[The rapid method for differentiating bacteria of Listeria strain].

An integrated indicator medium has been designed to differentiate Listeria bacteria from other microorganisms, which may be used at the first stage of diagnosis of the causative agent of listeriosis. The application of this medium makes it possible to simplify and to accelerate the detection of Listeria in the examination of different samples of foodstuffs, environmental objects, clinical material and to extend the range of Russian indicator culture media for the differentiation of this microorganism.

[Differentiantion of Listeria monocytogenes strains isolated in the Far East and European part of Russia on the basis of polymorphism of genes encoding invasion factors].

Forty Listeria monocytogenes isolates obtained in European and Far East regions of Russia were differentiated on the basis of polymorphism of 5 markergenes. Total length of concatemers obtained after sequencing of internal fragments of genes inlA, inlB, inlC, inlE and prs was 3029 b.p.

Low genetic diversity and epidemiological significance of Listeria monocytogenes isolated from wild animals in the far east of Russia.

The causative agent of listeriosis, a serious disease of humans and animals, Listeria monocytogenes is a ubiquitous bacterium that inhabits both anthropogenic and pristine environments. We report L. monocytogenes isolation from wild animals, humans, food and the environment of a far eastern region of Russia.

[Genes, encoding invasion factors in Listeria monocytogenes strains isolated in the European part and the far east of Russia].

The collection of 76 Listeria monocytogenes strains isolated from humans, animals and food products was screened with PCR to reveal genes, which encode invasion factors of the internalin family. Obtained results demonstrated the correlation between the strain specific polymorphism of the revealed internalin genes and the source of the strain.

[Adaptive ultrastructural changes in soil-resident Yersinia pseudotuberculosis bacteria].

After the prolonged residence (from 1 month to 2 years) in flow soil columns at 6 - 8 degrees C and 18 - 20 degrees C a complex of ultrastructural changes was detected in Y. pseudotuberculosis bacteria, depending on temperature, the duration of residence in the soil and, to a definite extent, on the strain. They were manifested in the form of cell-wall changes, the formation of the capsule and intercellular slime, changes in the ribosomal saturation of cytoplasm and the conformation state of DNA in the nucleoid zone.

[Microbiological characterization of Listeria monocytogenes isolated from different sources in the Primorsky Territory].

The results of the bacteriological study of material, taken from humans, rodents, hydro-bios and environmental objects (including foodstuffs) in the Primorsky Territory, for the presence of L. monocytogenes bacteria are given. 83 bacterial strains of the genus Listeria were isolated.

Effect of temperature on synthesis of polyphosphates in Yersinia pseudotuberculosis and Listeria monocytogenes under starvation conditions.

It was found that at low temperature (6-8 degrees C) in the absence of nitrogen supply and at the presence of phosphate ions in the medium, Yersinia pseudotuberculosis and Listeria monocytogenes are able to actively synthesize reserve substances as polyphosphates. Most of the bacterial polyphosphates are alkali-soluble, especially at the preliminary stage of cell growth (lag-phase). This is proved by electron microscopic studies of ultrastructure of model microorganisms.

[Investigation of relationships between marine diatoms and the bacterium Listeria monocytogenes].

Relationships between marine diatoms and the bacterium Listeria monocytogenes have been studied by routine algological methods and high-resolution video-enhanced differential interference contrast light microscopy. The study showed that the relationship between the listeria and the benthic diatom Navicula sp. has a parasitic character, whereas the relationship between the listeria and the planktonic diatom Phaeodactylum tricornutum is protocooperative.

[Experimental study on impact of salmon milt DNA on T-cellular immunity].

The impact of a biologically active food supplement containing salmon milt DNA on cellular immunity was experimentally studied. It was shown that the DNA had a dose-dependent stimulating effect on lymphocyte transformation, stimulated the DTH response and protected from experimental listeriosis infection.

[Influence of temperature on the variability of Listeria monocytogenes in the course of its prolonged existence in soil-packed water-circulating columns].

The capacity of L. monocytogenes for prolonged existence in the soil at different temperatures (18-20 degrees C and 6-8 degrees C) has been shown. The viability of these bacteria in the soil depends both on their properties and the temperature factor.

Adaptation variability of Yersinia pseudotuberculosis during long-term persistence in soil.

Adaptation changes in the morphological and biological characteristics of pathogenic Yersinia pseudotuberculosis inhabiting a model soil ecosystem for a long time were studied. Changes in cultural, biochemical, and morphological characteristics of Yersinia and a decrease or loss of virulence were observed under these conditions. The detected changes were phenotypical, i.

