Diversity of currently available on the market means of respiratory organs protection (MROP) dictates the necessity to assess the specimens in regard to the possibility of using them for work with dangerous biological agents. The review presents the analysis of modern personal protection equipment for respiratory organs. National and inter-state standards, national legislative and normative documents, foreign recommendations, materials from periodicals, related to the matters of selection and usage of MROP, as well as information on the MROP models provided by manufacturers have been studied. Considered are different types and modifications of filtering MROP and applicable to them requirements. Peculiarities of MROP usage when working with agents of infectious diseases are also analyzed. Based on the conducted research, recommendations on the selection and exploitation of MROP for work with infectious diseases agents have been put forward, problematic aspects that require complex scientific-technical and regulatory solutions in order to ensure the safety of the personnel involved in handling infectious disease agents have been identified. The following conclusions are drawn: to protect the staff performing operations with harmful and dangerous biological agents, it is necessary to use MROP with anti-aerosol barriers; the choice of modification for specific situations and working conditions should be based on the results of assessment of biological hazard and associated risks. Peculiarities of the options, exploitation, and decontamination of MROP, actions in case of an accident related to the breaching of MROP integrity must be covered in the regulatory document at the institutional level, according to which an officer is obliged to receive introductory and recurring instructions. Enhancement of regulatory procedures in the sphere of biological safety provision should aim at clarification of legitimacy of using specific MROP for work with harmful and dangerous biological agents. Preferences in the choice of MROP for work with PBA have been pointed out.

The overview contains information from Russian and foreign literature about composition and usage of nutrient media for brucellosis diagnosis and immunobiological preparations production. Nutrient media for cultivation, isolation, enrichment, identification and differentiation of Brucella and their L-form as well as transport media and synthetic media are considered. Advantages and disadvantages are described for some of the products. The overview also contains information about nutritional bases, growth factors and selective components included in these media. There is a particular focus on selective media, their history and improvement. The article gives the requirements for the inhibitory properties of these products and the disadvantages of using certain antimicrobial agents. The authors list nutrient media for various purposes, certified for use by the Russian regulatory documents, recommendations of World Health Organization and World Organization for Animal Health. Data about principles for assessing the quality of culture media and test strains used to control biological parameters of culture media are covered. The authors also present materials about the trends in nutrient media development for Brucella cultivation and isolation, methods of their application. In conclusion, they identify the need to conduct research in the sphere of the development of new nutrient media for Brucella isolation from the material contaminated by foreign microorganisms.

Objective of the study was to select the standardized substrate containing dry hydrolysate of casein for preparation of nutrient medium utilized for manufacturing bivalent chemical cholera vaccine under submerged cultivation of cholera vibrio strains in fermenters. Materials and methods. We used Vibrio cholerae O1 strains of classical biovar: strain 569B Inaba and strain M-41 Ogawa. Examined were two dry substrates of the medium: enzymatic hydrolysate of casein, Type I Himedia (India) and pancreatic hydrolysate of casein, produced by the State Scientific Center of Applied Microbiology and Biotechnology (Russian Federation). Produced under laboratory conditions at the premises of the RusRAPI “Microbe” medium was used as a control. Submerged cultivation was conducted in bioreactors during (9±1) h with aeration and automatic feeding of glucose and ammonia. Production of protective antigens was measured applying immunochemical and biological methods. Results and discussion. It is demonstrated that submerged cultivation of cholera vibrio production strains on nutrient media under study provides for synthesis of protective antigens the parameters of which comply with the requirements of normative documentation. More standardized and higher indicator values of the target product are ensured by cultivation of producer strains on nutrient medium with a substrate from dry enzymatic hydrolysate of casein, containing (1.5±0.1) g/l of amino nitrogen for the strain V. cholerae M-41 and (2±0.1) g/l – for V. cholerae 569 B. Transition to the use of standardized dry protein components of cultivation media does not lower the quality of the chemical cholera vaccine, but allows for the reduction of cost price and duration of technological process.

