969 resultados para Description verbale
Resumo:
When Campylobacter jejuni cultures that had been grown in broth at 39degreesC were subcultured into fresh medium at 30degreesC, there was a transient period of growth followed by a decline in viable-cell numbers before growth resumed once more. We propose that this complex behavior is the net effect of the growth of inoculum cells followed by a loss of viability due to oxidative stress and the subsequent emergence of a spontaneously arising mutant population that takes over the culture.
Resumo:
It has long been thought that the genera Mobiluncus and Falcivibrio contain the same organisms. Using a polyphasic approach, it was found that Mobiluncus curtisii and Mobiluncus mulieris were the same as Falcivibrio vaginalis and Falcivibrio grandis, respectively. As the genus name Mobiluncus takes precedence, it is proposed that F. vaginalis and F. grandis be transferred to the genus Mobiluncus. In agreement with previous studies, results from phenotypic tests did not support the separation of M. curtisii strains into its two subspecies, M. curtisii subsp. curtisii and M. curtisii subsp. holmesii. Phenotypic complexity within M. curtisii dictates that the species should be treated as a complex until more in-depth analyses of the species have been performed. Phylogenetic analyses, based on 16S rRNA gene sequences, demonstrated that the genus Mobiluncus was associated with Varibaculum cambriense and the two subspecies of Actinomyces neuii, and that A. neuii is only distantly related to Actinomyces sensu stricto.
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Fifteen strains of an anaerobic, catalase-negative, gram-positive diphtheroid-shaped bacterium recovered from human sources were characterized by phenotypic and molecular chemical and molecular genetic methods. The unidentified bacterium showed some resemblance to Actinomyces species and related taxa, but biochemical testing, polyacrylamide gel electrophoresis analysis of whole-cell proteins, and amplified 16S ribosomal DNA restriction analysis indicated the strains were distinct from all currently named Actinomyces species and related taxa. Comparative 16S rRNA gene sequencing studies showed that the bacterium represents a hitherto-unknown phylogenetic line that is related to but distinct from Actinomyces, Actinobaculum, Arcanobacterium, and Mobiluncus. We propose, on the basis of phenotypic and phylogenetic evidence, that the unknown bacterium from human clinical specimens should be classified as a new genus and species, Varibaculum cambriensis gen. nov., sp. nov. The type strain of Varibaculum cambriensis sp. nov. is CCUG 44998(T) = CIP 107344(T).
Resumo:
Phenotypic and phylogenetic studies were performed on three strains of Gram-negative, rod-shaped organisms recovered from dead birds of the tit families (blue tit, coal tit and long-tailed tit). Morphological, cultural and biochemical studies indicated that the organisms were related to the family Cardiobacteriaceae in the gamma-subclass of the Proteobacteria. Comparative 16S rRNA gene sequencing studies confirmed these findings and demonstrated that the bacterium represents a hitherto unknown subline within this family. The closest phylogenetic relative of the strains isolated from the birds was found to be Suttonella indologenes, although a sequence divergence of approximately 5 % demonstrated that the unknown bacterium represented a novel species. On the basis of the results of the phylogenetic analysis and phenotypic criteria, it is proposed that the bacteria recovered from the diseased birds represent a novel species, Suttonella ornithocola sp. nov., with strain B6/99/2(T) (=CCUG 49457(T)=NCTC 13337(T)) as the type strain.
Resumo:
Phenotypic and phylogenetic studies were performed on four isolates of an unidentified gram-negative, microaerotolerant, non-spore-forming, rod-shaped bacterium isolated from the feces of children. The unknown organism was bile resistant and produced acetic acid as the major end product of metabolism of peptides and carbohydrates. It possessed a low DNA G + C content of 31 mol %. Comparative 16S rRNA gene sequencing demonstrated that the four isolates were phylogenetically identical (100% 16S rRNA sequence similarity) and represent a hitherto unknown sub-line within the genus Cetobacterium. The novel bacterium displayed approximately 5% sequence divergence with Cetobacterium ceti, and can be readily distinguished from the latter by physiological and biochemical criteria. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown fecal bacterium be classified in the genus Cetobacterium, as Cetobacterium somerae sp. nov. The proposed type strain of Cetobacterium somerae is WAL 14325(T) (ATCC BAA-474(T) = CCUG 46254T).
