Dense Nutrient Medium Research Articles

Preventive Improvement of Wastewater Treatment Efficiency

This paper focuses on studying the effect of electrolytic water on wastewater decontamination processes, using model solutions and wastewater from the food-processing plant. The aqueous solutions under study were obtained by changing the redox potential (ORP), and pH of ordinary tap water using a pH corrector, which is a flow-through electrolyzer with a membrane separating the cathode and anode zones, and the solutions were obtained by adding to tap water a solution containing products of electrokinetic synthesis. Parameters that changed as a result of the study: ORP, TDS, pH. Solutions capable of almost complete inhibition of the vital activity and growth of microorganisms were obtained. Also, solutions were obtained that promoted their development, and when seeding them on a dense nutrient medium, there was continuous growth. Further research is advisable to detail the technical and economic indicators of water supply and sewerage schemes of municipal and industrial facilities with preventive water treatment processes.

Ступенчатый отбор высокопродуктивных по целлюлазной активности колоний гриба Тrichoderma viride

The paper presents the results of the stepwise selection of highly productive by cellulase activity colonies of the fungus Trichoderma viride ARCIM 13/10 (F-120). To obtain and select T. viride 13/10 colonies, dense nutrient media were used, in which the carbon sources were soluble substrates (2 % sucrose, 2 % sodium carboxy-methyl cellulose) and in-soluble, hardly hydrolyzeble substrates (Whatman No. 1 filter paper and cellulose produced by JSC «Mondi Syktyvkar Timber Industry Complex»). Cellulase activity of T. viride 13/10 col¬onies was assessed by saccharification of filter paper. As a result of the selection of the T. viride 13/10 strain carried out according to the scheme developed by us, it was possible to in¬crease the cellulase activity of the strain in comparison with its initial activity by 6,2–7,0 times. Further selection, especially with the use of mutagenic factors, can further increase the level of cellulase synthesis by the culture of the fungus T. viride.

Sensitivity of <i>Bordetella pertussis</i> biofilms to polyvalent pertussis serum Eugene M. Zaytsev

Aim. Study of the sensitivity of Bordetella pertussis biofilms to polyvalent pertussis serum.Materials and methods. The intensity of biofilm formation by strains of B. pertussis in round-bottomed polystyrene 96-well plates in the presence of polyvalent pertussis serum was estimated by staining with 0.1% gentian-violet solution. The serum titer was estimated as a highest dilution, which suppressed the growth of biofilm cultures.Results. Serum titers that completely suppressed the formation of biofilms by the studied strains ranged from : 1,000 to 1 : 20,000. Vaccine strain No. 475a (serotype 1.2.3) was characterized by the highest sensitivity to serum, the titer of which was 1 : 20,000. Vaccine strain No. 305 (serotype 1.2.0) and strains isolated from whooping cough patients in the period from 2001 to 2010: No. 287 (serotype 1.0.3), No. 178 (serotype 1.2.0), No. 317 (serotype 1.2.3) were sensitive to serum in the titers 1 : 1,000-1 : 2,000. Vaccine strain No. 703 (serotype 1.0.3) was resistant to all serum dilutions studied. When sowing supernatants from wells with biofilms on a dense nutrient medium, the growth of colonies typical for B. pertussis was observed. Similar results were obtained when seeding the supernatants of the cultures from the wells with no biofilm.Conclusion. These data indicate that B. pertussis strains are heterogeneous in sensitivity to pertussis serum. The growth of colonies typical for B. pertussis when culture supernatants are sown on a dense nutrient medium, in the absence of biofilms in the wells, indicates that the biofilm formation is suppressed by inhibiting the adhesion of microbial cells on the substrate, and not due to the bactericidal action of the serum.

