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1.
Vopr Pitan ; 89(3): 71-85, 2020.
Artículo en Ruso | MEDLINE | ID: mdl-32790260

RESUMEN

Bentonite nanoclay (NC) manufactured from the natural sedimentary mineral bentonite contains more than 90% montmorillonite. Currently, it is widely used in food industry as processed aids - adsorbents for the purification of vegetable oils and beverages. Clay minerals have also applications as food additives and components in composite package materials. In vitro studies have shown that various forms of NC exerted cytotoxicity in many cell lines, whereas in vivo evidence of NC oral toxicity is contradictory. Therefore, this study aimed to assess the acute oral toxicity of NC and to evaluate its toxicological characteristics in a subacute 92-day experiment on Wistar rats with a daily oral administration in doses of 1, 10, and 100 mg/kg body weight (bw). Material and methods. The NC acute toxicity was evaluated in 8 male and 8 female rats with the initial bw 236±10 and 203± 10 g, respectively. NC was administered as an aqueous dispersion intragastrically at a dose of 5 g/kg bw. On the 14th day (end of the experiment), an autopsy of the chest and abdominal organs was performed. The subacute experiment was carried out on 64 male rats with an average initial bw of 117±7 g. During the experiment the levels of anxiety and memory function were evaluated using the test "Conditional reflex of passive avoidance". On the 90th day of the experiment, diurnal urinary excretion of creatinine and selenium was evaluated. At the end of the experiment, the integral parameters, the state of the intestinal wall permeability were assessed. Hematological and biochemical parameters were examined in blood, the content of non-protein thiols and the number of cells in apoptosis were determined in liver, and the state of cultivated microbiome populations was studied in cecum. Results. The results of the determination of NC acute toxicity showed the absence of rat's mortality and specific pathological changes in the internal organs at a dose as large as 5000 mg/kg bw, which allowed attributing NC to the V hazard class. Nevertheless, under the conditions of the 92-day experiment, NC caused some adverse biological effects on rat's organism. So, even at an NC dose of 1 mg/kg bw, there was a sharp inhibition of the symbiotic bifidobacterium growth, an increase in platelet count, in LDL and the LDL/HDL ratio, together with the presence of hypertriglyceridemia. At a dose of 10 mg/kg bw, an increase in spleen mass and a decrease in the de Ritis coefficient (AsAT/AlAT) were established. At a dose of 100 mg/kg bw there were shifts in the leukocyte blood count, an excessive enterococci growth in the cecum, significantly increased animal bw, along with the decrease of AsAT/AlAT and the level of serum nitrogen metabolites, indirectly indicating inhibition of catabolic processes. However, at the highest dose of NC, intestinal absorption of the protein antigen - ovalbumin, was apparently completely blocked. Conclusion. The data obtained have shown that NC has potentially adverse effects on the rats mainly at a dose of 100 mg/kg bw, nevertheless, its NOAEL in the 92-day daily oral exposure experiment is probably less than 1 mg/kg bw.


Asunto(s)
Bentonita/efectos adversos , Industria de Alimentos , Nanoestructuras/efectos adversos , Administración Oral , Animales , Bentonita/farmacología , Ratas , Ratas Wistar
2.
Vopr Pitan ; 88(5): 17-23, 2019.
Artículo en Ruso | MEDLINE | ID: mdl-31710783

RESUMEN

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.


Asunto(s)
Campylobacter , Contaminación de Alimentos , Microbiología de Alimentos , Leche/microbiología , Reacción en Cadena de la Polimerasa , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Animales , Campylobacter/clasificación , Campylobacter/genética
3.
Bull Exp Biol Med ; 164(1): 68-74, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29119393

RESUMEN

Experimental model for in vitro evaluation of Campylobacter genus bacteria growth kinetics, inhibition, or inactivation is proposed. The model allows quantitative evaluation of the sensitivity to various types of stress exposure and promotes detection of the regularities of their transformation into uncultivable forms. The model implies the use of 96-well plates for parallel culturing of several subpopulations of the test strain in media with various parameters. The proposed algorithm includes evaluation of the proportion of viable CFU to total level of planktonic and uncultivable cells in the population, which is estimated by the content of genomic DNA in the samples by quantitative PCR (or real-time PCR) with ciaB, cdtB, or 16S rRNA primers. The presence of biofilm matrix is detected by the intensity of staining of polystyrene plates. This model can be used for evaluation of the most significant types of exposure, including low-dose antibacterial treatment, promoting the formation of stable microorganism variants. The model has been used to study the effects of culturing conditions on the characteristics of C. jejuni populations. The most characteristic feature of C. jejuni is reduction of the count of viable cells up to complete disappearance of cultivable forms under favorable conditions of growth. The level of viable cells in the populations decreased 10-fold and more, on average, after 48-h incubation. Not all strains exhibit this property, some strains retain their viability, which is detected by the culturing method, and contributes to biofilm formation.


