[The problem of the use of antibiotics in animal production and the appearance of antibiotic-resistant bacterial strains in man].

The application of various antibiotics (penicillin, tetracycline, chlortetracycline, oxytetracycline, chloramphenicol a.o.) as growth stimulators in feed-stuff for calves, lambs, pigs and for fattened poultry in low dosage (20-150 mg/kg feed), leads to the fact that already after a short time a great share of antibiotic-resistant strains appears in the intestinal flora, in which may be contained also pathogenic strains (e.g. species of Salmonella). In most cases a multifarious resistance is developed, conditioned by R-plasmides. Through the excretions of the animals a part of the resistant bacteria goes into the air and may taken up by man. The resistant bacteria may be transferred to man also by food-stuff of animal origin (meat, milk, eggs). The great increase of the settlement of the intestinal canal of man with resistant strains of bacteria is for a large part to be traced back to the acceptance of such germs from useful animals. Due to this development also the therapeutic effectiveness of many antibiotics in medicine is much decreased. In future only such antibiotics shall be used in the feeding of animals, which cannot be used therapeutically. Also other ergotropics are increasingly used.