Study of the effectiveness of using decamethoxin-based antiseptic compositions for treating endotracheal tubes in order to prevent the development of ventilator-associated pneumonia in intensive care patients

Annotation. The use of artificial lung ventilation in patients of intensive care unit often leads to airway contamination of conditionally pathogenic microorganisms and the development of ventilator-associated pneumonia. The clinical manifestations of ventilator-associated pneumonia can vary widely from mild to development of critical conditions accompanied by septic shock. This significantly worsens the patient's condition and prognosis for effective treatment. The paper presents the results of the study of the use of adhesive antiseptic compositions based on the domestic antiseptic drug decamethoxin in order to give antimicrobial properties to intubation tubes. An antibacterial adhesive was applied to the surface of segments of the endotracheal intubation tube, after which the samples were dried in a sterile box. The sensitivity of the microorganisms to the components of the antiseptic compositions was studied by the diameter of the growth retardation zone around the studied fragments of endotracheal intubation tubes placed in the thickness of the pre-seeded microorganism’s dense nutrient medium. The results were statistically analyzed using standard application package for biomedical research “STATISTICA 5.5”. It has been proved that adhesive film-forming compositions based on decamethoxin confer pronounced antimicrobial properties to endotracheal intubation tubes. The most susceptible to antimicrobial activity were gram-positive microorganisms of the genus Staphylococcus, and the most resistant were representatives of gram-negative bacteria of the genus Acinetobacter. The obtained research results allow us to predict the effectiveness of the use of adhesive hydrophilic and hydrophobic antiseptic compositions based on the domestic antiseptic decamethoxin to provide protective properties of the surface of endotracheal tubes, prevent the process of bacterial film formation and prevention of ventilator-associated patients.

Characteristics of microflora involved in the development of purulent paraproctitis and its sensitivity to ozone

Annotation. Despite significant advances in surgery to overcome purulent complications, the development of acute paraproctitis remains an extremely pressing problem, accounting for up to 4% of surgical pathology. This article is devoted to the study of the microbial spectrum of pathogens that contribute to the development of acute paraproctitis and Fournier gangrene, as the extreme degree of exposure of the subcutaneous adipose tissue of the external genitalia and perianal area in men. To study the microbial spectrum of pathogens of this pathology used the rules of intake, transportation of the studied material according to the Order of the Ministry of Health of Ukraine No. 234 on the organization of prevention of nosocomial infections in obstetric hospitals. The identification of isolated cultures was performed considering morphological, cultural and biochemical characteristics. Biochemical typing was performed using PLIVA diagnostic test systems – Lachema a. s. Brno, Czech Republic (NEFERMtest 24, STAPHYtest 16, ENTEROtest 24). To evaluate the effectiveness of the decontamination effect of ozonized sodium chloride solution, a quantitative suspension test was introduced with the introduction of a suspension of microorganisms isolated from the test material, followed by seeding on dense nutrient media to calculate the number of viable cells to reduce the exposure to the specified ex ante. The purpose of the study was to study the disinfecting effect of ozonated sodium chloride solution to improve the effectiveness of treatment of patients with acute paraproctitis. The results of the study indicate that the use of ozonated sodium chloride solution has significant advantages over the use of 0.02% solution of furacilin and decasan in the treatment of patients with acute paraproctitis and significantly reduces the risk of complications and accelerates the recovery of patients. The results of the research prove that the ozonated solution of sodium chloride in two dilutions (1:1), in contrast to other antiseptics, retains bactericidal action against the whole spectrum of bacteria that are most often involved in the development of acute paraproctitis. Thus, we consider it appropriate to include this solution in the scheme of complex treatment of patients with acute paraproctitis.

Spatial Visualization of Data on the Antibiotic Resistance of Vibrio cholerae Strains Isolated in Russia

