new virulent strains of Clostridium difficile
There's concern over new virulent strains of Clostridium difficile...leading to severe diarrhea and colitis.
C. difficile colitis usually occurs when broad-spectrum antibiotics "wipe out" normal GI flora...but do not suppress C. diff. This allows C. diff to grow and produce toxins.
C. diff infections used to occur most often with clindamycin and second- and third-generation cephalosporins.