Resumo:
Biochemical, molecular chemical and molecular genetic studies were performed on seven unidentified Gram-positive, rod-shaped organisms recovered from eagles. The strains were provisionally identified as Corynebacterium jeikeium with the commercial API Coryne system, but they were able to grow under anaerobic conditions and were non-lipophilic. Comparative 16S rRNA gene sequencing studies demonstrated that the isolates belonged phylogenetically to the genus Corynebacterium. Three strains were identified genotypically as Corynebacterium falsenii; the remaining four strains corresponded to a hitherto unknown lineage within the genus Corynebacterium, associated with a small subcluster of species that included Corynebacterium diphtheriae and its close relatives. The unknown bacterial strains were readily distinguished from these and other species of the genus by biochemical tests. Based on both phenotypic and phylogenetic evidence, it is proposed that the unknown bacterial strains from eagles should be classified as Corynebacterium aquilae sp. nov. (type strain is S-613(T)=CECT 5993(T)=CCUG 46511(T)).
Resumo:
Strains from anal swabs and chronic otitis externa in dogs were shown to be phylogenetically related to the Enterococcus faecium species group. They shared a number of phenotypic characteristics with these species, but they could be easily differentiated by biochemical reactions. In addition, the canine strains were unusual in their nearly complete failure to grow on sodium azide-containing enterococci-selective media and in their Voges-Proskauer reactions (usually negative). By using 16S rRNA sequencing and DNA-DNA hybridization of representative strains, as well as tDNA interspacer gene PCR and SDS-PAGE of whole-cell proteins, the group of canine strains was shown to constitute a novel enterococcal species. The name Enterococcus canis sp. nov. is proposed for this species, with LMG 12316(T) (= CCUG 46666(T)) as the type strain. Concurrently, the taxonomic situation and nomenclatural position of Enterococcus porcinus were investigated. As no phenotypic or genotypic differences were found between this species and Enterococcus villorum, the name E. porcinus is considered to be a junior synonym of E. villorum.
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Objective: To describe the use of a multifaceted strategy for recruiting general practitioners (GPs) and community pharmacists to talk about medication errors which have resulted in preventable drug-related admissions to hospital. This is a potentially sensitive subject with medicolegal implications. Setting: Four primary care trusts and one teaching hospital in the UK. Method: Letters were mailed to community pharmacists and general practitioners asking for provisional consent to be interviewed and permission to contact them again should a patient be admitted to hospital as a result of a medication error. In addition, GPs were asked for permission to approach their patients should they be admitted to hospital. A multifaceted approach to recruitment was used including gaining support for the study from professional defence agencies and local champions. Key findings: Eighty-five percent (310/385) of GPs and 62% (93/149) of community pharmacists responded to the letters. Eighty-five percent (266/310) of GPs who responded and 81% (75/93) of community pharmacists who responded gave provisional consent to participate in interviews. All GPs (14 out of 14) and community pharmacists (10 out of 10) who were subsequently asked to participate, when patients were admitted to hospital, agreed to be interviewed. Conclusion: The multifaceted approach to recruitment was associated with an impressive response when asking healthcare professionals to be interviewed about medication errors which have resulted in preventable drug-related morbidity.
Resumo:
Six strains of a previously undescribed catalase-positive coryneform bacterium isolated from clinical specimens from dogs were characterized by phenotypic and molecular genetic methods. Biochemical and chemotaxonomic studies revealed that the unknown bacterium belonged to the genus Corynebacterium sensu stricto. Comparative 16S rRNA gene sequencing showed that the six strains were genealogically highly related and constitute a new subline within the genus Corynebacterium; this subline is close to but distinct from C. falsenii, C. jeikeium, and C. urealyticum. The unknown bacterium from dogs was distinguished from all currently validated Corynebacterium species by phenotypic tests including electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as a new species, Corynebacterium auriscanis. The type strain of C. auriscanis is CCUG 39938T.
Resumo:
Three strains of a gram-negative, blood or serum requiring, rod-shaped bacterium recovered from human clinical specimens were characterised by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing showed the unknown rod-shaped strains are members of the same species as some fastidious isolates recovered from human blood specimens and previously designated "Leptotrichia sanguinegens". Based on phylogenetic and phenotypic evidence, it is proposed that the isolates from human sources be classified in a new genus Sneathia, as Sneathia sanguinegens gen. nov., sp. nov. The type strain of Sneathia sanguinegens is CCUG 41628T.
Resumo:
An unknown Gram-positive, catalase-negative, ovoid-shaped bacterium isolated from the submandibular abscess of a rabbit was subjected to a polyphasic taxonomic analysis. Comparative 16S rRNA gene sequencing demonstrated the unknown coccus represents a new subline within the genus Gemella. The unknown isolate was readily distinguished from other recognized members of the genus Gemella, namely Gemella haemolysans, Gemella bergeri, Gemella morbillorum, Gemella palaticanis and Gemella sanguinis, by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on both phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium is classified in the genus Gemella as Gemella cuniculi sp. nov. The type strain is CCUG 42726T.
