Gut microbiota and metabolic syndrome

Metabolic syndrome is associated with current diseases, such as obesity, diabetes, hypertension, which are accompanied by changes in the intestinal microbiota and the functioning of the immune and neuro-humoral systems of the body. Without detracting from the role of heredity and environmental factors, the intestinal microbiota makes a significant contribution to the development of metabolic disorders and obesity by modulating cascading enzymatic reactions of the macroorganism, interacting with receptors directly and/or using its own metabolites and signaling molecules.The purpose of study was to analyze the literature data obtained in the study of the role of the intestinal microbiota in the development of metabolic syndrome (MS).Results: A review of current literature on the role of intestinal microbiota in the development of metabolic syndrome is presented. The features of the mucosal microflora of the colon, the role of bacterial films, epithelial lining of the intestinal mucosa in the formation of the intestinal microbial-tissue complex as the leading links of metabolic disorders are discussed. The article presents data on the variability of short-chain fatty acids, bacterial genome in the development of obesity and type 2 diabetes.

Models of experimental pseudomonas keratitis: microbiological and clinical aspects

Annotation. Over the last ten years, there has been an increase in the incidence of bacterial keratitis caused by Pseudomonas aeruginosa, associated with contact lenses use. Certain features of the course of such keratitis, the mechanisms of corneal damage, the factors that affect the severity and depth of tissue destruction remain unclear. Therefore, the aim of our work was to model experimental pseudomonal keratitis in rabbits using different methods of infection and to investigate the microbiological and clinical aspects of keratitis depending on the method of infection. As a result of the study, we were able to reproduce superficial and deep keratitis with different methods of infection. Our proposed method cornea infection with bacterial films on a contact lens allowed to reproduce severe keratitis with a longer release of the pathogen from the surface of the affected cornea. It was also found that the results of microbiological examination of the material from the affected eye do not correlate with the course of severe keratitis: negative results of microbiological examination did not demonstrate the elimination of the pathogen from eye tissues, which deepens into corneal tissues, that was proved with microbiological examination of the cornea autopsy samples. These models of experimental keratitis can be used to study the pathomorphology, and pathophysiology of the keratitis caused by Pseudomonas aeruginosa, as well as to conduct experimental research of new antimicrobials and improve current guidelines for treatment of this pathology.

Swarming bacterial fronts: Dynamics and morphology of active swarm interfaces propagating through passive frictional domains

Swarming, a multicellular mode of flagella-based motility observed in many bacteria species, enables coordinated and rapid surface translocation, expansion and colonization. In the swarming state, bacterial films display several characteristics of active matter including intense and persistent long-ranged flocks and strong fluctuating velocity fields with significant vorticity. Swarm fronts are typically dynamically evolving interfaces. Many of these fronts separate motile active domains from passive frictional regions comprised of dead or non-motile bacteria. Here, we study the dynamics and structural features of a model active-passive interface in swarming Serratia marcescens. We expose localized regions of the swarm to high intensity wide-spectrum light thereby creating large domains of tightly packed immotile bacteria. When the light source is turned off, swarming bacteria outside this passivated region advance into this highly frictional domain and continuously reshape the interphase boundary. Combining results from Particle Image Velocimetry (PIV) and intensity based image analysis, we find that the evolving interface has quantifiable and defined roughness. Correlations between spatially separated surface fluctuations and damping of the same are influenced by the interaction of the interphase region with adjacently located and emergent collective flows. Dynamical growth exponents characterizing the spatiotemporal features of the surface are extracted and are found to differ from classically expected values for passive growth or erosion. To isolate the effects of hydrodynamic interactions generated by collective flows and that arising from steric interactions, we propose and analyze agent-based simulations with full hydrodynamics of rod-shaped, self-propelled particles. Our computations capture qualitative features of the swarm and predict correlation lengths consistent with experiments. We conclude that hydrodynamic and steric interactions enable different modes of surface dynamics, morphology and thus front invasion.

REVIEW ON - INGREDIENTS USED IN TOOTHPASTE FORMULATION

Different ingredients are used in toothpaste formulation to keep the oral health and to achieve multi claim products. We have variety of toothpaste available in market like anti-cavity, extra-whitening and toothpaste for sensitive teeth, toothpastes with stripes, clear etc. At Current scenario, toothpaste contains different ingredients like abrasives which help to wash off bacterial films and fluorides to harden the teeth against caries and have thickeners that will give the ribbon stand up. The role of foaming agents is to remove the fatty films. The sweeteners play the role as a non-nutritive which may help stop the attraction of bacteria. Toothpaste contains both active and inactive ingredients which have their role and will be proposed in accordance to the oral condition of individuals.

THE INHIBITORY AND DESTRUCTIVE ACTION OF THE SILVER NANOPARTICLE PREPARATION ON BIOFILMS FORMED BY CLINICALLY RELEVANT MICROORGANISMS

AIM: to obtain and investigate the activity of silver nanoparticles stabilized with arabinogalactan in relation to clinically relevant strains of filmforming microorganisms. MATERIALS AND METHODS: silver nanoparticles were obtained by reduction from silver nitrate in the presence of arabinogalactan with additional stabilization with dioctyl sodium sulfosuccinate. The shape and size of the nanoparticles were determined by the method of transmission electron microscopy, the zeta potential by the method of electrophoretic light scattering. The study of the effect of the nanoparticles on biofilm formation was carried out on 17 clinically relevant strains of bacteria isolated from blood culture and the clinical biomaterial of postoperative patients. RESULTS: the silver nanoparticles with an average diameter of 11.4 nm and a zeta potential of –24 mV were obtained. The minimum inhibitory concentration of the nanoparticles in relation to planktonic form of bacteria was 120 µg/ml; the use of the drug at a concentration of 100 µg/ml reduced the amount of CFU by 7 orders of magnitude compared with the initial culture. The study of the effect of silver nanoparticles on the formation of biofilms showed that, in the presence of the drug, the growth of biofilms was significantly reduced; at a drug concentration of 150 µg/ml, the growth of bacterial films was completely suppressed. Incubation of the formed daily biofilms with the silver nanoparticles in the concentration range from 150 to 120 µg/ml for 48 h resulted in the partial or complete destruction of the biopolymer matrix. CONCLUSION: the studied preparation of silver nanoparticles has a great potential for use in the treatment of infectious diseases caused by biofilm forming microorganisms.

