in tests with 41 gram-negative isolates , cefoxitin antagonized cephalothin , cefamandole , cefsulodin , cefotaxime , moxalactam , ampicillin , carbenicillin , piperacillin , mezlocillin , and azlocillin , but not cephalexin , mecillinam , or n-formimidoyl thienamycin .
C0002680
ampicillin
C0031955
piperacillin