979 resultados para Streptococcus pyogenes


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The purpose of this study was to isolate yeast (Candida) from the quarter milk of cow udders from 37 dairy farms in Brazil and to identify the different species involved in mastitis. The samples were collected between October 2002 and February 2003. Two-hundred-and-sixty milk samples from cows with clinical and subclinical mastitis were examined. Milk samples were plated onto Blood agar, Mac Conkey agar and Sabouraud dextrose agar. Forty-five (17.3%) samples were positive for the genus Candida. The Candida species isolated were C. krusei (44.5%), C. rugosa (24.5%), C. albicans (8.9%), C. guilliermondii (8.9%), and others (13.2%). We also isolated Escherichia coli (26.5%), coagulase-positive Staphylococcus (25.0%), Streptococcus spp. (8.1%), Enterobacter spp. (8.1%), and other fungi (8.1%), among others.

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Gelatin microparticles containing propolis ethanolic extractive solution were prepared by spray-drying technique. Particle,, with regular morphology, mean diameter ranging of 2.27 mu m to 2.48 mu m, and good entrapment efficiency for propolis were obtained. The in vitro antimicrobial activity of microparticles was evaluated against microorganisms of oral importance (Enterococcus faecalis, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis, Streptococcus mutans, Streptococcus sobrinus, Candida albicans, and Lactobacillus casei). The utilized techniques were diffusion in agar and determination of minimum inhibitory concentration. The choice of the method to evaluate the antimicrobial activity of microparticles showed be very important. The microparticles displayed activity against all tested strains of similar way to the propolis, showing greater activity against the strains of E. salivarius, S. sanguinis, S. mitis, and C albicans.

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The aims of this study were to estimate the changes in total bacterial counts (TBC) in poultry litter samples, consisting of rice hulls, after storage, and to identify pathogenic bacteria. For the countings Plate Count agar (Difco) was used. Enrichment and selective media such as blood agar, MacConkey, Baird Parker, brain and heart agar, and egg yolk solid media, and cooked meat and brain and heart infusion, incubated under aerobic or anaerobic conditions were used to isolate Staphylococcus aureus, Salmonella sp, Clostridium perfringens, C. botulinum, C. chauvoei, Campylobacter sp, Escherichia coli, and Corynebacterium sp. Litter samples were collected from the houses of the Veterinary School experimental aviary. A fully randomized experimental design was used with four treatments and four replications, for a total of 16 samples. A decrease in TBC was detected when treatment T1 (zero days of storage) was compared with treatments T2 (14 days of storage). on the other hand the treatments T3 (28 days of storage) and T4 (42 days of storage) presented significantly superior counting in relation to treatment T1. Some pathogenic bacteria of Enterobacteriaceae such as Escherichia coil, Proteus, Arizona, Providencia, Edwardsiella, as well as Staphylococcus aureus, S. epidermidis, different species of genus Clostridium as C. perfringens, C. sordelli, C. chauvoei, C. tetani and C. novyi as well as some strains of Corynebacterium pyogenes were isolated.

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Ingestion of transgalactosylated oligosaccharides (TOS) and other non-digestible oligosaccharides (NDOs) induces a significant increase in Bifidobacterium, Lactobacillus and some desirable species of Streptococcus populations in the gut of human and other animals (prebiotic effect). This change in the intestinal flora is responsible for several beneficial physiological effects such as a decrease of putrefactive products in the feces, lower blood cholesterol content, higher Ca2+ absorption, a smaller loss of bone tissue in ovariotomized female rats and a lower incidence of colon cancer. beta-Galactosidase from Penicillium simplicissimum, a strain isolated from soil, showed high galactosyltransferase activity when incubated with a highly concentrated lactose solution. Optimum pH and temperature ranges for hydrolytic activity were 4.0-4.6 and 55-60 degrees C, respectively, for a lactose concentration of 5.0% (w/v). Maximal galactosyltransferase activity was obtained at pH 6.5 and 50 degrees C and TOS synthesis was positively associated with lactose concentration in the reaction medium. Thus, when 50 ml of a 60% (w/v) lactose solution was incubated with 26.6 U of beta-galactosidase under the best pH and temperature conditions for transferase activity, a final product with 30.5% TOS (183 mg ml(-1)), 27.5% residual lactose and 42.0% monosaccharides was obtained. (C) 1999 Elsevier B.V. Ltd. All rights reserved.

