1.5.11 Микробиология

The oral cavity constitutes a complex, highly dynamic microbial ecosystem, and dysbiosis within this ecosystem plays a key role in the development of dental caries, which is primarily associated with Streptococcus mutans, S. sobrinus and Candida albicans. A promising approach to modulating the oral microbiome is the development of metabiotics based on oral lactobacilli, whose functional properties can be modified using sublethal ozone-induced stress. The aim of this study is to investigate the effect of low-dose ozone-induced oxidative stress on the adhesive and antagonistic activity of oral isolates of Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus. The strains were subjected to ozonation across a wide range of doses (0.000012–0.001440 mg/L). Adhesive activity, assessed using the Brillis method, exhibited a classic hormesis curve with maximum values at a dose of 0.000060 mg/L (at 25 seconds of exposure). The increase in the adhesion index was 13–14%, in the mean adhesion value 13%, and in the adhesion coefficient 6%. However, these changes did not reach statistical significance (p > 0.05) compared with the non-ozonised control and fell within the natural variability of the method. Antagonistic activity at optimal sublethal doses (0.000048–0.000060 mg/L) increased moderately compared with the control: inhibition zones increased by 1.9–3.3 mm depending on the test culture (S. mutans, S. sobrinus, C. albicans). The effect was strain-specific: L. plantarum exhibited greater activity against C. albicans, whilst L. rhamnosus was more active against cariogenic streptococci. The results obtained suggest that low-dose ozonation preserves the high level of adhesive activity of oral lactobacilli and moderately enhances their antagonistic potential.

The growth capacity of three hydrocarbon-oxidizing bacterial strains isolated from oil-contaminated soils in the southern Primorsky Krai was studied at various temperatures (5, 22, and 37˚C) and NaCl concentrations (10, 27.5, 35, and 40 g/L). Rhodococcus sp. 1A remained viable across the entire temperature range at a NaCl concentration of 35 g/L, Rhodococcus sp. 3B at 27.5 g/L, and Pseudomonas sp. 25 at 40 g/L. All bacterial strains demonstrated the ability to oxidize oil at concentrations of 1–5 %. At a concentration of 1 %, the degree of degradation ranged from 55.33–71.23 %, while at the maximum oil concentration (5 %), the oxidizing capacity decreased to 26.11–38.23 %. Biosafety testing revealed that all bacterial strains tested exhibited weak adhesion and lacked plasmacoagulase, fibrinolytic, and lecithinase activity. Hemolytic activity was detected only in Rhodococcus sp. 1A. Rhodococcus sp. 1A was resistant to 7 of 14 antibiotics, while Rhodococcus sp. 3B and Pseudomonas sp. 25 were resistant to 3 antibiotics.

The conducted study of prokaryotic communities of soil-like bodies (soloids) of caves in Vietnam allowed us to identify their microbiological specifics and significant differences from typical zonal soils. The total bacterial abundance, actinomycete mycelium length, and prokaryotic biomass in the investigated soloids were substantially lower than in soils, correlating with total organic carbon content under conditions of limited organic matter input from the external environment. The soloid microbiomes exhibited high taxonomic diversity dominated by the phyla Actinomycetota and Pseudomonadota. The highest bacterial abundance and diversity were recorded in the Thanvan Cave soloids, likely associated with a relatively high total carbon content. The phylum Actinomycetota showed the greatest genus-level richness, reflecting its resistance to diverse environmental stress factors, while for other phyla, genus abundance was an order of magnitude lower. Ecological indices (Shannon and Simpson) confirmed the highest α-diversity in the Thanvan Cave prokaryotic community. A comparison of microbiomes using the Bray–Curtis similarity metric and PCoA analysis revealed a distinct composition of the Pygmy Cave community and a pronounced similarity between all soloid microbiomes and leaf litter microbial assemblages, suggesting microbial input from the surface by air and water currents. The cluster analysis revealed the division of microbial communities into three groups reflecting the characteristics of their ecotopes. The obtained data on the high phylogenetic diversity and taxonomic richness of the cultivated bacterial complexes of soloids demonstrate their possible role as a prokaryotic depository and a potential source of biotechnologically valuable strains.