Bacterial film disintegration with electrochemically reduced water

This work aimed to study the fine structure of bacterial films grown on the inner tuber surface of flow reactor. Applying scanning electron microscopy (SEM) approaches, the detailed biofilm relief was visualized. The action of electrochemically reduced water (ERW) on the biofilm ultrastructure generated by the plankton form of E.coli and/or lacto bacteria was investigated. Treatments with an ERW solution were exhibited to destroy the biofilm organic polymer matrix and bacterial cells embedded in a matrix.

Element composition of ground water and speleothem “moon milkˮ in a karst cave Proshchal’naya (Far East)

Object of research.The aim of this work was the comparative analysis of element composition of groundwater (drip, fracture), water from the interior of the watercourse in a karst cave Proshchal’naya (Khabarovsk Territory) and the surface water of the nearest river Sagdy-Selanka. The great interest was the study of speleothem (dropstones) “moon milk” in the cave Proshchal’naya.Materials and methods.Speleothem “moon milk” was investigated with a scanning electron microscope (EVO-40HV, CarlZeiss, Germany) and silicon-drift x-ray detector X-MAX 80 мм2 . By ICP-MS method a comparative analysis of element composition of groundwater (drip, fracture), water from an internal stream in the cave Proshchal’naya and surface water of the river Sagdy-Selenka were carried out.Results.Maximum concentrations of calcium, iron and manganese was installed in the spring, between drip and fracture water and magnesium – in flowing waters (inland watercourse caves and Sagdy-Selanka R.). It was determined that visually plastic and homogeneous mass of speleothem “moon milk” is heterogeneous and contains various microstructures. Tubular microstructures were represented by richer elemental compo sition (C, O, Ca, Fe, Mn, Si, Al, and S) compared with club-shaped formations (C, O, Ca, and Na). The binding matrix in the composition of the “moon milk” were reticular structures similar to actinomycente mycelium and bacterial films. Findings. The results of studies conducted in a monsoon climate may be interesting for researchers which study karst processes in other climatic zones.

Sensitivity of biofilm and planktonic forms of non-fermenting bacteria to the action of antiseptics

It is known that bacteria colonize endotracheal intubation tubes [EIT], form biofilms. Bacterial cells that are in the film matrix are protected from the effects of external factors and differ in high levels of resistance to the action of antibiotics, antiseptics, and disinfectants. The purpose of our study was to determine the sensitivity of the antiseptics of biofilm and planktont forms of non-fermentable gram-negative bacteria to the action of the antiseptics of decamethoxin, chlorohexidine bigluconate, povidone iodine, hydrogen peroxide. In order to create bacterial biofilms, sterile fragments of the endotracheal tubes were placed in test tubes with meat-peptone broth and the daily culture of the studied strain of microorganisms was blocked. To determine the influence of antiseptics on biofilms of bacteria, the method of two successive dilutions was used. The results of a comparative study of the activity of antiseptic agents (decamethoxin, bichluconate chlorhexidine, povidone iodine, hydrogen peroxide) in relation to planktonic and biofilm forms of pseudomonad and acinetobacter strains testify that in all investigated antiseptics and bacterial films pseudomonads forms are more resistant to drags preparations than in planktonic form. In bichluconate, chlorhexidine and decamethoxin MBcK for a bacterial film are 3,2 times greater than for a planktonic form. The smallest difference MBtsK for planktonic and biofilm forms of pseudomonad was in the drug povidone-iodine. MBcC bichluconate chlorhexidine for the biofilm form of acinetobacter, in comparison with planktonic form, was 3,3 times higher, for decamethoxin in 3.7 times, for povidone-iodine in 3,5 times. Biopharmaceutical forms of gram-negative nonfermenting bacteria have the ability to achieve high levels of resistance to antiseptics.

EFFECT OF ANTIMICROBIAL AGENTS ON THE BIOFILM GROWTH OF CLINICAL ISOLATES

OBJECTIVE. To study the effect of active extracellular substances of lactobacilli and antimicrobial agents on the inhibition and destruction of the biofilms formed clinically relevant microorganism strains. MATERIALS AND METHODS. The study of the impact of different agents on the biofilmformation and growth was carried out on resistant clinical strains of microorganisms obtainedfrom patients with post-surgical infectious inflammatory complications. We used wound dressing solution, cutaneous antiseptic, filtrates of 19 clinical strains of lactobacilli and a strain of Lactobacillus plantarum from the probiotic «Lactobacterin dry» (Microgen Nizhny Novgorod, series 46 / 06-1209) as a reference strain-producer of bacteriocins for biofilm inhibition. Biofilms were incubated for 48 hours on glass carriers at 37°C and visualized with a light microscope at 960x magnifying. RESULTS. All substances possess a good inhibitory potential and have approximately same level of effect. The skin antiseptic and wound washing fluid have only an inhibiting effect on the biofilmformation process, while the having a bactericidal effect on plantonicform of the cells. The lactobacilli filtrate inhibited the biofilmformation and was also able to destroy preformed 24-hour bacterial films. CONCLUSION. The use of lactobacilli bacteriocins can reveal additional opportunities for combating the infection associated with biofilm forming microorganisms.