Aim. The aim was to develop an integrated online and updated geographic information system (GIS) for the systematiza tion and analysis of information on V. cholerae El Tor antibiotic resistance.Material and methods. The method of serial dilutions in a dense nutrient medium (MUK 4.2.2495-09) was used to determine the sensitivity/resistance to 22 antibacterial preparations of V. cholerae O1 El Tor strains isolated from people and from aquatic environmental objects in Russia in 2005–2016. The development of the Internet version of the GIS was carried out using programming languages HTML, JavaScript and PHP and cartographic data obtained from the corporation Rostelecom (Russia) and the community OpenStreetMap.Results. A comparative analysis of the antibiotic resistance of the strains by regions of the Russian Federation and by isolation time showed an increase of strains resistant to streptomycin, ampicillin, rifampicin and furazolidone, the appearance of cultures resistant to nalidixic acid and ceftriaxone, reduced resistance to trimethoprim/sulfamethoxazole in 2012–2016 compared to 2005–2009. In the Stavropol Krai, the isolated V. cholerae O1 El Tor were characterized by resistance to furazolidone (33.3%) and trimethoprim/sulfamethoxazole (100%); in the Primorsky Krai — to ampicillin, streptomycin, rifampicin (7%), furazolidone (43%), trimethoprim/sulfamethoxazole (100%); in the Irkutsk region and Kalmykia, to ampicillin (8.3% and 11%), furazolidone and trimethoprim/sulfamethoxazole (11% and 89%).Conclusion. The GIS developed allows to collect and analyze information on the antibiotic resistance of V. cholerae O1 El Tor, and to select the strains for given properties.

Spatial Visualization of Data on the Antibiotic Resistance of Vibrio cholerae Strains Isolated in Russia

Aim. The aim was to develop an integrated online and updated geographic information system (GIS) for the systematiza tion and analysis of information onV. choleraeEl Tor antibiotic resistance.Material and methods. The method of serial dilutions in a dense nutrient medium (MUK 4.2.2495-09) was used to determine the sensitivity/resistance to 22 antibacterial preparations of V. cholerae O1 El Tor strains isolated from people and from aquatic environmental objects in Russia in 2005–2016. The development of the Internet version of the GIS was carried out using programming languages HTML, JavaScript and PHP and cartographic data obtained from the corporation Rostelecom (Russia) and the community OpenStreetMap.Results. A comparative analysis of the antibiotic resistance of the strains by regions of the Russian Federation and by isolation time showed an increase of strains resistant to streptomycin, ampicillin, rifampicin and furazolidone, the appearance of cultures resistant to nalidixic acid and ceftriaxone, reduced resistance to trimethoprim/sulfamethoxazole in 2012–2016 compared to 2005–2009. In the Stavropol Krai, the isolatedV. choleraeO1 El Tor were characterized by resistance to furazolidone (33.3%) and trimethoprim/sulfamethoxazole (100%); in the Primorsky Krai — to ampicillin, streptomycin, rifampicin (7%), furazolidone (43%), trimethoprim/sulfamethoxazole (100%); in the Irkutsk region and Kalmykia, to ampicillin (8.3% and 11%), furazolidone and trimethoprim/sulfamethoxazole (11% and 89%).Conclusion. The GIS developed allows to collect and analyze information on the antibiotic resistance ofV. choleraeO1 El Tor, and to select the strains for given properties.

Microscopic fungi of lithobiont communities of Argentine Islands Region: Data from the 22nd Ukrainian Antarctic Expedition

The identification of the diversity of microscopic fungi of lithobiont communities of the Argentine Islands in specimens collected during the 22nd Ukrainian Antarctic Expedition was the purpose of this work. Samples of rock, soil, mosses and lichens of rock micro-habitats of “Crustose lichen sub-formation and fruticose lichen and moss cushion sub-formation” were used in the work. These samples were used for extracting and cultivation of filamentous fungi on dense nutrient media. Determination of physiological and biochemical characteristics and identification of yeast-like fungi were performed using a microbiological analyser ‘Vitek-2’ (‘Bio Merieux’, France). Cultivation of microorganisms was carried out at temperatures from +2 to +37 °C. In results cultures of microscopic fungi of Zygomycota (Mucor circinelloides), Ascomycota (species of the genera cf. Tlielebolus, Talaromyces), representatives of the Anamorphic fungi group (Geomyces pannorum, species of the genera Alternaria, Acremonium, Aspergillus, Penicillium, and Cladosporium) were isolated from Antarctic samples. Microscopic fungi Penicillium spp. were dominated after the frequency in the studied samples (54.5%). Rhodotorula rubra and Candida sp. among isolated yeast fungi, and dark pigmented fungi represented by Aureobasidium pulhdans and Exophiala spp. were identified. The biological properties of a number of isolated fungi (the potential ability to synthesise important biologically active substances: melanins, carotenoids, lipids) are characterised. Mycobiota of rock communities of Argentine Islands is rich on filamentous and yeast fungi similarly to other regions of Antarctica. A number of fungi investigated are potentially able to synthesise biologically active substances. The dark pigmented species of the genera Cladosporium, Exophiala, Aureobasidium pulhdans, capable of melanin synthesis; ‘red’ yeast Rhodotorula rubra (carotenoid producers and resistant to toxic metals); Mucor circinelloides and Geomyces pannorum, lipid producers, are among these fungi. Yeast-like fungi assimilated a wide range of carbohydrates, which will allow them to be further used for cultivation in laboratory and process conditions. The collection of technologically promising strains of microorganisms, part of the Culture Collection of Fungi at Taras Shevchenko National University of Kyiv (Ukraine), is updated with isolated species (strains) of filamentous fungi and yeast – potential producers of biologically active substances, obtained within this study.

