ATI RN
mastering microbiology test bank Questions
Question 1 of 5
The Staphylococcus aureus toxin, which can cause scalded skin syndrome (SSS), is:
Correct Answer: D
Rationale: The correct answer is D: epidermolytic toxin. This toxin specifically targets the epidermis, leading to exfoliation seen in scalded skin syndrome (SSS). Hemolysis (
A) refers to the destruction of red blood cells, not relevant to SSS. Enterotoxins (
B) cause food poisoning, not SSS. Leucocidins (
C) target white blood cells, not pertinent to SSS.
Therefore, the epidermolytic toxin (
D) is the correct choice for causing SSS.
Question 2 of 5
Which of the following is used to test for bacterial antibiotic susceptibility?
Correct Answer: C
Rationale: The correct answer is C: Kirby-Bauer disk diffusion test. This test is used to determine the antibiotic susceptibility of bacteria by measuring the zone of inhibition around antibiotic-soaked paper disks. It helps identify which antibiotics are effective against the bacteria being tested. This test is crucial in guiding antibiotic treatment decisions.
A: Gram stain is used to classify bacteria based on their cell wall composition and morphology, not for antibiotic susceptibility testing.
B: Catalase test is used to differentiate between catalase-positive and catalase-negative bacteria, not for antibiotic susceptibility testing.
D: Endospore stain is used to detect the presence of endospores in bacteria, not for antibiotic susceptibility testing.
Question 3 of 5
Which of the following bacteria are unable to synthesize ATP?
Correct Answer: A
Rationale: The correct answer is A: Chlamydia. Chlamydia lacks the essential enzymes for ATP synthesis and relies on host cell ATP. Enterococci, Rickettsia, and Staphylococci possess the necessary enzymes for ATP synthesis through cellular respiration. Chlamydia's inability to synthesize ATP makes it dependent on the host cell for energy production, distinguishing it from the other bacteria listed.
Question 4 of 5
What would be the conclusion?
Correct Answer: B
Rationale:
Step-by-step rationale for choice B being correct:
1. The conclusion should be based on evidence or observations.
2. "Doubtful" suggests uncertainty, indicating lack of definitive safety.
3.
Choice A is too absolute without considering potential risks.
4.
Choice C uses extreme language without proper evidence.
5.
Choice D is overly definitive without considering varying levels of contamination.
Therefore, choice B is the most reasonable conclusion.
Question 5 of 5
Precipitation reaction can be converted into agglutination reaction by coating soluble antigen onto
Correct Answer: D
Rationale: The correct answer is D: All of these. Coating soluble antigen onto Bentonite particles, RBCs, or Latex particles can convert a precipitation reaction into an agglutination reaction. This is because soluble antigens bind to their specific antibodies, causing the particles to clump together, visible as agglutination. Bentonite particles, RBCs, and Latex particles all provide surfaces for the antigen-antibody interaction to occur, leading to agglutination.
Therefore, all of these options are correct for converting precipitation reactions to agglutination reactions.