[Antimicrobial action of the combined preparation sulfamoxole/trimethoprim in vitro (author's transl)].

A number of different methods were used to test the in vitro antimicrobial activity of the combination of N1-(4,5-dimethyl-2-oxazolyl)-sulfanilamide (sulfamoxole) and 2,4-diamino-5-(3,4,5-trimethoxy-benzyl)-pyrimidine (trimethoprim). 1. The minimum bacteriostatic inhibitory concentratiions of the sulfamoxole/trimethoprim combination (5 + 1) (CN 3123; Nevin; Supristol) were determined for 131 gram-positive and gram-negative strains of bacteria. More than 88% of the strains tested were found to be highly sensitive to the combination (M1C 0.1-3.75 mug/ml). 2. Comparative studies with the combinations sulfamoxole/trimethoprim and sulfamethoxazole/trimethoprim revealed no relevant differences of the M1C-values. 3. The synergistic effects of sulfamoxole and trimethoprim can be demonstrated with the aid of the agar dilution and agar diffusion tests using various types of bacteria and different ratios of sulfamoxole and trimethoprim. 4. Results obtained by studies on growth kinetics also demonstrate the synergistic and potentiating effect of combining sulfamoxole with trimethoprim and bactericidal properties are achieved.