Objective of the study was to use geographic information systems to create an electronic database of anthrax burials and electronic cadastres in the Stavropol Territory. Materials and methods. ESRI - ArcGIS10 software was used as a GIS platform. Results and discussion. A retrospective analysis of the epizootiologic and epidemiological situation on anthrax in the Stavropol Territory was carried out. It was revealed that 352 anthrax stationary potentially hazardous sites were located in the territory of all 26 districts, in 16 of which 52 were abandoned anthrax burials. The greatest epidemiological risk is posed by 22 cattle burial grounds, in which animal corpses were buried (42.3 %). 30 cattle burial grounds with ash burials (57.7 %) pose a lower potential danger. The arrangement of anthrax burial sites in the Stavropol Territory has a number of disadvantages, only 23 cattle burial grounds (44.2 %) have a satisfactory veterinary and sanitary state. Based on the information obtained, an electronic geographic information database of anthrax cattle burial grounds was created for each district of the Stavropol Territory. The structure of the database is presented in the form of a table, which contains all the basic information about the burial, including geographical coordinates. The information was then entered into the ArcGIS10 program, using the geographical method. Each point, plotted on the map, contains the description of the animal burial ground, presented in the table. Thus, the main layer of the geographic information system is created. It can be overlaid with other layers that carry information about the location of the anthrax stationary potentially hazardous sites, the nature of the soil, objects located in the territory. In addition, electronic cadastral atlases of the location of anthrax cattle burials in each district of the Stavropol territory have been created. Electronic cadastral atlases are easier to use, do not require specialized personnel and applicable computer GIS system, but at the same time can give the necessary information about a particular burial in the Stavropol Territory.

Objective of the study was to analyze the stability of the preparation of a live plague vaccine made using an experimental nutrient medium over its shelf life. Materials and methods. A series of live plague vaccine based on Yersinia pestis EV NIIEG strain prodused using experimental nutrient medium were utilized in this work. Most significant qualitative parameters of the preparation were studied: microbe cell content, viability, thermal stability, mass loss during the process of drying, and immunogenicity. Results and discussion. The stability of the vaccine produced using the nutrient medium based on hydrolysate of condensed corn steep extract was monitored over a specified shelf life (three years). A comparative analysis of the viability of all experimental vaccine series was carried out at certain time intervals - short-term storage (up to 3 months) and before the expiration date. During storage, there was an insignificant decrease in the percentage of living microbial cells, while in no series the viability decrease reached below the regulated levels of 25 %. Such a decrease is natural for a “live preparation” and is not critical within the obtained limits. The rest of the studied indicators practically did not change. Thus, the analysis of the data obtained indicates that in all the periods of observation the drug retained the stability of the main regulated indicators. The studies confirm the feasibility of using this referred nutrient medium based on hydrolyzed corn steep extract in industrial production of the plague live vaccine preparation.

Objective - development of the unified interdepartmental approach to realization of complex epidemiological and epizootiological inspection of anthrax burials and animal refuses (AB/AR) with law compliance of standard requirements of the administrative, veterinary and sanitary-and-epidemiological legislation for solving the problems of expert estimation of object’s biological hazard, sanitary-protective zoning and rational land tenure. Materials and methods. Standard-methodical documentation and literature sources were analyzed, the official data, reference books, inventory registration and statement documents, information materials and the data of Veterinary Institutions, Rospotrebnadzor, Rosselkhoznadzor, municipal formations and other establishments were used. The data of complex epizootiological and epidemiological investigation of 27 AB/AR in five entities of Siberia and Far East over 2013-2017 were summarized. Results and discussion. For the first time the algorithm was unified and the technique of complex epidemiological and epizootiological inspections of anthrax burials (refuses) with known location was developed according to the requirements of veterinary and sanitary-and-epidemiologic rules to aid the specialists of the Rospotrebnadzor and Veterinary Science Institutions. Introduction of complex epizootiological-and-epidemiological inspection of anthrax burials (refuses) taking into account the retrospective and operative epizootiological-and-epidemiological analysis of the situation on anthrax in the Siberian administrative territory, studying of sanitary-veterinary condition of an object in aggregate with the results of laboratory examinations of samples for anthrax will permit to estimate the biological danger of anthrax burials (refuses), to solve problems of its preservation and/or utilization with the subsequent reduction of the areas of sanitary-protective zone of the object and rational land tenure.

