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51.
52.
Rebecca J. Traub Julie Macaranas Mathirut Mungthin Saovanee Leelayoova Thomas Cribb K. Darwin Murrell R. C. Andrew Thompson 《PLoS neglected tropical diseases》2009,3(1)
Differentiation of the fish-borne trematodes belonging to the Opisthorchiidae, Heterophyidae and Lecithodendriidae is important from a clinical and epidemiological perspective, yet it is impossible to do using conventional coprological techniques, as the eggs are morphologically similar. Epidemiological investigation therefore currently relies on morphological examination of adult worms following expulsion chemotherapy. A PCR test capable of amplifying a segment of the internal transcribed spacer region of ribosomal DNA for the opisthorchiid and heterophyid flukes eggs taken directly from faeces was developed and evaluated in a rural community in central Thailand. The lowest quantity of DNA that could be amplified from individual adults of Opisthorchis viverrini, Clonorchis sinensis and Haplorchis taichui was estimated at 0.6 pg, 0.8 pg and 3 pg, respectively. The PCR was capable of detecting mixed infection with the aforementioned species of flukes under experimental conditions. A total of 11.6% of individuals in rural communities in Sanamchaikaet district, central Thailand, were positive for ‘Opisthorchis-like’ eggs in their faeces using conventional parasitological detection techniques. In comparison to microscopy, the PCR yielded a sensitivity and specificity of 71.0% and 76.7%, respectively. Analysis of the microscopy-positive PCR products revealed 64% and 23% of individuals to be infected with O. viverrini and C. sinensis, respectively. The remaining 13% (three individuals) were identified as eggs of Didymozoidae, presumably being passed mechanically in the faeces following the ingestion of infected fishes. An immediate finding of this study is the identification and first report of a C. sinensis–endemic community in central Thailand. This extends the known range of this liver fluke in Southeast Asia. The PCR developed herein provides an important tool for the specific identification of liver and intestinal fluke species for future epidemiological surveys. 相似文献
53.
The effect of dipicolinic acid (DPA) or its calcium chelate (CaDPA) on the spectral characteristics of nucleic acids was examined. Dipicolinic acid was found to displace ethidium gromide from DNA; this indicates that it may bind by intercalation. On interaction with DNA, the ultraviolet absorption spectrum revealed downfield shifts and caused progressive diminution in both DNA and dipicolinate chromophores. The strength and type of interaction may be ion-specific but not discriminatory to any type of base pairing. Spectral analysis also indicated that both dipicolinate and calcium dipicolinate bound to different RNA species, although the mechanism of binding was not elucidated. We conclude that the interaction of dipicolinate/ calcium dipicolinate with nucleic acids is a mechanism whereby water can be removed from spore polynucleotides, increasing their stability to denaturation. 相似文献
54.
J R Murrell D Koller T Foroud M Goedert M G Spillantini H J Edenberg M R Farlow B Ghetti 《American journal of human genetics》1997,61(5):1131-1138
An autosomal dominant presenile dementia affecting 39 individuals in a seven-generation, 383-member pedigree has been studied at Indiana University. In the affected members of this family, clinical symptoms occurred early in life, with an average age at onset of 48.8 years. The presenting clinical features include disequilibrium, neck stiffness, dysphagia, and memory loss. As the disease progresses, further cognitive decline, superior-gaze palsy, and dystaxia also are observed. The average duration from onset of symptoms to death is approximately 10 years. Neuropathologic studies of nine affected individuals showed neuronal loss in several areas of the CNS, as well as argentophilic tau-immunopositive inclusions in neurons and in oligodendroglia. A limited genomic screen by use of DNA samples from 28 family members localized the gene for this disorder to a 3-cM region on chromosome 17, between the markers THRA1 and D17S791. The gene for tau also was analyzed, through samples from the family. 相似文献
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56.
I.R. McDonald M. Upton G. Hall R.W. Pickup C. Edwards J.R. Saunders D.A. Ritchie J.C. Murrell 《Microbial ecology》1999,38(3):225-233
Abstract
Methane production and methane oxidation potential were measured in a 30 cm peat core from the Moorhouse Nature Reserve, UK.
