
Staphylococcal scalded skin syndrome is most common in:
Correct Answer: A
Rationale: The correct answer is A: infants. Staphylococcal scalded skin syndrome is most common in infants because their immune systems are not fully developed, making them more susceptible to Staphylococcus aureus infections. This bacteria produces exotoxins that cause the skin to blister and peel, characteristic of the syndrome. Adolescents, young adults, and the elderly have more mature immune systems, making them less vulnerable to this specific infection. Therefore, infants are at a higher risk for developing Staphylococcal scalded skin syndrome compared to other age groups.