16 research outputs found
Seroplrevalence of <i>Anaplasma phagocytophilum</i> and <i>Ehrlichia</i> sp. among people affected by tick bites
Background. In spring and summer, the population of the Baikal region regularly comes into contact with the pathogens transmitted through the bites of ixodid ticks. In the Center for Diagnosis and Prevention of Tick-Borne Infections (Irkutsk, Russian Federation), we annually detect anaplasmas of the Anaplasma phagocytophilum species, as well as Ehrlichia chaffeensis/E. muris in both ixodid ticks and blood samples from people who have been bitten by ticks. At the same time, there are no data in open sources on the incidence of human granulocytic anaplasmosis and human monocytic ehrlichiosis in the Baikal region. Currently, there is very little information on the studies of intensity of the immune response to anaplasmas and ehrlichia in people living in the surveyed area, although this information is critical for assessing the frequency of contacts and the risk of infection of people in a territory endemic for tick-borne infections. The aim. To update information on the presence and prevalence of specific immunoglobulins M and G to A. phagocytophilum and Ehrlichia sp. among the population of the Irkutsk Region affected by tick bites. Materials and methods. In total, 204 samples of blood serum from the residents of the Irkutsk Region who were registered to be bitten by ticks were analyzed for the presence of IgM and IgG to human monocytic ehrlichiosis and human granulocytic anaplasmosis agents. Results. IgG to A. phagocytophilum were found in 9 samples, IgG to E. chaffeensis/E. muris – in 1 sample; no IgM to both pathogens were found in any sample. Conclusions. The results obtained indicate regular infection of the population with anaplasmas and ehrlichia which is a testifies to the existence of active natural foci of human monocytic ehrlichiosis and human granulocytic anaplasmosis in the Baikal region. To clarify the real epidemic role of these infections, a detailed study of the immune status is required both among healthy individuals and among patients with symptoms of an infectious disease
Development of DNA aptamer selection approach based on membrane ultrafiltration of aptamer/target complex
Background. Aptamers are small single-stranded DNA or RNA molecules that have an affinity for a specific target molecule. The main method of aptamers construction is the technology of systematic evolution of ligands with exponential enrichment (SELEX). However, the exact approach depends on the nature of target molecules, and is selected and optimized by each researcher independently. The article describes the technique of production of aptamers to the tick-borne encephalitis virus (TBEV) using membrane ultrafiltration with a molecular weight cut-off of 100 kDa. As a result, the pool of aptamers with observable affinity for TBEV is successfully selected and enriched.The aim. To develop the technique suitable for selection of specific DNA aptamers to a live, crude TBEV suspension directly in cell culture supernatant.Materials and methods. The selection of aptamers was carried out using a modified SELEX DNA aptamer technology in combination with semipermeable membrane ultrafiltration using Vivaspin 6 (Sartorius, Germany) concentrators of molecular weight cut-off of 100 kDa. Enrichment of a specific pool of aptamers was performed using real time polymerase chain reaction. Aptamers were sequenced with automated Sanger sequencing method. The direct virucidal effect of the aptamers was determined by the decrease in the titer of the infectious virus after incubation with the aptamer.Results. The pool of aptamers to TBEV was selected and enriched. This aptamer pool expressed affinity both to the infectious TBEV and to the TBEV antigen. Sixteen aptamers were sequenced from this pool and four of them were synthesized and tested for antiviral activity against TBEV. No antiviral activity was observed.Conclusions. The technique developed that can be successfully used to select aptamers to a live virus culture for the viruses comparable in size to TBEV or larger
NECESSITY TO IMPROVE THE EMERGENCY DIAGNOSTICS OF TICK-BORNE INFECTIONS IN PEOPLE BITTEN BY IXODID TICKS ABROAD OF THE RUSSIAN FEDERATION
Introduction. Annually, there are several patients attended the Center for Diagnosis and Prevention of Tick-borne Infections in Irkutsk after bites of ticks that happened outside the Pribaikalye region or abroad. In such cases, the attacking ticks do not belong to convenient species that are usual for Eastern Siberia. Consequently, the spectrum of pathogenic microorganisms transmitted by these ticks may significantly differ from those that are detected by usual laboratory tests. Thus, both physicians and laboratory personnel may have difficulties in proper detection and identification of pathogens as well as in diagnosing and treating of such patients.The purpose of the study was the analysis of potential risks of human infection with the pathogens that are common in foreign countries outside the Russian Federation.Material and methods. The article uses information from electronic databases created by the authors during 2007-2017.Results and discussion. During 11 years of observations, 52 tick bites were registered in 20 countries, with 48 of them in the Eastern Hemisphere (92.3 %), three (5.8 %) in the United States and one (1.9 %) in the Republic of Cuba. The results indicate a real danger of infection by tick-borne pathogens of people traveling as the tourists and with business purposes to the countries of Europe, Asia and America. Conclusion. It is necessary to improve the existing algorithm for diagnosis, prevention and treatment for people bitten by ixodid ticks outside the Russian Federation, taking into account the possibility of infection by inconvenient imported infections
Interaction of Surfactants with Poloxamers 338 and Its Effect on Some Properties of Cream Base
The aim. Study of the interaction of surfactants with poloxamer 338 (P338) and the effect of P338 on the properties of cream bases.