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Pseudomonas aeruginosa LBI isolated from petroleum-contaminated soil produced rhamnolipids (RLLBI) when cultivated on soapstock as the sole carbon source. HPLC-MS analysis of the purified culture supernatant identified 6 RL homologues (%): R-2 C-10 C-10 28.9; R-2 C-10 C-12:1 23.0; R-1 C-10 C-10 23.4; R-2 C-10 C-12 11.3; R-2 C-10 C-12 7.9; R-2 C-10 C-12 C-12 5.5. To assess the potential antimicrobial activity of the new rhamnolipid product, RLLBI, its physicochemical properties were studied. RLLBI had a surface tension of 24 mN m(-1) and an interfacial tension 1.31 mN m(-1); the cmc was 120 mg l(-1). RLLBI produced stable emulsions with hydrocarbons and vegetable oils. This product showed good antimicrobial behaviour against bacteria: MIC for Bacillus subtilis, Staphylococcus aureus and Proteus vulgaris was 8 mg l(-1), for Streptococcus faecalis 4 mg l(-1), and for Pseudomonas aeruginosa 32 mg l(-1). RLLBI was active against phytopathogenic fungal species, MIC values of 32 mg l(-1) being found against Penicillium, Alternaria, Gliocadium virens and Chaetonium globosum. Due to its physicochemical properties and antimicrobial behaviour, RLLBI could be used in bioremediation treatment and in the food, cosmetic and pharmaceutical industries.

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The effect of milk processing on rheological and textural properties of probiotic low-fat yogurt (fermented by two different starter cultures) was studied. Skim milk fortified with skim milk powder was subjected to three treatments: (1) thermal treatment at 85C for 30 min; (2) high hydrostatic pressure (HHP) at 676 MPa for 5 min; and (3) combined treatments of HHP (676 MPa for 5 min) and heat (85C for 30 min). The processed milk was fermented using two different starter cultures containing Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus and Bifidobacterium longum at inoculation rates of 0.1 and 0.2%. Rheological parameters were determined and a texture profile analysis was carried out. Yogurts presented different rheological behaviors according to the treatment used, which could be attributed to structural phenomena. The combined HHP and heat treatment of milks resulted in yogurt gels with higher consistency index values than gels obtained from thermally treated milk. The type of starter culture and inoculation rate, providing different fermentation pathways, also affected the consistency index and textural properties significantly. The combined HHP and heat treatment of milks before fermentation, and an inoculation rate of 0.1% (for both cultures), led to desirable rheological and textural properties in yogurt, which presented a creamy and thick consistency that does not require the addition of stabilizers.

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The effect of milk processing on the microstructure of probiotic low-fat yogurt was studied. Skim milk fortified with skim milk powder was subjected to three treatments prior to innoculation: thermal treatment at 85 degrees C for 30 min, high hydrostatic pressure at 676 MPa for 5 min, and combined treatments of high hydrostatic pressure (HHP) and heat. The processed milk was then fermented by using two different starter cultures containing Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus, and Bifidobacterium longum. The microstructure of heat-treated milk yogurt had fewer interconnected chains of irregularly shaped casein micelles, forming a network that enclosed the void spaces. on the other hand, microstructure of HHP yogurt had more interconnected clusters of densely aggregated protein of reduced particle size, with an appearance more spherical in shape, exhibiting a smoother more regular surface and presenting more uniform size distribution. The combined HHP and heat milk treatments led to compact yogurt gels with increasingly larger casein micelle clusters interspaced by void spaces, and exhibited a high degree of cross-linking. The rounded micelles tended to fuse and form small irregular aggregates in association with clumps of dense amorphous material, which resulted in improved gel texture and viscosity. (C) 2007 Elsevier Ltd. All rights reserved.

