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.