[Antibacterial activity of sisomicin in comparison with gentamicin].

The antibacterial activity of sisomicin -- a new aminoglycoside antibiotic -- as compared with gentamicin was tested on 521 bacterial strains of different species in a serial-dilution test. Staphylococci, streptococci, E. coli, Klebsialla-Enterobacter, indole-psitive Proteus strains, pseufomonads, Salmonads, Salmonellae, and Serratia marcescens were inhibited to the extent of 100% at a maximun of 4.0 mug/ml. Sisomicin showed a higher antibacterial activity against part of the bacterial species. Gentamicin-resistant pseudomonads and Klebsiella (clinical isolates) were still inhibited to the extent of 42 and 67%, respectively, by sisomicin. In addition to the determination of the MIC values for the use of different liquid media, investigations on the determin ation of the minimal bactericidal concentration (MBC), the effect of serum, pH, and inoculum on the bacterial activity, and investigations on the resistance development in vitro were also carried out.