when the piperacillin-amikacin combination was tested against pseudomonas aeruginosa , enterobacter cloacae , escherichia coli and serratia marcescens , early synergism ( 5th hour ) , was weak , but after 24 hours piperacillin reduced the regrowth observed with the aminoglycoside , and synergism was much more pronounced irrespective of the species investigated .
C0002499
amikacin
C0002556
aminoglycoside