Materials and methods. Solutions of the surfactants and P338 as well as cream bases were under study. The average hydrodynamic diameter (Dh) and zeta potential (ζ‑potential) were determined by the light scattering intensity and electrophoretic mobility of micelles. The electron paramagnetic resonance (EPR) spectra of spin probes in micelles, solvents and bases were obtained; the type of spectrum, isotropic constant (AN), rotational correlation times (τ) and anisotropy parameter (ε) were determined. Liquids and cream bases were studied by capillary and rotational viscometry; the flow behaviour and yield stress (t0), dynamic and apparent viscosity (η) as well as the hysteresis (thixotropic) area (AH) were determined. The microstructure of the bases was examined by optical microscopy. The strength of adhesion (Sm) was assessed by the pull-off test, and the absorption of water was studied by dialysis.
Results. Under the impact of P338 the hydrodynamic diameters of micelles formed by cationic, anionic and nonionic surfactants decreased as well as the absolute values of their ζ‑potential became lower, but the microviscosity of the micelle nuclei increased. There was also a change in the structure of the aggregates of surfactant with fatty alcohols; EPR spectra, which were superpositions characteristic for the lateral phase separation, converted into triplets that indicated the uniform distribution of lipophilic probes in the surfactant phase. When the content of P338 increased to 17 %, the rheological parameters of the bases increased drastically, the flow behaviour and the microstructure changed. The bases had the consistency of cream within temperature range from 25 °C to 70 °C and completely restored their apparent viscosity, which had decreased under shear stress. P338 enhances the adhesive properties of the bases. Due to their microstructure, cream bases have a lower ability to absorb water compared to a solution and gel containing 17 % and 20 % P338, respectively.
Conclusions. The structure of surfactant micelles and aggregates of surfactants with fatty alcohols changed under impact of P338 due to the interaction of surfactants with P338. As a result of this interaction, at a sufficiently high concentration of P338, the microstructure and flow behaviour of bases changed, their rheological parameters, which remain high at temperatures from 25 °C to 70 °C, increased significantly, and water absorption parameters decreased. The bases with P338 were more adhesiv
Chromosomal Passports Provide New Insights into Diffusion of Emmer Wheat
International audienceEmmer wheat, Triticum dicoccon schrank (syn. T. dicoccum (schrank) schÜbl.), is one of the earliest domesticated crops, harboring a wide range of genetic diversity and agronomically valuable traits. The crop, however, is currently largely neglected. We provide a wealth of karyotypic information from a comprehensive collection of emmer wheat and related taxa. In addition to C-banding polymorphisms, we identified 43 variants of chromosomal rearrangements in T. dicoccon; among them 26 (60.4%) were novel. The T7A:5B translocation was most abundant in Western Europe and the Mediterranean. The plant genetic resources investigated here might become important in the future for wheat improvement. Based on cluster analysis four major karyotypic groups were discriminated within the T. dicoccon genepool, each harboring characteristic C-banding patterns and translocation spectra: the balkan, asian, european and ethiopian groups. We postulate four major diffusion routes of the crop and discuss their migration out of the Fertile Crescent considering latest archaeobotanical findings
Chromosomal Passports Provide New Insights into Diffusion of Emmer Wheat
International audienceEmmer wheat, Triticum dicoccon schrank (syn. T. dicoccum (schrank) schÜbl.), is one of the earliest domesticated crops, harboring a wide range of genetic diversity and agronomically valuable traits. The crop, however, is currently largely neglected. We provide a wealth of karyotypic information from a comprehensive collection of emmer wheat and related taxa. In addition to C-banding polymorphisms, we identified 43 variants of chromosomal rearrangements in T. dicoccon; among them 26 (60.4%) were novel. The T7A:5B translocation was most abundant in Western Europe and the Mediterranean. The plant genetic resources investigated here might become important in the future for wheat improvement. Based on cluster analysis four major karyotypic groups were discriminated within the T. dicoccon genepool, each harboring characteristic C-banding patterns and translocation spectra: the balkan, asian, european and ethiopian groups. We postulate four major diffusion routes of the crop and discuss their migration out of the Fertile Crescent considering latest archaeobotanical findings
Generalized idiogram of wheat A and B genome chromosomes.