Resumo:
Two strains of a previously undescribed Actinomyces-like bacterium were recovered in pure culture from infected root canals of teeth. Analysis by biochemical testing and polyacrylamide gel electrophoresis of whole-cell proteins indicated that the strains closely resembled each other phenotypically but were distinct from previously described Actinomyces and Arcanobacterium species. Comparative 16S rRNA gene-sequencing studies showed the bacterium to be a hitherto unknown subline within a group of Actinomyces species which includes Actinomyces bovis, the type species of the genus. Based on phylogenetic and phenotypic evidence, we propose that the unknown bacterium isolated from human clinical specimens be classified as Actinomyces radicidentis sp. nov. The type strain of Actinomyces radicidentis is CCUG 36733.
Resumo:
Three strains of a previously undescribed Actinomyces-like bacterium were isolated from human clinical sources (urine, urethra and vaginal secretion). Biochemical testing and PAGE analysis of whole-cell proteins indicated that the strains were phenotypically homogeneous and distinct from previously described Actinomyces and Arcanobacterium species. Comparative 16S rRNA gene sequencing studies showed the bacterium to be a hitherto unknown subline within a group of Actinomyces species which includes Actinomyces bovis, the type species of the genus. Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium from humans be classified as Actinomyces urogenitalis sp. nov. The type strain of Actinomyces urogenitalis is CCUG 38702T (= CIP 106421T).
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A unique parameterization of the perspective projections in all whole-numbered dimensions is reported. The algorithm for generating a perspective transformation from parameters and for recovering parameters from a transformation is a modification of the Givens orthogonalization algorithm. The algorithm for recovering a perspective transformation from a perspective projection is a modification of Roberts' classical algorithm. Both algorithms have been implemented in Pop-11 with call-out to the NAG Fortran libraries. Preliminary monte-carlo tests show that the transformation algorithm is highly accurate, but that the projection algorithm cannot recover magnitude and shear parameters accurately. However, there is reason to believe that the projection algorithm might improve significantly with the use of many corresponding points, or with multiple perspective views of an object. Previous parameterizations of the perspective transformations in the computer graphics and computer vision literature are discussed.
Resumo:
It is generally assumed that the variability of neuronal morphology has an important effect on both the connectivity and the activity of the nervous system, but this effect has not been thoroughly investigated. Neuroanatomical archives represent a crucial tool to explore structure–function relationships in the brain. We are developing computational tools to describe, generate, store and render large sets of three–dimensional neuronal structures in a format that is compact, quantitative, accurate and readily accessible to the neuroscientist. Single–cell neuroanatomy can be characterized quantitatively at several levels. In computer–aided neuronal tracing files, a dendritic tree is described as a series of cylinders, each represented by diameter, spatial coordinates and the connectivity to other cylinders in the tree. This ‘Cartesian’ description constitutes a completely accurate mapping of dendritic morphology but it bears little intuitive information for the neuroscientist. In contrast, a classical neuroanatomical analysis characterizes neuronal dendrites on the basis of the statistical distributions of morphological parameters, e.g. maximum branching order or bifurcation asymmetry. This description is intuitively more accessible, but it only yields information on the collective anatomy of a group of dendrites, i.e. it is not complete enough to provide a precise ‘blueprint’ of the original data. We are adopting a third, intermediate level of description, which consists of the algorithmic generation of neuronal structures within a certain morphological class based on a set of ‘fundamental’, measured parameters. This description is as intuitive as a classical neuroanatomical analysis (parameters have an intuitive interpretation), and as complete as a Cartesian file (the algorithms generate and display complete neurons). The advantages of the algorithmic description of neuronal structure are immense. If an algorithm can measure the values of a handful of parameters from an experimental database and generate virtual neurons whose anatomy is statistically indistinguishable from that of their real counterparts, a great deal of data compression and amplification can be achieved. Data compression results from the quantitative and complete description of thousands of neurons with a handful of statistical distributions of parameters. Data amplification is possible because, from a set of experimental neurons, many more virtual analogues can be generated. This approach could allow one, in principle, to create and store a neuroanatomical database containing data for an entire human brain in a personal computer. We are using two programs, L–NEURON and ARBORVITAE, to investigate systematically the potential of several different algorithms for the generation of virtual neurons. Using these programs, we have generated anatomically plausible virtual neurons for several morphological classes, including guinea pig cerebellar Purkinje cells and cat spinal cord motor neurons. These virtual neurons are stored in an online electronic archive of dendritic morphology. This process highlights the potential and the limitations of the ‘computational neuroanatomy’ strategy for neuroscience databases.