La sensibilité bactérienne à l'association sullaméthoxazole-trimethoprime. Etude portant sur 3210 souches

The sensitivity to the combination of sulfamethoxazole and trimethoprim of 3210 recently isolated bacterial strains has been examined. The strains of E. coli, which represented 48,3 % of the total number of the Gram negative organisms isolated, were sensitive in 98 % of cases, Klebsiella, Enterobacter, Serratia, Proteus and Citrobacter in 70 to 94 % of cases. 55 % of Providencia and 66 % of Moraxella were sensitive. But susceptibility was fairly rare in Pseudomonas aeruginosa (5,2 %). The strains of Staphylococus aureus which represented 55,3 % of the total number of cocci isolated, were sensitive in 98 % of cases. Sensitivity was demonstrated in only 20 % of strains of Streptococcus foecalis and in 43 % of the other Streptococci. From 1970 to 1972, the percentage of sensibility remained similar. The enhanced susceptibility to trimethoprim in the presence of sulfamethoxazole occurs usually when the organisms are sensitive to sulphonamide. When the organisms are resistant to sulphonamide, synergy may only be demonstrated in 55 % of cases. To find out theses cases, it could be useful to test the susceptibility to sulfamethoxazole-trimethoprim combination and to each of the components.