[In vitro bactericidal effect of cefotetan-aminoside combinations]

Bactericidal activity of cefotetan-gentamicin combinations was studied on 6 bacterial strains: S. aureus, K. pneumoniae, E. cloacae, S. marcescens, P. vulgaris, P. stuarti. Time kille curves technic was performed with final concentrations of cefotetan: 4 at 32 mg/l, and of gentamicin: 0.25; 0.5; 1; 2; 8 mg/l and with an 10(6) CFU/ml inoculum. Cefotetan at 4 mg/l was not able to obtain a 0.01% (percentage of survivors) bactericidal activity before 24 h. The combination cefotetan-gentamicin (0.25 to 2 mg/l according to the strains) were bactericidal (0.01% of survivors) before 24 h: 1 to 6 h according to the strains, more rapidly than with gentamicin alone at the same concentration. This more rapid bactericidal activity obtained by cefotetan-gentamicin combination seems to indicate this combination in the treatment of severe infections in immunocompromised patients.