[Effect of fosfomycin on cellular immune reactions as affected by cyclophosphamide or corticosteroids]

The effect of fosfomycin (FM) has been examined on the "footpad swelling reaction" (FPSR) as a model for cellular immunity and on the course of experimental infection with FM resistant E. coli using normal and immunocompromised mice. FM given the day of immunization improved FPSR response progressively up to a dose of 30 mg/kg, higher doses had no effect. If FM was injected 1 or 3 days after immunization doses of 30 mg/kg induced a considerable stimulation, whereas higher doses were inhibitory. In contrast to the high dose of 50 mg of FM per kg, 30 mg/kg increased the stimulatory effect induced by small doses of CY and reduced the inhibitory effect of high CY doses. The depressing effect of hydrocortisone (HC) was also reduced by 30 mg/kg of FM, but not by the higher one. In experimental infection with E. coli, FM in doses of 30 mg/kg was more effective than the higher ones in reducing mortality rate. Comparable results were obtained with CY pretreated animals.