[Minor antibiotics residues in food: what are the risks for consumers].

The problem of contamination of foodstuffs with antibiotic residues does not lose its relevance everywhere, and the most widespread are the quantities of contaminants at the level of regulated values. This raises the concern of specialists in the field of production and processing of livestock products and initiates their appeal to scientific organizations of the hygienic profile for an explanation of the potential health risks associated with the consumption of low doses of antibiotics with food. Material and methods. Analysis and synthesis of data from scientific sources and official documents in the field of assessing health risks when consuming antibiotics with food, with an emphasis on the effects of minor amounts [at the level of sub-inhibitory values below minimum inhibitory concentrations has been carried out. Results and discussion. The issues of direct and indirect human exposure to antibiotics in low doses, including the formation of resistance of intestinal bacteria and the acceleration of the evolution of microbes, accumulation in the organism, the likelihood of allergic reactions, as well as preservation in foodstuffs during heat treatment, have been highlighted. The role of low doses of antibiotics as analogues of biologically active metabolites of bacteria is demonstrated, which, without exerting a toxic effect on the macroorganism, serve as triggers of changes in the microbial ecosystems of humans, animals and habitats through the mechanism of switching on regulation transcription in microbes and activation of horizontal transfer of genes encoding resistance and associated traits. The negativity of the disproportionately wide use of tetracyclines in agriculture, as the cause of the globalization of transferable resistance, has been emphasized, which was justified by the data on the ability of their sub-inhibitory doses to induce the expression of the largest number of mechanisms of its formation and most strongly provoke the horizontal transfer of linked genes between microbes. The need to preserve the current in the EAEU MRL for tetracyclines (0.01 mg/kg product), located in the concentration zone 0.05-0.1 minimum inhibitory concentrations for most sensitive bacteria, safe in terms of resistance induction, has been confirmed. Conclusion. Adequate rationing of antibiotics in food is recognized as a risk management measure for both direct and indirect negative consequences for human health, since the need to ensure MRLs requires manufacturers to strictly adhere to doses, duration of use and withdrawal periods of drugs. This reduce the likelihood of developing resistance in the gastrointestinal tract of animals, the load of the environment by resistant microbes and their transmission along the food chain. The underlying establishment of microbiological acceptable daily intake should be improved by including the selection of intestinal bacteria co-resistance under the influence of a regulated drug, as a marker of the induction of horizontal transfer of resistance genes, in the biological endpoints of determining.

[Dried fruits marketed in Russia: multi-mycotoxin contamination].

Mycotoxins (MT) - secondary metabolites of micromycetes - are natural contaminants of plant products. Fruits are particularly susceptible to fungal contamination and MT accumulation due to high sugar content. It can occur at any production stage: during vegetation, drying and storage. The most hazardous MT - aflatoxins (AFLs) and ochratoxin A (OTA) - are regulated in dried fruits in some countries. However, their maximum levels (ML) were not set in Russia yet. The present research was aimed at the evaluation of MT contamination of dried fruits marketed in Russia. Material and methods. 54 samples of dried dates (n=11), apricots (n=9), raisins (n=9), prunes (n=7), figs (n=6), apples (n=3) and mixtures for compote (n=9) were analyzed for 32 MTs by HPLC-MS/MS with positive/negative ESI in the MRM mode. Results. OTA and fumonisins (FBs) were the major regulated contaminants, their occurrence proved to be 10 and 17% correspondingly. Emergent metabolites of Fusarium spp. enniatin A (ENN A, 22%) and beauvericin (BEA, 15%); Penicillium spp. mycophenolic and cyclopiazonic acids (MPA and CPA, about 19%); Alternaria spp. tentoxin (TE, 17%) were detected also. Two-thirds of positive samples were contaminated with two and more MTs. All studied samples could be referred as safe within the EU regulations. Conclusion. Some kinds of dry fruits proved to be susceptible to contamination with particular MTs. Characteristic pattern for raisin was the OTA and MPA combination, for figs - FBs and CPA. According to literature data concerning occurrence and safety of MTs and the results of our survey, the long-term monitoring of AFLs and OTA in dry fruits and AFLs, OTA, FBs and CPA in figs from different regions of Russia is necessary to assess the need for setting of MLs of these MTs.