[Effect of cultivation temperature on nucleic acid level in bacteria Listeria monocytogenes and Yersinia pseudotuberculosis].

The relationship between the multiplication of bacteria, the content of nucleic acid and the specific rate of their growth during their batch cultivation in nutrient broth and mineral medium at temperatures of 37 degrees C and 4-6 degrees C was studied in the causative agents of saprozoonotic infections with L. monocytogenes and Y. pseudotuberculosis used as typical representatives of such bacteria.

Ultrastructure of Yersinia pseudotuberculosis inhabiting the soil for a long time.

Ultrastructural changes in the population of pathogenic Yersinia pseudotuberculosis inhabiting a model soil ecosystem for a long time were studied. Changes in the bacteria were mainly adaptive until the 8th month of the experiment, their capacity to binary division was preserved. After 9 months cell structure changed: extracellular amorphous matrix appeared, probably due to increased mucus production.

[Epidemiological hazards of low-temperature food storage].

Refrigerator food storage lose its preventive value. This is particularly associated with the specific features of the pathogens of saprozoonosis which can easily adapt to low temperatures and feed deficit. Pseudotuberculosis agents were used to show that saprozoonosis pathogens can live and feed in a warm-blood being and in the environment.

[The biochemical mechanisms of energy support in Yersinia pseudotuberculosis cells at a low cultivation temperature].

The object of the study was the first stage of biological oxidation: the transfer of hydrogen electrons to the components of the respiratory chain of Y. pseudotuberculosis cells by NAD and NADF, coenzymes of pyridine-dependent dehydrogenases, having labile redox properties. The study revealed that in the low-temperature cultivation of Y.

Autotrophic assimilation of CO2 and C1-compounds by pathogenic bacteria.

We demonstrate for the first time that the pathogenic bacteria Yersinia pseudotuberculosis and Listeria monocytogenes (pathogens of saprozoonoses) are capable of chemolithoautotrophic assimilation of CO2. Low temperature is favorable for better absorption of CO2 by these bacteria; this is supported by increased enzymatic activity of carbonic anhydrase acting as the supplier of the substrate to the site of carboxylation. Data of radioisotopic methods indicate that assimilated labeled carbon of CO2 is incorporated into all major cell biopolymers.

[The diagnostic value of the polymerase chain reaction in tuberculosis].

The comparative study of material obtained from tuberculosis patients in the Vladivostok Tuberculosis Dispensary was carried out with the use of polymerase chain reaction (PCR), the bacterioscopic and bacteriological methods. The study was made on different groups of tuberculosis patients (in the phase of the active course of the disease and after convalescence), patients with nonspecific pulmonary diseases and persons having contacts with tuberculosis patients. The study revealed that PCR was 2-3 times more effective than the other above-mentioned methods and made it possible to obtain results as early as 3-5 days after material was taken.

[The ecological aspects of listeriosis in the Maritime Territory].

In the process of batch cultivation the strains under study are capable of prolonged growth at low temperature in rich and poor nutrient media (with the term of observation equal to 4 months), while at a temperature of 37 degrees C microbial populations quickly die (in 8-35 days). In the absence of compounds containing carbon, hydrogen and nitrogen in the nutrient medium, Listeria can proliferate under such conditions. As established with the use of gas chromatography and the radioisotopic method, they can uptake carbon dioxide, hydrogen and nitrogen from the air gas mixture, using carbon of the first gas for the synthesis of the main biopolymers (proteins, lipids, carbohydrates, DNA and RNA) and the second one as the source of energy.

[The gas trophicity of pathogenic bacteria].

Yersinia pseudotuberculosis and Listeria have been shown to be capable of assimilating carbon dioxide from the air and using its carbon for the synthesis of biopolymers of the bacterial cell. These microorganisms, the causative agents of saprozoonotic infections, have also been found to be capable of assimilating molecular nitrogen from the air in small amounts. The data on the influence of the growth conditions of the cultures (hydrogen concentration, the presence of carbon dioxide and oxygen, temperature) on the activity of acetylene reduction by microbial cells.

[The biochemical characteristics of the products of the vital activity of Yersinia pseudotuberculosis in relation to the cultivation temperature].

For the first time the metabolic processes, taking place during "cold" cultivation of Y. pseudotuberculosis and involving organic and amino acids, were shown to be more economical, thus permitting the bacteria to maintain its viability for a rather long time at low temperature without the need to consume these substances from outside. At higher temperature the bacteria switches its metabolic paths to the consumption of nutrient substances in greater amounts from outside, increasing its constructive metabolism.