Questions discussed in this work concern the problem of emerging and re-emerging infections, in particular smallpox and avian flu caused by highly virulent strain H5N1. Data presented evidence the real threat that emerging and re-emerging infections pose to public health and the necessity to carry out fundamental investigations in this direction at national and international levels.

Represented are the results of analysis of epizootic and epidemic situation with tularemia in the Russian Federation for 15 years (1992-2006) based on the data of Plague-Control Center. Brief analysis of epidemic situation in 2005 is presented separately.

The role of birds in the circulation of the virus of Congo-Crimean hemorrhagic fever (CCHF) is described in the paper. Investigation of 758 samples of birds revealed the virus CCHF antigen to be present in 19 (2.51 % ± 0.57) rooks' samples. Corvidae were shown to be a full-fledged co-member of the Crimean hemorrhagic fever (CHL) natural foci in the territory of Rostov Region. Epidemiologic significance of this bird family consists in dissemination of the CCHL virus, expansion of the existing natural CHL foci, and thereby supporting the formation of new ones. Ecologic and epizootiologic role of Corvidae should be taken into consideration while conducting epidemiologic surveillance in HCL natural foci.

Within the frames of an analytical review, modern approaches are described whose development is considered to be very important in order to rationally operate secure working procedures at the facilities of medical and biological profile. Peculiarities of formulating the methods to assess biological hazards are analyzed together with the ways of their objectivization. The place and the role of biological safety as a scientific trend are discussed in relation with the problem of availability of practical application of the "risk theory" elements with the aim of making governing decisions based on complex, well established estimations. The architecture of the system of modeling and estimation of potential danger associated with handling pathogenic biological agents is enunciated.

Using polymerase chain reaction with reverse transcription (RT-PCR) rRNA tick-borne borreliosis (Lyme borreliosis) etiological agent was detected in suspensions of ticks Ixodes ricinus. Infection rate was 7.1 %. Morbidity increase and substantially high level of Lyme borreliosis seroprevalence in the population of this region (3.9 %) evidence that Borrelia circulate in the territory of Stavropol region and ticks I. ricinus are vectors and the reservoir of the disease in this area. Monitoring of ixodes ticks quantity and their examination for carriage of Lyme borreliosis etiological agent will give the opportunity to forecast the possibility of infectioning people, living in enzootic territory.

A retrospective epidemiologic analysis of leptospiroses for the period from 2001 to 2006 revealed the most intensive morbidity in the Southern, Central and Volga Districts with their mean intensive indices being 1.7+0.3, 1.0+0.3, 0.8+0.4, their respective portions of the total sickness rate for Russia constituting 31.5, 27.6, 25.5 percent respectively. A tendency to decreased leptospiroses morbidity was observed in all seven federal districts and in the Russian Federation as a whole.

Cellular morphologic variations of Yersinia pseudotuberculosis strain 164/84 were assessed depending on the cultivation temperature and the plague agent's fra-operon carriage by these cells. Notably slower population growth of the two isogenic variants of strain 164/84 (fra⁺ and fra^-) was observed at the cultivation temperatures of 4 to 6 °C as compared with those at 26-28 °C and 36-38 °C. Only late growth stages at the temperatures of 36 to 38 °C brought about significant differences between the fra⁺ and fra^- cell variants expressed in the occurrence of relatively bigger cells in the population of the capsule forming Y. pseudotuberculosis variant.

Comparative electrophoretic investigation was carried out to study antioxidative enzymes (superoxide dismutase, catalase and peroxidase) in strains of Yersinia pestis, Yersinia pseudotuberculosis, Escherichia coli and Salmonella typhimurium. It was shown that Yersinia antioxidative enzymes are different from E. coli and S. typhimurium enzymes in electrophoretic motility. Their expression depends on cultivation temperature and plasmid content. Peculiarities of catalase-peroxidase expression were determined in strains of plague etiological agent of Ulegei subspecies, in strains of pseudotuberculosis etiological agent of IV serovar and in strains isolated from humans.

Examined were phenotypic peculiarities of mutants of Burkholderia phylogenetically-related pathogenic species (B. pseudomallei, B. mallei, B. cepacia) resistant to fluoroquinolones and cephalosporins. It was shown that strains with Pfx^R (Ofx^R), Cfz^R markers acquire high multi-drug resistance to antibiotics of different classes. Strain resistance changes under blocking influence of verapamil - inhibitor of calcium membrane channels. Mutant strains differ in production of extracellular enzymes (proteases, lecithinase, lipase) and virulence.

New data on stimulating effect of serotonin biogenic amine on the growth of plague microbe were obtained. A new method for Yersinia pestis isolation from material under consideration, contaminated with concomitant microflora, including environmental objects, by means of bacteriologic method was worked out using serotonin. This method allows reducing the periods of biological accumulation of plague etiological agent down to 24 hours, and increasing the number of colony-forming units (CFU) of plague microbe. Serotonin inhibitory effect to the synthesis of polypeptide with molecular mass of 22 kD was recognized in conditions of cultivating on Hottinger's agar (pH 7.2) at 28 °C during 24 hours.

For the first time specific Ig was obtained from blood plasma of donors immunized by combined anthrax vaccine. This Ig conforms to quality standards for intravenous immunoglobulins and includes antibodies to Bacillus anthracis protective antigen in titer 1:1600 - 1:3200. Therapeutic and prophylactic efficacy of experimental-production series of preparation was demonstrated in experiments with animals.

Influence of nanoparticles of colloid gold (CG) and silver (CS) on immunobiological properties of antigens and possibility of their application as adjuvants for antibody formation stimulation were studied. It was shown that F1 capsule antigen of plague microbe conjugated with nanoparticles of CG and CS possesses more strongly expressed immunogenic properties than original F1 antigen independently of the way of injection. Gold and silver sols with antigens are stable, capable to stimulate specific antibody generation subject to less antigen burden, comfortable for use, do not cause general and local reactions. All these facts give the opportunity to use them in immunologic practice as adjuvants when engineering immunobiological preparations.

Immunochromatographic analysis with luminescent detection for indication of bacteria, viruses and toxins and apparatus for its carrying out were developed. The suggested approach is several times more sensitive as regards microorganisms and toxins detection than the traditional immunochromatographic analysis which is based on the reaction of antibodies marked by colloid gold. The set for immunochromatographic luminescent analysis (SIL-1) was offered on the basis of this elaboration. It can be considered as technical instrument for express analysis of environmental samples, for indication of biological affecting agents in case of emergency situations (terrorist attacks on transport and in populated area), for screening of mail, or facilitation of biopathogen identification after the stage of biological enrichment of selected samples.

Health of the population living in the cities of Rostov region was studied to detect priority non-infectious diseases really influencing the characteristics of general disease incidence of the population. These findings allow to correct therapeutic and prophylactic measures in pre-admission stage, to work out and take administrative decisions aimed at detection and treatment of patients with stated pathologies in pre-admission stage and prophylaxis among people included in risk groups.