[Risk assessment of glucoamylase and xylanase complex from Aspergillus awamori Xyl T-15].

The introduction of methods for food production using microbial synthesis, including those obtained with the help of genetically modified (GM) microorganisms, at the present stage, allows to increase production volumes and reduce the cost of food. At the same time, such products in accordance with TR CU 021/2011 "On food safety" are classified as a "novel food"¼ and can be placed on the market only after its risk estimation for health. The emergence of new data and research methods in the last years has made it necessary to improve the risk assessment system for this category of food. The aim of the research is to develope risk assessment approaches of food obtained by microbial synthesis on the example of the GM strain Aspergillus awamori Xyl T-15 and the enzyme preparation (EP) (a complex of glucoamylase and xylanase) produced by it. Material and methods. Outbred ICR mice (CD-1) and Wistar rats (males and females) were used in the experimental studies. Investigations of GM strain A. awamori Xyl T-15 virulence and its ability to disseminate internal organs have been carried out. Acute and subacute (during 80 days) toxicity of EP (a complex of glucoamylase and xylanase) have been studied. Results. The presented experimental data allow us to make a conclusion about the avirulence of the A. awamori Xyl T-15 strain, the lack of ability to disseminate internal organs (invasiveness). At the same time, the strain is characterized by the ability to produce mycotoxins (ochratoxin, fumonisin B2, T-2 and HT-2 toxins). The EP, a complex of glucoamylase and xylanase from A. awamori Xyl T-15, has a low oral acute toxicity for rats (LD50>5000 mg/kg). I ntragastric EP administration at doses of 10, 100 and 1000 mg/kg of body weight during 80 days had not revealed adversely affect on the rate of weight gain in animals, indicators of anxiety and cognitive function, and some studied biochemical indicators. At a dose of 100 mg/kg b.w. or more, there were changes in the relative mass of organs (lungs, kidneys, adrenal glands), small shifts in the parameters of erythropoiesis and leukocyte formula, at a dose of 1000 mg/kg b.w. - an increase in oxidative DNA destruction. T he most pronounced and dose-dependent was the effect of the EP on hepatocyte apoptosis. According to this indicator, the not observed adverse effect level (NOAEL) for EP is not more than 100 mg/kg b.w. in terms of protein. The main target organ for the toxic effect of EP is the liver. Conclusion. The data obtained demonstrate the necessity to conduct an additional analysis of the risks of possible negative effects of EP, namely, to study its impact on the gut microbiocenosis and the immune status of experimental animals, to analyze the presence of determinants of pathogenicity and antibiotic resistance, DNA of selective marker genes of A. awamori Xyl T-15 strain by PCR analysis and DNA sequencing methods.

[Microbiological safety of food: development of normative and methodical base].

