<prompt> Clindamycin is the drug of choice in -Methicillin resistance Staph. AureusMycoplasma pneumoniaeBacteroidis fragilisPseudomonus infection  <response>: In general, B. fragilis is susceptible to metronidazole, carbapenems, tigecycline, beta-lactambeta-lactamase inhibitor combinations e.g., Unasyn, Zosyn, and ceain antimicrobials of the cephalosporin class, including cefoxitin. The bacteria have inherent high-level resistance to penicillin. Production of beta lactamase appears to be the main mechanism of antibiotic resistance in B. fragilis. Clindamycin is no longer recommended as the first-line agent for B. fragilis due to emerging high-level resistance 30 in some repos Ref Harrison20th edition pg 1079 