Asunto(s)
Biopelículas , Campylobacter/crecimiento & desarrollo , Carne/microbiología , Animales , Campylobacter/aislamiento & purificación , Técnicas de Cultivo de Célula , Microbiología de Alimentos , Aves de Corral/microbiología
4.
Bull Exp Biol Med ; 162(4): 474-478, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28243912

RESUMEN

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.


Asunto(s)
Biopelículas/efectos de los fármacos , Campylobacter jejuni/efectos de los fármacos , Cloro/farmacología , Desinfectantes/farmacología , Enterobacteriaceae/efectos de los fármacos , Modelos Biológicos , Animales , Biopelículas/crecimiento & desarrollo , Campylobacter jejuni/fisiología , Colorimetría , Colorantes/química , Medios de Cultivo/química , Medios de Cultivo/farmacología , Enterobacteriaceae/fisiología , Contaminación de Equipos , Tecnología de Alimentos , Violeta de Genciana/química , Vidrio , Humanos , Plantas/microbiología , Poliestirenos , Estrés Fisiológico
5.
Vopr Pitan ; 86(5): 34-41, 2017.
Artículo en Ruso | MEDLINE | ID: mdl-30695626

RESUMEN

А screening study on the detection of campylobacteria in raw food products, semi-finished products and objects in the external environment in the poultry processing industry was conducted. The highest level of detection of campylobacteria is set for raw poultry products, including carcasses of broilers, turkeys and quail. A general accordance of getting Campylobacter in raw materials and food products with inadequate sanitary treatment of separate areas of production has been established: in most cases Campylobacter spp. was extracted from the samples, contaminated with coliform bacteria and Salmonella. It is shown that the frequency of contamination of raw poultry with pathogens is largely dependent on the cooling of the carcasses. When using the immersion method, the conditions for cross contamination with pathogens through water bath cooling are present (45% of samples infected with Campylobacter spp.). Under combined use of super-cooled water and aerosols Campylobacter were also detected quite often in 27% of samples. Contamination by pathogens was the lowest in evaporative cooling method with the use of antimicrobial hydrospray (less than 5% positive samples), allowing to recognize this method as the most promising for the production of microbiological safe products. The work on optimization of nutrient medium composition and adaptation recommended methodological scheme of analysis for detection and species identification of bacteria of the genus Campylobacter was carried out. Formulation of traditionally used growth media was modified, and balanced composition of growth and selective components was matched in accordance with the requirements of existing standards. Given the urgency of increasing the effectiveness of the methods of control of campylobacteria in foods and the lack of domestic analogues of the culture media in the Russian Federation, an optimized method for the production of dry nutrient media for the detection, identification and storage of campylobacteria isolated from food products and clinical material was developed. The conducted study allowed to develop Technical conditions 21.20.23-006-01897222-2016 «Dry culture medium for detection of bacteria of the genus Campylobacter¼ and «Instruction for use of culture media¼. Depending on the purpose of the medium produced in the following versions: the selective broth for enrichment of campylobacteria; differential selective agar for isolating and quantifying of Campylobacter spp.; semi-solid nutrient agar for cryostorage of Campylobacter strains. The list of criteria for assessing the quality of commercially available lots of dry media included: solubility, pH, gel strength of agar, the content of amine nitrogen, specificity, selectivity, growth and inhibitory properties. The practical application of these media in terms of the national laboratories will significantly simplify the use of existing standards developed based on international ISO standards, but not adapted to the main range of commercial media and reagents used in routine food control for the presence of campylobacteria.

6.
Vopr Pitan ; 86(1): 17-27, 2017.
Artículo en Ruso | MEDLINE | ID: mdl-30645886

RESUMEN

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.

