44 research outputs found

    Vibrio parahaemolyticus-specific Halobacteriovorax From Seawater of a Mussel Harvesting Area in the Adriatic Sea: Abundance, Diversity, Efficiency and Relationship With the Prey Natural Level

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    This research aimed to study the abundance and molecular diversity of Vibrio parahaemolyticus-specific Halobacteriovorax strains isolated from seawater of the Adriatic Sea and the relationship between predator and prey abundances. Moreover, predator efficiency of the Halobacteriovorax isolates toward V. parahaemolyticus and Vibrio cholerae non-O1/O139 strains was tested. V. parahaemolyticus NCTC 10885 was used as primary host for the isolation of Halobacteriovorax from seawater by the plaque assay. Molecular identification was performed by PCR detection of a fragment of the 16S rRNA gene of the Halobacteriovoraceae family members. Moreover, 700 bp PCR products were sequenced and compared between them and to clones described for other sampling sites. Vibrio counts were performed on TCBS agar from 100 ml of filtered water samples and presumptive colonies were confirmed by standard methods. Predatory efficiency of Halobacteriovorax isolates was tested by monitoring abilities of 3-day enrichments to form clear lytic halos on a lawn of Vibrio preys, by the plaque assay. Out of 12 seawater samples monthly collected from June 2017 to May 2018, 10 were positive for V. parahaemolyticus specific Halobacteriovorax with counts ranging from 4 to 1.4 × 103 PFU per 7.5 ml. No significant relationship was found between Halobacteriovorax and Vibrio abundances. The 16SrRNA sequences of our Halobacteriovorax strains, one for each positive sample, were divided into three lineages. Within the lineages, some sequences had 100% similarity. Sequence similarity between lineages was always <94.5% suggesting that they may therefore well belong to three different species. All Halobacteriovorax isolates had the ability to prey all tested Vibrio strains. Additional research is necessary to assess whether stable strains of Halobacteriovorax are present in the Adriatic Sea and to understand the mechanisms by which Halobacteriovorax may modulate the abundance of V. parahaemolyticus and other vibrios in a complex marine ecosystem

    Bdellovibrio bacteriovorus to control Escherichia coli on meat matrices

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    Bdellovibrio bacteriovorus is a predator micro-organism towards other Gram-negative bacteria. We tested B. bacteriovorus to control Escherichia coli growth on chicken slices and canned beef. Moreover, we analysed B. bacteriovorus's lytic ability on eight toxigenic or multidrug-resistant E. coli strains. In chicken slices, the predator induced the highest prey reduction (4.3 log) respect to control at 6 h. In canned beef, the predator induced the highest prey reduction (2.1 log) respect to control at 6 h. Moreover, B. bacteriovorus showed lytic ability towards all tested E. coli strains. B. bacteriovorus could control E. coli and other pathogenic and spoilage bacteria in those meat-based foods that have a shelf life <10 days. It could integrate modified atmosphere packaging (MAP) to prolong the shelf life and improve the safety of pre-packed fresh meat, meat preparations and meat products. In future applications on meat-based foods, B. bacteriovorus could also minimise the use of additives

    Genotypic Diversity of Streptococcus mutans in Caries-Free and Caries-Active Preschool Children

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    Aim. The aim of the present paper was to evaluate the genotypic diversity of S. mutans in caries-free and caries-active preschool children in Brazil. Design. Twenty-eight preschool children were examined regarding caries experience by the dmft index. DNA from 280 isolates of S. mutans was extracted. S. mutans evaluated using to the PCR method, with primers for the glucosyltransferase gene. The genetic diversity of S. mutans isolates was analyzed by arbitrary primed-PCR (AP-PCR) reactions. The differences between the diversity genotypic and dmft/caries experience were evaluated by χ2 test and Spearman's correlation. Results. The Spearman correlation test showed a strong association between genotypic diversity and caries experience (r = 0.72; P < .001). There were more S. mutans genotypes in the group of preschool children with dental caries, compared with the caries-free group. Among the children with more than 1 genotype, 13 had dental caries (2 to 5 genotypes) and 4 were caries-free (only 2 genotypes). Conclusion. Our results support the previous findings of genetic diversity of S. mutans in preschool children being associated with dental caries. The investigation of such populations may be important for directing the development of programs for caries prevention worldwide