Today, probiotic drugs are widely used for therapeutic purposes as treatment and restoration of gastrointestinal health, as well as in cosmetics and food industries. The popularity of probiotics, in turn, stimulates large-scale research aimed at identifying potential risks, unique properties and confirming positive effects of probiotic strains of microorganisms on human and animal body. In this work, content of 10 antibiotic resistance genes (ARG) in 10 probiotic drugs belonging to different generations was quantified. Our study revealed a significant ARGS diversity in the studied drugs, which indicates the risk of ARGS horizontal transfer from probiotic bacteria to pathogenic microflora. The abundance of ARG copies in the samples decreased in the following order: vanB > blaCTX-M > mphA > sul2 > blaVIM-1 > vanA > tetO > aadA2 > mecA > ermB. The analysis of ARG genes frequency revealed the predominance of genes that determine resistance to streptomycin (aadA2), tetracyclines (tetO), macrolides (ermB), as well as β-lactam antibiotics (blaVIM-1). In contrast, the mphA (macrolide resistance) and mecA (methicillin resistance) genes were the least frequent, detected in 60% of the tested probiotics. The listed ARGs were present in all studied probiotic preparations. Widespread availability of over-the-counter probiotics-used across multiple industries-raises concerns about potential risks linked to uncontrolled effects on human and animal microbiota.

The increasing number of nicotine-addicted Russians who smoke vapes has become one of the problems of the modern world. There is an urgent question about whether smoking electronic cigarettes (vaping) is a safe alternative to traditional cigarette smoking. In this study, genotoxicity and pro-oxidant properties of 8 liquids for electronic nicotine delivery systems (ENDS) with different characteristics, aerosols of these liquids, as well as their components (propylene glycol and glycerin) have been studied. Biotesting of the studied substances was carried out using a battery of whole-cell bacterial lux biosensors. Among all the studied toxic effects, DNA damage was most often recorded, and the induction of oxidative stress by peroxides was the least frequent. No connection was found between the number of toxic effects and the nicotine content in liquids. However, it is likely that a connection exists with the flavors of liquids, which may be due to insufficient quality control of the flavoring materials included in their composition. The most toxic liquids selected for this study turned out to be sweet (Tropical, Cactus and Strawberry, Pepsi, Pink lemonade). Aerosols of the main components of liquids (glycerin and propylene glycol) for electronic nicotine delivery systems have the property of damaging DNA and proteins, as well as the ability to induce oxidative stress in cells, so even nicotine-free liquids cannot be considered safe for human health. Further studies are needed to clarify the specific toxicity mechanisms of liquids for ENDS.

Bacterial biofilms formation is one of pathogenic factors of many microorganisms that are dangerous to humans. Antibiotics are becoming less and less effective against biofilm-forming microorganisms, therefore it is necessary to search for alternative solutions, and the use of medicinal plants as a potential source of antibiofilm agents may be one of them. The effect of 10 medicinal plants alcohol extracts on bacterial biofilms formation was investigated in this research. The studies were performed on two model strains of microorganisms – Acinetobacter calcoaceticus VKPM B-10353 and Escherichia coli CDC F-50. The bacterial biofilms biomass was evaluated using the crystal violet staining method. The number of living cells in bacterial biofilms was studied by fluorescein diacetate staining. The extract of common wormwood (Artemisia absinthium L.) inhibited the formation of bacterial biofilm the most. The maximum stimulating effect on bacterial biofilm biomass formation was recorded for extracts of common oregano (Origanum vulgare L.) and common tansy (Tanacetum vulgare L.). The greatest inhibitory effect on the number of living cells in bacterial biofilms was demonstrated by the extract of common agrimony (Agrimonia eupatoria L.), while the stimulating effect was demonstrated by the extract of greater plantain (Plantago major L.). However, it should be noted that plant extracts had different effects on different bacterial strains and, moreover, plant extract in different concentrations can have a multidirectional effect on the same strain. Thus, extensive screening studies are needed to identify compounds of plant origin that are promising for clinical use.

