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

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

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

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

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

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

Epizootiologic Monitoring of Natural Focus of Tularemia in the Stavropol Region in 2010-2017

Objective of the study was an assessment of the current epizootiological situation on tularemia in the Stavropol Region. Materials and methods. Processed were the data of laboratory investigations of the field material over the period of 2010-2017. All field samples were studied in the laboratories of the Stavropol Anti-Plague Institute using PCR and bioassay. Results and discussion. This paper presents the analysis of the epizootiological situation for the period of 2010-2017 in the Stavropol Region. The species composition and the number of the main carriers of tularemia have been established. Epizootic activity of the focus is defined by mice of the genus Sylvaemus. Data on the isolation of strains from ticks, small mammals and environmental objects are presented and processed. According to our studies, over the past seven years, infection with tularemia agent has been detected in seven species of mammals: S. uralensis, Microtus arvalis, M. socialis, Mus musculus, Crocidura suaveolens, Erinaceus roumanicus, Lepus europaeus. For the period of epizootic monitoring between 2010 and 2017 37 strains of the causative agent were isolated from small mammals - 12 (32.4 %), ectoparasites - 9 (24.3 %), and environmental objects - 16 (43.2 %). All isolated strains have been identified as Francisella tularensis holarctica biovar II, eryR

Modern Epidemiological and Epizootiological Situation on Ixodic Tick-Borne Borreliosis in the South of the European Part of Russia

The aim is to analyze the current epidemiological and epizootiological situation on ixodic tick-bome borreliosis in the South of the European part of Russia. Materials and methods. The research materials were the epidemiological and epizootiological data for 2014-2018 provided by the Rospotrebnadzor Departments, the Hygiene and Epidemiology Centers of the North Caucasian and Southern Federal Districts, and regional anti-plague institutions: Stavropol, Volgograd and Rostov-on-Don research anti-plague institutes, Astrakhan, Dagestan, Kabardino-Balkar, Black Sea, North Caucasus, Elista plague control stations, as well as the plague control station of the Republic of Crimea. The data of scientific publications on epizooitological monitoring, the species composition of vectors and agents of tick-borne borreliosis involved in the epizootic and epidemic process in the region were studied. In the study descriptive, analytical epidemiological methods, retrospective epidemiological and cartographic analyzes were used. Results and discussion. It has been noted that in 1999, the incidence of tick-borne borreliosis in the South of the European part of Russia, has occurred in 11 of the 15 administrative regions. The incidence of tick-borne borreliosis in the Republic of Kalmykia, has not been recorded since 2007, in the Chechen Republic - since 2014. To clarify the sources of tick-borne borreliosis infection in the territory of the Krasnodar and Stavropol Territories, the Volgograd and Rostov Regions, the Republic of Dagestan and the Karachay-Cherkess Republic, and also, to determine the boundaries of natural and natural-anthropurgic foci of ixodic tick-borne borreliosis constant epizootiological monitoring is required. In addition, it is necessary to create a unified algorithm for monitoring natural foci, to analyze data using modern geographic information and statistical tools