[Changes in the drug resistance of coliform bacteria in the digestive tract of poultry under the influence of antibiotics at different dosages].

Changes in drug-sensitivity of hen intestinal flora following various chloramphenicol, kanamycin and gentamycin dose applications to the fodder rations were studied under experimental conditions. Selection of resistant strains was observed following chloramphenicol application of "nutrient", prophylaxis and medicative doses as well as selection of strains resistant to 6 antibiotics following chloramphenical, kanamycin and gentamycin application in medicative doses. It was proven that some of these strains are carriers of conjugative plasmides possessing markers of tetracycline-, chrloamphenical-, kanamycin-, spectinomycin-, ampicylin- and gentamycin-resistance.