Combined therapy of Salmonella infection in chickens by antimicrobial agents followed by cultured cecal bacteria.

Week-old chickens infected with Salmonella infantis when one day old were treated with antimicrobial drugs either given alone or followed by peroral inoculation of bacterial culture. The bacteria were derived from the cecal contents of adult chickens. The antimicrobial drugs used were: neomycin, neomycin plus oxytetracycline, neomycin plus polymyxin, and sulfadiazine plus trimethoprim. The combined therapy with oxytetracycline plus neomycin and bacterial culture seemed to be the most effective, although the efficacy varied between the parallel trials. Sulfadiazine plus trimethoprim followed by treatment with the bacterial culture decreased the infection rate. The bacterial culture alone also had a slight anti-salmonella effect. When only antimicrobials were given, salmonellae rapidly reappeared in the intestines when the therapy was stopped.