[INTESTINAL FAILURE AND YERSINIA PSEUDOTUBERCULOSIS TRANSLOCATION IN THE DEVELOPMENTOF EXPERIMENTAL GENERALIZED INFECTION].

THE OBJECTIVE: To determine the value of intestinal failure and translocation of bacteria Y. pseudotuberculosis, and normal intestinal microbiota in the initiation and generalization of infection in experimental pseudotuberculosis in conventional white mice, as well as pathological manifestation of it as a response to the adhesion and colonization of the mucosus membrane by pathogenic bacteria Y. pseudotuberculosis. MATERIALS AND METHODS: Experimental models of pseudotuberculosis in conventional white mice used the pathogenic Y. pseudotuberculosis 147 serotype I strain, containing a calcium-dependence plasmid with a molecular weight of 47 MDa. Cultivation of the pseudotuberculosis pathogen given its psychrophilic was performed on Hottinger agar at a temperature of (4-5) °C. The lactobacilli strain L plantarum 8P-A3 was isolated from a lyophilized commercial probiotic Lactobacterin (manufactured by "NPO Microgen", Russia) and used to obtain native culture supernatant fluid of lactobacilli, the composition of which was detected by gas-liquid chromatography with mass-selective detection. Gentamicin for parenteral administration was manufactured by JSC "Biochemist", Russia. Pathomorphological examination was performed on the 4-6th day of the experiment. Fragments of the small intestine, liver, kidneys, and lungs from dead animals were chosen for examination. Tissues were fixed in 10% neutral formalin, dehydrated in isopropanol and embedded in paraffin. Preparations were stained with Ehrlich hematoxylin and eosin, examined on the microscope "Mikmed-2" (JSC "LOMO", Russia) under magnification x 200-x1000. Statistical processing of the experimental results was carried out according to the method of Kerber in modification of I.P. Ashmarin and A.A. Vorobyov. RESULTS: The role of intestinal failure and translocation of bacteria Y. pseudotuberculosis, and normal intestinal microbiota in the initiation and generalization of infection in animals has been found. It has been proved that the oral administration of supernatant fluid containing microbial metabolites to animals as intramuscular administration of gentamicin equally prevent the development of generalized pseudotuberculosis and intensity of pathomorphological changes in the intestine and other organs of animals. CONCLUSION: Metabolites of the probiotic lactobacilli strain L plantarum 8P-A3 jugulate the development of pseudotuberculosis at an early stage of the pathological process in experimental animals infected with pathogen Y pseudotuberculosis, not only causing the preservation of the colonization resistance of the intestinal mucosa that prevents the adhesion and colonization of the pathogen, but also through their antimicrobial impact on the dissiminated pseudotuberculosis patho-gen bacteria in animals.

[COMPARATIVE EXPERIMENTAL EVALUATION OF THE EFFECTIVENESS OF MODERN PROBIOTICS, PREBIOTICS, SYNBIOTICS AND METABIOTICS FOR CORRECTION OF INTESTINAL MICROBIOCENOSIS IN ANIMALS WITH ANTIBIOTIC-ASSOCIATED DYSBIOSIS].

Probiotics for decades were leading in the arsenal of tools for correction of intestinal microbiocenosis. However, the response of representatives of intestinal microbiota to enteral intake of probiotics is variable, and in some individuals may be missing. Despite the fact that scientists still disagree on the necessity of forced settlement of normal microbiota at intestinal dysbiosis, large number of medicinal products, functional foods, dietary supplements, which efficiency is not always straightforward, is available for sale. The results of comparative experimental study of the effectiveness of 18 modern preparations for correction of intestinal microbiocenosis at antibiotic-associated dysbiosis in animals are presented. Conclusion is done on the need to evaluate efficacy and safety of tools developed for intestinal microbiota correction in animal experiments, followed by confirmation of clinical trials.

[Survival of probiotic microorganisms in the conditions in vitro imitating the process of human digestion].

