Pharmacology · single question
Clindamycin is effective against all of the following organisms EXCEPT:
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Correct answer: B. Pseudomonas aeruginosa
- A. Clindamycin is active against Bacteroides fragilis, making it useful for intraabdominal and anaerobic infections.
- B. Pseudomonas aeruginosa is a gram-negative aerobic rod intrinsically resistant to clindamycin. Clindamycin works primarily against gram-positive organisms and anaerobes — it has no activity against Pseudomonas. ✓
- C. Clindamycin covers methicillin-sensitive Staphylococcus aureus (MSSA), and even some MRSA in certain regions.
- D. Clindamycin covers Streptococcus pyogenes (Group A Strep), one of its classic uses including dental infections.