Studies of ticks of the genus Dermacentor (Acari; Ixodidae) on the natural occurrence of tularemia pathogen in the conditions of the Central Pre-Caucasian region

The purpose of the research is the assessment of the Francisella tularensis occurrence in nature in ticks of the genus Dermacentor; understanding the physiological age in terms of tick infection with tularemia pathogen.Materials and methods. For the period from 2015 to 2019, we examined 8449 specimens of Dermacentor marginatus (916 pools), 8674 specimens of D. reticulatus (705 pools), and 109 specimens of D. niveus (40 pools) for tularemia infection. To assess the dependence of tularemia pathogen found in ticks of different physiological ages, we examined 2440 specimens of D. marginatus (360 pools), and 3349 specimens of D. reticulatus (412 pools) for the period from 2016 to 2019. Studies of ixodid ticks infected with tularemia pathogen were performed by the Natural Focal Infection Laboratory of the Stavropol Anti-Plague Institute. Pools of ixodid ticks were examined for the pathogen DNA of tularemia using reagent kits for identifying Francisella tularensis DNA by polymerase chain reaction with fluorescence hybridization of results recorded in real time.Results and discussion. The infection rate of the tularemia pathogen in ticks in the Central Pre-Caucasian region ranged from 0.044–1.127% in D. marginatus and 0.035–1.455% in D. reticulatus in different years. The greatest number of F. tularensis was isolated from the III physiological age ticks. For D. reticulatus ticks, no statistically significant dependence of the detected tularemia pathogen on physiological age was found

Possible changes of state and relevant timescales for a neutron star in LS I +61{\deg}303

The properties of the short, energetic bursts recently observed from the gamma-ray binary LS I +61{\deg}303, are typical of those showed by high magnetic field neutron stars, and thus provide a strong indication in favor of a neutron star being the compact object in the system. Here, we discuss the transitions among the states accessible to a neutron star in a system like LS I +61{\deg}303, such as the ejector, propeller and accretor phases, depending on the NS spin period, magnetic field and rate of mass captured. We show how the observed bolometric luminosity (>= few x 1E35 erg/s), and its broad-band spectral distribution, indicate that the compact object is most probably close to the transition between working as an ejector all along its orbit, and being powered by the propeller effect when it is close to the orbit periastron, in a so-called flip-flop state. By assessing the torques acting onto the compact object in the various states, we follow the spin evolution of the system, evaluating the time spent by the system in each of them. Even taking into account the constraint set by the observed gamma-ray luminosity, we found that the total age of the system is compatible with being ~5-10 kyr, comparable to the typical spin-down ages of high-field neutron stars. The results obtained are discussed in the context of the various evolutionary stages expected for a neutron star with a high mass companion.Comment: 12 pages, 6 figures. Accepted for publication in Ap

Genetic Profiling of the Causative Agents of Natural-Focal infections, Circulating in the Stavropol Territory

Objective of the study was genetic typing of the strains and nucleic acid isolates of causative agents of natural focal infections, both bacterial and viral etiology, accumulation of data on genetic features of regional strains cir­culating in the Stavropol Territory. Material and methods. To study the genetic spectrum of causative agents of natural- focal infections, analysis of the strains and nucleic acids isolates detected in the samples of field and clinical material was carried out. Indication of causative agents of natural focal infections in the samples was carried out by PCR. For genetic typing of the strains and DNA/RNA isolates of natural focal infections agents, MLVA and sequencing of genome regions with subsequent phylogenetic analysis were used. The analysis of territorial distribution of the causative agent genetic variants and mapping was performed in ArcGIS 10.1. Results and conclusions. MLVA-25 typing of 20 strains of Francisella. tularensis, MLVA-10 typing of 4 Coxiella burnetii isolates, species identification of 20 isolates of Rickettsia sp., sub-species genetic typing of 40 RNA isolates of CCHF virus and 8 RNA isolates of hantaviruses circulating in the Stavropol Territory in 2016-2017 were performed. The studied strains of F. tularensis belong to eight MLVA genotypes. They are mainly confined to specific areas. The isolates of C. burnetii have the same MLVA type. Rickettsia, belonging to 5 species: R. massiliae R. raoultii, R. sibirica, R. aeschlimannii, R. slovaca, RNA-isolates of hantavirus of the «Tula» genotype and variants of the CCHF virus of the Europe-1 and Europe-3 genotypes were identified. The obtained data can be used in the epidemiological investigation of possible cases of infectious diseases to determine the source and pathways of infection

