Microorganisms are able to form biofilms on surfaces of biotic and abiotic nature. In turn, in human biotopes there are optimal conditions for the implementation of biofilm-forming activity. Moreover, in medical practice, polymeric materials are often used for drainage or prosthetics, which can also be successfully colonized by bacteria. However, in laboratory practice, the formation of biofilms is usually evaluated on glass or polystyrene. The purpose of the study is to evaluate the methodological features of studying the biofilm-forming activity of microorganisms on the surface of synthetic polymeric materials. We used strains of Staphylococcus aureus ATCC 25923, Escherichia coli K-12, Candida albicans ATCC 10231, as well as synthetic polymeric materials - DentLight Flow light-curing composite material (nano-hybrid fluid composite; Russia), glass ionomer chemical curing Fuji 1 (Japan), cement for temporary fixation of orthopedic constructions TempBond NE (USA), acrylic, polyurethane and polyvinyl chloride. The formation of biofilms in flat-bottomed ELISA plates in this study was considered as a control group. If the polymer belonged to cold curing materials, sterile flat-bottomed tablets were used, the bottom of which was filled with a thin layer of plastic. After hardening of the plastic, biofilms were formed in the tablets. In the second series of experiments, hot cured materials cut into equal parts 5×5×1 mm in size were placed in the wells of a plate and again used to determine biofilm formation with subsequent coloring. To extract the dye, the pieces were transferred to a new plate to exclude the amount of film biomass formed on the walls of the plate wells. In both cases, cultivation was carried out at 37° C for 24-48 hours. The biomass of the film was stained with fuchsin. Statistical data processing was performed using t-Student criterion. For the threshold level of significance, the value p <0.05 was taken. It is established that the proposed options for determining biofilm forming ability are available and indicative. It was revealed that the same microorganisms have individual biofilm formation indicators for each polymer material. The light curing dental composite and polyvinyl chloride exhibit the more pronounced antiadhesive properties than cements and polyurethane. Up to date, most of the studies of biofilm formation have been carried out using glass or polystyrene, which, as a rule, are not used for the manufacture of prostheses, catheters, drains, etc., which makes it difficult to assess the true film-forming activity of microorganisms. The proposed methodological approaches, especially the second option for preparing testing samples, solve this problem. In general, the proposed approaches to testing biofilm-forming activity on polymers are very simple to implement and generally available. For an adequate study of the biofilms formation, it will be advisable to use polymer materials, directly used in medicine, rather than polystyrene tablets, the material of which is found exclusively in laboratory practice.

Subject. Changes in the activity of certain saliva enzymes, due to certain factors and in certain clinical conditions of the human body, can affect oral hygiene, as well as indirectly on the activity of the carious process. Of particular interest is the enzyme — alpha-amylase, which is due to its ability to cleave dextrans and levans, which are the basis of the matrix of the bacterial film. The article presents data on changes in the activity of saliva alpha-amylase in microecological disorders in the intestine and acute respiratory viral diseases, as well as its effect on the level of oral hygiene. The goal — the assessment of changes in the activity of saliva alpha-amylase in microecological disorders in the intestine and acute respiratory diseases, taking into account the level of oral hygiene. Methods. To determine the activity of alpha-amylase, a set of reagents "Amylase-Vital" was used according to the manufacturer's instructions, proportionally reducing the volume of reagents for the procedure in titration plates. The volunteers, divided into groups with severe acute respiratory syndrome, microecological intestinal disorders, and a control group, received mixed saliva and evaluated their oral hygiene status. Results. The inverse relationship between the severity of intoxication syndrome in severe acute respiratory syndrome and the level of saliva alpha-amylase activity is shown. In addition, a correlation was established between an increase in human body temperature and a decrease in the activity of alpha-amylase. There is also a link between the presence of decompensated intestinal dysbiosis in humans and the activity of the enzyme. The dependence between the decrease in the activity of the studied enzyme and the increase in biofilm formation on the organs of the oral cavity was revealed. Conclusions and Relevance. The conducted studies open up a promising direction for the development of additional diagnostic criteria based on the determination of the activity of saliva alpha-amylase. In addition, the data obtained on the deterioration of oral hygiene indicate the need for a comprehensive approach to the treatment of patients in this category with the mandatory involvement of a dentist.

