minimal inhibitory concentrations were determined by using the macrodilution test and activity was compared with nalidixic acid , norfloxacin , ampicillin , piperacillin , ceftazidime and gentamicin for gram-negative rods , norfloxacin and gentamicin for staphylococcus strains , and norfloxacin , ampicillin , piperacillin and gentamicin for enterococci .
C0002680
ampicillin
C0031955
piperacillin