This paper represents a review of the current literature data concerning general principles of bacterial biofilm formation, stages of biofilm production and its structural and functional organization, as well as the data concerning involvement of different enzyme systems with the process of biofilm functioning. Carried out is the analysis of the data on the peculiarities of biofilm formation by pathogenic Y. pestis, Y. pseudotuberculosis, and Y. enterocolitica. Displayed are the data on the role of hmsHFRS-operon genes, located in pigmentation chromosomal region of Y. pestis, in the process of biofilm structure formation, and the data on its regulation by hmsP and hmsT genes. Summarized are the results of the recent years' investigations devoted to the genetic determinancy of the plague agent biofilm formation processes, and in particular to the involvement of genes encoding synthesis of lipopolysaccharide (waaA, yrbH and gmhA) and polyamines (speA and speC), as well as rcsA and phoP-phoQ regulatory genes with biofilm formation procedures. Represented are the results of our own investigations concerning the studies of peculiarities of biofilm formation by plague agent strains of different subspecies on the abiotic surfaces and on the nematode model - Caenorhabditis elegans. Discussed is the role of the biofilm in the complex life span of the plague agent. Noted is biofilm significance not only for facilitation in plague transmission by fleas, but also for Y. pestis preservation in the environment, out of the organism of a warm-blooded host.

According to modern views, protection of an organism from different pathogens is achieved through functioning of the two chains of immune system - innate and acquired ones. Initially, receptors of non-specific immunity, including Toll-like receptors, identify conservative pathogen-associated molecular structures. The subsequent activation of signaling pathways leads to rapid neutralization and elimination of foreign agent. Concurrently, initiation of the adaptive immunity, and realization of pro-inflammatory reactions' cascade take place. The review summarizes literature data concerning peculiarities of innate and adaptive types of immunity in case of interaction between macro-organism and Bacillus anthracis. Protective antigen, lipoprotein, cell wall components, anthrolysine O, CpG DNA sequence and others are the potential ligands of Toll-like receptors in B. anthracis. Demonstrated are the results of experiments that bear evidence of the fact, that synthetic agonists of Toll-like receptors influence realization of B. anthracis cytotoxicity and course of infection in laboratory animals. Modificators of Toll-like receptor functions can be used as immunostimulators for designing of effective means of anti-infectious protection. Innate and adaptive components of the immunity, having their own unique mechanisms of the specific B. anthracis identification, interact with each other, strengthen and complement each other.

This analytical review is devoted to matters of human melioidosis serodiagnostics and prospects of its development and enhancement. Materials of the publications cited reflect particular significance of the specific antibody detection, for both the early and retrospective diagnostics of human melioidosis, as well as for the correct treatment of patients.
Summarized are the data on modern approaches to the selection of serodiagnostics methods in the endemic and non-endemic areas, on the advantages and limitations of the most widely applicable methods for the specific antibody detection (indirect hemagglutination test and solid-phase ELISA). In recent years, development of commercially available enzyme-linked test systems for the detection of antibodies to human melioidosis agent has become an object of intense interest, as this will provide for solid-phase ELISA implementation into the laboratory practice for early detection of melioidosis cases in humans.

Analysis of the long-term data made it possible to identify three periods of epizootic activity of the Central Caucasian high-mountain natural plague focus against the background of the overall downward trend. In the third period (2000-2010) the focus was shown to be under the intense negative influence of natural and anthropogenic factors that stipulated its depression. The natural factors were weather conditions unfavorable for life-sustaining activity of mountain ground-squirrels, the main plague carriers in this focus. Anthropogenic pressure over the focus manifested as follows. The quantity of cattle decreased, that resulted in decrease of territories of the mountain pasturelands, the natural habitats of mountain ground-squirrels. As areas suitable for life-sustaining activity of the mountain ground-squirrel populations reduced, the number of their settlements declined. With account taken for the effect of the anthropogenic influence stated above, short-term and medium-term prognoses of epizootic activity of Central Caucasian high-mountain natural plague focus indicate of rare non-intensive epizooties.

Among main factors that influence intensity of tick-borne encephalitis foci one can distinguish the numbers of core vector (here, taiga tick Ixodes persulcatus) and the percentage of infected ticks. This paper shows the results of five-year monitoring of the tick-borne encephalitis focus, which is situated near Irkutsk city. Detected are the variations in numbers and infestation of the core vector of tick-borne encephalitis, both spatial and temporal. Cause-effect connection between these factors and human TBE morbidity is not found. However, morbidity rates of the Irkutsk population, observed on the annual basis, bear evidence of high activity and intensity of the foci. In this regard, a number of preventive measures is put forward, but further observations concerning all the parameters that influence foci activity are required.

