Bacterial growth kinetics of Escherichia coli and mycobacteria in the presence of brodimoprim and metioprim alone and in combination with sulfamerazine and dapsone (VI).

Bacterial growth kinetics and checkerboard titration experiments have been performed to determine the inhibitory power of metioprim (I) and brodimoprim (II) alone and in combination with diaminodiphenylsulfone (DDS) using Escherichia coli and mycobacteria as test organisms. The evaluated potency of the new TMP derivatives alone and in combination is compared to TMP and other derivatives. A strongly synergistic activity of I and II in combination with DDS against E. coli and various mycobacteria is observed which is also operative in case of highly DDS-resistant mycobacterial strains. The implication of these findings for the development of a combined chemotherapy with these drugs against atypical mycobacterial infections - especially leprosy - is discussed.