Taxonomic Diversity of Micromycete Complexes in the Root Zone of a Perennial Wild Species of Sunflower Helianthus Grosseserratus

The aim of our research was to determine the peculiarities of the formation of the taxonomic structure of micromycete complexes in the root zone of the perennial wild species of sunflower Helianthus grosseserratus when grown in the South of Ukraine. Soil samples taken from the root zone of two samples of perennial wild sunflower Helianthus grosseserratus 1630 and H. grosseserratus 1201, which were grown for more than 20 years in one place in the collection nursery of the Institute of Oilseed Crops of NAAS of Ukraine, were studied. Areas where plants are grown have not been treated with herbicides. Samples of fallow soil served as a control. Soil - chernozem ordinary low-humus leached. Soil samples for analysis were taken at the end of the growing season. To isolate microscopic fungi from the soil, the generally accepted method of serial dilutions was used, followed by sowing of the soil suspension on a dense nutrient medium Chapek-Dox. The method of sowing - deep, dilution of the suspension - 1: 1000. Duration of fungi cultivation - 7-14 days in a thermostat at a temperature of 28оС. The experiment was repeated five times. The complex of fungi-micromycetes in soil samples was determined using determinants and original works. The similarity of the species composition of the soil mycobiota of the fallow and the root zone of wild sunflower was determined by the Sorensen coefficient. Reliable indicators of similarity when comparing the species composition of two different associations were considered those in which the Sorensen coefficient was more than 50%.The analysis of the taxonomic structure of the studied mycocenoses revealed qualitative differences in the genus and species composition of micromycete fungi in the rhizosphere of wild sunflower species and fallow soil. In total, of the 29 species of micromycetes we isolated, 11 were found only in the soil of the fallow. According to our data, only 4 species (A. alliaceus, Paecilomyces lilacinus, F. oxysporum var. orthoceras, M. racemosus) were common species in the soil samples of fallow and root zone Helianthus grosseserratus 1630 and H. grosseserratus 1201. The species diversity of micromycetes of the root zone of H. grosseserratus 1201 was wider, and, accordingly, more similar to the soil of the fallow - 15 common species. Micromycetes that were typical for both fallow soil and sunflower are saprotrophs of A. niveus, P. canescens, P. crustosum, P. nigricans, P. thomii, as well as opportunistic species Verticillium album and V. lateritium. A comparative analysis of the lists of species composition of micromycete complexes revealed significant differences between the mycocenoses of the root zone of wild sunflower and fallow soil, as evidenced by the calculated Sorensen coefficients. The data indicated that the similarity of the species composition of the mycobiota H. grosseserratus 1201 with fallow was 66.7% (Cs = 0.67), and Helianthus grosseserratus 1630 - only 35.8% (Cs = 0, 35). The coefficient of similarity of the species composition of the mycobiota of the root zone of wild sunflower was 0.47, which is apparently due to the peculiarities of the composition of the root exudates of plants and their selection zones, which affect the formation of microbial complexes of the rhizosphere and edaphosphere.