This paper describes the outbreak of West Nile fever in the Rostov Region in 2010 and evaluates its ecological and epidemiological peculiarities. From 15^th of July till 22^nd of September 2010, detected were the 64 cases (1, 480_0/0000) of the disease, which were characterized by vector-born mechanism of transmission. Peak of morbidity coincided with mass breeding of Culicidae, increase in the number of Culex mosquitoes, and reoccurring growth of Aedes mosquito population. Diffuse type of the epidemiological process, higher rates of the cases among urbanites, infected in the country-side area, were the characteristic features of that outbreak. West Nile virus antigen was detected by means of IFA in samples taken from An. maculipennis and Cx. pipiens mosquitoes, wild and synanthropic birds, Rh. rossicus ticks, house and wood mice, which facilitates identification of the core factors for the agent circulation and West Nile fever natural focus formation.

Presented are the literature data on the efficiency of bacteria preservation at temperatures ranging from -20 to -196 °C in the protective media containing such cryoprotectors as glycerol, dimethyl sulfoxide, carbo-hydrates, substances of protein origin specified by regulatory guidelines. Most of the focus is on the publications reporting the results of the long-term bacteria preservation at sub-zero temperatures, optimization of the protective media for pathogenic bacteria, and usage of the compounds with potential cryoprotective activity. Noted is the necessity for approbation of the specified protective media for the conserved bacteria species at the applied preserving temperatures. One of the approaches to the enhancement of the low-temperature preservation techniques is a search for natural protectors, which can provide for surviving of bacteria in the unfavorable conditions, including low temperatures, and a search for possibility to integrate these natural protectors into the cryoprotective media. Displayed are the results of effective application of glycerol-betaine, and polysaccharides of Arctic microorganisms for the low-temperature bacteria preservation.

Displayed are the results of studies concerning adhesion of spores of Bacillus anthracis vaccine strains to the erythrocytes of humans and other mammals using photocolorimetry technique. Determined are the differences in adhesive capacity of spores of B. anthracis vaccine strains № 55 VNIIVVM, STI-I and II Tsenkovsky. Discovered is the fact that the level of adhesive activity of B. anthracis № 55 VNIIVVM spores to the mammalian erythrocytes depends upon the sensitivity of the species to the anthrax agent.

Determined is the complete genome sequence of Kolarovo-2008 strain (Siberia subtype) of Tick-borne encephalitis virus (TBEV), isolated from a tick in the suburbs of the Tomsk city. Nucleotide sequence analysis testifies of the fact that the level of genetic differences within the Siberian subtype of TBEV amounts to 10 % of the nucleotide sequence and to 7 % of amino-acid sequence for certain virus genes. 3'-HTO of the genome of Siberian subtype has the highest rate of variability and the homology level ranging from 65 to 97 %. Kolarovo-2008 and Vasilchenko (isolated in Novosibirsk in 1969) strains have the highest level of genome homology. The level of dissimilarity between the two Tomsk strains is substantially higher: the total number of amino-acid substitutions in Tomsk Zausaev and Kolarovo-2008 strains equals to 124, and 3'HTO level of homology is 79 %. Identified genetic variability of the Siberian subtype of TBEV is of a great importance for further development and enhancement of tick-borne encephalitis virus diagnostics.

Worked out is the multilocus PCR test-system which makes it possible to identify Vibrio cholerae O1 strains on the basis of rfb gene detection, to determine their biovar - either Classical or El Tor by testing cas3 or rtxC genes respectively, and at the same time to differentiate them into typical (which carry ctxB^Eltor gene) and genetically altered (which carry ctxB^Class gene) variants. Efficacy and specificity of the test-system is demonstrated by the analysis of 64 natural V. cholerae strains of various serogroups and biovars, and 13 strains of enterobacteria and other species of Vibrio genus. Relation of the studied V. cholerae El Tor isolates to the typical or altered vibrio variants is proved out by ctxB gene sequencing.

The usage of modern gene engineering methods makes it possible not only to identify anthrax strains isolated from soil, but also to hold out comparative molecular genetic assays with these strains. Carried out was the laboratory research of 80 soil samples isolated from the old animal burial site using microbiological and genetic techniques. Epidemiological significance of the isolated strains was evaluated on the basis of the results of PCR with species-specific primers and multi-locus VNTR-analysis data. Extracted were the six strains, three of which were classified as B. anthracis, and the rest - as closely related bacillus. Demonstrated was the possibility to use this particular complex method for anthrax strains typing and their differentiation from closely related microorganisms.

Presented are the results of investigation of therapeutic effectiveness of liposomal and suspension forms of immunoglobulins, prepared on the basis of 10 % goat immunoglobulin against Ebola fever. The most pronounced therapeutic and preventive effect on guinea pigs with experimental Ebola fever was achieved by double administration of suspended immunoglobulin against Ebola fever. The incubation period increased twofold, 37,5 % of infected animals survived. The results achieved are perspective for further development of new immunoglobulin preparations on the basis of liposomes and nanoemulsions.

Developed is the highly sensitive and specific immuno-enzyme test-system, which is perspective for the detection of L. pneumophilia, serogroup 1. Isolated are the three hybrid cell lines that secrete monoclonal antibodies to specific epitopes of L. pneumophilia, serogroup 1 lipopolysaccharide antigen. Hyper immune rabbit sera, characterized by highly specific activity and specificity, are obtained using lipopolysaccharide antigen.