Objective of the study was to determine the origin of Y. pestis strains that widely disseminated in natural plague foci of Northern, North-Western Caspian Sea region and Fore-Caucasus in the second half of the XX century. Materials and methods. We have carried out the investigation of properties and whole genome sequencing of 22 Y. pestis strains, isolated between 1923 and 2003 in five natural foci of the souslik type, situated in Northern and North-Western Caspian Sea region and Fore-Caucasus. Phylogenetic analysis was conducted using the data of whole genome SNP-typing, based on 1348 identified SNPs. The search of SNPs in the core genome was performed with the help of Wombac 2.0 software. Phylogenetic relations were analyzed using Maximum Likelihood dendrogram, GTR model. Results and discussion. All the studied strains from the foci of Northern, North-Western Caspian Sea region and Fore-Caucasus fall into phylogenetic branch 2. MED1of medieval biovar. On the basis of whole genome SNP-analysis, existence of two groups of closely related strains, comprising the strains dated 1923-1945 and 1962-2003, has been revealed. The predecessors of the 1962-2003 strains from the Northern, North-Western Caspian Sea region and Fore-Caucasus on the phylogenetic tree are the strains from Northern Aral Sea region that go back to 1945. It testifies to the fact that synchronized activation of a group of natural foci in Caspian Sea lowland and Fore-Caucasus in 1975-1979, after prolonged 20-37 year long breaks, could be caused by the dissemination of the strains from the Northern Aral Sea region. The data of epizootic observations indicate that activation of Volga-Ural sandy plague focus in 1960s preceded the start of registration of plague epizooties in the territory of natural foci of souslik type in Northern, North-Western Caspian sea region and Fore-Caucasus.

Objective of this study was the molecular genetic characteristics of uropathogenic strains of Escherichia coli, isolated from urine of patients with urinary tract infections in Saratov City, in order to determine the phylogenetic groups and subgroups to which the strains belong, and to identify the genetic markers associated with virulence. Materials and methods. Molecular genetic characteristics of 102 strains of uropathogenic E. coli which were isolated from urine of patients with urinary tract infections, was performed. PCR was used to determine the frequency of oc-currence of genes (fimH, pap, sfa, afa, iha, irp2, iuc, iroN, hlyA, vat, usp, set-1, kpsMT, iss, cva, ompT) associated with factors of adhesion, iron intake, toxigenicity, resistance to action of serum (complement) and persistence, as well as belonging of studied strains to the specific phylogenetic groups and subgroups (by amplification of genes chuA,yjaA and TspE4.C2). Results and discussion. It was revealed that E. coli strains isolated from patients with urinary tract infections in Saratov city belonged to different phylogenetic groups and subgroups (A₁, B₁, B2₃, D₃ и D₂) and differed in their set of genes, which encode the basic virulence factors. At the same time, detection of uropathogenic E. coli which belong to the B2₃ subgroup was the most frequent. Moreover, the strains of this phylogenetic subgroup differed from others in the largest set of genes which encode virulence factors of the etiological agent. In all studied strains of uropathogenic E. coli which belong to different phylogenetic groups and subgroups the presence of genes responsible for the synthesis of siderophores (irp2, iuc, iroN), resistance and persistency (ompT) and adhesion factors (fimH, iha) was revealed. Therefore, strains of uropathogenic E. coli isolated from patients with urinary tract infections in Saratov city belong to different phylogenetic groups and subgroups and have a different set of genetic markers of virulence that can affect the degree of pathogenicity of the etiological agent, and the course of the disease.

Objective of the study was to construct the recombinant Y. pestis strain producing fluorescent protein GFP and analysis of the prospects of its usage for investigation of interaction of the agent with the protozoa, and also macroorganism of mammals (rodents). Materials and methods. To create the strain producing fluorescent protein GFP, we used the natural Y. pestis strain isolated in 2016 in Gorno-Altai high-mountain plague focus. Fluorescent protein gen was inserted into commercial vector pTurboGFP-B via electroporation. Properties of the obtained recombinant Y. pestis strain 367 pTurboGFP-B were studied using microbiological, biological, and molecular-genetic methods. Results and conclusions. The plague agent strain, containing vector plasmid pTurboGFP-B which encodes synthesis of green fluorescent protein GFP, and being resistant to ampicillin was constructed applying electroporation. The designed Y. pestis strain, producing green fluorescent protein, does not differ from the stock strain by its cultural-morphological, biochemical properties, virulence and survivability in mixed culture with Acanthamoeba castellani. On solid nutrient media, recombinant strain and its subcultures, obtained from infected animals, formed colonies of greenish-yellow color, becoming fluorescent under UV-light. In preparations from animals and from co-cultures with amoeba, fluorescent cells of plague agent were observed. The constructed strain can be utilized as a model one for investigation of interactions between plague agent and cells of protozoa (soil amoeba, nematodes) and mammals under laboratory conditions.

