Search results for "Hybridization"
showing 10 items of 812 documents
Selective growth-inhibitory effect of 8-hydroxyquinoline towards Clostridium difficile and Bifidobacterium longum subsp. longum in co-culture analyse…
2014
The major risk factor for Clostridium difficile infection (CDI) is the use of antibiotics owing to the disruption of the equilibrium of the host gut microbiota. To preserve the beneficial resident probiotic bacteria during infection treatment, the use of molecules with selective antibacterial activity enhances the efficacy by selectively removing C. difficile. One of them is the plant alkaloid 8-hydroxyquinoline (8HQ), which has been shown to selectively inhibit clostridia without repressing bifidobacteria. Selective antimicrobial activity is generally tested by culture techniques of individual bacterial strains. However, the main limitation of these techniques is the inability to describe …
Specific DNA probes to detect Escherichia coli strains producing cytotoxic necrotising factor type 1 or type 2
1994
Cytotoxic necrotising factors type 1 (CNF1) and type 2 (CNF2) are produced by many Escherichia coli strains isolated from man and animals with intestinal or extra-intestinal colibacillosis. In most laboratories, CNF-producing strains are detected by a cell cytotoxicity assay and confirmed with a neutralisation assay or a mouse footpad assay. In this study, we sought to determine whether DNA probes could detect clinical isolates of E. coli producing CNF2 or CNF1, or both, without the need for cell cultures or animal assays. Two internal fragments of the gene encoding CNF2 were used as DNA probes: a 875-bp XhoI-PstI DNA fragment and an adjacent 335-bp PstI-ClaI fragment. A positive response w…
Enzyme-linked immunoassay for detection of PCR-amplified DNA of legionellae in bronchoalveolar fluid.
1995
A nonradioactive method is described that detects 10 to 100 legionellae in 1 ml of bronchoalveolar lavage fluid. DNA is purified by a proteinase K-phenol protocol or with a commercial DNA preparation kit and amplified by PCR with amplimers specific for the 16S rRNA gene of Legionella pneumophila. The upstream primer is 5' biotinylated. The amplification product is immobilized on streptavidin-coated microtiter plates. Because of the high binding capacity, no removal of nonincorporated biotin from the PCR product is required. After alkaline denaturation, the single-stranded PCR product is hybridized with a 5' digoxigenin-labeled probing oligomer. The amplification product is then detected by …
Detection of hepatitis B virus DNA by polymerase chain reaction in serum and liver of children with chronic hepatitis B negative for hepatitis B viru…
1992
Hepatitis B virus (HBV) DNA was detected by polymerase chain reaction in the serum of 87 and liver tissue of 40 children with chronic hepatitis B, negative for HBV DNA by dot blot and Southern blot hybridization, respectively. In sera HBV DNA could be detected in 73 hepatitis B surface antigen carriers; 14 were hepatitis B e antigen (HBeAg), 56 were anti-HBe-seropositive and 3 had neither HBeAg nor positive anti-HBe. In 14 anti-HBe-positive patients no HBV DNA could be found. Viral sequences in liver tissue were present in 33 specimens; 20 were HBeAg and 13 were anti-HBe-seropositive. All of the 7 negative children had anti-HBe. Our results confirm polymerase chain reaction to be a more sen…
Eukaryotes Are a Holophyletic Group of Polyphyletic Origin.
2020
Because of the polyphyletic origin of the eukaryotic monophylum, eukaryogenesis within prokaryotes is not comparable with mammal origin within paraphyletic reptiles. Both synapomorphies and plesiomorphies represent apomorphies and are indeed suitable for defining monophyletic (holophyletic and paraphyletic) groups. Alphaproteobacteria (Bacteria) and Asgard (Archaea) are the ancestors of LECA (the Last Eukaryotic Common Ancestor). The presence of ESPs in Asgard does not dispute the polyphyletic origin of eukaryotes ; it only further corroborates it. “Candidatus Prometheoarchaeum syntrophicum” is the closest relative to eukaryotes and the only Asgard with available microscopy data. This newly…
Characteristics of Escherichia coli strains belonging to enteropathogenic E. coli serogroups isolated in Italy from children with diarrhea.
1996
Fifty-five Escherichia coli strains belonging to enteropathogenic E. coli (EPEC) serogroups were examined for phenotypic and genetic factors associated with virulence. The strains were isolated in Italy from children with diarrhea and identified as EPEC by clinical laboratories using commercially available antisera. O:H serotyping showed that 35 strains (27 of O26, O111, and O128 serogroups) belonged to 11 serotypes considered to be classical EPEC O:H serotypes. The other 20 isolates were classified as 15 nonclassical EPEC O:H serotypes. All the potential EPEC virulence factors associated with bacterial adhesion (localized adherence, fluorescentactin staining test positivity, presence of th…
Hybridization of mouse lemurs: different patterns under different ecological conditions
2011
Abstract Background Several mechanistic models aim to explain the diversification of the multitude of endemic species on Madagascar. The island's biogeographic history probably offered numerous opportunities for secondary contact and subsequent hybridization. Existing diversification models do not consider a possible role of these processes. One key question for a better understanding of their potential importance is how they are influenced by different environmental settings. Here, we characterized a contact zone between two species of mouse lemurs, Microcebus griseorufus and M. murinus, in dry spiny bush and mesic gallery forest that border each other sharply without intermediate habitats…
Characterization of a complex rearrangement involving chromosomes 1, 4 and 8 by fish and array-CGH
2012
Complex chromosomal rearrangements (CCRs) are structural aberrations involving more than two chromosomes with at least three breakpoints. CCRs can be divided into familial and de novo. Balanced CCR are extremely rare in humans and are at high risk of producing unbalanced gametes. Individuals with balanced CCR are usually phenotipically normal but report fertility problems, recurrent miscarriages or congenital anomalies in newborn offsprings as consequence of either meiotic failure or imbalanced chromosomes segregation.We describe the case of an unbalanced CCR involving chromosomes 1, 4 and 8 found in a girl with developmental delay, hexadactilia and microcephaly. The rearrangement, apparent…
Confocal technology in fluorescence in situ hybridization evaluation for cancer: a diagnostic improvement.
2013
During the cancer routine diagnosis course, we commonly use fluorescence in situ hybridization (FISH) technique. FISH studies are conducted for genes amplification analyses (ErBb2/Neu) and also for genes translocation studies such as CMYC, BCL6, or BCL2. Usually, FISH evaluation is carried out with fluorescence microscopy and photographed with sensitive cameras. An alternative technology to the fluorescence microscopy is using the confocal microscopy for the evaluation of these samples. Some advantages of confocal microscopy are as follows: First, the use of a laser and pinhole instead of using 511983 IJSXXX10.1177/1066896913511983International Journal of Surgical PathologyCampos et al. res…
145 Multifunction Role of Osteonectin/SPARC during Human embryonic and Feta Development
1991
The temporal and spatial distribution of osteonectin/SPARC was investigated during different stages of human development by in situ hybridization and histochemistry Specific mRNA was associated with(a) tissues exhibiting high rates of matrix production (skin, vessels, tendons fetal mesenchyme), (b) cells involved in the process of mineralization (osteoblasts, chondrocytes, odontoblasts), (c)production of basement membranes (glomeruli and (d) steroid synthesis (adrenal gland, Leydig cells) In the growth plate, expression was found in the upper hypertrophic and proliferative but not in the mineralized zone. Histochemistry detected osteonectin extra-cellularly in mineralized tissues, whereas o…