Deletion of recA gene in Francisella tularensis 15/10 genome leads to the increase in its sensitivity to ultraviolet irradiation, reduction of the homologous recombination capacity, and a slight decline of virulence for mice. Efficacy of Francisella tularensis 15/10ΔrecA reproduction within microphage-like cells, its resistance to normal rabbit serum, and protective properties on the mouse model of tularemia are the same as in original Francisella tularensis 15/10.

Presented are the results of B. anthracis molecular typing of in the scope of work of the Reference center for the anthrax agent monitoring. Summarized is the experience of genotyping application in epidemiological investigation of anthrax outbreaks. MLVA-genotyping (8-25 VNTR-loci analysis) of B. anthracis strains, isolated in Russia and in neighboring regions is shown to provide the correct comparison of genotypes with the data of the global MLVA-data bank. The major tasks of reference center for the development of approaches to B. anthracis genotyping are identified. These approaches include research of additional genotyping methods such as SNP analysis, SNR analysis with assessment of the described loci variability and identification of new polymorphic regions.

Immobilization of anti-B. anthracis monoclonal antibodies (MAbs) on latex microparticles was studied, the optimal load of these MAbs was determined to be 20 µg for 50 µl of the stock latex suspension. The highest sensitivity of latex agglutination test was observed for 1E6 MAbs. Latex suspensions with immobilized MAbs were lyophilized. Their sensitivity and specificity were shown to be highly competitive with those of the stock liquid latex suspension. Latex diagnosticum for Bacillus anthracis spores detection was constructed on the basis of these lyophilized reagents, developed and approved was the regulatory documentation that included their application instructions and technical specifications. Carried out were inter-laboratory and commission tests of experimental prototypes of the designed latex diagnosticum. These preparations demonstrated high sensitivity (from 1·10⁵ to 2·10⁶ spores/ml and even more) and specificity (absence of cross-reactions with spores of different species of sporogenous bacilli at concentration of 10⁸ spores/ml).

This paper reviews basic modern trends in obtainment of anti-rabies immunoglobulin with enhanced properties. One of these trends is associated with the substitution of organ-tissue antigen by cultural antigen at the stage of producer immunization. Analyzed are the results of research connected with the use of the cell-cultures grown Rabies virus in production of heterologous anti-rabies immunoglobulin. The study testifies of applicability of the transferred Vero cell culture as a substrate for rabies antigen preparation. In addition to this, specified are the advantages of the rabies cultural antigen usage over the organ-tissue one at the stage of hyper-immune serum production.

Presented is a comprehensive approach to utilization of the wastes that appear in the process of heterologous anti-rabies immunoglobulin production (packed red cells, fibrin, and alcohol-containing products). Specific immunoglobulin is extracted from the surface of red blood cells using desorption technique. Additional yields of immunoglobulin after exposure of erythrocytes to non-ionic detergent amount to 10-19 % of the output. Rich protein supplement feeding for horses-producers is obtained from spray-dried packed red cells. Solid nutritious substrate for microbiological media production is obtained from fibrin using enzymic hydrolysis method. The efficiency of the fibrin hydrolysate-based media is 1.5-2 times higher in comparison with that of the media based on the digest of meat and casein, as demonstrated by the results of Vibrio cholerae scaled cultivation. Furthermore, worked out is the technology of ethanol regeneration after the rivanol-ethanolic precipitation of gamma globulin, alcohol content by volume being (93±1) % after the regeneration. It is demonstrated that the regenerated alcohol can be used as a precipitator in the process of anti-rabies serum fractioning. All in all, the developed techniques make it possible to utilize the wastes of anti-rabies immunoglobulin production and provide for further use of derivatives while producing medical immunobiological preparations.

Carried out is the analysis of 217 cases of cutaneous anthrax. Displayed are the results of investigation of peculiarities of anthrax clinical progression and epidemic manifestations in the South of Kyrgyz Republic.

The aim of the study is to assess how successfully the trainees obtain skills of post mortem examination of laboratory animals, with strict observance of the rules of safe work with pathogenic biological agents of I-II groups, during their training at professional retraining courses. Individual continuous chronometry is offered as the assessment method. The obtained results can be used for planning of practical training, drafting the time-table, standardization of work of instructors.

Presented are data on investigation of protective properties of free and liposome-entrapped forms of gentamicin against aerogenic infection caused by melioidosis agent. Comparative study identified that immobilization of gentamicin into liposomes increased substantially the ED₅₀ of the preparation. This, probably, can be related to higher sorbtion of liposomal preparation by parenchymal organs including lungs.

Presented is a historical essay on the work of one of the oldest Russian anti-plague institutions - Astrakhan Plague Control Station. Noted is the fact that specialists of this institution made a substantial contribution to the development of the theory of plague natural focality and other contagious infections, as well as to the provision for and implementation of measures for epidemiological surveillance and prophylaxis of plague and other particularly dangerous infectious diseases in the territory of the North-West Caspian sea region.