ИСТИНА

Antibiotic resistance is a global health and development threat. The number of drug-resistant pathogens increase with widespread usage of antibiotics. Most currently used methods for measuring bacterial sustainability are based on ability of the cells to grow on media with antibiotics. Thus, the analysis rate in these methods is limited by the time required for the cells to grow. The average time that sustainability test takes is 1-2 days. In this study we have developed a rapid method of antimicrobial resistance detection using MTT assay and Raman spectroscopy. This method uses MTT reagent (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) to determine the effect of the drug on the level of metabolism in bacteria and Raman spectroscopy to detect MTT reduced form formazan with high specificity and sensitivity. This method reduced the assay time to 2 hours. The optimal conditions for the MTT assay were selected. Raman spectroscopy was performed in different laser wavelengths. The method was applied on different antibiotics and bacterial strains and effectiveness of the method was proven. Also, we developed a way to highly increase sensitivity of analysis with Surface-enhanced Raman spectroscopy (SERS). The use of SERS - membranes for bacteria filtration increased the signal strength of formazan by more than 500 times. With Raman microscope, the sensitivity had reached the single-cell levels of detection.