Immuno-Chromatographic Test System Application for Rapid Detection of <I>Francisella tularensis</I> Lipopolysaccharide in Monitoring of Natural Foci

Immuno-chromatographic test systems are shown to be applicable for rapid detection of tularemia microbe lipopolysaccharide for identification of Francisella tularensis strains isolated in natural foci, and in epizootiologic survey – for the analysis of suspensions of ixodic ticks and internal organs of dead animals

Algorithm of Laboratory Diagnostics Applied for Examination of Ixodic Ticks for Tularemia

Put forward is the algorithm of laboratory diagnostics applied for examination of Ixodic ticks (IT) for tularemia. It involves carrying out primary screening of tick suspensions for the presence of species-specific fragments of DNA and antigen. It is recommended that laboratory analysis starts with PCR, taking into account its high sensitivity and diagnostic value. Pools with positive PCR tests are subjected to verification by means of enzyme-linked immunosorbent assay and immune-chromatographic tests. In case of tularemia antigen detection, these pools of IT are examined with the help of biological or bacteriological techniques to isolate the agent

Исследования клещей рода Dermacentor (Acari; Ixodidae) на естественную встречаемость возбудителя туляремии в условиях Центрального Предкавказья

The purpose of the research is the assessment of the Francisella tularensis occurrence in nature in ticks of the genus Dermacentor; understanding the physiological age in terms of tick infection with tularemia pathogen.Materials and methods. For the period from 2015 to 2019, we examined 8449 specimens of Dermacentor marginatus (916 pools), 8674 specimens of D. reticulatus (705 pools), and 109 specimens of D. niveus (40 pools) for tularemia infection. To assess the dependence of tularemia pathogen found in ticks of different physiological ages, we examined 2440 specimens of D. marginatus (360 pools), and 3349 specimens of D. reticulatus (412 pools) for the period from 2016 to 2019. Studies of ixodid ticks infected with tularemia pathogen were performed by the Natural Focal Infection Laboratory of the Stavropol Anti-Plague Institute. Pools of ixodid ticks were examined for the pathogen DNA of tularemia using reagent kits for identifying Francisella tularensis DNA by polymerase chain reaction with fluorescence hybridization of results recorded in real time.Results and discussion. The infection rate of the tularemia pathogen in ticks in the Central Pre-Caucasian region ranged from 0.044–1.127% in D. marginatus and 0.035–1.455% in D. reticulatus in different years. The greatest number of F. tularensis was isolated from the III physiological age ticks. For D. reticulatus ticks, no statistically significant dependence of the detected tularemia pathogen on physiological age was found.Цель исследований: оценка естественной встречаемости Francisella tularensis в клещах рода Dermacentor; выяснение связи физиологического возраста и зараженности клещей возбудителем туляремии.Материалы и методы. За период с 2015 по 2019 гг. на зараженность туляремией исследовано 8449 экз. Dermacentor marginatus (916 пулов), 8674 экз. D. reticulatus (705 пулов) и 109 экз. D. niveus (40 пулов). Для оценки зависимости обнаружения возбудителя туляремии в клещах разного физиологического возраста нами за период с 2016 по 2019 гг. исследовано 2440 экз. D. marginatus (360 пулов) и 3349 экз. D. reticulatus (412 пулов). Исследования на зараженность иксодовых клещей возбудителем туляремии проводили в лаборатории природно-очаговых инфекций Ставропольского противочумного института. Пулы иксодовых клещей исследовали на наличие ДНК возбудителя туляремии с использованием наборов реагентов для выявления ДНК Francisella tularensis методом полимеразной цепной реакции с гибридизационно-флуоресцентным учетом результатов в режиме реального времени.Результаты и обсуждение. Зараженность клещей возбудителем туляремии в Центральном Предкавказье в разные годы колеблется в пределах 0,044–1,127% у D. marginatus и 0,035–1,455% у D. reticulatus. В наибольшем количестве F. tularensis выделяли от клещей III физиологического возраста. Для клещей D. reticulatus не выявлено статистически значимой зависимости обнаружения возбудителя туляремии от физиологического возраста

Assessment of the Application of Erythrocytal Diagnosticum (Lyophilizate) in Detecting Tularemia Agent in Natural Foci

