bacteria's mutagenesis studies by modified turbometer method

Author: Tamaz Mdzinarashvili
Co-authors: T. Mdzinarashvili, M. Khvedelidze, N.Turkadze, I. Papukashvili, E. Lomadze, N.Shengelia
Keywords: Turbotimeter, Bacterie grow, Mutageneses
Annotation:

Nowadays, studying antibiotics, germs and their resistance has reached the highest level in the scientific world. Because around us an amount of microbes are huge, so their influence on living system are very important. Not only health depends on them, but also a creation of sterility area, for exemple food produced stuffs. After many various experiments and measurements scientists predicted, that using antibiotics (regarded as “world savers”) in a couple of years, will be totally in vain, because germs will gain resistance towards antibiotics. As it seems, without any doubt, dilemma may cause lethal and fatal results for the whole humanity, but there is always a hope, isn’t there?! To study the process of bacterial growth, it is important to determine how the timing of bacterial growth changes in response to variability of composition of media, or if we introduce an antimicrobial drug or bacteriophage into the media. Using the method of turbidimetry, we showed that bacterial growth pattern is influenced not only by just presence of the antimicrobial drug, but also the concentration of the drug into the medium, as different concentrations of the drug showed different patterns of growth. The bacterial proliferation is ceased at certain ratio between bacterial cells and antibiotics' molecules, and this ratio in microbiology has got a special term- minimum inhibitory concentration, MIC. The experiments held by us concerns the dependence of bacteria E. coli proliferation on the miscellaneous external conditions. The roles of these conditions were played by various antibiotics, particularly by Ampiox and Gentamycin. We used to conduct our experiments on E.coli C bacteria. The effect of these antibiotics' action was determined according to bacterial proliferation. It was found out that bacterial proliferation depends on the amount of antibiotics, more precisely the bacterial proliferation is ceased at certain ratio between bacterial cells and antibiotics' molecules, and this ratio in microbiology has got a special term- minimum inhibitory concentration, MIC. It was used the turbidimeter in our experiments that enabled us to observe the variability of bacteria by means of measuring the turbidity of the solution real-time mode and exactly this method enabled us to define the MIC for these both antibiotics. In addition, by means of using the turbidimeter we observed a very important case of interaction between bacteria and antibiotic such as acquired resistance when adding the same antibiotic the second times to bacteria which could not affect the bacterial proliferation any more. Moreover, this methods enabled us ascertain that the autocrine signaling is responsible for this acquired resistance. It is interesting that turbidimeter also showed that heating the solution by 20 degrees forced this resistance to vanish. According to our results, receptor proteins on the bacterial cell membrane are not saturated with antibiotics or bacteriophages fully and there are free unbound membrane receptors, which we hypothesize is the reason for uninhibited bacterial growth.