a number of differences were seen in vitro , in particular : ( i ) the lower activity of kanamycin , ( ii ) the greater activity of tobramycin against pseudomonas , ( iii ) the greater activity of gentamicin and sisomicin against serratia , and ( iv ) the generally similar results with tobramycin , gentamicin , and sisomicin against species other than pseudomonas and serratia , with the ranking in order of decreasing activity being sisomicin , gentamicin , and tobramycin .
C0037209
sisomicin
C0017436
gentamicin