The main results and prospects of fundamental and applied hygienic research of the laboratory of biosafety and nutrimicrobiome analysis of the Federal Research Centre of Nutrition, Biotechnology and Food Safety (hereinafter - the Institute of Nutrition) in the direction of developing a regulatory and methodological framework for assessing the microbiological safety of food are reviewed. The formation of microbiological regulation as a scientific analytical and administrative managerial process in the former USSR and the Russian Federation is considered in the context of historical data, including personal contribution of the scientists of the Institute of Nutrition and other specialists. The basic principles of regulation are emphasized: the scientific validity of the established criteria and requirements, the feasibility, technological attainability, differentiation according to the degree of danger to the health of consumers, preventive nature. The resource of the national normative and methodological base in the field of microbiological food safety at the turn of the century is characterized, the features of the introduction of the microbiological risk assessment (MRA) methodology in the substantiation of Russian norms and measures for the prevention of food infections are described. The information is given on the developed guidance documents on MRA and on the examples of norms adopted on its basis. The article covers the issues of reglamentation the requirements for food safety and reducing the spread of new pathogens Stx-Escherichia coli, Listeria monocytogenes, Enterobacter sakazakii, Campylobacter spp. in the food chain based on risk-oriented approaches. The necessity of taking specific measures for the prevention of cross-contamination in the poultry processing industry is substantiated, taking into account the evidence of the high adaptability of C. jejuni isolated from domestic raw poultry. In the sanitarian-mycological aspect, the monitoring perspective of mould fungi, taking into account their chemotypes, in cereals and non-grain plant products is shown to predict the risk of mycotoxin accumulation and take timely measures. The need to assess the impact on the population, taking into account the characteristics of consumption in the country, as well as the development of criteria for indirect risk of residues are argued for regulation of the antibiotics in food. In light of the challenges in the field of agro- and food technologies to public health at the present stage, contributing to the acceleration of microbial evolution and the emergence of new risks in food, the priority tasks of improving the regulatory and methodological base for assessing microbiological safety have been identified, with an emphasis on the introduction into the process of substantiating the norms of innovative OMICs-technologies based on the achievements of genomics, transcriptomics, proteomics, metabolomics, bioinformatics.

[The study of the raw milk contamination by bacteria of the genus Campylobacter using traditional microbiological methods and quantitative PCR assay].

Gastroenterocolitis caused by Campylobacter bacteria are the most common acute infectious zoonotic foodborne diseases. One of the important factors for the transmission of infection is contaminated dairy products, so the assessment of contamination of raw milk with Campylobacter is necessary to develop effective measures to suppress the growth of the pathogen and ensure the safety of products. The aim of the study was to assess the microbial characteristics of raw milk samples and the nature of their contamination with thermophilic bacteria of the Campylobacter genus. Material and methods. A total of 60 samples of raw milk from the central regions of the Russian Federation and 48 experimentally infected samples of raw milk were studied. To assess the microbial contamination of milk, the number of extraneous microflora was determined, including coliform bacteria (CFB). The identification and quantification of bacteria of the genus Campylobacter was carried out by cultural methods in comparison with quantitative PCR assay. For PCR, primers were used that detected the speciesspecific sequence of C. jejuni 16s rRNA, the presence of the cytotoxic toxin gene cdtB and the invasion gene ciaB. Results and discussion. A significant part of the samples of raw milk (31.6%) was characterized by high levels of microbial contamination exceeding 106 CFU/cm3. Gram-negative bacteria were the dominant type of bacterial microflora, their levels were comparable with the detected values of the total number of microorganisms. Coliform bacteria were found in all studied samples, and their content in 90% of the samples reached 105 CFU/cm3, and in some samples - 107 CFU/cm3. Campylobacter spp. detection rate in raw milk was 8.3%, and their number ranged from 0.1 to 100 CFU/cm3 (average 2.0×10 CFU/cm3). The isolated strains of campylobacters were identified as a C. jejuni species. In the study of the microbial background of the examined samples of raw milk, a comparative analysis of their contamination by campylobacters by rti-PCR was simultaneously carried out. The majority of samples (over 60%) were positive for the presence of 16s rRNA genomic sequence, and they were characterized by the highest values of total bacterial contamination and the amount of coliforms. The use of a multi-primer approach (simultaneous testing for the presence of 16s rRNA and the gene of cytoletal toxin cdtB C. jejuni) reduced the number of positive cases of Campylobacter DNA detection to 16.6%, which suggests a greater informative value of the cdtB gene for the detection of viable, including uncultivated cells. An indicative assessment of the results in a quantitative format showed levels of 104-106.5 genomic equivalents of the DNA in 1 cm3, suggesting the possible presence of viable Campylobacter cells in the tested probes with a significantly greater frequency than that established by cultural method. Conclusion. At low levels of Сampylobacter contamination the microbiological methods do not provide reliable detection of the pathogen due to massive contamination of raw milk by extraneous microflora. Campylobacter spp. were detected by the culture method in 8.3% of cases, while the use of multi-primer PCR assay with cdtB and ciaB genes can double the detection of C. jejuni in raw milk samples.

