["In vitro" determination of bacterial sensitivity to tobramycin (author's transl)].

The authors report the tobramycin minimal inhibitory concentration (MIC) of 264 strains (dilution in Mueller-Hinton agar). Staphylococcus aureus (96 strains) have a MIC of 0.02 mcg/ml, 80 % being inhibited by 0.07 mcg/ml. Most Enterobacteriaceae (70 strains) are sensitive to 0.7 mcg/ml ; Providencia are the most resistant (MIC 11.88 mcg/ml). Among Pseudomonas aeruginosa (98 strains, MIC : 11.57 mcg/ml) 50 % are inhibited by 0.30 mcg/ml, 80 % by 18.8 mcg/ml. Relationships of MIC to zone diameters with the use of 10 mcg (D 10) and 30 mcg (D 30) tobramycin discs allow to draw the regression line which is respectively : y = -- 0,331 x + 6,64 and y = -- 0.263 x + 7,68. The strains are sensitive with an inhibition diameter greater than or equal to 16 mm (D 10) or greater than or equal to 18.5 mm (D 30).