Representatives of the genus Vibrio cholerae differ in the structure of lipopolysaccharide, in particular, its O-polysaccharide chains (O-antigen), which determines the serological specificity of vibrios. Currently, the water-phenolic method is used to obtain the lipopolysaccharide preparation. However, this technique relates to harsh chemical methods, leads to a change in original molecular organization of biopolymer, violating its structure and biological properties. Modern technologies in the development of diagnostic kits for the immunosuspension reaction of volume agglomeration allow for obtaining synthetic carriers with different reaction groups on the particle surface capable to bind antigens/antibodies. The aim of this study was to construct cholera antigenic polymeric diagnostic kit based on the lipopolysaccharide of Vibrio cholerae O1 serogroup. Materials and methods. The lipopolysaccharide was used as a sensitizer obtained through the author's modification of enzymatic purification from the cell membranes of Vibrio cholerae using ultrasonic disintegration. Results and discussion. The resulting sensitin contains small impurities of protein (1.5 %) and nucleic acids (0.1 %). Diagnosticum is characterized by high analytical sensitivity in agglomeration reaction with commercial and experimental rabbit serum to Vibrio cholerae O1 serogroup (1:640 - 1:5120) and analytical specificity (the diagnosticum does not interact with heterologous sera, with serums to pathogens of acute intestinal infections, as well as with sera from healthy donors). A polymeric antigenic cholera diagnosticum designed to detect antibodies to lipopolysaccharide of Vibrio cholerae in the blood serum of patients who were ill, suspected of the disease or vaccinated people has been constructed.

Objective of the work was to conduct tests of disinfectants against pathogens of melioidosis and glanders. Materials and methods. 10 strains of the causative agent of melioidosis, 4 strains of the glanders pathogen, and 5 strains of B. thailandensis were studied. All of them possessed biochemical, morphological, tinctorial, cultural and enzymatic properties typical of the respective species. The following disinfectants were used in the study: alkyldimethylbenzylammonium chloride (Sigma-Aldrich, USA), glutaraldehyde, chloramine B, hydrogen peroxide medical, MD-1 (Medical Disinfection LLC, Russia), CAT-18 (LLC Satellite, Russia), SAT-19 (Satellite LLC, Russia), ODS-15 (Satellite LLC, Russia), Ecotab-Active (Novodez JSC, Russia), Septodez-Forte (Novodez, JSC Russia). As test objects, tiles, ceramics, linoleum, painted wood, lining oilcloth, linen with and without sick discharge, dishes with and without food residues, medical products made of glass, plastic, rubber, silicone and metal were used. The criterion for the activity of the disin¬fectant was the lack of growth of microorganisms on solid and liquid nutrient media. To achieve statistical reliability, all tests were performed three times. Results and discussion. The conducted studies allow us to recommend B. pseudomallei 97 and B. thailandensis 264 as test strains for evaluating the bactericidal activity of new disinfectants in the laboratory against glanders and melioidosis infections. All studied disinfectants have a pronounced activity against glanders and melioidosis pathogens and can be used in concentrations from 0.1 to 2.5 %, for 60 minutes exposure.

