[Pharmacological, toxicological, microbiological and pathohistological studies of gentamycin complex II].

The acute toxicity was determined of the gentamycin complex II (GMC-II) for albino mice, containing gentamycin components in a varying ratio. The LD50 at intraperitoneal application was 347.7 mg/kg body mass, while at oral application it was 5,180 mg (4933 divided by 5439) mg/kg body mass. Histopathologically, (mice killed with high doses of GMC-II, given orally) there were diffuse hyperemia of the liver, parenchymal degeneration of the kidney tubuli epithelium, and edema and emphysema of the lungs. The local tolerance with regard to a 5 per cent solution of GMC-II applied to the conjunctiva of rabbits at twofold treatment proved to be good. Determined were the minimal inhibiting concentrations of 14 species of pathogenic organisms of great interest to veterinary medicine (Bacillus anthracis, Erysipelothrix insidiosa, Salmonella gallinarum, Escherichia coli, etc.). The antibacterial spectrum of GMC-II was similar to that of gentamycin sulphate, however, for some pathogenic organisms higher concentrations were required to produce and antimicrobial effect. Similarly to gentamycin sulphate GMC-II had limited absorbtion in the alimentary canal of clinically normal newborn pigs and of birds. At a high rate (0.05 g/kg body mass) GMC-II applied via the crop to birds it was found to maintain the lowest therapeutic concentration in the serum. At the rate of 0.012 (equal to 12000 IU) per kg of body mass for 24 hours GMC-II produced therapeutic effects in newborn pigs affected with colibacteriosis.