1,721,026 research outputs found
Effects of probiotic administration upon the composition and enzymatic activity of human fecal microbiota in patients with irritable bowel syndrome or functional diarrhea
No full textIn a clinical trial, 10 patients suffering from irritable bowel syndrome or functional diarrhea were administered the probiotic preparation VSL-3. Preliminary results indicated that administration of VSL-3 improved the clinical picture and changed the composition and biochemistry of fecal microbiota. Titer variations of intestinal bacterial groups were evaluated by culture and PCR techniques. A significant increase in lactobacilli, bifidobacteria and Streptococcus thermophilus was observed as a consequence of probiotic treatment, while enterococci, coliforms, Bacteroides and Clostridium perfringens did not change significantly. The strains Bifidobacterium infantis Y1 and Bifidobacterium breve Y8, included in VSL-3, were specifically detected in feces of patients treated with the probiotic by using strain-specific PCR primers. In addition, fecal β-galactosidase increased and urease activities decreased as a result of changes in the intestinal microbiota induced by VSL-3 administration. © 2001 Éditions scientifiques et médicales Elsevier SAS
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Cloning of the gene for cholesterol oxidase in Bacillus spp., Lactobacillus reuteri and its expression in Escherichia coli
No full textThe cloning of the cholesterol oxidase gene in several Gram-positive bacteria, including Lactobacillus reuteri of intestinal origin, was obtained. Only the transformants of Escherichia coli harbouring the recombinant plasmid pCHOA showed a good intracellular enzyme activity. The heterologous gene was stably maintained in Gram-positive transformants but no enzyme activity was detected
Studi genetici e biochimici del plasmide pLHJ1 di Lactobacillus helveticus subsp. jugurti S36.2.
No full textQuantitative detection of probiotic Bifidobacterium strains in bacterial mixtures by using real-time PCR
No full textStrain-specific rRNA-targeted primers were designed for the quantitative detection of Bifidobacterium infantis Y1, B. breve Y8 and B. longum Y10 used in a pharmaceutical probiotic product (VSL-3). PCR and real-time PCR techniques with the selected primers were employed for the direct enumeration of the bifidobacteria in the probiotic preparation and for studying their kinetic characteristics in batch cultures. These analysis revealed that B. infantis Y1 was the predominant strain in the probiotic product and that its growth rate was the highest. Since B. infantis Y1, B. breve Y8 and B. longum Y10 are co-cultured during the industrial production of VSL-3, the kinetic characteristics of these strains can explain their different concentrations in the probiotic preparation. A validation of the PCR quantification method was performed by identifying a representative number of isolates from the bacterial mixtures with automated ribotyping. The methodology described represents a useful tool for the specific quantitative detection of bacterial strains and species in complex mixtures such as pharmaceutical preparations, dairy starter cultures, faecal samples and biopsies
Characterization and molecular cloning of Bifidobacterium longum cryptic plasmid pMB1
No full textThe small cryptic plasmid pMB1 (1.9 kb), previously isolated from Bifidobacterium longum, has been characterized by physical mapping. Two cloning vectors, pMR3 and pDG7, carrying chloramphenicol and ampicillin resistances derived from pJH101, have been electroporated in Escherichia coli
Plasmid screening in thermophilic Bacillus: Physical characterization and molecular cloning
No full textScreening for the plasmid content of 94 strains belonging to ten species of thermophilic bacilli mainly referred toBacillus stearothermophilus was carried out. Twenty-seven of the strains tested were found to harbor one or more plasmids ranging in size from 1.7 to>50 kb. The physical map of the smallest plasmid, pBC1, is reported. Southern hybridization experiments showed that pBC1 hybridized strongly with the other small plasmids, weakly with medium-sized plasmids, and not at all with the largest plasmids and chromosomal DNA. pBC1 was cloned into pHV14 and pJH101 vectors, and the chimeric plasmids obtained were used to transformEscherichia coli andBacillus subtilis
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