Objective of the study was to determine the modem epizootic and epidemic peculiarities of hemorrhagic fever with renal syndrome in the south of the European part of Russia. Materials and methods. Data of statistical documentation (epidemiological survey of the infectious disease focus, annual summary reports dated 2009-2018) and epizootic monitoring data submitted by the Rospotrebnadzor Administrations and the Centers of Hygiene and Epidemiology in the constituent entities of the Southern and the North Caucasian Federal Districts were used. Descriptive, analytical methods and retrospective epidemiological analysis were applied. Results and discussion. The circulation of hantavirus in the Volgograd and Astrakhan Regions, Stavropol and Krasnodar Territories, Republics of Adygeya, Kalmykia and Crimea was confirmed. However, two geographically and genetically isolated groups of hantaviruses circulating in the Volgograd Region and in the mountain-foothill zone of the Krasnodar Territory and the Republic of Adygeya were the most epidemiologically significant. Over the period of 2009-2018, 152 HFRS cases with annual fluctuations from 4 to 25 cases were registered. Almost all patients lived in the Volgograd Region (44 cases), where the incidence is caused by the HFRS-Puumala virus, or in the Krasnodar Territory (98 cases), where the HFRS Hantavirus Dobrava-Ap circulates. In HFRS patients with the HFRS-Dobrava-Ap virus severe clinical forms were noted at twice the rate, a fatal outcome in one patient with HFRS-Puumala was recorded. The correct preliminary diagnosis was made for 56.3 per cent of patients in the Volgograd Region and only for 31.7 per cent of patients in the Krasnodar Territory and in the Republic of Adygeya. There are different types of natural HFRS foci in the European south of Russia, they vary by the type of hosts and hantaviruses circulating in them - Puumala, Dobrava, Tula, and Dobrava-Ap. Natural foci where of HFRS-PUU and HFRS-DOB-Ap viruses circulate have high epidemic potential. Severe forms of the HFRS are more often observed in patients with the HFRS-DOB-Ap virus.

Objective of the work was to conduct an extended study of Legionella strains isolated from epidemiologically significant environmental objects during the preparation and conduct of mass events in the territory of the Russian Federation in 2013-2014 . Materials and methods. Studied were 53 strains of Legionella pneumophila, isolated from epidemiologically significant objects during the preparation and conduct of a number of mass events (ME): XXVII World Summer Universiade, XXII Olympic Winter Games and XI Paralympic Winter Games, Sochi; Summer Health Promotion Campaign in 2014, Republic of Crimea; IV Caspian Summit, Astrakhan, 2014. Strains were analyzed using multilocus sequencing, time-of-flight mass spectrometry (MALDI-ToF-MS) and atomic force microscopy. Legionella strains were typed by multilocus sequencing in accordance with the algorithm of the European Legionellosis Research Group “Sequence-Based Typing protocol for epidemiological typing of L. pneumophila". Results and discussion. Strains of L. pneumophila, legionellosis agent, were isolated in the territory of the Republic of Crimea, Moscow, Kazan, Sochi, Astrakhan and characterized. According to the results of slide agglutination, 17 L. pneumophila strains were assigned to 1 serogroup , 37 - to 2-14 serogroups. Based on the data obtained by multilocus sequencing, in accordance with the algorithm of the European Working Group on Legionellosis Surveillance, allelic profiles of all the studied L. pneumophila strains were identified; their belonging to 7 sequence types was established. Using the method of time-of-flight mass spectrometry, legionella strains were characterized, their protein profiles were studied, and a database was formed. Using the method of scanning probe microscopy, information was obtained on the morphology of the cells of 18 legionella strains and the features of their surface structures. Using the methods of multilocus sequencing, time-of-flight mass spectrometry, and atomic force microscopy, molecular-genetic, proteomic, and morphometric features of Legionellosis pathogen strains that circulate in epidemiologically significant sites in the Russian Federation were determined.

Objective: to determine genospecies composition of Borrelia in the ixodid ticks of various species in natural foci of Ixodes tick-borne borreliosis (ITB) in the South of Western Siberia. Materials and methods. A total of 1148 examples of ticks collected from vegetation and 2183 examples of ticks withdrawn from persons seeking medical help have been tested by bacteriological (sowing in BSK-H medium, SIGMA, USA) and Real Time PCR methods. Genotyping of Borrelia was performed by sequencing. Results and conclusions. Infection of Ixodes ticks with borrelia ranged from 22.4 % in the Altay Republic to 56.9 % in the Novosibirsk Region. Reliable differences in borrelia infection rates of ticks I. persulcatus and I. pavlovskiy have not been established (average levels of infection 40 % and 38.8 %, respectively). The study of isolates of borrelia sp. circulating in natural foci of the West Siberia showed the presence of at least four genospecies of pathogenic borrelia (B. garinii, B. afzelii, B. bavariensis, B. miyamotoi). 30 nucleotide sequences of the rrf (5S)-rrl (23S) intergenic spacer were submitted to GenBank database. The detection rate of genospecies B. garinii and B. afzelii of different types of ticks (I. persulcatus and I. pavlovskiy) has no significant difference. More frequent occurrence of B. garinii in comparison with that of B. afzelii was determined. The level of I. persulcatus ticks infection with B. miyamotoi was significantly lower than that with genospecies B. garanii and B. afzelii. DNA of B. spielmanii and B. miyamotoi was detected in ticks D. reticulatus. Further evaluation of the role of ticks D. reticulatus in the distribution of borrelia in ticks in natural foci of the Russian Federation is necessary.

