The review presents data on the antigenic structure and the current classification of epidemically significant serovariants of Listeria. Description of species-specific properties of serovariants of Listeria, which may be common for two or more species, and common antigens with staphylococci and typhoid and paratyphoid bacteria, are given. It has been shown that only the antigenic scheme of Listeria monocytogenes is of practical interest for medical microbiology. Importance of serotyping in the epidemiological analysis to determine the source of infections and ways of its spreading has been determined. Differences in the designation of serovariants in the diagnosis of listeriosis in medical practice are observed. High level of adaptive properties of Listeria, its ability to reproduce in an abiotic environment, including food, susceptibility of immunodeficient individuals, prevalence of food pathway of infection pose a significant danger of increased sickness rate with listeriosis. Serological diagnostics of Listeria has not been developed in detail, and the existing serological methods are aimed at identifying specific antibodies to listeria. Advantages of the serological method include: quick results and the possibility to study any biological material. Currently available serological methods have a number of disadvantages: low reliability of results and low specificity of the study. The most promising method for identification of a serological group of cultures, according to the world classification, is the multiplex PCR method, based on the correlation between the serogroup of an isolate and the presence of specific open reading frames in its genome.

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.

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Background. To obtain reliable results of laboratory studies on the identification of Listeria, the presence of certified diagnostic agglutinating Listeria sera is required. An important step in the manufacturing process of such medical devices for in vitro diagnostics requires effective nutrient media for the accumulation of listeriosis microbe. Aim of the research. To develop an effective nutrient medium for the accumulation of bacterial mass of Listeria. Materials and methods. The object of the study was an experimental culture medium for Listeria cultivation. As a control, we used nutrient agar for the cultivation of microorganisms (fish meal hydrolysate, FMH-agar) and meat-peptone agar with 1 % glucose (MPA with 1 % glucose). The specific activity of nutrient media during cultivation of the test strain Listeria monocytogenes 766 was evaluated using a complex of microbiological methods. Results. The optimal base of the nutrient medium for Listeria cultivation has been selected: pancreatic hydrolysate of river magpie fish (Rutilus rutilus lacustris) and hydrolysate of meat water production waste. The qualitative and quantitative composition of the nutrient medium has been developed, its physical, chemical and biological properties have been studied. It was found that after 24 hours of incubation at 37 °C, the nutrient medium provided the growth of typical Listeria colonies. The germination rate was 85 %, which is higher compared to the growth of the culture on MPA with 1 % glucose and GRM agar by an average of 21 % (p < 0,05). Conclusion. The experimental culture medium for Listeria cultivation provided growth of colonies of the test strain L. monocytogenes 766 with the preservation of characteristic cultural, morphological and biochemical properties, and, in terms of germination and growth rate, exceeded the control media. The developed nutrient medium provides effective growth of Listeria and can be used as a medium for the accumulation of microbial mass.