[The effect of the in-vitro interaction of antibacterial preparations on Brucella melitensis].

The character of drug interaction in 18 various combinations of sisomicin, amikacin, gentamicin, cefotaxime, doxycycline, trimethoprim and nitroxaline was studied by the chess board method with respect to 25 strains of Brucella melitensis. The synergistic effect with respect to the majority of the cultures was observed with the use of the combinations of gentamicin, amikacin or sisomicin with doxycycline. The combinations of the aminoglycosides with cefotaxime and sisomicin or gentamicin with rifampicin had a summation effect on the majority of the cultures. With the use of the combinations of cefotaxime with nitroxaline or trimethoprim and rifampicin with nitroxaline the effect on the majority of the cultures was indifferent. The effect was mainly antagonistic with the use of the combinations of amikacin with rifampicin, gentamicin with trimethoprim and cefotaxime with doxycycline. The effect of the combinations of gentamicin with nitroxaline and cefotaxime with rifampicin was different with respect to different strains of B. melitensis. It was indifferent, antagonistic or summation depending on the strain.