    Effect of ketogenic mediterranean diet with phytoextracts and low carbohydrates/high-protein meals on weight, cardiovascular risk factors, body composition and diet compliance in Italian council employees

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    <p>Abstract</p> <p>Background</p> <p>There has been increased interest in recent years in very low carbohydrate ketogenic diets (VLCKD) that, even though they are much discussed and often opposed, have undoubtedly been shown to be effective, at least in the short to medium term, as a tool to tackle obesity, hyperlipidemia and some cardiovascular risk factors. For this reason the ketogenic diet represents an interesting option but unfortunately suffers from a low compliance. The aim of this pilot study is to ascertain the safety and effects of a modified ketogenic diet that utilizes ingredients which are low in carbohydrates but are formulated to simulate its aspect and taste and also contain phytoextracts to add beneficial effects of important vegetable components.</p> <p>Methods</p> <p>The study group consisted of 106 Rome council employees with a body mass index of ≥ 25, age between 18 and 65 years (19 male and 87 female; mean age 48.49 ± 10.3). We investigated the effects of a modified ketogenic diet based on green vegetables, olive oil, fish and meat plus dishes composed of high quality protein and virtually zero carbohydrate but which mimic their taste, with the addition of some herbal extracts (KEMEPHY ketogenic Mediterranean with phytoextracts). Calories in the diet were unlimited. Measurements were taken before and after 6 weeks of diet.</p> <p>Results</p> <p>There were no significant changes in BUN, ALT, AST, GGT and blood creatinine. We detected a significant (p < 0.0001) reduction in BMI (31.45 Kg/m<sup>2 </sup>to 29.01 Kg/m<sup>2</sup>), body weight (86.15 kg to 79.43 Kg), percentage of fat mass (41.24% to 34.99%), waist circumference (106.56 cm to 97.10 cm), total cholesterol (204 mg/dl to 181 mg/dl), LDLc (150 mg/dl to 136 mg/dl), triglycerides (119 mg/dl to 93 mg/dl) and blood glucose (96 mg/dl to 91 mg/dl). There was a significant (p < 0.0001) increase in HDLc (46 mg/dl to 52 mg/dl).</p> <p>Conclusions</p> <p>The KEMEPHY diet lead to weight reduction, improvements in cardiovascular risk markers, reduction in waist circumference and showed good compliance.</p

    Effect of Silicon dioxide coating of acrylic resin surfaces on Candida albicans adhesion.

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    Acrylic resin has been used in the manufacture of prostheses, however, in the oral cavity, this material starts to retain microorganisms capable of causing gingival inflammation due its porosities. The aim of this study was to evaluate the influence of the use of silicon dioxide as a coating layer applied onto acrylic resin, on the adhesion of Candida albicans (Ca). After the incubation period in Sabouraud Dextrose Broth, a total of 1 ml of the Ca suspension was added to plate wells, each well containing a specimen of acrylic resin. The adhesion ability of Ca on acrylic resin was determined by counting colonies. Three groups (n = 6) of acrylic resin were assessed: with polishing (RP); without polishing (RW); with polishing and coating layer of silicon dioxide (RPC). Ca deposited on the surface of the acrylic resin was also observed using Scanning Electron Microscopy (SEM). Statistical assessment by Kruskal-Wallis and Student-Newman-Keuls Method were done (α = 2%). There was significant difference among the groups. The RPC group showed the lowest growth, with an average of 5.59 Log CFU/cm 2 ; there was a statistically significant difference in relation to group RW, which presented a growth of 6.07 Log CFU/cm 2 and to group RP with 5.91 Log CFU/cm 2 (p < 000.1). SEM images demonstrated that in the RP and RPC group, the surface of the resin had greater regularity, and smaller number of microorganisms. The application of silicon dioxide coating on acrylic resin appears to be a promising alternative, and its use can help in reducing the adhesion of Ca in prostheses