Antibiotic resistance genes (ARGs) are emerging pollutants, and lake sediments have been recognized as an important reservoir and hotspot for ARGs spread. ARGs present in lake sediments may enter overlying waters and infiltrate groundwaters due to environmental changes and external influences. In this study, ten ARGs were studied, including resistance genes to macrolides (ermB and mphA), sulfonamides (sul2), tetracycline (tetO), carbapenems (blaVIM), vancomycin (vanA, vanB), aminoglycosides (aadA2), methicillin (mecA), cephalosporins and monobactams (blaCTX-M), integrons of classes 1-3 (intI1, intI2, intI3) and bacteriocenosis of bottom sediments of Lake Manych-Gudilo. Presence of all 10 investigated ARGs, as well as integrons of two classes (intI1 and intI3) was noted. The number of ARG copies in bottom sediments can be arranged in the following descending order: blaCTX-M > sul2 > aadA2 > blaVIM > vanB > tetO > ermB > vanA > mphA > mecA. At the genus level, Streptococcus (8.55%), an unspecified genus of the family Rhodobacteraceae (6.25%), and an unspecified genus of the order Bacteroidales (5.03%) prevailed. The dominant phyla were Proteobacteria (38.80%), Bacteroidetes (19.75%), and Firmicutes (11.85%). Using the functional annotation of prokaryotic taxa (FAPROTAX), the presence of 41 functional groups was determined. A larger proportion of taxa belonged to functional groups such as chemoheterotrophs, aerobic chemoheterotrophs, and groups involved in the sulfur cycle.

The aim of the work was to study the levels of interleukins (IL-1β, IL-23,IL-13) in the blood serum of experimental animals and the effect of information drugs on the aging processes in animals. The object of the study were white experimental male rats, which were divided into 3 main and control groups. Rats of groups I and II were exposed to informational drugs. In the experiment, group III was under the influence of the "Activation Therapy" programs of the Artemis-Dom apparatus (a set of weak electromagnetic signals for the correction of physiological disorders). The greatest changes were found in the production of IL-1 and IL-23. Their level before treatment was increased to varying degrees. IL-13 production turned out to be reduced. After treatment with informational drugs, a decrease in the level of IL-1 and IL-23 was registered. The greatest decrease in these interleukins was found in group III; in it, an increase in IL-13 was noted relative to the control values. The authors have shown that the cytokine balance in the aging process of experimental animals is characterized by the production of pro-inflammatory and anti-inflammatory molecules. The accumulation of levels of some and a sharp decrease in others (before treatment), contributes to the development of cellular hypoxia and so-called "oxidative stress". This will have negative consequences for the aging body. It is concluded that the recorded changes in the cytokine profile may be involved in the violation of cellular regulation processes, which plays an important role in the development of endothelial dysfunction syndrome, which forms a variety of pathological processes. The authors have shown that the noted changes in the cytokine profile can participate in the violation of cellular regulation processes, which plays an important role in the development of endothelial dysfunction syndrome, which forms various forms of pathologies. Restoring the balance of interleukins (after treatment) helps to prevent the effects of aging in rats. The positive effect of information preparations on the aging processes in the studied laboratory animals was noted

Postbiotics are a new group of drugs of microbial origin. Unlike probiotics, the main acting agents on the organism in the case of postbiotics are not living cells of microorganisms, but their metabolites or individual cell elements (such as fragments of membranes and cell walls. Postbiotics study, despite the insufficient number of studies in this area, is a promising direction for the development of new drugs of microbial origin aimed at improving the quality of life of humans and animals.

