[Electrooptic analysis for investigation of antibiotics synergistic action with respect to Escherichia coli].

The effect of ampicillin and kanamycin on the electrophysical properties of Escherichia coli K-12 was studied. Significant changes in the orientation spectra of the cell suspensions incubated with various concentrations of the antibiotics were observed only at the first five frequencies of the orienting electric field (10-1000 kHz). Ampicillin in a concentration of 1.0 mcg/ml and kanamycin in a concentration of 0.5 mcg/ml practically had no effect on the value of the electrooptic (EO) signal of the cells of the strain susceptible to the antibiotics. However, a significant change in the EO signal was recorded, when the cells were incubated in the presence of both ampicillin (1 mcg/ml) and kanamycin (0.5 mcg/ml), that was due to the synergistic effect of the antibiotics. Therefore, possible registration and investigation of antibiotics synergistic effect by electrooptic analysis of cell suspensions was shown, which suggested that electrooptic methods were rather efficient in control of antibiotic action on microorganisms.