7.
Vopr Pitan ; 85(1): 66-74, 2016.
Artículo en Ruso | MEDLINE | ID: mdl-27228703

RESUMEN

The study of the responses to cold exposure in Campylobacterjejuni (C. jejuni)--one of the most common foodborne pathogens is important for elucidating the mechanisms of acquisition of products contaminated with campylobacter, hazardous properties. These data are also necessary to create effective systems of microbiological controls at all stages of production and storage of food. 5 pairs of oligonucleotide primers were selected for detecting of genes cadF, cdtB, ciaB, flaA, iamA, encoding the main factors of pathogenicity of foodborne pathogens Campylobacter jejuni--adhesion and invasion of epithelial cells, production of CDT-toxin and mobility. To quantify the expression levels of target genes of C. jejuni a comparative method of determining the amount of amplification products of genes encoding pathogenicity factors of Campylobacter spp. has been developed using real-time PCR with intercalating dyes. To calculate and quantify gene expression the mathematical models have been obtained that allow extrapolation of threshold cycles of amplification to the initial number of copies of RNA/DNA in the tested samples. It has been established that exposure of C. jejuni at low temperatures +4 degrees C did not lead to increased levels of expression of genes cdtB and ciaB. However, in the populations of C. jejuni subjected to freezing, followed by incubation at optimum for the pathogen temperature of +42 degrees C, the increase in expression of mRNA encoding protein subunit B of CDT-toxin and antigenic marker of invasion took place. The number of copies of RNA in C. jejuni after stress exposure increased by 1.14-2.6 lg in comparison with intact cultures. CdtB and ciaB gene expression in C. jejuni can serve as an indicator of cell response to stress and helps to restore the functions of the bacterial cells after the termination of cold exposure and return of the pathogen in conditions favourable to the realization of its pathogenic potential.


Asunto(s)
Infecciones por Campylobacter/metabolismo , Campylobacter jejuni , Enfermedades Transmitidas por los Alimentos/metabolismo , Regulación Bacteriana de la Expresión Génica , Estrés Fisiológico , Factores de Virulencia/biosíntesis , Campylobacter jejuni/metabolismo , Campylobacter jejuni/patogenicidad , Humanos
8.
Vopr Pitan ; 85(3): 27-35, 2016.
Artículo en Ruso | MEDLINE | ID: mdl-30645900

RESUMEN

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.

9.
Vopr Pitan ; 85(5): 52-9, 2016.
Artículo en Ruso | MEDLINE | ID: mdl-29381302

RESUMEN

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.


Asunto(s)
Campylobacter , Comida Rápida/microbiología , Contaminación de Alimentos , Microbiología de Alimentos , Alimentos Crudos/microbiología
10.
Vopr Pitan ; 84(4): 55-65, 2015.
Artículo en Ruso | MEDLINE | ID: mdl-26852532

RESUMEN

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.


Asunto(s)
Antígenos CD/inmunología , Citocinas/inmunología , Inmunidad Celular/efectos de los fármacos , Linfocitos/inmunología , Nanoestructuras/efectos adversos , Dióxido de Silicio , Animales , Relación Dosis-Respuesta a Droga , Linfocitos/patología , Masculino , Ratas , Ratas Wistar , Dióxido de Silicio/efectos adversos , Dióxido de Silicio/farmacología
11.
Vopr Pitan ; 83(5): 33-42, 2014.
Artículo en Ruso | MEDLINE | ID: mdl-25816624

RESUMEN

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.


Asunto(s)
Bacterias/aislamiento & purificación , Contaminación de Alimentos , Microbiología de Alimentos , Lactuca/microbiología , Bacterias/clasificación , Humanos
12.
Gig Sanit ; (3): 76-8, 2012.
Artículo en Ruso | MEDLINE | ID: mdl-23088139

RESUMEN

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.


Asunto(s)
Silicatos de Aluminio/toxicidad , Bentonita/toxicidad , Mucosa Gástrica/efectos de los fármacos , Higiene , Hígado/efectos de los fármacos , Nanopartículas/toxicidad , Animales , Arcilla , Modelos Animales de Enfermedad , Mucosa Gástrica/patología , Hígado/patología , Masculino , Ratas , Ratas Wistar , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
13.
Vopr Pitan ; 81(3): 24-9, 2012.
Artículo en Ruso | MEDLINE | ID: mdl-22888667

RESUMEN

The data on nomenclature, classification and taxonomy of aerobic spore-forming Bacillus cereus are summarized. The main features of the two types of diseases, caused B. cereus, and statistical information on outbreaks of food-borne disease caused by B. cereus are presented. The detailed description of emetic toxin cereulide properties are given. The analysis of existing methods for detection of the presence of B. cereus and their toxins in foods are conducted. The data on the use of different cell models for studying the cytotoxic effects and the enterotoxigenic properties of B. cereus are described. Results of own researches allowed to conclude that certain types of products, primarily made from milk and vegetable raw materials, can be a source of transmission to humans of toxins produced by B. cereus. It is shown that in the absence of competing vegetative microflora increases the risk of accumulation of toxins produced by the most stable populations, including toxigenic spore B. cereus. Tested and proposed for the practical implementation of the dry culture media on the basis of the balanced growth and selective components, dyes and buffer mixtures. The developed environment were used for the isolation and identification B. cereus during microbial control these groups of foods.


