Observations on Antibiotic Treatment of Bacterial Infections of Cortisone-Treated Mice

The influence of cortisone on the chemotherapeutic effect of antibiotics in experimental bacterial infections in mice has been studied. Cortisone has little or no effect on the protective action of penicillin against streptococcus infections in mice. When administered in doses which regularly protect non-cortisone treated mice, streptomycin, aureomycin, terramycin, chloramphenicol, neomycin and polymyxin B, failed to protect mice treated with cortisone. This reversal of successful antibiotic treatment occurred in mice treated with large doses (0.8 mg) but did not occur in mice treated with small doses (0.2 mg) of cortisone.