1000 resultados para ENTEROTOXINAS (PRODUÇÃO)
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Aeromonads are inhabitants of aquatic ecosystems and are described as being involved in intestinal disturbances and other infections. A total of 200 drinking water samples from domestic and public reservoirs and drinking fountains located in São Paulo (Brazil), were analyzed for the presence of Aeromonas. Samples were concentrated by membrane filtration and enriched in APW. ADA medium was used for Aeromonas isolation and colonies were confirmed by biochemical characterization. Strains isolated were tested for hemolysin and toxin production. Aeromonas was detected in 12 samples (6.0%). Aeromonas strains (96) were isolated and identified as: A. caviae (41.7%), A. hydrophila (15.7%), A.allosacharophila (10.4%), A. schubertii (1.0%) and Aeromonas spp. (31.2%).The results revealed that 70% of A. caviae, 66.7% of A. hydrophila, 80% of A. allosacharophila and 46.6% of Aeromonas spp. were hemolytic. The assay for checking production of toxins showed that 17.5% of A. caviae, 73.3% of A. hydrophila, 60% of A. allosacharophila, 100% of A. schubertii, and 33.3% of Aeromonas spp. were able to produce toxins. The results demonstrated the pathogenic potential of Aeromonas, indicating that the presence of this emerging pathogen in water systems is a public health concern
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A total of 72 strains of Staphylococcus aureus were examined for the production of staphylococcal enterotoxins (SE) A, B, C, D and toxic shock syndrome toxin (TSST-1). The strains were isolated from milk samples from cows with mastitis in dairy herds of São Paulo State, Brazil. Off 72 isolates, 38 (52.8%) produced SEA, 38 (52.8%) SEB, 32 (44.4%) SED, 28 (38.9%) SEC and 27 (37.5%) TSST-1. From the 72 strains, 66 (91.7%) produced, at least, one or more toxin, including TSST-1.
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Food poisoning can cause infection on its consumers by the presence of pathogenic bacteria, such as Salmonella and Staphylococcus aureus. Therefore, it is important to check its quality, which can be affected by many factors. The sanitary quality of foods can be assessed by thermotolerant coliform. Since food safety is a matter of great concern, this study aimed to evaluate the hygienic sanitary conditions of samples of ice cream and desserts marketed in the city of Botucatu, by determining the most probable number (MPN) of thermotolerant coliform, identification and enumeration of coagulase positive staphylococci and verification of classical enterotoxin production by strains of S. aureus and also for detecting the presence of Salmonella sp. Among the ice cream analyzed, 56.3% were unfit for consumption and between the creamy desserts, the percentage of unfit samples was 33.3%. Coagulase positive Staphylococcus and Salmonella were not found in the samples. It is then an inadequacy in handling and / or storage conditions in a considerable number of samples, indicating need for improvement in the conditions of preparation
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Linhagens de estafilococos coagulase negativos e pauciprodutores de enterotoxina de A a E, com capacidade de síntese variando de 1,4 a 16ng/mL oriundas de sítios anatômicos de cabras sadias, procedentes da Espanha, foram estudadas com o intuito de se avaliar a capacidade de desenvolvimento e produção de enterotoxina estafilocócica ("SE"), em alimentos experimentalmente inoculados. Para tal, leite integral "tipo longa vida" e presunto cozido foram, de maneira isolada e em duplicata, inoculados com 14 linhagens teste, S.caprae, duas amostras; S.chromogenes; S.cohnii; S.epidermidis; S.haemolyticus, duas amostras; S.hyicus; S.lentus; S.sciuri; S.xylosus, duas amostras; e S.warneri, duas amostras; previamente caracterizadas bioquimicamente. Estes substratos alimentícios, uma vez inoculados, foram mantidos em estufa a 30°C, durante 24 e 48h de incubação e, neste período, submetidos à contagem de células estafilocócicas em ágar Baird Parker e à avaliação de presença de "SE", através do ensaio de "ELISA-SET-EIA, Enzyme Linked-Immunosorbent Assay," e "RPLA, Reversed Passive Latex Agglutination Assay". Os resultados obtidos evidenciaram, tanto em leite integral "tipo longa vida" como em presunto cozido, desenvolvimento mínimo estipulado em 10(6) e máximo de 10(9)UFC/g ou mL do alimento, decorridas 48h de incubação.De acordo com as condições aplicadas neste experimento não apresentaram, contudo, em nenhuma ocasião produção de "SE" que pudesse ter sido detectada .
