Resistance to antibiotics used to treat urinary tract infection with Escherichia coli (E. coli) is becoming a growing problem worldwide. The purpose of the paper is to determine whether there is a combination of antibiotics that works better than the individual antibiotics in E. coli treatment. Survival of the bacterium must be short to prevent the formation of a resistance mechanism. There is a wide choice of medicines used in the treatment of urinary infections, and in this work they are selected according to the mechanism of action. The difference between ampicillin, ciprofloxacin, rifampicin and strepromycin is the target of action in the bacterial cell. The work we investigated the effect of various concentrations and combinations of antibiotics: ampicillin-ciprofloxacin, ampicillin-rifampicin and ampicillin-streptomycin, to survival of E. coli. In order to investigate the effect of the amount of nutrients in the medium on antibiotic activity, we used the nutrient-rich Luria-Bertani medium and nutritionally poor medium M9 Minimal salts. By determining the minimum inhibitory concentration (MIC) with the help of growth curves and antibiograms, the bacteriostatic action of antibiotics was investigated, and the mortality curve was bactericidal antibiotic activity. The E. coli bacterial growth curve has established a normal growth of the bacterium according to previous research. The minimum inhibitory concentration was determined by the addition of antibiotics to bacterial culture. The ampicillin and ciprofloxacin MICs are 12.5 μg / ml, streptomycin 25 μg / ml and rifampicin 100 μg / ml, which is consistent with literature values. Combinations of antibiotics made up of MICs of each individual antibiotic showed better and faster action than individual antibiotics. By comparing the kill curves of individual antibiotics, we proved that the amount of nutrients in the medium does not affect the action of antibiotics. Comparison of the kill curves of a combination of antibiotics on Luria- Bertani plates and plates M9 Minimal salts suggests that there is a difference in the action of antibiotics. Combinations of antibiotics, unlike individual, depend on the amount of nutrients in the medium. We have confirmed the same result of the kill curves obtained by the antibiogram. The results obtained by experimental work lay the foundations for numerous research into the metabolisms of antibiotic combinations in the future.