CULTIVATION OF BORDETELLA PERTUSSIS BIOFILMS ON ABIOTIC SUBSTRATE

Aim. Selection of optimal conditions for the cultivation of Bordetella pertussis biofilms and comparative assessment of the ability of different strains to form biofilms. Materials and methods. Used a vaccine strain of B. pertussis № 475 and selected from this strain strain № 475а, characterized by high virulence. Cultures of strains grown on dense nutrient medium (DNM) and liquid nutrient medium (LNM) were used as inoculates for biofilms production. The intensity of biofilms formation in round-bottom 96-well polystyrene plates was estimated by staining with 0,1% gentian-violet solution. Results. Daily cultures of the strain № 475 with LNM formed moderate biofilms in the range of doses 5 — 1,25 IOU (international optical units) /ml, in the absence of growth at lower doses. The daily cultures of this strain with the DNM formed a dense biofilms when planting a doses in the range from 10 to 1,25 IOU/ml, moderate from 0,625 to 0,157 IOU/ml and weak biofilms at a dose of 0,079 IOU/ml. Strain № 475а with the DNM formed dense biofilms in the doses range of 10 to 0,04 IOU/ml and only at the dose of 0,02 IOU/ml were formed moderate biofilms. Conclusion. A simple and informative method has been developed to evaluate the ability of B. pertussis strains to form biofilms in polystyrene plates. Cultures obtained with the DNM formed a more significant biofilms than cultures with LNM. Identified high ability to biofilms formation by a selected strain №. 475a, compared to the original strain № 475.

VIBRIO CHOLERAE EL TOR ANTIBIOTIC RESISTANCE GATHERED FROM ENVIRONMENTAL OBJECTS ON THE TERRITORY OF THE RUSSIAN FEDERATION

The paper presents the analysis of Vibrio cholerae El Tor strains antibiotic resistance gathered from environmental objects on the territory of the Russian Federation during 2007–2016. We determined the sensitivity of 268 strains of V. cholerae El Tor to 12 antibacterial drugs by the method of serial dilutions in a dense nutrient medium. The strains showed resistance to 1–7 antibacterial drugs. The emergence of quinolone resistance in polyresistant strains of V. cholerae E.

TIME-KILL ASSAY: AN EFFICACY OF SYNERGY BETWEEN CARBAPENEMS AND CLODRONIC ACID

Abstract. Currently, a search for augmenting antibiotics activity is still crucial due to elevated frequency of detecting carbapenem-resistant Gran-positive bacterial isolates. To resolve this, it might be reasonable to combine carbapenems metal-â-lactamase (MâL) inhibitors. Unfortunately, no MâL inhibitors approved for treatment of carbapenem-resistant infections are currently available. Pathogenic bacteria may survive antibiotic attack, exert tolerance and persistence accompanied with the ongoing infectious process. In connection with this, determining dependence between antimicrobialrelated bactericidal effect and exposure time on microbes at 4, 8, 12 and 24 hours after the onset, a so called time-kill assay, is necessary. A synergy between both agents was noted upon reduced microbial population by ≥ 3 log10. A checkerboard array followed by seeding the microplate well contents onto a dense nutrient medium at various time points were used to assess a synergistic efficacy of carbapenems applied together with clodronic acid against MâL-producing VIMgenotype P. aeruginosa 532/14 clinical isolate obtained from patients with infectious complications (minimal inhibitory concentrations [MIC] for imipenem or meropenem were 512 μg/ml), microbial burden 106 CFU/ml. Optical density was measured at two wavelengths (490 and 630 nm) in ELx800 reader, within 4–24 hour exposure time to determine time of logarithmic growth phase emerging in test culture. It is noteworthy that magnitude of optical density is a difference between two bichromatic measurements resulting in remarkably reduced inaccuracy due to scratches or fingerprints left on the plate. It was found that clodronic acid exhibited a synergic bactericidal effect with carbapenems against a clinically resistant MâL-producing VIM-genotype P. aeruginosa 532/14 strain. Upon that, imipenem-related antimicrobial activity was evident as early as 8 hours after the onset decreasing cell growth down to 1.4 log10 compared to control, whereas 12 hours later it resulted in total inhibition of test strain by decreasing growth of the test strain by 6 log10. Meropenem in combination with clodronic acid showed a more pronounced activity: complete absence of P. aeruginosa 532/14 growth by 8 hours of incubation, growth suppression by 3.2 log10, which reached 6 log10 12–24 hours after the onset. Time-kill assay allows to identify efficient combinations of carbapenems and MâL inhibitors, which is of great importance for increasing therapeutic efficacy of patients with severe purulent-septic complications.

