In vitro and in vivo antibacterial activity of KW1070, a new aminoglycoside antibiotic.

KW1070, a new aminoglycoside antibiotic with the novel aminocyclitol, fortamine, has a broad spectrum of activity in vitro and in vivo against gram-positive and gram-negative bacteria. The minimum inhibitory concentrations of KW1070 are similar to those of kanamycin against aminoglycoside-susceptible strains, slightly less than those of gentamicin or 3',4'-dideoxykanamycin B. Minimal bactericidal concentrations were found to be near minimal inhibitory concentrations. KW1070 was active in vitro against many aminoglycoside-resistant bacterial strains that possess aminoglycoside-inactivating enzymes, particularly AAC(6'), AAC(2'), AAD(2''), and APH(3'). The activities of KW1070 in mice infected with Staphylococcus aureus, Escherichia coli, Proteus sp., and Serratia marcescens compared favorably with the activities of amikacin and kanamycin; KW1070 was also singificantly active in mice infected with resistant strains bearing the aminoglycoside-inactivating enzymes listed above.