The distribution of known groups of methanogens and methane oxidizing bacteria throughout this peat core was assessed. Using
16S rRNA gene retrieval and functional gene probing with genes encoding key proteins in methane oxidation and methanogenesis,
several major groups of microorganisms were detected. Methane production and oxidation was detected in all depths of the peat
core. PCR amplification and oligonucleotide probing experiments using DNA isolated from all sections of the peat core detected
methanotrophs from the groups Methylosinus and Methylococcus and methanogens from the groups Methanosarcinaceae, Methanococcaceae, and Methanobacteriaceae. 16S rDNA sequences amplified with the Methylosinus-specific primer were shown to have a high degree of identity with 16S rDNA sequences previously detected in acidic environments.
However, no methanogen sequences were detected by the probes available in this study in the sections of the peat core (above
7 cm) where the majority of methanogenesis occurred, either because of low methanogen numbers or because of the presence of
novel methanogen sequences.
Received: 9 March 1999; Accepted: 21 June 1999 相似文献
57.
Single‐cell genomics based on Raman sorting reveals novel carotenoid‐containing bacteria in the Red Sea 下载免费PDF全文
Yizhi Song Anne‐Kristin Kaster John Vollmers Yanqing Song Paul A. Davison Martinique Frentrup Gail M. Preston Ian P. Thompson J. Colin Murrell Huabing Yin C. Neil Hunter Wei E. Huang 《Microbial biotechnology》2017,10(1):125-137
Cell sorting coupled with single‐cell genomics is a powerful tool to circumvent cultivation of microorganisms and reveal microbial ‘dark matter’. Single‐cell Raman spectra (SCRSs) are label‐free biochemical ‘fingerprints’ of individual cells, which can link the sorted cells to their phenotypic information and ecological functions. We employed a novel Raman‐activated cell ejection (RACE) approach to sort single bacterial cells from a water sample in the Red Sea based on SCRS. Carotenoids are highly diverse pigments and play an important role in phototrophic bacteria, giving strong and distinctive Raman spectra. Here, we showed that individual carotenoid‐containing cells from a Red Sea sample were isolated based on the characteristic SCRS. RACE‐based single‐cell genomics revealed putative novel functional genes related to carotenoid and isoprenoid biosynthesis, as well as previously unknown phototrophic microorganisms including an unculturable Cyanobacteria spp. The potential of Raman sorting coupled to single‐cell genomics has been demonstrated. 相似文献
58.
Chen Y Dumont MG Neufeld JD Bodrossy L Stralis-Pavese N McNamara NP Ostle N Briones MJ Murrell JC 《Environmental microbiology》2008,10(10):2609-2622
Peatlands represent an enormous carbon reservoir and have a potential impact on the global climate because of the active methanogenesis and methanotrophy in these soils. Uncultivated methanotrophs from seven European peatlands were studied using a combination of molecular methods. Screening for methanotroph diversity using a particulate methane monooxygenase-based diagnostic gene array revealed that Methylocystis-related species were dominant in six of the seven peatlands studied. The abundance and methane oxidation activity of Methylocystis spp. were further confirmed by DNA stable-isotope probing analysis of a sample taken from the Moor House peatland (England). After ultracentrifugation, (13)C-labelled DNA, containing genomic DNA of these Methylocystis spp., was separated from (12)C DNA and subjected to multiple displacement amplification (MDA) to generate sufficient DNA for the preparation of a fosmid metagenomic library. Potential bias of MDA was detected by fingerprint analysis of 16S rRNA using denaturing gradient gel electrophoresis for low-template amplification (0.01 ng template). Sufficient template (1-5 ng) was used in MDA to circumvent this bias and chimeric artefacts were minimized by using an enzymatic treatment of MDA-generated DNA with S1 nuclease and DNA polymerase I. Screening of the metagenomic library revealed one fosmid containing methanol dehydrogenase and two fosmids containing 16S rRNA genes from these Methylocystis-related species as well as one fosmid containing a 16S rRNA gene related to that of Methylocella/Methylocapsa. Sequencing of the 14 kb methanol dehydrogenase-containing fosmid allowed the assembly of a gene cluster encoding polypeptides involved in bacterial methanol utilization (mxaFJGIRSAC). This combination of DNA stable-isotope probing, MDA and metagenomics provided access to genomic information of a relatively large DNA fragment of these thus far uncultivated, predominant and active methanotrophs in peatland soil. 相似文献
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60.
Frost JM Monk D Stojilkovic-Mikic T Woodfine K Chitty LS Murrell A Stanier P Moore GE 《PloS one》2010,5(10):e13556