МОРФОЛОГИЯ ПОПУЛЯЦИЙ САЛЬМОНЕЛЛ В ВОДНОЙ СРЕДЕ И ИХ СПОСОБНОСТЬ К ФОРМИРОВАНИЮ БИОПЛЕНОК

The aim of the work is to study the survival strategy of salmonella populations in water medium with the formation of biofilms and L-transformation processes. Materials and methods. Salmonella typhimurium №1957 was chosen as a test culture. For the quantitative account of the growth of Salmonella and their morphology, an accelerated method of serial dilution was used with a seeding of 0,05 ml on membrane filters No. 4-5 production «Vladipor» placed on the dense nutrient medium of the BSA. Biochemical properties were determined by accelerated method using MTS-Salm system. For SEM, the preparations were fixed with an aqueous solution of glutaraldehyde, dehydrated with propylene oxide. The preparations were sprayed with platinum or gold ions on the «Hitachi-E-102» installation. The work was carried out on a scanning electron microscope Hitachi TM3030. Research results. The study of Salmonella preparations from water samples in vitro by method SEM showed that after 7 days of Salmonella existence in water at temperature of 26 ° C, the populations were united in microcolonies, covered from all sides by dense biofilm. After 2 months, the main part of the salmonella population was represented by the formed multilayer biofilm. After 6 months (observation period) at 26°C, the population of Salmonella cells was at the stage of L-transformation.

Long-Term storage of Tularemia Agent strains

Keeping microorganisms alive, saving initial practically vital properties, is a major issue in microbiology. Objective of this research was to study preservation of the key biological properties of lyophilized cultures of 18 F. tularensis strains of different subspecies from the cultures collection of the «48 Central Research Institute» of the Ministry of Defense of the Russian Federation under varying conditions of preliminary preparation (including animalization through the guinea pigs’ body or without it). The microbe storage life at below-freezing temperatures ranged from 5 to 50 years. Materials and methods . The survival of microbes in the process of drying and subsequent storage was determined in accordance with the commonly-accepted methods; morphological, cultural, biochemical, antigenic, and pathogenic properties of F. tularensis strain cultures with different storage term and conditions for preparation to lyophilization were assessed and compared with datasheet specification. The results and conclusions . The research showed that under preliminary stabilization of F. tularensis strain properties using animalization, the storage in lyophilized state at below-freezing temperatures under vacuum for up to 50 years or less protected them from changes in phenotypic properties. At the same time, after lyophilization of cultures, which were repeatedly sub-cultured on dense nutrient media without initial signs of properties’ breach, phenomena of dissociation, the decrease in titers of cultures in the agglutination reaction from 2 to 4 times, and an increase in LD50 index by times were found.

Quality Assessment of the Live Plague Vaccine Prepared Using nutrient Medium on the Basis of Hydrolysate of Concentrated Corn steep

Objectiveof the study was to test the nutrient medium based on the enzymatic hydrolysate of corn extract condensed for a scaled production of live plague vaccine and to check the quality of the obtained batches against the specified parameters.Materials and methods.A dense nutrient medium based on corn extract was used to grow biomass in the process of live plague vaccine production. The quality parameters of the vaccine preparation obtained were studied by the regulated methods set forth in the regulatory documentation.Results and conclusions. The vaccine was monitored at all stages of its manufacture, including control of the finished dosage form, in strict accordance with the approved regulatory documentation. All the experimental production series complied with the specified indices. Approbation of the production cycle environment for live plague vaccine manufacturing showed efficiency of the conditions and the possibility of environment’s application in the industrial production of the preparation.

Polyresistent microflora in the structure of microorganisms divided from blood of patients of the general hospital.