Tularemia is a zoonotic disease with a wide geographical dissemination, and its causative agent Francisella tularensis can be used as a bioterrorism agent. The aim of the study was to evaluate the use of a set of reagents “Erythrocytic immunoglobulin dry tularemia diagnosticum” (“DET-Ig”) with the help of control test strains and field material from natural tularemia foci. Materials and methods. Using the introduced erythrocyte diagnosticum, we studied the decontaminated cultures of test strains (F. tularensis Miura, F. tularensis 55, F. tularensis Schu, F. tularensis 15 NIIEG, Brucella abortus 544, B. melitensis 16-M, B. suis 1330, and Yersinia enterocolitica 64, Y. enterocolitica 178, Y. enterocolitica 383) and environmental samples suspected of containing F. tularensis. Results and discussion. It has been proven that the developed diagnosticum is specific, sensitive, and easy to use for routine diagnostics of tularemia. In the course of laboratory tests of the experimental series of the DET-Ig reagent kit, the possibility of qualitative determination of the tularemia agent in bacterial cultures, biological material and environmental samples in the reaction of indirect hemagglutination was demonstrated. Comparison of the results of use of erythrocyte diagnosticum in liquid and lyophilized forms showed the advantages of drugs after lyophilization: the possibility of transportation and long-term storage at any temperature conditions in various climatic conditions; the setting of the reaction is possible without the use of special diluents. The guaranteed storage term is set for two years (observation period). The results obtained indicate the prospects of introducing the developed drug into healthcare practice

Description of the Scenario Machine

We present here an updated description of the "Scenario Machine" code. This tool is used to carry out a population synthesis of binary stars. Previous version of the description can be found at http://xray.sai.msu.ru/~mystery//articles/review/contents.htmlComment: 32 pages, 3 figures. Corrected typo

A magnetar-like event from LS I +61 303 and its nature as a gamma-ray binary

We report on the Swift-BAT detection of a short burst from the direction of the TeV binary LS I +61 303, resembling those generally labelled as magnetar-like. We show that it is likely that the short burst was indeed originating from LS I +61 303 (although we cannot totally exclude the improbable presence of a far-away line-of-sight magnetar) and that it is a different phenomena with respect to the previously-observed ks-long flares from this system. Accepting as a hypothesis that LS I +61 303 is the first magnetar detected in a binary system, we study which are the implications. We find that a magnetar-composed LS I +61 303-system would most likely be (i.e., for usual magnetar parameters and mass-loss rate) subject to a flip-flop behavior, from a rotational powered regime (in apastron) to a propeller regime (in periastron) along each of the LS I +61 303, eccentric orbital motion. We prove that whereas near apastron an inter-wind shock can lead to the normally observed LS I +61 303behavior, with TeV emission, the periastron propeller is expected to efficiently accelerate particles only to sub-TeV energies. This flip-flop scenario would explain the system's behavior where a recurrent TeV emission was seen appearing near apastron only, the anti-correlation of GeV and TeV emission, and the long-term TeV variability (which seems correlated to LS I +61 303's super-orbital period), including the appearance of a low TeV-state. Finally, we qualitatively put the multi-wavelength phenomenology in context of our proposed model, and make some predictions for further testing.Comment: The Astrophysical Journal, in pres

Results of Epizootiological Monitoring of Natural Foci for Bacterial Vector-Borne Infections in Caucasian Mineral Waters Region of the Stavropol Territory in 2018–2020

The aim of the study was to assess the epizootiological situation on bacterial vector-borne infections in Caucasian Mineral Waters area of the Stavropol Territory over the period of 2018–2020.Materials and methods. 3494 specimens of ticks (473 pools), 257 specimens of small mammals, 9 regurgitates of birds of prey and mammals, 7 excreta samples of small mammals, and 2 water samples were tested. Laboratory research of the field material was carried out using molecular-genetic, serological, biological methods. Statistical analysis of laboratory results was conducted using Microsoft Excel 2010. The data were mapped using QGIS 2.18 software.Results and discussion. The study revealed that the 44.8 % of collected ticks were positive for tick-borne borreliosis, 21.5 % – for tick-borne rickettsiosis, 10.3% – for human granulocytic anaplasmosis, 2.7 % – for Q fever, 0.84 % – for tularemia. There has been an increase in the percentage of positives for tick-borne borreliosis agent samples (more than three times) and a decrease in this indicator for human granulocytic anaplasmosis (1.5 times) as compared with 2010–2012. Investigation of tick infection with the agents of Q fever and tick-borne rickettsioses has not been previously conducted in the region. During the period under review, 19 pools of ticks had mixed infection, which indicates that there are combined foci of bacterial natural-focal infections with vector-borne transmission in the recreation zone of the Stavropol Territory. This necessitates preventive measures and systematical epizootiological surveys in the Caucasian Mineral Waters region