Background. Development of nutrient media ensuring the maximum growth rate of pathogens of dangerous infectious diseases while preserving their biological properties is extremely important. A promising direction in this area seems to be the use of synthetic microbial growth biostimulants. The aim of the work is to study the possibility of improving nutrient media for the cultivation of Listeria and Staphylococcus using a biologically active compound tris(2-hydroxyethyl)ammonium 4-chlorophenylsulfanylacetate. Materials and methods . The object of the study was experimental nutrient medium for the cultivation of Listeria used for the culturing of the test strain Listeria monocytogenes 766. As a comparison medium, commercial medium Fraser broth to which agar was added at a concentration of 1.5 %, was used. The test strain Staphylococcus aureus ATCC 6538-P (FDA 209-P) was cultivated on meat-peptone agar with 1% glucose. The compound tris(2-hydroxyethyl) ammonium (4-chlorophenyl)sulfanylacetate at a concentration of 10–4 wt. % was studied as a growth stimulator. A nutrient medium without a stimulant served as a control. The specific activity of nutrient media (germination rate, medium sensitivity, growth rate and stability of the main biological properties of microorganisms) was evaluated by the microbiological method. Results . Studies have shown that the addition of a growth stimulator to nutrient media contributes to the growth of colonies (by 10–50 %) and a decrease in the time of their development. When growth stimulator was added to the nutrient medium for the cultivation of Listeria, the initial growth of colonies of the L. monocytogenes 766 test strain after 12 hours of cultivation and growth of colonies of the test strain S. aureus ATCC 6538-P after 6 hours of cultivation on the meat-peptone agar with 1% glucose was observed. Conclusion . Thus, the addition of a growth biostimulator tris(2-hydroxyethyl)ammonium 4-chlorophenylsulfanyl acetate at a concentration of 10–4 wt. % in the nutrient medium accelerates the growth of Listeria and Staphylococcus, allows to reduce the time of issuance of the analysis result in half.

Objective of the study was a complex pheno- and genotypic investigation of Yersinia pestis I-3595 and Y. pestis I-3596 strains, isolated from marmots that were the source of human infection in 2015. Materials and methods. A comprehensive microbiological, molecular-genetic and mass-spectrometric studying of Y. pestis ssp. pestis strains, isolated from two grey marmots that became a cause of the plague case in Gorno-Altai high-mountain focus in 2015, was performed using up-to-date methods. Results and conclusions. It was established that the studied Y. pestis strains belonged to the main subspecies. Results of plasmid screening, multilocus VNTR-and mass-spectrometric analyses showed that those strains were closely related to Y. pestis variant detected in the focus in 2012 and in 2014, and circulating in Northwest Mongolia and Tuva natural focus.

The study ofsampling ofstrains of Y. pestis ofmain and altam subspecies was implemented. The modern technique of identification of microorganisms was applied using MALDI-TOF mass spectrometry analysis. The evaluation of biological safety of method of sampling preparation was implemented. To supplement the identification base “BioTyper” the spectrum of typical strains of Y. pestis were obtained. The enhanced identification base was used to evaluate possibilities of application of MALDI-TOF technology for identification and taxonomic differentiation of Y. pestis from other representatives of genus of Yersinia. In the process of study a complete concordance of results of mass spectrometry identification and classic cultural method was observed. On the basis ofmass spectrometry characteristic of analyzed sampling the differentiation between strains of Y. pestis of subspecies pestis and strains of subspecies altaica was implemented. The study results testify the effectiveness of application of mass spectrometry analysis for reliable interspecies and intraspecific differentiation ofplague agent. The simplicity and velocity of sampling preparation and implementation of analysis and low cost of active storage allow considering the MALDI-TOF technology of mass spectrometry identification as highly perspective method for laboratory diagnostic of plague agent.

The goal of this work was to develop methodological approaches to identification of the Vibrio genus representatives using the MALDITOF mass-spectrometric analysis technologies. The aspects of the biological safety in sample preparations for mass-spectrometric analysis were studied, reference spectra of six typical V. cholerae strains were developed. Identification of 55 strains, representatives of the Vibrio genus, including 45 V. cholerae strains with different epidemic importance, was performed using the MALDI Biotyper 3.0 basis comprising V. cholerae reference spectra. The possibility of reliable definition of the tested strain taxonomic belonging to the species level was demonstrated. Thus, the results completely corresponded to the data of classical microbiological identification. Stability and reproducibility of the offered research method was experimentally shown. The results allow identification of the Vibrio genus representatives to be implemented with the use of the mass-spectrometric analysis as an effective method that defines a species belonging of the basic Vibrio genus representatives in the shortest terms.

AIM:Development of methodological approaches for identification of leptospira by using MALDI-TOF direct protein profiling technology.MATERIALS AND METHODS:Analysis of cell proteins of 34 leptospira strains was carried out in Microflex LT by using "MALDI Biotyper 3.0 for identification and classification of microorganisms" program.RESULTS:19 reference spectra of reference leptospira strains from 7 species were generated and imported into MALDI Biotyper 3.0 database. Identification of 6 strains with undetermined taxonomic position was carried out.CONCLUSION:The approved method allows determination of leptospira species with accuracy that depends on their adaptation to nutrient media, preparation approach and sample storage conditions for mass-spectrometry.

The study of sampling of strains of Y. pestis of main and altaic subspecies was implemented. The modern technique of identification of microorganisms was applied using MALDI-TOF mass spectrometry analysis. The evaluation of biological safety of method of sampling preparation was implemented. To supplement the identification base "BioTyper" the spectrum of typical strains of Y. pestis were obtained. The enhanced identification base was used to evaluate possibilities of application of MALDI-TOF technology for identification and taxonomic differentiation of Y. pestis from other representatives of genus of Yersinia. In the process of study a complete concordance of results of mass spectrometry identification and classic cultural method was observed. On the basis of mass spectrometry characteristic of analyzed sampling the differentiation between strains of Y. pestis of subspecies pestis and strains of subspecies altaica was implemented. The study results testify the effectiveness of application of mass spectrometry analysis for reliable interspecies and intraspecific differentiation of plague agent. The simplicity and velocity of sampling preparation and implementation of analysis and low cost of active storage allow considering the MALDI-TOF technology of mass spectrometry identification as highly perspective method for laboratory diagnostic of plague agent.

The article presents the results of development and practical implementation of system of polymerase chain reaction testing in realtime operation mode to detect agent of plague in field material. In laboratory conditions the system demonstrated good results and hence it was applied in conditions of field laboratory of epidemiologic team during planned epizootologic examination of Gorno-Altaisk hot spot of plague. The sampling consisted of more than 1400 objects. It was demonstrated that high sensitivity and specificity is immanent to proposed system. The adaptation of the system to the real time amplifier Smart Cycler (Cephid, USA) having some specific technical characteristics makes it possible to consider the proposed test-system as an effective sensitive and precise instrument for screening studies in the process of regular epizootologic examinations of hot spots of plague.

The article presents the results of development and practical implementation of system of polymerase chain reaction testing in real-time operation mode to detect agent of plague infield material. In laboratory conditions the system demonstrated good results and hence it was applied in conditions of field laboratory of epidemiologic team during planned epizootologic examination of Gorno-Altaisk hot spot of plague. The sampling consisted of more than 1400 objects. It was demonstrated that high sensitivity and specificity is immanent to proposed system. The adaptation of the system to the real time amplifier "Smart Cycler" (Cephid, USA) having some specific technical characteristics makes it possible to consider the proposed test-system as an effective sensitive and precise instrument for screening studies in the process of regular epizootologic examinations of hot spots of plague.