Formation of Biofilms by Foodborne Pathogens and Development of Laboratory In Vitro Model for the Study of Campylobacter Genus Bacteria Based on These Biofilms.

We analyzed the formation of biofilms by 7 strains of Campylobacter genus bacteria and 18 strains of Enterobacteriaceae genus bacteria that were isolated from plant and animal raw materials, from finished products, and swabs from the equipment of the food industry. Biofilm formation on glass plates, slides and coverslips, microtubes made of polymeric materials and Petri dishes, and polystyrene plates of different profiles were analyzed. When studying the process of films formation, different effects on bacterial populations were simulated, including variation of growth factor composition of culture media, technique of creating of anaerobiosis, and biocide treatment (active chlorine solutions in a concentration of 100 mg/dm3). The formation of biofilms by the studied cultures was assessed by the formation of extracellular matrix stained with aniline dyes on glass and polystyrene surfaces after incubation; 0.1% crystal violet solution was used as the dye. The presence and density of biomatrix were assessed by staining intensity of the surfaces of contact with broth cultures or by optical density of the stained inoculum on a spectrophotometer. Biofilms were formed by 57% Campylobacter strains and 44% Enterobacteriaceae strains. The intensity of the film formation depended on culturing conditions and protocols, species and genus of studied isolates, and largely on adhesion properties of abiotic surfaces. In 30% of Enterobacteriaceae strains, the biofilm formation capacity tended to increase under the influence of chlorine-containing biocide solutions. Thus, we developed and tested under laboratory conditions a plate version of in vitro chromogenic model for evaluation of biofilm formation capacity of C. jejuni strains and studied stress responses to negative environmental factors.

[Antibiotic resistance of Campylobacter jejuni strains isolated from food products].

Campylobacter jejuni is a leading member of the genus Campylobacter which cause up to 90% of laboratory confirmed cases of campylobacteriosis. The most important characteristic defining the biological features of C. jejuni is their sensitivity to antibiotics. Agricultural intensification, expansion of the range of the used disinfectants and antiseptics, uncontrolled use of antibiotics in animal production is increasingly leading to the selection of the most resistant forms of Campylobacter with antibiotic resistance and multiple virulence factors. The study of antibiotic resistance of C. jejuni isolated from food and environment need for the development of new approaches for laboratory diagnosis of campylobacteriosis and confirmation of the role of food path of transmission, for creation the system of preventive measures to reduce the risk of contamination of food by Campylobacter spp. in Russia. The aim of this study was to investigate the phenotypic profiles of antibiotic resistance of Campylobacter spp. isolated from poultry and the environment in the poultry processing industry. In the analysis of 110 samples of raw poultry products and swabs from surfaces of the equipment 55 strains of the genus Campylobacter were selected, including 46 strains of C. jejuni. For study sensitivity of these strains to 15 antimicrobials (8 classes) disk diffusion assays were done using the EUCAST protocol. The following antibiotics were used: nalidixic acid, ciprofloxacin, erythromycin, gentamicin, amikacin, kanamycin, tetracycline, oxytetracycline, doxycycline, clindamycin, lincomycin, ampicillin, chloramphenicol, florfenicol, cefotaxime. All C. jejuni strains were resistant to cephalothin, which confirms their belonging to this species. 89% of the strains were insensitive to nalidixic acid, which indicates the reduction of informativeness of this test, traditionally used in the standard scheme of species identification of Саmpylobacter spp. Most of the investigated isolates were resistant to ciprofloxacin (96.3%) and tetracycline (88.6%), 34% of strains had resistance to erythromycin; 40% of tested C. jejuni were multi-resistant to four or more antibiotics. The data indicate a high prevalence of antibiotic-resistant strains among campylobacteria, contaminated poultry products during the processing of raw materials.

