Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov; State Research Center of Applied Microbiology, Obolensk, Moscow region, Russia
Essential changes in the orientation spectra (OS) of cell suspensions incubated at different concentrations of kanamycin, were found to occur only in the first 5 frequencies of the orienting electrical field (10 — 1,000 kHz)). The maximum change in the intensity of the electrooptical signal occurred at a concentration of kanamycin of 10 μg/ml. Antibiotic concentration of 5 μg/ml caused no changes in OS. During the incubation of the cells with tetracycline (1.7, 2.5, 5.0 μg/ml) no changes in OS of the cell suspension were registered. Considerable changes in the intensity of the electrooptical signal occurred during the incubation of the cells with kanamycin (5 μg/ml) and tetracycline (1.7 μg/ml) simultaneously, which was due to the synergic action of these two antibiotics. Thus, as found with the use of the electrooptical analysis, the joint action of kanamycin and tetracycline could increase their antibacterial effect. The results demonstrated the effectiveness of using electrophysical methods for the study of the mechanism of action of antibiotics on bacterial cells and for the control of such action.
Zh. Mikrobiol. (Moscow), 2005, No. 1, P. 3—7