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Pós-graduação em Biologia Geral e Aplicada - IBB
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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We studied the molecular epidemiology of Staphylococcus aureus strains potentially toxigenic, isolated from the production process of Minas frescal cheese in a small dairy plant in the state of São Paulo. For this, samples were taken during the period from June 2008 to July 2009. Samples were collected from the surface of the receiving and storage tanks of raw milk, the surface of the balance tank of pasteurized milk, the water supply system, the pipes and equipments, the hands of the handler and from the packaged cheese, totaling 140 samples. The colonies isolated on Baird-Parker Agar confirmed as Gram positive and positive for catalase, coagulase and acetoin production, were submitted to extraction of bacterial DNA using the Invitek - Uniscience® kit. Confirmation of the isolated species and enterotoxins SEA, SEB, SEC, SED and TSST-1 toxin was carried out through the amplification of specific fragments of chromosomal DNA. Among the 74 strains of isolated coagulase-positive staphylococci, only 41 (55.4%) strains were confirmed as Staphylococcus aureus, of which 25 (61.0%) were positive to the presence of staphylococcal toxins. The most frequently identified enterotoxin was SEA. The toxigenic strains of Staphylococcus aureus were more frequently isolated from hands of the handler (16.0%), raw milk receiving tank (12.0%), pasteurized milk for cheese making (12.0%) and fresh white cheese ready for consumption (12.0%).
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Staphylococcus is one of the more important causes of the called Foodborne Disease(FD), being that from the 40 species described from genus, the more important is Staphylococcus aureus. During years believed that the S. aureus was the only specie from genus able to produce enterotoxins, responsable for the clinical frame in humans, but latest studies report the isolation of other species both positive coagulase (PC) as negative with enterotoxigenic potential. The symptoms of this intoxication appear after a short period of incubation (2-6 hours) and usually characterized by nausea, vomits, abdominal ache, diarrhea, and rarely is fatal. For the toxin to be formed in food is necessary that bacteria population to be at least 105 UFC/g, being that such toxins characterized by presenting great resistance front of gastrointestinal proteases and of homemade termical treatment. Among the main foods that might carry the microorganism, the milk and its derivatives have highlights. The contamination of the product might happen as from the milk from cows with clinical and/or subclinical mastitis, as the Staphylococcus genus is one of the main agents etiologic from this disease, equipments utensils badly sanitized equipments and utensils and from the manipulators. The control of these factors configures as fundamental condition for the achievement of a safe, quality product, which doesn’t offer risk to the consumers
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, Programa de Pós-Graduação em Saúde Animal, 2016.
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The production of ethyl esters by alcoholysis is an alternative for splitting triacylglycerols due to the possibility of using low temperatures, which results in oxidative protection of the polyunsaturated fatty acids. Ethyl esters produced under mild conditions of temperature could be used as substrate for obtaining structured lipids. The reaction parameters of production of ethyl esters from fish oil with high content of omega-3 fatty acids by alcoholysis were optimized using response surface methodology. An experimental design (2³) (with levels +1 and -1, six axial points with levels -alpha and +alpha and three central points) was applied. The variables investigated were concentration of catalyst, amount of ethyl alcohol and temperature. Ethyl ester conversion was monitored by high performance size exclusion chromatography (HPSEC) and the best result obtained was 95% conversion rate. The optimal conditions were 40 °C, 1% of NaOH and 36% of ethanol.
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Isomaltulose, a functional isomer of sucrose, is a non-cariogenic reducing disaccharide; has a low glycemic index; selectively promotes growth of beneficial bifidobacteria in the human intestinal microflora; and has greater stability than sucrose in some foods and beverages. Isomaltulose is a nutritional sugar that is digested more slowly than sucrose, and has health advantages for diabetics and nondiabetics. Immobilization techniques, especially entrapment of the cells, are widely used for conversion of sucrose into isomaltulose. Immobilization offers advantages such as minimum downstream processing, continuous operation and reusability of cells. Isomaltulose is currently considered to be a promising sugar substitute.
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Alginate microparticles were prepared by an emulsion method aiming oral controlled release of antigens to fish. The effects of emulsification temperature and impeller type on particle morphology, average diameter, and size distribution were evaluated. Microparticles contaning formalin-killed Flavobacterium columnare cells (a model antigen) were prepared and characterized regarding bacterial release and particle stability when exposed to Nile tilapia (Oreochromis niloticus) typical gastrointestinal conditions. This methodology allowed the production of microparticles containing up to 14.3 g/L of bacterin, stable at a pH range from 2.0 to 9.0 for 12 h and smaller than 35 μm.
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Poorly soluble drugs have low bioavailability, representing a major challenge for the pharmaceutical industry. Processing drugs into the nanosized range changes their physical properties, and these are being used in pharmaceutics to develop innovative formulations known as Nanocrystals. Use of nanocrystals to overcome the problem of low bioavailability, and their production using different techniques such as microfluidization or high pressure homogenization, was reviewed in this paper. Examples of drugs, cosmetics and nutraceutical ingredients were also discussed. These technologies are well established in the pharmaceutical industry and are approved by the Food and Drug Administration.