Currently, in the diagnosis of diseases, a decisive place is given to laboratory methods, which should be informative, relatively simple to perform and rapid. The article describes the approbation of a method for rapid detection of Escherichia coli and bacteria of Escherichia coli group in the oral cavity. Research involved 44 volunteers, who were sampled from the oral cavity, followed by incubation in Koda’s medium. The study used oral (n=11) and gingival fluids (n=11); smears-prints from the oral mucosa (n=11); dental biofilm (n=11). After 24 hours, the change in color and transparency of the medium was assessed. The preservation of the initial green color and transparency by the medium meant the absence of E. coli and bacteria of Escherichia coli group in the sample. A change in the color of the medium to yellow, turbidity and / or the formation of bubbles indicated the presence of E. coli and bacteria of Escherichia coli group. In parallel, the material was inoculated onto Endo agar, followed by identification of strains to species. As a result of the study, a complete coincidence of the results of the classical bacteriological method and the method using Koda medium was shown. In the latter case, a significant advantage is the speed of obtaining the result (18-20 hours), in contrast to the classical method, the interpretation of the results of which is available only after 72 hours or more. All of this is in line with the state of the art in clinical microbiology and rapid diagnosis based on «point-of-care testing / doctor’s office» diagnostic principle. The presented method can be successfully applied in clinical practice for topical diagnosis of microorganisms E. coli and bacteria of Escherichia coli group in the oral cavity.

It is known that the concentration of alpha-amylase in saliva can determine its catalytic activity, the decrease of which occurs during various pathological processes in the oral cavity. The overwhelming number of methods for determining the catalytic activity of enzymes involve the use of a large volume of reagents and samples, which makes it difficult to study saliva in large groups. The purpose of the study is to evaluate the possibility of using the microvariation of the reaction to determine the activity of saliva alpha-amylase, as well as to analyze the dependence of the enzyme activity on its concentration. Materials and methods. Saliva was obtained from 15 people with intact periodontal disease and the dentition, without somatic pathology. For in vitro studies, alpha-amylase solutions were prepared with an enzyme concentration of 10; five; 2.5; one; 0.5 and 0.25 mg / ml ex tempore. To save samples and reagents, the volume of the reaction participants was proportionally reduced. The further analysis procedure was carried out according to the instructions of the manufacturer of the «AMYLASE-VITAL» reagent kit to determine the activity of alpha-amylase. Statistical analysis of the results was performed using the Student’s t-test in the program Statistica 7.0. Results. The comparability of the results of determining the activity of alpha-amylase using the classical and microplate variants of the reaction is shown. With an increase in alpha-amylase concentration from 0 to 2.5 mg / ml, a directly proportional increase in enzyme activity is observed. In the case of an increase in the concentration of alpha-amylase above 2.5 mg / ml, a decrease in its activity is shown, which may be due to the precipitation of a part of the enzyme. The activity of the enzyme in saliva of practically healthy individuals using the microvariation of the reaction was 528.6 ± 2.4 U / l. In conclusion the use of a microvariant of the reaction for determining the activity of alpha-amylase may be justified for a large number of subjects. A linear dependence of the enzyme activity on its concentration in the range of 0-2.5 mg / ml is shown.

MS EDSS state, convert from RRMS to SPMS or die. Patients have a fixed annual probability of relapse and death. RRMS patients with EDSS score Ͻ7 were eligible for disease modifying therapies (DMTs). Patients with SPMS or EDSS score Ն7 received best supportive care. Transition probabilities were based on natural history of RRMS. Efficacy (i.e. on relapse rates and disability progression) was obtained from a mixed treatment comparison of published results. Health utilities were obtained from Orme et al (2007). Resources use (physician consultations; ambulatory care; hospitalization, other drugs, services, DMT monitoring and administration) were validated by an experts' panel and valued using Brazilian official lists. Annual discount rate of 5% was applied both to costs and outcomes. Probabilistic sensitivity analysis (PSA) was performed. RESULTS: Adopting WHO threshold, base case analysis showed fingolimod is more effective and less costly (dominant) versus IFN-␤-1a 44mcg (incremental costs: -26,567BRL; QALY: 0.223) and cost-effectiveness versus IFN-␤-1a 30mcg; IFN-␤-1a 22mcg and IFN-␤-1b 300mcg, with ICER (BRL/QALY): 29,306; 6,725 and 52,626, respectively (Ͻ3 GDP/capita or BRL 57,000.00; 1USD ϭ 2.055BRL). PSA has confirmed the consistency of base case results. CONCLUSIONS: In the treatment of patients with RRMS, fingolimod provides superior effectiveness and represents good value for money in comparison with the most common first line therapies by the health care payer in Brazil.