Objective of the study was the search for proteins of the vaccine strain Yersinia pestis EV NIIEG with potential properties of allergens. Materials and methods. 3256 genomic proteins of Yersinia pestis EV NIIEG strain taken from the GenBank database were analyzed. Protein allergenicity was determined using computer information software. The Allpred program, integrated into the Protein Structure Discovery system, for predicting proteins as allergens, uses not only the primary sequence of amino acids, but also their spatial structure, as well as the physicochemical properties of amino acids. For all potential allergens found, their intracellular localization was additionally determined using the CELLO v.2.5 program: subCELlular Localization predictor and similarity to known human allergens in the AllergenOnline program. Results and discussion. Computer analysis of 3256 proteins revealed 170 (5.22 %) potential allergenic proteins of the vaccine strain Y. pestis EV NIIEG. Of these, 53 (31.18 %) relate to proteins with an unknown function (hypothetical protein), and 16 (9.41 %) relate to membrane proteins (membrane protein). The highest indicator of protein attribution to allergen was 0.824568569477881, and was observed in protein EXU71465.1 (autotransporter). Similarities to known allergens were found in 12 (7.06 %) of the predicted allergenic proteins. Of these, 4 (2.35 %) proteins have analogues with plant allergens, 5 (2.94 %) - with allergens from the animal kingdom, and 3 (1.76 %) - with yeast and mold allergens. The most promising when creating new hypoallergenic vaccines and drugs for diagnosing intensity of immunity in vaccinated individuals the allergen proteins belonging to the group of extracellular ones and outer membrane proteins have been identified. In Yersinia pestis EV NIIEG vaccine strain 38 of these or 22.35 % have been detected.

Human pathogenic hantaviruses, belonging to the family Hantaviridae, genus Orthohantavirus, are disseminated worldwide and cause hemorrhagic fever with renal syndrome (HFRS) in Europe and Asia. In the Far East of Russia Hantaan (HTNV), Amur (AMRV) and Seoul (SEOV) viruses are etiologic agent of HFRS, while the human pathogenic potential of other seven hantaviruses, circulating in this region, has not been researched adequately yet. Objective of the study was genetic identification of hantaviruses, associated with HFRS in the Far East of Russia during 2015-2018. Materials and methods. Blood samples of 64 HFRS patients from Jewish Autonomous Region, Khabarovsk and Primorsky Territories were analyzed for hantavirus RNA using reverse transcription polymerase chain reaction. Results and discussion. A total of 19 viral RNA isolates from HFRS patients were genetically typed. Etiologic agents of HFRS were three pathogenic hantaviruses: HTNV (13 isolates), AMRV (3 isolates), SEOV (3 isolates). Three genetic lineages were identified among HTNV, two lineages among AMRV One genetic variant of SEOV virus was identified among HFRS patients, which was more close to the strains from South-Eastern Asia than to those from the neighboring countries.

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, ery^R.

Objective was to experimentally substantiate the possibility to use the finite cell line CHO-K1 for measuring specific activity of cholera toxin and component of the vaccine choleragen-anatoxin in the process of chemical cholera vaccine manufacturing. Materials and methods. The studies involved the finite cell line CHO-K. The registration of results of bio-indication method was performed visually with the help of inverted microscope and photometrically - in colorimetric test for the assessment of metabolic activity of the cells at the wave length of 595 nm. Results and discussion. The proposed method allows for determining the toxin-production activity of Vibrio cholerae 569B strain during submerged cultivation in bioreactor and specific activity of choleragen-anatoxin by anatoxin binding measuring using cell cultures. The results correlate with the data obtained using intradermal Craig’s technique, GM1-ELISA and radial passive immune hemolysis (RPIH). Introduction of cell culture method into practice will provide for significant decrease in the volumes of usage of animals at the stages of manufacturing of chemical bivalent cholera vaccine.