Restorative & Materials · single question
Clindamycin is effective against all of the following EXCEPT which organism?
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Correct answer: C. Pseudomonas aeruginosa (gram-negative aerobic rod — intrinsically resistant)
- A. Group B Streptococcus is generally susceptible to clindamycin.
- B. Chlamydia is susceptible to clindamycin (though azithromycin or doxycycline are preferred for chlamydial infections).
- C. Correct. Clindamycin is effective against gram-positive organisms (Streptococcus, Staphylococcus), anaerobes (Bacteroides, Prevotella), and some other organisms. However, PSEUDOMONAS AERUGINOSA is intrinsically resistant to clindamycin — it is a gram-negative aerobe with outer membrane and efflux pump resistance mechanisms that clindamycin cannot overcome.
- D. Group A Streptococcus is susceptible to clindamycin (an alternative to penicillin for SBE prophylaxis in penicillin-allergic patients).
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