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"Antimicrobial activity of crude extratcs of Petiveria alliacea L.". Petiveria alliacea L. (Phytolaccacea) is an herbaceous plant of great importance in traditional medicine. This species have been widely used in several applications such as antirheumatic, anticarcinogenic, anti-flu, antitussive, analgesic, insecticidal, acaricidal, as well as bactericide and fungicide. Currently, the pathogenic microorganisms are acquiring resistence against the traditional antibiotics, and the search for new herbal antimicrobial agents has been intensified. The objective of this study was to evaluate the antifungal and antibacterial activity of several leaf crude extracts of P. alliacea against several strains of bacterias and yeasts namely Bacilus subtilis, Pseudomonas aeruginosa, Escherichia coli, Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Candida parapsilosis, Candida kefyr and Candida albicans, using microdilution method. Promising results were observed for the 70% v/v ethanolic extract which presented minimum inhibitory concentration (MIC) from 250 to 760 mu g/mL for yeast. For the bacteria strains tested the MIC ranged between 240 to 3960 mu g/mL, depending of the extractive solution tested.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Aiming to know the influence of the pluviometric precipitation over the physical chemical and bacteriological characteristics of the water coming from three sources of public supply, and to verify the probable origin of faecal contamination, tests of total coliforms, faecal coliforms, faecal streptococci and mesophilic microorganisms, as well as the determination of pH, temperature and turbidity of 156 water samples were done. The samples were taken from a stream, a drain and an artesian well, located in the city of Jaboticabal, SP, Brazil. The results obtained showed that the occurrence of pluviometric precipitation determined a significant increase of the number of total coliforms in the water samples from the stream. The use of the ratio CF/EF, indicate the probable origin of the faecal contamination only in the samples of the water coming from the stream, which were defined as being of human origin. In relation to the physical-chemical composition it was noticed that the influence of the pluviometric precipitation over the turbidity appeared to be higher and significant in the samples of water of the stream.

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Cara inchada of cattle (CI) is a periodontitis which occurs in calves in several regions of Brazil. Its progressive lesions, caused mainly by Bacteroides melaninogenicus and Actinomyces pyogenes, could lead to loss of teeth, malnutrition and possibly death of affected animals. For further analysis of the pathogenesis of this disease the influence of streptomycin on the adherence of the causative bacteria to oral epithelial cells of cattle was determined. Production of streptomycin by soil bacteria (Actinomycetes) in Brazil had been suggested by several authors. In our studies, streptomycin in subinibitory concentrations increased tenfold the rate of adherence with B. melaninogenicus (from 0.4 to 4.0 bacteria per bovine epithelial cell). On the contrary, streptomycin did not influence significantly the adherence of A. pyogenes nor streptococci of the viridans group. Thus, streptomycin could be a contributing factor to the development of the periodontal infections with B. melaninogenicus.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The study was carried out to test the ability of Enterococcus faecium, Lactobacillus acidophilus, L. jugurti, Streptococcus thermophilus and L. delbrueckii ssp bulgaricus to decrease cholesterol in vitro and to grow in the presence of bile salts. Both properties were dependent on the species under study. The cultures were also inoculated into soymilk fortified with dry milk whey powder as single or mixed starters. The physicochemical and sensory evaluations of the fermented products showed that E. faecium plus L. jugurti (ratio 1:1) is the best combination, and this mixture also produces a 43% decrease in cholesterol. © Springer-Verlag 1999.

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A revision was accomplished in the literature on the quinolones, antibacterial class that presents wide action spectrum, focusing, mainly, the sparfloxacin, third generation fluorquinolone which has potente activity against Gram positive organisms, including Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA), Gram negative organisms, Legionelia spp, Mycoplasma spp, Chlamydia spp and Mycobacterium spp, including multidrug resistant organisms.