    The role of reactive oxygen species in adipogenic differentiation

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    Interest in reactive oxygen species and adipocyte differentiation/adipose tissue function is steadily increasing. This is due in part to a search for alternative avenues for combating obesity, which results from the excess accumulation of adipose tissue. Obesity is a major risk factor for complex disorders such as cancer, type 2 diabetes, and cardiovascular diseases. The ability of mesenchymal stromal/stem cells (MSCs) to differentiate into adipocytes is often used as a model for studying adipogenesis in vitro. A key focus is the effect of both intra- and extracellular reactive oxygen species (ROS) on adipogenesis. The consensus from the majority of studies is that ROS, irrespective of the source, promote adipogenesis. The effect of ROS on adipogenesis is suppressed by antioxidants or ROS scavengers. Reactive oxygen species are generated during the process of adipocyte differentiation as well as by other cell metabolic processes. Despite many studies in this field, it is still not possible to state with certainty whether ROS measured during adipocyte differentiation are a cause or consequence of this process. In addition, it is still unclear what the exact sources are of the ROS that initiate and/or drive adipogenic differentiation in MSCs in vivo. This review provides an overview of our understanding of the role of ROS in adipocyte differentiation as well as how certain ROS scavengers and antioxidants might affect this process.The South African Medical Research Council in terms of the SAMRC's Flagship Award Project SAMRC-RFA-UFSP-01-2013/STEM CELLS, the SAMRC Extramural Unit for Stem Cell Research and Therapy and the Institute for Cellular and Molecular Medicine of the University of Pretoria.http://www.springer.comseries/5584hj2019GeneticsImmunologyOral Pathology and Oral Biolog

    Friction stir lap welding of aluminium alloys

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    The friction stir welding of lap sheets can be performed considering different variables in terms of process parameters, tool configuration, welding typology and so on. The proposed investigation deals with the friction stir welding of blanks, with the same thickness, performed under lap configuration with the sheets welded, in one-side and in both sides as well, with different tool geometries and tool rotation-wise. The double side allows to extend the weld through the whole thickness leading to better mechanical welding properties at the blank to blank interface. The weld morphology has been investigated through microstructure observations performed on the transverse area, with respect to the welding velocity, of each joint. The tensile shear strength of the joint in one-side weld is generally lower than that detected in two side weld

    Evaluation of equine hemograms using the ADVIA 120 as compared with an impedance counter and manual differential count

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    Background: The ADVIA 120 is an automated laser cell counter widely used in veterinary medicine. Although specific software for equine samples is available and validated, only a few reports have been published comparing the ADVIA 120 with other methods for equine hemogram evaluation. Objectives: The purpose of this study was to compare the hematologic values and reference intervals obtained on the ADVIA 120 with those obtained on an impedance cell counter and manual differential counts in healthy horses. Methods: EDTA-anticoagulated blood samples were obtained from 114 clinically healthy horses of various breeds, both sexes, and 2-6 years of age. Samples were stored for up to 12 hours at 4°C and then analyzed on the ADVIA 120 and the Hemat 8. A 100-cell to 200-cell differential leukocyte count was performed by 3 independent observers on May-Grünwald-Giemsa-stained smears. Intra-assay precision of the ADVIA 120 was determined by analyzing 5 replicates each of 10 of the blood samples. Results: Results from the ADVIA were significantly higher than those from the impedance counter for RBC count, total WBC count, hemoglobin concentration, red cell distribution width, MCH, and MCHC, and significantly lower for HCT and platelet count. Significantly higher neutrophil and basophil counts and significantly lower lymphocyte counts were obtained with the ADVIA 120 compared with manual counts. Based on Passing-Bablok regression analysis, RBC and platelet counts were in good agreement between the 2 analyzers; a constant and proportional bias was present for other values. Coefficients of variation for erythrocyte parameters on the ADVIA were < 1%, but were higher for platelet (6%), total WBC (2%), differential WBC (4%-30%), and reticulocyte (75%) counts. Conclusions: Results obtained with equine samples on the ADVIA 120 were comparable with those obtained on an impedance counter; reference intervals differed statistically but overlapped. The ADVIA had poor precision for reticulocyte and differential leukocyte counts such that the latter should always be verified on smears
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