The aim of our research was to evaluate the structure and the determination of the phenotypes of antibiotic resistance of microflora isolated from patients' blood in a multidisciplinary hospital during the period from 2013 to 2017. The material was taken into BacT / ALERT bottles containing nutrient media, followed by incubation of blood. In case of a positive result, the material from the vials was dispersed into dense nutrient media. Species identification was carried out using commercial biochemical API test systems and MALDITOF mass spectrometry. The antibiotic resistance of the isolated microorganisms was evaluated by a classical disc-diffusion method. From 2013 to 2017, 3504 blood tests were performed, of which 16.8% were positive. Of the isolated strains, 69.6% were Gram-positive, 27% were Gram-negative, and 3.4% were fungi. The structure of Gram-positive bacteria included Staphylococcus spp - 71.46%, Enterococcus spp. - 21.22% and Streptococcus spp - 7.32%. Staphylococcus aureus (47,8%) prevailed among staphylococci (in 62.14% were methicillin-resistant) and coagulase-negative staphylococci. Among the genus Enterococcus spp, Enterococcus faecalis prevailed (27% resistant to macrolides, 14% to fluoroquinolones) and Enterococcus faecium (69% resistant to penicillins, fluoroquinolones, macrolides). Streptococcus pneumoniae, Streptococcus pyogenes and streptococci from the group of alpha-greening were isolated from streptococci. Clinically significant types of streptococci in 33.3% were resistant to macrolides and fluoroquinolones. In the structure of gram-negative bacteria, Enterobacteriaceae prevailed - 71.07% (Klebsiella pneumoniae, E. coli); the proportion of non-fermenting Gram-negative bacteria (NFGOB) was 28.93%. Most Gram-negative bacteria were producers of extended-spectrum beta-lactamases (BLBRs). In NFGOB structure allocated Acinetobacter baumanii - 56,5% (81% polyresistant), Pseudomonas aeruginosa - 30,4% (50% - Carbapenemase Producing Organisms), Stenotrophomonas maltophilia - 10,9%. Thus, microbiological research in septic blood conditions is an integral part of the diagnostic search, selection of etiotropic therapy and monitoring of its effectiveness.

Control of primary adhesion of microorganisms and formation of biofilms on stomatological materials used for transdental implantation in dental stabilizing operations.

Transdental implantation is an effective way to restore the lost biomechanical properties of a resected or amputated tooth. The choice of structural materials for the implant is the most important stage of treatment, in relation to the adhesion of aggressive microbiota to them. To characterize the adhesion of microorganisms of periodontopathogenic and cariogenic groups in vitro to experimental samples of zirconium dioxide and titanium alloys using cultural and electronic microscopic methods of adhesion evaluation as the first stage of biofilm formation. Samples for the experiment were prepared in the form of a tablet of standard form, on which the test strains were applied in an amount of 106CFU/ml. After shaking the unattached cells with ultrasound, they were seeded into dense nutrient medium to determine their number. In total, 14 strains of perodontopathogenic and cariogenic groups (including 3 reference strains) were used in the experiment. Scanning electron microscopy was used to visualize the adhesion of microorganisms. The results of the adhesion test to titanium nickelide and zirconium dioxide showed a significant reduction in adhesion for all microorganism species. In all variants (with all strains) the adhesion values to titanium nickelide and zirconium dioxide were statistically significantly lower than when using samples from a traditional titanium alloy. In scanning electron microscopy, single cells of test strains of perodontopathogenic microorganisms were determined on zirconium dioxide samples, while a considerable number of cells and the initial phase of biofilm formation were observed on the compared structural materials. Zirconium dioxide can be considered as an optimal choice material for the manufacture of transdental implants, which, in terms of its technological characteristics and low adhesion characteristics of microbes, is superior to the traditionally used titanium alloys.