Asunto(s)
Bacillus cereus/patogenicidad , Toxinas Bacterianas/toxicidad , Depsipéptidos/toxicidad , Microbiología de Alimentos/normas , Enfermedades Transmitidas por los Alimentos/microbiología , Enfermedades Transmitidas por los Alimentos/prevención & control , Bacillus cereus/clasificación , Bacillus cereus/aislamiento & purificación , Bacillus cereus/metabolismo , Toxinas Bacterianas/metabolismo , Seguridad de Productos para el Consumidor , Depsipéptidos/metabolismo , Enfermedades Transmitidas por los Alimentos/epidemiología , Humanos
14.
Vopr Pitan ; 81(6): 12-8, 2012.
Artículo en Ruso | MEDLINE | ID: mdl-23530431

RESUMEN

The article gives an overview of information international networks of monitoring the microbiological food safety in the world. The most famous are the European Network of Food Safety (EFSN), Global network for disease surveillance, Foodborne (GFN), International Network for the determination of molecular subtypes of bacterial food patogens (PulseNet), International Network of Food Safety (INFOSAN). The network EFSN is engaged development of information database and of warning systems to assess food safety. GFN supervises of foodborne pathogens (Salmonella, Campylobacter, E. coli, S. typhi, Shigella, Listeria monocytogenes, C. botulinum) in food, biomaterials, samples of products from centers of infection. PulseNet International is a network of National and regional laboratory networks dedicated to tracking foodborne infections world-wide. Each PulseNet laboratory utilizes standardized genotyping methods and sharing information in real-time. The resulting surveillance provides early warning of foodborne disease outbreaks. The International Food Safety Authorities Network (INFOSAN) is a global network emergency contact points for communication between the INFOSAN secretariat and national food safety authorities. In Russia, the contact point in the International Network INFOSAN is Rospotrebnadzor. Microbiological food safety is estimated by testing the finished product. This measure does not reflect the level and range of microbial contamination of food, does not provide a forecast of diseases caused by food. In conclusion, reported the need for the organization of monitoring of microbial food contaminants in Russia.


Asunto(s)
Análisis de los Alimentos/métodos , Análisis de los Alimentos/normas , Enfermedades Transmitidas por los Alimentos/prevención & control , Salud Global , Cooperación Internacional , Humanos
15.
Vopr Pitan ; 80(3): 31-6, 2011.
Artículo en Ruso | MEDLINE | ID: mdl-21842751

RESUMEN

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.


Asunto(s)
Productos Lácteos Cultivados , Hematopoyesis , Inmunidad Celular , Intestinos , Probióticos/farmacología , Animales , Bifidobacterium/inmunología , Intestinos/inmunología , Intestinos/microbiología , Lactobacillus acidophilus/inmunología , Masculino , Ratas , Ratas Wistar
16.
Vopr Pitan ; 78(2): 42-6, 2009.
Artículo en Ruso | MEDLINE | ID: mdl-19514342

RESUMEN

In experiments in rats it is set, that peroral introduction with the feed of mould spores in a doze 10(3) CFU/g results in a disbalance of microbiocenosis of intestine. It shows up violation of localization of bifido- and enterobacteria and their increased growth in a small intestine. Thus, also antagonistic activity of an aerobic component of microflora is reduced and frequency of detection of potential-pathogenic types of enterobacteriaceae is increased. Entering of fungi spores at a dose 10(6) CFU level is accompanied by more expressed infringements of aerobic populations of intestinal microflora in rats.


Asunto(s)
Microbiología de Alimentos/normas , Hongos/crecimiento & desarrollo , Intestinos/microbiología , Animales , Bifidobacterium/crecimiento & desarrollo , Enterobacteriaceae/crecimiento & desarrollo , Heces/microbiología , Alimentos/normas , Masculino , Ratas , Ratas Wistar , Esporas Fúngicas/crecimiento & desarrollo
17.
Vopr Pitan ; 69(4): 43-9, 2000.
Artículo en Ruso | MEDLINE | ID: mdl-11107644

RESUMEN

The rapid microbiological methods of quality control food in the HACCP systems. The paper contain the summary of the hazard analysis control point concept for the control of food microbiological safety. It characterises the express methods that can detect and identify the Food Poison Organisms, including the methods for the rapid detection and enumeration of microorganisms by means of a new impedance measuring systems, molecular-biologic methods and DNA-diagnostic methods.


Asunto(s)
Análisis de los Alimentos/normas , Inspección de Alimentos/normas , Microbiología de Alimentos/normas , Bacterias/clasificación , Bacterias/aislamiento & purificación , Técnicas Bacteriológicas/normas , Análisis de los Alimentos/métodos , Inspección de Alimentos/métodos , Control de Calidad
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