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Typing

About: Typing is a research topic. Over the lifetime, 5010 publications have been published within this topic receiving 146539 citations.


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Journal ArticleDOI
TL;DR: A DNA amplification test was developed for the sensitive detection of the diarrhoea-associated sub group F adenovirus in clinical specimens and there was a strong correlation between results of typing obtained with PCR and restriction enzyme typing of Ad40 and Ad41, and also positivity using subgroup F specific probes in dot blot hybridizations.

40 citations

Journal ArticleDOI
TL;DR: The household setting shows the household setting as an important reservoir of M. tuberculosis transmission, and argues in favor of routine and extensive screening of the family contacts of TB patients, and is the first to provide a molecular epidemiological investigation performed within family-households in Poland.

40 citations

Journal ArticleDOI
TL;DR: A simplified method for typing HLA-A, B, and C alleles by direct sequencing of polymerase chain reaction (PCR) products amplified from genomic DNA that could allow large-scale handling of samples for clinical use.
Abstract: Molecular testing is gradually replacing standard typing techniques in the field of HLA because it allows higher resolution, which has significant functional implications. Although several techniques have been so far described for this purpose, the definitive means to determine which alleles are present in a particular sample is to identify their sequence. We describe a simplified method for typing HLA-A, B, and C alleles by direct sequencing of polymerase chain reaction (PCR) products amplified from genomic DNA that could allow large-scale handling of samples for clinical use. The template is the product of a nested PCR. A first round of PCR amplifications from genomic DNA is performed with three different sets of primers, one pair specific for each locus. The PCR products encompass exons 2 and 3, the regions of interest to determine the allele present. These fragments are a mixture of both alleles present in one locus. In a second round of PCRs using the first fragment as template, exons 2 and 3 are separately amplified and simultaneously tailed with sequences corresponding to fluorescent-labeled commercial primers. The sense and antisense sequence of each exon is obtained and compared with a database of all known HLA-A, B, or C alleles. Heterozygous positions are determined and the most probable alleles assigned. This simplified procedure has the practical advantage of allowing high-resolution typing of clinical material by utilizing the same genomic DNA used for standard molecular typing of HLA class I.

40 citations

Journal ArticleDOI
TL;DR: The low extent of sequence heterogeneity in the species suggests a recent emergence of this bacterium as a human pathogen, and a genome-wide sequence-based typing method is proposed, named multispacer typing.
Abstract: Bartonella quintana is a worldwide fastidious bacterium of the Alphaproteobacteria responsible for bacillary angiomatosis, trench fever, chronic lymphadenopathy, and culture-negative endocarditis. The recent genome sequencing of a B. quintana isolate allowed us to propose a genome-wide sequence-based typing method. To ensure sequence discrimination based on highly polymorphic areas, we amplified and sequenced 34 spacers in a large collection of B. quintana isolates. Six of these exhibited polymorphisms and allowed the characterization of 4 genotypes. However, the strain variants suggested by the noncoding sequences did not correlate with the results of pulsed-field gel electrophoresis (PFGE), which suggested a higher degree of variability. Modification of the PFGE profile of one isolate after nine subcultures confirmed that rearrangement frequencies are high in this species, making PFGE unreliable for epidemiological purposes. The low extent of sequence heterogeneity in the species suggests a recent emergence of this bacterium as a human pathogen. Direct typing of natural samples allowed the identification of a fifth genotype in the DNA extracted from a human body louse collected in Burundi. We have named the typing technique herein described multispacer typing.

40 citations

Journal ArticleDOI
TL;DR: Although all three methods were concordant, AP-PCR was found to be the least time-consuming method, and the suggestion that P. gingivalis can be transmitted between spouses is supported.
Abstract: Summary. Porphyromonas gingivalis is associated strongly with severe periodontitis, but little information is available on possible transmission routes of this species. This study evaluated three DNA-based molecular typing methods for use in epidemiological surveys of P. gingivalis. In total, 32 isolates from eight married couples were investigated by : (i) restriction endonuclease analysis (REA) of whole chromosomal DNA; (ii) hybridisation of DNA fragments with ribosomal DNA (ribotyping); and (iii) amplification of DNA by the polymerase chain reaction with arbitrary primers (AP-PCR). The data obtained with the three methods were in broad agreement : in six of the eight couples, the isolates from husband and wife were indistinguishable, but isolates from unrelated individuals showed distinct types with all three methods. For some isolates, minor differences in REA pattern were obtained which could not be correlated with differences in ribotype or AP-PCR type. Ribotyping showed differences between isolates from one individual, which were indistinguishable with the other two methods. The patterns obtained with ribotyping or AP-PCR were simple in comparison to the relatively complex REA patterns. Although all three methods were concordant, AP-PCR was found to be the least time-consuming method. The data support the suggestion that P. gingivalis can be transmitted between spouses.

40 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023329
2022690
2021145
2020126
2019136
2018147