[The study of the contamination and the levels of Campylobacter spp. during the processing of selected types of foods].

The purpose of the work was to study the nature of the Campylobacter spp. contamination during the processing of food products of plant and animal origin (raw poultry and beef meat, raw milk, leafy salads, sliced raw vegetables). In the study of 148 samples 50 strains of Campylobacter spp. (33.8%) were found. For the main phenotypic characteristics they were identified as C. jejuni spp. jejuni and C. jejuni spp. doylei (over 75%). The highest level of detection of campylobacteria (over 45%) was set for raw poultry, including the carcasses of chickens broilers, quails, turkeys and their semi-finished products. 19 of the 27 strains from poultry were identified as C. jejuni. Among the strains isolated from the environment, including swabs from equipment surfaces, 91% of the isolates were also presented by C. jejuni. It was found that the investigated foodstuffs were characterized by high levels of contamination with bacteria of the family Enterobacteriaceae, the content of which was comparable with the identified values of total viable bacteria (cfu). Salmonella was detected in 19% of the investigated poultry samples and in 14.3% of raw cow milk. In the study of swabs from surfaces of poultry processing equipment, the frequency of detection of Campylobacter strains was 38.7%, Salmonella - 12.9%. Most commonly Campylobacter and Salmonella were detected in the zones of primary processing of poultry: the frequency of isolation of Salmonella in slaughter corner was 25%, Campylobacter - 43%. When testing the swabs taken in the cooking zone of «fast food¼ restaurants Campylobacter and Salmonella were not detected. For studying the swabs from equipment surfaces and the environment for the presence of Campylobacter spp. a modified technique of sampling was developed. The method includes a comprehensive analysis in the test area with the use of three types of media for transportation and incubation of Campylobacter spp. (Preston broth with blood, Brucella broth, Cary-Blair medium), that increase the probability of detection of these pathogens.

[Toxicological evaluation of colloidal nano-sized silver stabilized polyvinylpyrrolidone. IV. Influence on intestinal microbiota, immune indexes].

Nano-sized colloidal silver (NCS) stabilized with polyvinylpyrrolidone (PVP) containing nanoparticles (NPs) of silver with a diameter of 10-80 nm was administered to growing male rats (body weight 80±10 g) during the first 30 days by intragastric gavage and then for 62 days with diet consumed in doses of 0.1, 1.0 and 10 mg/kg of body weight per day based on silver (Ag). The control animals received deionized water and PVP. The composition of microbiota from the cecum was studied using standard microbiological methods with determination of the main and transient components, together with antagonistic activity of symbiotic bifidobacteria. Expression of antigens CD45RA, CD3, CD4, CD8, CD161a on lymphocytes (Ly) of peripheral blood was determined by flow cytometry; blood serum levels of cytokines IL10, IL13, TNFα were examined by ELISA. It was shown that subacute administration of colloidal Ag in all studied doses did not lead to significant changes in the composition of the main components of normal microbiota, providing, however, the inhibitory effect on the growth of some transitory components probably including opportunistic species of microorganisms. Among the studied immunological parameters decreased amount of B-Ly was noticed at the highest dose of the NCS, while changes in the other parameters of the immune system were depended ambiguously on the dose of the product. The results were analyzed in conjunction with the data of previous publications concerning the impact on the NCS on integrated, morphological, hematological, biochemical and enzymological indexes of animals in the 92-day experiment. It was concluded that significant symptoms of NCS sub-acute oral toxicity manifested starting from a dose of 1 mg/kg body weight of Ag, and the maximum not observed adverse effect dose (NOAEL) can be estimated as 0.1 mg/kg body weight.

