[Studies on the antibacterial activity of the combination sulfamoxole/trimethoprim (CN 3123) (author's transl)].

After giving a survey on the situation of antibiotic resistance in the region of Northern Bavaria during 1973/74 and comparing the activity of a sulfamethoxazole (SMZ) trimethoprim (TMP) combination to other commonly used antibiotics and chemotherapeutic agents, the results of tests with the new combination of N1-(4,5-dimethyl-2-oxazolyl)-sulfanilamide) (sulfamoxole) and 2,4-diamino-5-(3,4,5-trimethoxy-benzyl)-pyrimidine (trimethoprim) at a ratio of 5:1 (CN 3123; Nevin, Supristol) are compared to those of tests with TMP/SMZ. This was done by correlating the inhibition zone diameters and, on the other hand, by referring to a great number of sensitivity evaluations in routine diagnostic tests. According to the size of the inhibition zone, CN 3123 showed a somewhat greater activity on Enterococcus (fecal streptococci), Escherichia coli, and Klebsiella aerogenes, whereas the TPM/SMZ combination had apparently a stronger antibacterial effect in vitro against Proteus mirabilis, Staphylococcus aureus, and the Achromobacter-group. Analysis of sensitivity readings from routine diagnosis demonstrated accordance of CN 3123 with TMP/SMZ in 92.6% (first series) and 94.2% (second series), respectively. These results should be considered critically in view of the manifold factors which influence sensitivity tests in the agar diffusion method.