Which antibiotic covers CA-MRSA and anaerobes?

Which antibiotic covers CA-MRSA and anaerobes?

• A. Clindamycin
• B. Amoxicillin
• C. Doxycycline
• D. Aztreonam

Answer: (A)

You need an antibiotic with activity against both community-associated MRSA and anaerobic bacteria. Clindamycin fits because it inhibits the 50S ribosomal subunit, giving strong activity against CA-MRSA strains seen in skin and soft-tissue infections, and it also covers anaerobes such as Bacteroides and other oral/gut anaerobes. This makes it useful for mixed infections where both MRSA and anaerobes are involved, like certain abscesses or dental/oral infections. Amoxicillin isn’t reliable for CA-MRSA and isn’t a good anaerobe provider on its own; doxycycline does cover many CA-MRSA strains but its anaerobic coverage is limited; aztreonam covers Gram-negative aerobes and lacks MRSA and anaerobic coverage. So clindamycin is the best match for this combination of activities. Be mindful of potential inducible resistance in some strains and the risk of C. difficile with clindamycin.

You need an antibiotic with activity against both community-associated MRSA and anaerobic bacteria. Clindamycin fits because it inhibits the 50S ribosomal subunit, giving strong activity against CA-MRSA strains seen in skin and soft-tissue infections, and it also covers anaerobes such as Bacteroides and other oral/gut anaerobes. This makes it useful for mixed infections where both MRSA and anaerobes are involved, like certain abscesses or dental/oral infections. Amoxicillin isn’t reliable for CA-MRSA and isn’t a good anaerobe provider on its own; doxycycline does cover many CA-MRSA strains but its anaerobic coverage is limited; aztreonam covers Gram-negative aerobes and lacks MRSA and anaerobic coverage. So clindamycin is the best match for this combination of activities. Be mindful of potential inducible resistance in some strains and the risk of C. difficile with clindamycin.