[Toxicological assessment of nanostructured silica. III. Microecological, hematological indices, state of cellular immunity].

This paper is the third in a series of publications on the experimental study of subacute oral toxicity of nanostructured silicon dioxide (SiO2). We used commercial nanostructured SiO2, obtained by hydrolysis of tetrachlorosilane in the gaseous phase, with the size of the primary nanoparticles (NPs) of 5-30 nm. The aqueous dispersion of SiO2 after treatment with ultrasound was administered to rats with initial weight of 80 +/- 5 g for the first 30 days by intragastric gavage and further for 60 days with diets in doses of 0.1; 1.0; 10 and 100 mg/kg body weight per day. Animals of the control group were treated with deionized water. The amount of basic and transient populations of gut microbiocenosis, hematological indexes were measured using standard methods. Specific content of the B-lymphocytes (CD45RA+), total T-lymphocytes (CD3+), T-helper cells (CD4+), T-cytotoxic cells (CD8+), NK-cells (CD161a+) in general population of lymphocytes was evaluated byflow cytometry; serum cytokine levels of TNF-alpha, IL-6, IL-10 were determined by ELISA. No significant changes in the qualitative and quantitative composition of the intestinal microbiota populations regardless of the dose of administered nanomaterial have been found. This gave reason to believe that the postulated mechanism of the toxic effects of the NPs of SiO2, mediated by modification of the composition of the intestinal microflora and the corresponding changes in its functional activity, apparently, is not realized. The main target of nanostructured SiO2 was the T-cellular system of the immune system of animals, that was manifested in the significant decrease of the number of leukocytes (33%), number of T-helper cells (13%), CD4/CD8 ratio (27%) and increasing the number of cytotoxic lymphocytes (19%) and the level of TNF-alpha (590%). The value of the maximum dose (NOAEL) of nanostructured SiO2, has no effect on T-cell immunity was not more than 100 mg/kg body weight per day.

[Study of microbial contamination of processed fresh vegetables and lettuce].

Investigations of microbial contamination and species composition of the Enterobacteriaceae family in fresh vegetables and lettuce has been conducted. The objects of study were new types of fresh ready-to-eat vegetable foods - salads, sliced vegetables and mixtures thereof, sampled at the main stages of production, including washing, antimicrobial treatment with sodium hypochlorite, and packaging in the film under vacuum. Quantitative analysis of Enterobacteriaceae levels in fresh and packaged vegetables and salads showed that their part in the total amount of microbial contaminants is large enough. Average Enterobacteriaceae content ranged from 2,14 to 3,34 lg cfu/g, reaching in some samples values 4,38-4,74 lg, comparable with the levels of total bacteria. Considerable species diversity of microflora contaminating ready-to-eat vegetable products has been found. Bacteria of the genera Enterobactel; Pantoea, Citrobacter, Serratia, Pseudomonas, Kluyvera, Klebsiella, Escherichia, Rahnella, Acinetobacter were found in the salads and sliced vegetables. In the tested samples most frequently detected Enterobacter spp. - 37% of identified strains and Pantoea spp - 25% of strains. The data on the composition and levels of microbial contaminants in vegetable and salad products highlight not only the need to monitor coliform bacteria - traditional indicators of faecal contamination of raw materials, but also the need to introduce criteria for the amount of Enterobacteriaceae.

[Rapid determination of food grain infection by fungi Fusarium and their species detection (part 1)].