AN ACCELERATED METHOD OF DIPHTHERIA GENE DIAGNOSTICS BASED ON ISOTHERMAL AMPLIFICATION TO DETECT DNA OF THE CAUSATIVE AGENT

Aim. Development of an accelerated method of gene diagnostics of diphtheria based on isothermal amplification for detection of DNA of the causative agent. Materials and methods. The study was carried out in typical collection strains from GKPM-Obolensk, as well as in 135 strains of C. diphtheriae isolated from bacteriological laboratories of the regions of Russian Federation and sent to the Gabrichevsky Moscow Research Institute of Epidemiology and Microbiology Strain isolation was carried out in accordance with Ml 4.2.698-98 and 4.2.3065-13. Chromosomal DNA was isolated by standard heating method, as well as using 3 commercial kits. Detection of the amplification results was carried out in horizontal electrophoresis in 1.5% agarose gel. Results. The developed method of gene diagnostics was established to allow detection of DNA of toxigenic C. diphtheriae strains of 2 biovars, as well as DNA of non-toxigenic tox-gene bearing strains (NTTB) of C. diphtheriae mitis biovar with mechanisms of lack of expression of diphtheria toxin gene due to the presence of deletion or mobile genetic IS element in the tox gene. Non-toxigenic tox-gene bearing C. diphtheriae strain with the mechanism of lack of diphtheria toxin gene expression due to the presence of transposon in the tox gene are identified as non-toxigenic. Evaluation of the analytical sensitivity in comparative studies using 3 commercial kits for FNA isolation has shown that sensitivity reached 4.5x 101 GE/ml using Ribo-prep kit. H igh specificity of the developed method is shown, it was evaluated in 18 strains of 16 other members of the Corynebacterium genus and 20 typical strains of microorganisms isolated from oropharynx or causing infections of the respiratory tract. Approbation of the developed method was carried out in model experiments in imitators of clinical samples by infection of single-use sterile dry tampons by consecutive dilutions of the bacterial cultures (with parallel seeding into dense nutrient media) and was 103 GE/ml. Conclusion. The developed method of accelerated gene diagnostics of the diphtheria infection has a high diagnostic effectiveness, specificity and sensitivity, allows to detect 103 - 4.5x10 GE/ml C. diphtheriae in clinical material with simultaneous verification of toxigenic and non-toxigenic strains.

Влияние циклоферона на антибиотикорезистентность <i>Staphylococcus aureus</i>

Целью исследования явилось изучение влияния циклоферона на чувствительность Staphylococcus aureus к антибиотикам. Опыты поставлены на 36 штаммах золотистого стафилококка, выделенных от больных с гнойными ранами различной локализации. Использовали циклоферон, который в количестве 0,9 мл добавляли к 0,1 мл суточной агаровой культуры стафилококков в концентрации 109 КОЕ/мл, инкубировали в течение 60 мин, затем высевали на плотную питательную среду и после культивирования в течение 18 – 24 ч при 37 °C определяли чувствительность микроорганизмов к ампициллину, доксициклину, фузидину, фурагину, линезолиду, цефтриаксону, эритромицину диско-диффузионным методом. Показана возможность регуляции антибиотикорезистентности золотистых стафилококков с помощью циклоферона — преимущественное увеличение числа золотистых стафилококков, чувствительных к изученным антибиотикам и снижение количества умеренно-резистентных и резистентных к ним штаммов. Установлен препарат (цефтриаксон), к которому в условиях in vitro после инкубации с циклофероном в 1,9 раза увеличилось число чувствительных штаммов (p < 0,05), в 2,3 раза снизилось количество умеренно-резистентных культур (p < 0,05), резистентные культуры не зарегистрированы. Полученные результаты открывают перспективы для изучения сочетанного действия циклоферона и цефтриаксона в клинических условиях.

Modification of the Method of Receiving of Insertion Mutants with the EZ::TN5 System.

We demonstrated the possibility of obtaining insertion mutants by a modified technique using EZ::TN5 system during culturing of the recipient strain on a dense nutrient medium and exclusion of the centrifugation stage. The frequency of transposon mutants of E. coli 10979/EZ::TN5 was 2×10-6. Genetically modified strains were characterized by kanamycin resistance, inability to L-malate assimilation, changes in the expression of individual proteins of protein mass-spectra (5096.3, 6252.9, and 9067.7 Da), and the presence of fragments in genomic DNA amplified by specific forward and reverse primers that were homologous to Tn5 transposon insertion sites. The modified procedure for obtaining insertion mutants by using EZ::TN5 system was not inferior by the efficiency to the standard procedure, but shortens experiment duration, simplifies it, and reduces the risks related to working with group 2 pathogenicity microorganisms.