Pharmacology · single question
Which bacterium is RESISTANT to Clindamycin?
Show answer and explanation
Correct answer: C. Pseudomonas aeruginosa
Clindamycin is effective against Gram-positive cocci and most anaerobes. It is INTRINSICALLY RESISTANT against ALL aerobic Gram-negative bacteria, including Pseudomonas aeruginosa, which has outer membrane barriers and efflux pumps that prevent clindamycin action.
- A. Incorrect. S. viridans is generally susceptible to clindamycin.
- B. Incorrect. MSSA is typically susceptible to clindamycin.
- C. CORRECT. Pseudomonas aeruginosa has intrinsic resistance to clindamycin — it is outside clindamycin's spectrum.
- D. Incorrect. Fusobacterium nucleatum (anaerobic) is susceptible to clindamycin and metronidazole.