On the biological degradation of white phosphorus On the biological degradation of white phosphorus   1 Institute of Organic and Physical Chemistry named after A.E. Arbuzov. Kazan Scientific Center of the Russian Academy of Sciences. Arbuzov St., 8. Kazan, 420088. Republic of Tatarstan. Russia. E-mail: mindubaev-az@yandex.ru 2 Kazan (Volga Region) Federal University. University St., 18. Kazan, 420008. Republic of Tatarstan. Russia. Abstract For the first time different taxonomic groups of microorganisms (fungi, Streptomyces and bacteria) are inoculated on culture medium containing white phosphorus as the single source of phosphorus. On these media microorganisms grew and have not experienced phosphorus starvation. It is the world's first example of the inclusion of white phosphorus in the biosphere cycle of elemental phosphorus. The highest concentration corresponds to 5000 times excess of MPC of white phosphorus in wastewater. The comparison of the sequences of ribosomal genes of the fungus, steadily metabolizing the white phosphorus, with sequences of the GenBank database, allowed us to identify this microorganism as a new strain of Aspergillus niger, to which we have assigned the number A. niger AM1. Inoculation of A. niger AM1 in medium containing just two sources of phosphorus (phosphate and white phosphorus) demonstrated that P4 does not exhibit toxic properties in relation to this microorganism. In the presence of white phosphorus it grows at the same rate as in the absence thereof. This is the only example of the lack of white phosphorus toxicity to a living organism. Our previous studies have demonstrated the absence of white phosphorus toxicity for Aspergillus niger AM1. However, the toxic properties of the substances are of different nature. It is of great interest to study the genotoxicity – a possible source of mutations. In the present work SOS-lux test has demonstrated genotoxicity of white phosphorus. This result is obtained for the first time – all the available literature sources reported no genotoxic properties of white phosphorus. Allium test showed the mitotoxic effect of white phosphorus on eukaryotic cells. A very interesting and unexpected result was the discovery of a mutant Aspergillus niger AM1. In comparison with an ancestral strain this mutant possesses an unusual morphology and grows more intensively in culture medium with white phosphorus. Three strains of A. niger, sent from the All-Russian collection of microorganisms, also showed much higher resistance to white phosphorus than bacteria. According to preliminary data, resistance to white phosphorus the A. niger is fixed in the genome.

The paper aims to assess the impact of urbanization on the quantitative characteristics and species composition of microbial communities of the urban soils of Rostov-on-Don. 10 soil samples characterized by a dramatically different level of anthropogenic impact and transformation have been studied. The microbial communities of the upper horizons of weakly disturbed natural soils (Haplic chernozem) were compared to those from the urbic horizons of the Technosols in the central part of the city. It has been shown that the process of urbanization leads to a fundamental change in the microbial communities of urban soils in the steppe zone. There is a decrease in species diversity in the microbial communities. In addition, in anthropogenically transformed soils there is an increased number of copiotrophic bacteria compared to weakly disturbed soils. The number of aerobic spore-forming bacteria of the order Bacillales decreases several times. The species composition also changes, which is manifested in the disappearance of typical species from microbial complexes of anthropogenically transformed soils. The proportion of rapidly growing species of bacteria (r-strategists) is increased in the microbial communities of urban soils, indicating that the soils are under stress. The stability of the soil ecosystem is impaired and this may lead to the loss of its ecological functions. In addition, an increase in the proportion of microorganisms with antioxidant pigments was observed in anthropogenically transformed soils.

Non-ribosomally synthesized metabolites and the genetic mechanisms of their synthesis in the implementation of the fungicidal effect of Bacillus and Paenibacillus bacteria (review) Pathogenic fungi that cause damage to agricultural crops pose a serious threat to the agricultural industry. The development of biological products based on bacteria - natural antagonists of fungi is the most environmentally safe strategy to withstand it. The purpose of this review was to systematize the existing data on bacteria antagonistic to pathogenic fungi of the genus Fusarium and the mechanisms for this antagonism’s implementation. The review lists the main mechanisms, as well as a number of genes responsible for these mechanisms. These genes can be an important element in the development of a genetic screening system for strains that are effective antagonists of pathogenic fungi.

The effect of humic substances on microbial activity of the soil under fruit trees Gorovtsov Andrey V.,  Bezuglova Olga S., Polienko Elena A., Popov Artem E. Abstract The use of humic preparations for the treatment of fruit trees is one of the most poorly studied aspects of the application of this group of plant stimulators. There is especially little knowledge about the processes occurring in the soil, and virtually no data on the response of soil microbial communities in the root zone to such kind of treatment. The paper presents the data of microbiological analysis of soil under the mature fruit trees (apple, cherry) and young trees in the nursery (cherry, plum) after the treatment with  humic preparation BIO-Don. It has been shown that treatment of fruit trees with humic substances resulted in the activation of many groups of bacteria in the soil under the plants. The most pronounced reaction was observed for oligotrophic and aminoheterotrophic bacteria, a weaker response for reacted aminoautotrophic bacteria, and almost no reaction was noted for oligonitrophilic bacteria, actinomycetes and soil fungi. However, the observed changes in the dynamics of mineral nutrients suggest that the activation of the soil bacteria contributes significantly to the obtained yield increase. The article is prepared on the basis of the plenary report on the second international conference "Problems and prospects of biological farming", held on-line on November 27, 2016.

