The effect of trimethoprim-sulphonamide, trimethoprim and sulphonamide on the occurrence of resistant enterobacteriaceae in human intestinal flora.

After the administration of various antimicrobial agents for chemotherapeutic purposes a general change in the intestinal flora of the patient is often observed. In contrast, the combination trimethoprim-sulphonamide causes in most cases a strong selective decrease in the number of Enterobacteriaceae organisms for treatment periods as long as four to 12 weeks. The results correspond to clinical experience with trimethoprim-sulphonamide therapy in urinary tract infection where reinfections with resistant organisms are the exception.