Pharmacology · single question
Clindamycin acts on all of the following organisms EXCEPT:
Show answer and explanation
Correct answer: D. Pseudomonas aeruginosa
- A. Clindamycin IS effective against MSSA (methicillin-susceptible Staph aureus) and some MRSA strains.
- B. Clindamycin IS effective against most anaerobic bacteria — this is one of its primary indications (dental infections, intraabdominal infections).
- C. Clindamycin IS effective against most Streptococcus species and is used as an alternative to amoxicillin for dental prophylaxis in penicillin-allergic patients.
- D. Clindamycin does NOT cover PSEUDOMONAS AERUGINOSA. Pseudomonas is an aerobic Gram-negative rod — clindamycin is effective primarily against ANAEROBIC bacteria and some Gram-positive cocci (Staph, Strep). Pseudomonas requires specific antibiotics: antipseudomonal penicillins (piperacillin-tazobactam), carbapenems, or fluoroquinolones.