Microbial biomass and basal soil respiration of quarry-dumps systems with different substrates Dmitrakova Ianina Aleksandrovna, Abakumov Evgenij Vasilevich. Abstract: The study was carried out at nonreclaimed and recultivated quarries with different soils in the North-West of Russia. The basic biological indicators such as microbial biomass content, basal soil respiration and  metabolic quotient were measured. For all quarries the level of microbiological activity is low.

Photobacterium phosphoreum as an object for studying the biological effects of the CeO2 nanoparticles Gretsky Igor Alexandrovich, Zholobak Nadezhda Mikchailovna, Scherbakov Alexander Borysovich, Ivanov Vladimir Konstantinovich, Gromozova Elena Nikolaevna Abstract: The effect of nanoceria (CND), that have different physical and chemical properties – the used producing methods, Zeta potential, the presence of the stabilizer – on the the intensity of luminescence of Photobacterium phosphoreum IMV B-7071 was studied. It is shown that the high crystallinity nanoceria after 30 minutes after addition stimulated the cells luminescence, whereas the effects of citrate-stabilized CND depend essentially on the toxic effects the stabilizer sodium citrate.

The Influence of Electromagnetic Irradiation of Millimeter Range on the Ability of Pathogenic Corynebacteria to Biofilm Formation Theoretical and experimental substantiation of millimeter waves in different frequency bands influence on the formation of pathogenic corynebacteria subpopulations with low and high ability to form biofilms is presented in the article. It was experimentally proved that electromagnetic waves in 61,0 GHz frequency range, stimulated ability of corynebacteria to form biofilms; irradiation 42,2 GHz frequency range, on the contrary, inhibited these properties.

To the question of enhancing of productivity for flat open systems for microalgae culturing E. Onyshchenko In our research we identify the ways to enhance industrial productivity of green microalgae culturing in open pond systems. For effective large - scale implementation of controlled culturing, technologies providing high productive growth in conditions of natural light irradiation are required. Light conversion efficiency with two different culturing methods for Chlorella in conditions duplicating light energy density, typical for middle latitude meteo- climatological conditions is compared.

Study of the sensitivity of hospital S. aureus strains to the action of disinfectants Has been studied the sensitivity of strains of S. aureus, isolated from hospitals environmental objects (air of manipulation rooms, swabs from the surfaces of medical equipment, uniforms of the medical staff) to modern disinfectants. It was established that the highest activity possessed chlorine compounds, and means based on peracetic acid.

Investigation of thermal resistance and antagonistic properties of the yeast Saccharomyces cerevisiae Using antagonistic properties of some bacteria to inhibit other (pathogenic) has been studied for many years, while little attention was paid to study such properties in yeast. The yeast metabolites and yeast cells action on gram-negative and gram-positive microorganisms was different. Live yeast cells were the most antagonistically active against gram-positive microorganisms and their metabolites - in relation to gram-negative.  

The epithelial-mesenchymal transition is one of the sources of the emergence of new cancer stem cells in response to cancer chemotherapy. The initiation of this process depends on a number of transcription factors - Snail, Twist, Zeb, which regulate the activity of genes, involved in cellular phenotype and inter-tissue interactions. In turn, Snail, Twist, Zeb are targets for the regulation of the nuclear factor kappa bi (NF-kappaB) cascade, one of the leading signaling pathways of cell adaptation and defence both under normal conditions and in the pathogenesis of a wide range of diseases, including various oncologies. This review study examines the interaction of NF-kappaB with genes regulating epithelial-mesenchymal transition in cancer cells. The mechanisms of information transfer and the activation pathways of the NF-kappaB signaling pathway and the regulatory network of transcription factors of the epithelial-mesenchymal transition are considered. Data on the factors of initiation of epithelial-mesenchymal transition with the NF-kappaB participation are presented. Roles of specific components in NF-kappaB signaling pathway are presented separately in this trigger, as well as cooperation with other signaling cascades involved in the tumors development. It also demonstrates the usage of various pharmacological, including protein, inhibitors of the NF-kappaB cascade to prevent EMT triggering. In conclusion, the facts about the regulation of NF-kappaB activity due to the reverse loop formed by the products of the target genes of the Snail, Twist, Zeb factors are presented. This work is of interest to specialists in the field of cell biology, human genetics and molecular oncology