PURPOSE OF THE STUDY: Assessment of survival bifidobacteria and lactobacteria under the conditions in vitro, simulating digestion in human stomach and intestine, and study of survival probiotic and indigenous microorganisms in co-cultivation on solid nutrient medium. MATERIALS AND METHODS: Probiotic microorganisms from commercial preparations Bifidobacterin and Lactobacterin, clinical isolates lactobacillus (Lactobacillus acidophilus No 1, L. brevis No 2) were used in experiments. Survival study of probiotic microorganisms was performed on a model in vitro, simulating the process of digestion in the human body. Assessment of the relationship of probiotic microorganisms and indigenous microorganisms was carried out in co-cultivation in vitro on solid nutrient medium. RESULTS: A significant reduction in the number of viable probiotic microorganisms during their incubation in model media was set as well as suppression of probiotic microorganisms growth by cultures of a clinical strains of lactobacillus, corresponding to biocompatibility by type "host against probiotic". CONCLUSION: While choosing probiotics in the treatment of dysbacterioses the character of relationship between probiotic microorganisms and indigenous microorganisms of a patient is recommended to be preliminarily tested. Also microorganisms of own microflora should be stimulated using modern prebiotics.

[Comparative assessment of survival of probiotic microorganisms from commercial preparations under the conditions in vitro].

PURPOSE OF THE STUDY: Assessment of survival of probiotic microorganisms from commercial preparations under the conditions in vitro simulates digestion in human stomach and intestine. MATERIALS AND METHODS: Probiotic microorganisms from domestic and foreign commercial preparations were used in experiments. Study of survival of probiotic microorganisms was carried out on the model in vitro simulates the conditions of digestion in the human body. RESULTS: A significant reduction in the number of viable probiotic microorganisms in the 20 of 23 studied commercial preparations during their incubation in the model media is established. Probiotic microorganisms in the preparations Bactisubtil, Sporobacterin and Biosporin possess a good survival under the conditions in vitro. CONCLUSION: The selection of probiotics for the correction of intestinal microbiocenosis requires an individual approach that takes into account the character of relations of probiotic microorganisms and indigenous microorganisms of patient as well as the possibility of using advanced prebiotics in the combine treatment of dysbacteriosis.

[Experimental study of sensitivity of probiotic microorganisms to antibacterial drugs].

PURPOSE OF THE STUDY: Investigation of sensitivity of probiotic microorganisms to antibacterial drugs. MATERIALS AND METHODS: Probiotic microorganisms from domestic and foreign commercial preparations were used in experiments. The study of sensitivity of probiotic microorganisms to antibacterial drugs was carried out using solid nutrient medium containing calculated amount of antibacterial drugs. RESULTS: Probiotic microorganisms are mainly sensitive to the representatives of the major classes of antibacterial drugs. Only some of the studied microorganisms are resistant to 1-4 antibiotics. CONCLUSION: When choosing a probiotic in the treatment of dysbacteriosis need to consider whether th antibiotic therapy was carried out. The use of antimicrobial drugs, even in therapeutic doses, reduces the viability of probiotic microorganisms and their survival in the gut.

Immobilization of recombinant firefly luciferase. Physicochemical properties and application.

Immobilization of the recombinant Luciola mingrelica and Photinus pyralis firefly luciferases on BrCN-activated Sepharose was investigated. The catalytic properties and analytical characteristics of the immobilized recombinant and native luciferases were comparatively studied. The catalytic properties of the immobilized recombinant L. mingrelica luciferase are close to those of the native luciferase, but the former enzyme appeared to be significantly more stable. The immobilized recombinant luciferases can be used for ATP assay within the 0.01-10000 nM range.

[Physicochemical properties of recombinant luciferase from the firefly Luciola mingrelica and its mutant forms]. / Fiziko-khimicheskie svoistva rekombinantnoi liutsiferezy svetliakov Luciola mingrelica i eë mutantnykh form.

Physico-chemical properties of the recombinant L. mingrelica luciferase synthesized by E. coli cells have been studied. The catalytic and spectral properties of recombinant luciferase were similar to those of the native enzyme but the former was less stable in the presence of the additional Cys residue. The mutant forms of L. mingrelica firefly luciferase with point mutations Cys-82-->Ala, Cys-260-->Ala, Cys-393-->Ala and Thr-204-->Asp, have been constructed using the method of site-specific mutagenesis. Mutations Cys-82,260,393-->Ala changed slightly the Km values for ATP and luciferin but did not influence kcat. The Cys-393-->Ala mutant appeared to be more stable in comparison with the native enzyme. Mutation Thr-204-->Asp resulted in a 8-fold increase in the ATP binding constant and in a 2-fold increase in the kcat, thus indicating that Thr-204 may be located in the ATP-binding region of luciferase. Dithiothreitol, ethylene glycol, bovine serum albumin and trehalose had a stabilizing effect on the native, recombinant and mutant luciferases.