Currently contamination of food grains with Fusarium spp. is determined by conventional mycological methods and can last up to 30-40 days. The method specificity is highly dependent on the subjective evaluation of the researchers. The alternative to traditional mycological methods is detection by PCR. The purpose of the study was to improve the contamination analysis method of food grains infected by Fusarium for analysis time reducing and species detection specificity increasing. Investigations were carried out on food grains samples harvested in 2009-2011 from 5 federal regions of Russia. On the first stage, 100 grains were sowing on potato-sucrose medium and then incubated at 24 degrees C for 7-10 days. At the second stage, the Fusarium species composition grown from food grains was estimated by two methods. The first method was mycological for monospore isolates. The second one was PCR analysis of DNA extracts from the combined sample of Fusarium mycelium which grew on a foodgrains sample. Species-specific primers of such mycotoxins producers as F. graminearum, F. culmorum, F. sporotrchiodes, F. langsethiae, F. poae, F. avenaceum, F. tricinctum were used for PCR detection. The species composition of viable Fusarium spp. fungi revealed in foodgrains samples by mycological method completely concided with the results of PCR analysis. In result, the method that combines traditional mycological sowing for detection of viable species with PCR species detection of the mycelium in integrated sample has been developed. The method significantly reduces test duration (3-4 times) by excluding the sieving step in obtaining monospore fungi isolates for further species identification. The method also allows obtaining reliable data on the viable Fusarium species including producers of toxins in foodgrains. Thus, the idea of improving of the identification stage allowing reducing labor costs and increasing of the method specificity was realized.

[Direct detection of T-2- and HT-2-mycotoxins producers of fungi the genus Fusarium in food grain by PCR (report 2)].

The improvement of the Fusarium DNA extraction method has been undertaken in order to reduce the error of PCR analysis for detection of toxigenic Fusarium species, including those contained in the grain in the uncultureted state, directly in the grain. The efficiency of Fusarium DNA extraction methods (nucleotides sorption and CTAB method) has been compared. The efficiency of CTAB method combined with 10-fold weight increase of milled grain sample has been demonstrated. This approach revealed a greater number of Fusarium species, than PCR analysis of combined Fusarium mycelium from the same samples. The uncultureted F. langsethiae was detected in the DNA extract from a sample of barley, which was not identified in the combined sample of the mycelium. This sample of the grain has the highest levels of T-2/NT-2-toxins--0,075/0,345 mg/kg (determined by HPLC) among positive samples. F. sporotrichioides--a potential producer of T-2- and HT-2-toxins has been revealed by PCR method in other grain samples both containing and not containing these toxins. The biosynthesis of T-2- and HT-2-toxins on the PSA-medium in vitro has been studied for 10 single-spores F. sporotrichioides isolates, allocated from grain. Synthesized T-2-toxin content (measured by ELISA) ranged from 0.4 to 184.5 mg per l of medium. Three strains showed very high levels from 117.2 to 184.4 mg/l, two of which have been isolated from barley which don't contain these toxins. The absence of the toxin in grain samples does not guarantee the absence of high-level producers of mycotoxins. The direct detection of Fusarium spp. in grain by PCR analysis with extraction of fungal DNA by CTAB method along with increased sample weight has been shown to make possible the detection of a more number of species of Fusarium (including uncultureol strains) compared with mycological method with PCR analysis of the combined sample of the mycelium.

[Toxicological and sanitary characterization of bentonite nanoclay].

Intragastric administration of nanoclay to rats during 28 days led to reductions in the relative weight of the liver, the activity of its conjugating enzymes, the antagonistic activity of bifidoflora, and the hyperproduction of colonic yeast microflora. The findings lead to the conclusion that nanoclays that may be present in foods must be the object of sanitary regulation.

[The influence assessment of probiotic fermented milk products on intestinal microflora, hematological indices and cellular immunity in rats (report 1)].

Influence of probiotic fermented milk products on the intestinal flora, hematological parameters and immune status of the experiment in vivo at rats is studied. Entering in digestive tract of probiotic strains of Lactobacillus acidophilus NK-1 and Bifidobacterium bifidum 791 at the level of hundreds of millions CFU in a day (from 1,7 x 10(8) to 9 x 10(8) CFU) in composition fermented milk products renders on the whole positive, but not significant statistically influence on the indexes of colon microflora and immune status of rats, and it must be extended for the achievement of reliable effect.