<p>A and B—wheat genomes; 1–7—homoeologous groups; S and L—short and long arm of a chromosome, respectively. Large permanent C-bands are shown as solid blocks; polymorphic C-bands are shown as shaded blocks; small inconsistent C-bands are indicated by dashed lines. Positions of C-bands are numbered at the right-hand side of each chromosome. The 112 C-bands considered in “chromosomal passports” are shown in red; 38 C-bands most essential for discrimination of karyotypic groups are indicated with *.</p
Main karyotypic groups/types distinguished among <i>T</i>. <i>dicoccon</i> accessions on the basis of visual analysis of C-banding patterns.
<p>Left side—A-genome chromosomes, right side—B-genome chromosomes; 1–7—homoeologous groups. Chromosomal groups: Balkan, European, Asian, Ethiopian (PI 94664, Saudi Arabia); chromosomal types: Bal (PI 434996, Montenegro), Vol (k-30728, Nizhny Novgorod); WEM-1 type prevailing in European-Mediterranean emmer lines with 7A:5B translocation (k-1730, Germany); WEM-2 (PI 352332, Belgium); WEM-Sp (PI 275998, Spain); Trc (k-14937, Georgia); Irn (TA10540, Iran), Mor (k-22246, Morocco). Small red arrows indicate positions of small group-specific bands; large red arrows show the positions of C-bands with an enlarged size or group-specific supernumerary C-bands; blue arrows indicate group-specific bands with a decreased size (small arrow) or the positions of bands that are missing in the group-specific chromosome variant (large arrow). Large black arrows show the breakpoint position in region-specific translocation variants: T7AS.7AL-5BS and T5BL.5BS-7AL—rearranged chromosomes formed as a result of the T7A:5B translocation; T4AS:1BL and T1BS:4AL—rearranged chromosomes formed as a result of the T4A:1B translocation; T1AS.1AL-6AS and T6AL.6AS-1AL—rearranged chromosomes formed as a result of the T1A:6A translocation; T4BS:6BL and T6BS:4BL—rearranged chromosomes formed as a result of the T4B:6B-1 translocation (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128556#pone.0128556.s016" target="_blank">S3</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128556#pone.0128556.s017" target="_blank">S4</a> Tables).</p
Diversity of chromosomal rearrangements and translocation lineages identified in domesticated emmer.
<p>Translocation types are designated according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128556#pone.0128556.s016" target="_blank">S3</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128556#pone.0128556.s017" target="_blank">S4</a> Tables. Translocation variants described in previous papers [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128556#pone.0128556.ref035" target="_blank">35</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128556#pone.0128556.ref046" target="_blank">46</a>] are shown in red and novel translocation variants found in this study are indicated in blue. Red arrows define translocation lineages, i.e. a series of related translocations occurring one after another. A detailed description of all translocation variants is given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128556#pone.0128556.s016" target="_blank">S3</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128556#pone.0128556.s017" target="_blank">S4</a> Tables.</p
Embedding of 545 emmer wheat accessions into three dimensions by non-metric multidimensional scaling (NMDS).
<p>NMDS is based on the Hamming distance calculated on the C-banding patterns (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128556#pone.0128556.s015" target="_blank">S2 Table</a>). Each point represents a single accession. The four colors blue, red, green and orange are based on k-medoids and represent the European, Balkan, Asian, and Ethiopian, respectively. Additionally, black is used for Dicoccoides and other taxa.</p